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Ho Duc Hung,1 Duong Dinh Chinh,2 Pham Van Tan,3 Nguyen Viet Duong,1 Nguyen Quoc Anh,3 Nguyen Huu Le,4 Ho Xuan Tuan,5 Nguyen Tuan Anh,6 Nguyen Thi Thuy Duong,7 Vu Duy Kien8 1Quynh Lap National Leprosy Dermatology Hospital, Hoang Mai Town, Nghe An, Vietnam; 2Nghe An Department of Health, Vinh City, Nghe An, Vietnam; 3Vietnam National Eye Hospital, Hanoi, Vietnam; 4Nghe An Eye Hospital, Vinh City, Nghe An, Vietnam; 5School of Medicine and Pharmacy, The University of Da Nang, Da Nang City, Vietnam; 6Hanoi Medical University, Hanoi, Vietnam; 7National Institute of Hygiene and Epidemiology, Hanoi, Vietnam; 8OnCare Medical Technology Company Limited, Hanoi, VietnamCorrespondence: Ho Duc HungQuynh Lap National Leprosy Dermatology Hospital, Quynh Thien Ward, Hoang Mai, Nghe An, VietnamTel +84 912287851Email hoduchung0905@gmail.comPurpose: To assess the prevalence of myopia and associated factors among secondary school children in a rural area of Vietnam.Methods: A school-based cross-sectional study of children in grades six to nine was conducted in four secondary schools in Hoang Mai town, Nghe An Province, Vietnam, during December 2018 and January 2019. The status of myopia was defined as a spherical equivalent objective refractive error of − 0.50 D or worse in either eye. A case–control study was conducted to explore factors associated with myopia, where children with myopia were considered to be cases, and children without myopia were considered to be controls. Factors associated with myopia were analyzed using univariate and multivariate logistic regression.Results: The prevalence of myopia among secondary school children was 14.2% (95% CI: 12.7– 15.7%) and tended to increase with grade, from 10.5% in grade six to 17.7% in grade nine. Myopia prevalence in girls was significantly higher than in boys. Factors associated with myopia were a mother with a college/university education (OR = 2.5, 95% CI = 1.2– 5.3), parents who wore spectacles (OR = 2.0, 95% CI = 1.1– 3.8), distance from near work (OR = 5.2, 95% CI = 3.5– 7.9), and taking breaks after 30 minutes of continued reading (OR = 1.6, 95% CI = 1.1– 2.5). However, there were inverse associations with myopia for children belonging to the wealthiest households (OR = 0.2, 95% CI = 0.1– 0.5) and time spent performing outdoor activities (OR = 0.6, 95% CI = 0.4– 0.9).Conclusion: Our study showed that the prevalence of myopia is considerable among secondary children in rural areas of Vietnam. The prevalence of myopia tended to increase among children in higher grade levels. Thus, appropriate interventions should be developed and conducted to deal with the issue of school-age myopia.Keywords: myopia, vision impairment, prevalence, secondary school children, rural, Vietnam

AIM OF THE STUDY: Allanblackia floribunda Oliv. (Clusiaceae), an evergreen tree of the rain-forest has long been used in traditional African medicine to treat hypertension. The aim of this study was to evaluate the protective effect of Allanblackia floribunda aqueous extract on alcohol- and sugar-induced hypertension in rats. MATERIAL AND METHODS: Alcohol-induced hypertensive rats (AHR) were obtained by oral administration of ethanol (3 g/kg/day) while sucrose (5, 6 and 7% in drinking water) was used for sucrose-induced hypertensive rat (SuHR). Both models of animals concomitantly received either aqueous extract (200 or 400 mg/kg; p.o.) or nifedipine (10 mg/kg; p.o.) all along the 8 weeks of experiment. Blood pressure and heart rate were measured using the direct cannulation method. The effects of the plant extract on lipid profile, oxidative stress markers, as well as on kidney and liver functions were evaluated at the end of the treatment by the colorimetric method. RESULTS: At the doses of Allanblackia floribunda (200 and 400 mg/kg/day) significantly prevented (21.74; 26.65% and 11.71; 24.58% of reduction) the increase in mean blood pressure on AHR and SuHR, respectively. Administration of the plant extract at the dose of 400 mg/kg led to the prevention of total cholesterol (42.82%), HDL-cholesterol (36.59%) and triglycerides (9.67%) increase in serum lipid in AHR as compared to the untreated AHR. In SuHR, the extract significantly prevented the high concentrations of total cholesterol (44.08%) and triglycerides (33.05%) induced by sucrose treatment as compared to the untreated SuHR, without affecting that of HDL-cholesterol. Allanblackia floribunda (200 and 400 mg/kg) also prevented the increase in atherogenic index by 54.45 and 42.94% in AHR and by 23.70 and 44.32% in SuHR, respectively. Allanblackia floribunda (400 mg/kg) prevented the increase in bilirubine (19.59 and 16.56%), urea (33.36 and 28.2%), ALT (29.55 and 33.09%) and AST (36.28 and 37.12%) of AHR and SuHR, respectively. Treatment with plant extract significantly prevented the increase of superoxide dismutase (SOD), malondialdehyde (MDA) and catalase and the decrease of reduced glutathione (GSH) concentration in aorta, heart, kidney and liver of AHR and SuHR. CONCLUSION: These results demonstrate that the aqueous extract of Allanblackia floribunda can prevent alcohol- and sugar-induced hypertension and oxidative stress in rats. These findings could therefore justify its use in traditional medicine. [ABSTRACT FROM AUTHOR]

Objective. The present study was carried out to establish the chemical profile of the methanolic extract of Polyalthia longifolia stem bark and investigate its antibacterial property against some human pathogenic bacteria. Methods. The extract was analysed using liquid and gas chromatography coupled to mass spectrometry. Antibacterial activity of P. longifolia extract against some human pathogenic bacteria was screened using the AlamarBlue method, and MIC and MBC were determined. Results and Conclusion. Liquid chromatography-mass spectrometry (LC-MS) revealed the presence of 21 compounds among which 12 were identified. Gas chromatography-mass spectrometry (GC-MS) allowed identification of 26 compounds, the three major ones being the following: cis vaccenic acid (17.79 %), 3-ethyl-3-hydroxyandrostan-17-one (13.80 %) and copaiferic acid B (12.82 %). P. longifolia extract was active against Gram-positive bacteria with MIC ranging from 1 to 2 mg ml -1 and MBC from 2 to 6 mg ml -1 . This study demonstrated the bactericidal effect of the methanolic extract of Polyalthia longifolia stem bark against some human pathogenic bacteria, including methicillin-resistant S. aureus . This effect could be related to the presence in the extract of a broad diversity of well-known compounds with established pharmacological properties. These results support the ethnomedicinal use of P. longifolia stem bark in Cameroon for the management of methicillin-resistant S. aureus (MRSA)-related infections., Competing Interests: The authors declare that there are no conflicts of interest., (© 2023 The Authors.)

Aim: This study is aimed at establishing phenolic compound profile and assessing the possible antiulcer activities of aqueous extracts of some staple plant foods from the West and North-West regions of Cameroon against chronic gastric ulcer models in rats., Materials and Methods: Phenolic constituents of extracts were evaluated using HPLC-DAD. Aqueous extracts of Corchorus olitorius , Solanum nigrum , Vigna unguiculata , Triumfetta pentandra , "nkui" spices, and "yellow soup" spices were tested at two doses (200 and 400 mg/kg). After treatments, animals were sacrificed, healing percentage and antioxidant status (catalase, superoxide dismutase, and glutathione peroxidase) were evaluated, and histological examination of gastric mucosa was realized., Results: HPLC-DAD revealed that p-hydroxybenzoic and protocatechuic acids were the phenolic compound present in all extracts. Oral administration of extracts (200 and 400 mg/kg) significantly reduced ulcer surface value and significantly increased mucus production compared to the control groups ( p < 0.05). Histological study supported the observed healing activity of different extracts characterized by a reduced inflammatory response. Moreover, administration of aqueous extracts increased the activity of antioxidant enzymes., Conclusion: This study revealed that aqueous extracts of Solanum nigrum , Corchorus olitorius , Vigna unguiculata , Triumfetta pentandra , "yellow soup" spices, and "nkui" spices possess healing antiulcer effects against models of gastric ulcers. The antiulcer mechanisms involved may include increase of gastric mucus production and improvement of the antioxidant activity of gastric tissue. These activities may be due to the phenolic compounds identified in the extracts, especially p-hydroxybenzoic and protocatechuic acids present in all extracts and with known antioxidant, cytoprotective, and healing properties. However, all the diets may promote the healing process of chronic ulcers caused by excessive alcohol consumption/stress., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Hauberline Domegne Mikwangock et al.)

Paracetamol is a commonly used analgesic/antipyretic whose long-term intake or overdose is associated with renal and hepatic injuries. The aim of this study was to determine the hepatonephroprotective mechanisms of the aqueous extract of Amblygonocarpus andongensis stem bark (AEAASB) on renal and hepatic failure resulting from paracetamol overdose. Forty-five rats were divided into nine groups ( n = 5); these were treated once daily for 8 days with 5 ml/kg distilled water (normal, negative, and satellite controls); 0.9% normal saline and 140 mg/kg N-acetyl-cysteine (positive controls); 125, 250, and 500 mg/kg AEAASB (test groups); and 500 mg/kg AEAASB (satellite test). On day 8 after different treatments, hepatonephrotoxicity was induced in all the groups except the normal group by oral administration of a single dose of paracetamol (1000 mg/kg). Urinary, hematological, serum, and oxidative stress parameters and in vitro antioxidant activity of AEAASB were evaluated. Histological sections of the liver and kidney were performed. AEAASB significantly decreased urea, creatinine, transaminases, alkaline phosphatase, and bilirubin ( p < 0.001) at 500 mg/kg compared to the negative control. Significant decreases in hepatic ( p < 0.01) and renal ( p < 0.001) malondialdehyde levels were associated with increases in superoxide dismutase, catalase, and reduced glutathione levels in 500 mg/kg AEAASB compared with the negative control. Histological analysis showed that AEAASB prevented paracetamol-induced renal and liver tissue damage. Furthermore, AEAASB revealed a very strong antioxidant activity (inhibitory concentration 50 = 180  μ g/ml, antioxidant activity index = 5.55) with an ability to scavenge 63.03% 2,2-diphenyl-2-picrylhy-drazyl radical and reduced ferric iron by 52.68 mgEqVitC/100 g DM. The hepatonephroprotective effect of AEAASB might result from its ability to improve the antioxidant status through the stimulation of antioxidant factors and the scavenging of free radicals. This property could be ascribed to the presence of some classes of bioactive compounds such as phenolic compounds in great amounts., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 O. Baponwa et al.)

Objective: The objective of this study was to elucidate the antisecretory mechanism of the root bark aqueous extract of Diospyros mespiliformis (RBAEDM) in Wistar rats. Materials and methods . RBAEDM was tested on three experimental animal models of gastric acid hypersecretion including pyloric ligation (PL), PL with histamine, and carbachol pretreatments. The ulcerated surface, mucus mass, pH, gastric acidity, and pepsin activity were determined. Some bioactive compounds revealed by qualitative phytochemistry were quantified. Some markers of oxidative stress in vivo such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and in vitro antioxidant tests (ABTS: 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, DPPH: 2,2-diphenyl-2-picrylhydrazyl, and FRAP: ferric reducing antioxidant power) were determined., Results: In the three models studied, RBAEDM resulted in increases in the percentages of inhibition ranging from 9.50 to 59.52% of gastric ulcer and mucus mass. This increase was accompanied by the reduction in acidity and pepsin activity. The administration of RBAEDM resulted in a significant decrease ( p < 0.05, p < 0.01) in MDA levels correlated with a significant increase ( p < 0.05, p < 0.01) in CAT and nitrite levels compared with the negative control. RBAEDM has the ability to scavenge ABTS and DPPH radicals and to reduce FRAP, and the inhibitory concentration of 50% (IC 50 ) of the ABTS radical was 220  μ g/mL compared with the butylhydroxytoluene (BHT) control (175  μ g/mL). Quantitative phytochemistry revealed abundant polyphenols, flavonoids, tannins, saponins, and anthocyanin., Conclusion: RBAEDM protected gastric mucous membrane for gastric acid by mechanisms that would involve both anticholinergic and antihistaminergic pathways., Competing Interests: The authors declare that they have no conflicts of interest regarding the publication of this study., (Copyright © 2022 Vandza Luc Vandi et al.)

Ethnopharmacological Relevance: Information collected from local traditional healers reported that Eremomastax speciosa (Hochst.) Cufod. has for a long time been used to manage gastric ulcers in many regions of Cameroon and beyond. This traditional use is supported by numerous studies. However, efficacy of this plant has never been tested in case of chronic gastric ulcers associating Helicobacter pylori infection., Aim of the Study: This study was designed to investigate curative effects of the aqueous extract of E. speciosa leaves (AEESL) against chronic gastric ulcers associated to Helicobacter pylori infection., Materials and Methods: Two experimental methods of chronic gastric ulcers, involving H. pylori infection, were performed using Wistar rats, namely: acetic acid-induced ulcers and "unhealed ulcers". E. speciosa extract was tested at three doses (100; 200; 400 mg/kg) and at the end of experiments, some in vivo antioxidant parameters were measured, bacterial load in stomach tissue calculated and histopathological examinations performed., Results: E. speciosa reduced ulcer index at all the doses and significantly increased mucus production as well as antioxidant (mainly SOD and GSH) level. Bacterial load in stomach significantly decreased (p < 0.05) in extract-treated groups (200 and 400 mg/kg) as confirmed by histopathological observations. The extract was found to be non toxic to healthy and cancerous cells (IC 50  > 1000 μg/mL)., Conclusions: E. speciosa accelerated healing of gastric ulcers even in presence of indomethacin, while decreasing bacterial loads in rats' stomachs. These results provide supplementary support to the use of E. speciosa in ethnomedicine and open new perspectives regarding development of a herbal-based monotherapy able to efficiently replace/supplement standard antiulcer tri/quadritherapy., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Introduction and Importance: The partial androgen insensitivity syndrome (PAIS) is a rare genetic disorder, which needs to be diagnosed early and provided suitable treatment. One-stage sex reassignment surgery can be considered as one of the treatment options for PAIS patients., Case Presentation: A 44-year-old patient with PAIS was admitted to our hospital. After getting a consultation, the patient decided to choose the one-stage sex reassignment surgery to be reassigned to be a female. The surgery consisted of breast augmentation and genital surgery. After 8 months of follow-up, the patient's breast had a desired shape and volume. The clitoris was in normal size with normal sensation, and the neovagina was 8 cm in depth with a smooth mucosal surface. We also observed that the minor labia were symmetric. The patient reported achieving orgasms with sex toys., Clinical Discussion: The one-stage sex reassignment surgery for the PAIS patient is safe and reduces treatment time for patients. It could also bring many benefits to the patients, such as reducing the incision, preventing gonadoblastoma and giving a sense of the patient's female gender which helps the patient feel confident and improve her quality of life. Thus, the one-stage surgery should be indicated for the patient at middle-aged who shouldn't be delayed anymore to have normal female breast and external genitalia., Conclusion: The one-stage sex reassignment surgery was performed safely and successfully on the delayed presentation of the PAIS patient. This could be an effective and appropriate approach to treat late-diagnosed PAIS patients., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: Opilia celtidifolia is a plant used in Cameroonian ethnomedicine to cure jaundice. The aim of this study was to evaluate the hepatoprotective activity of O. celtidifolia leaves aqueous extract in rats subjected to ethanol-induced liver damage. Material and Methods . 36 rats including 18 males and 18 females were divided into 6 groups of 3 males and 3 females each, namely, 3 control groups (normal, negative, positive) and 3 test groups. The normal and negative control groups were given distilled water (5 ml/kg), the positive control group received silymarin (100 mg/kg), and the test groups were given O. celtidifolia extract at the doses of 100, 200, and 400 mg/kg. All groups, except the normal control, received concomitantly and daily 40% ethanol (4 g/kg) for 3 weeks to induce hepatotoxicity. Biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, and lipid profile (total cholesterol, HDL, LDL, and triglycerides) were evaluated. Histological sections of the liver, kidneys, and lungs were examined. Qualitative and quantitative phytochemical analysis of the extract were carried out., Results: The groups treated with the extract at the doses of 200 and 400 mg/kg showed a significant decrease ( p < 0.001) of transaminases (ALT and AST), ALP, and bilirubin compared with the negative control. These results were confirmed by observation of histological sections of the liver that confirmed protective action of extract against ethanol-induced hepatocellular injury., Conclusion: O. celtidifolia possesses hepatoprotective properties that could be related to its high content of tannins and saponins in the leaves aqueous extract., Competing Interests: The authors declare that they have no conflicts of interest regarding the publication of this paper., (Copyright © 2020 A. P. Amang et al.)

Objective: This work investigated the healing and antisecretory effects of the aqueous extract of Eremomastax speciosa on "unhealed gastric ulcers" associated with gastric acid hypersecretion., Materials and Methods: "Unhealed gastric ulcers" were induced using indomethacin following the establishment of acetic-acid-induced chronic gastric ulcers. The extract (200 and 400 mg/kg, per os) was administered concomitantly with indomethacin (1 mg/kg, subcutaneously). The effects of the extract on both basal and histamine-stimulated gastric acid secretion were determined. Mucus secretion and oxidative stress parameters were measured, and histological assessment of ulcer healing was carried out., Results: The extract significantly promoted the healing process in rats subjected to "unhealed gastric ulcers" (82.4-88.5% healing rates). Treatment with the extract significantly reduced the basal (25.95-49.51% reduction rates) and histamine-stimulated (24.25-47.41%) acid secretions. The healing effect of the extract was associated with a significant ( p < 0.05) increase of mucus secretion and concentrations of antioxidant enzymes compared with the controls. The extract at the highest dose showed normalization of the mucosa, without glandular destruction and with the disappearance of fibrosis and lymphocyte infiltration., Conclusion: The abilities of the extract to increase mucus secretion, to reinforce antioxidant status, and to inhibit acid secretion would be some of the mechanisms by which this extract would accelerate the healing process in "unhealed gastric ulcers."

Objective. We studied prosexual effects of Eremomastax speciosa aqueous extract in male adult rats. Materials and Methods. 100 and 500 mg/kg of extract were administered orally (days 0, 1, 4, 7, 14, and 28 (posttreatment)). The sexual behavior of rats receiving a single dose (500 mg/kg) was also evaluated after pretreatment with Lω-NAME (10 mg/kg), haloperidol (1 mg/kg), or atropine (5 mg/kg). Controls received distilled water or testosterone enanthate (20 mg/kg/day/3 days (s.c.) before the test). Results. The extract (days 1-14) had no significant effect on mount, intromission, and ejaculation frequencies but on day 28 (14 days after treatment), it increased frequency of mounts and intromissions at 500 mg/kg. Mount, intromission, and ejaculation latencies reduced and postejaculatory intervals decreased but the effect did not persist 2 weeks after treatment. Extract prosex effects were greatly reduced by atropine and completely abolished by haloperidol, while Lω-NAME increased mount latency and potentiated extract effect on intromission and ejaculation latencies. Conclusion. In summary, E. speciosa extract can have positive effects on male sexual motivation and performance when administered for two weeks at the dose of 500 mg/kg. The effects (dopaminergic and/or cholinergic dependent) tend to appear during the posttreatment period.

The effects of the aqueous extract of Moringa oleifera on swimming performance and related biochemical parameters were investigated in male Wistar rats (130-132 g). Four groups of rats (16 per group) were fed a standard laboratory diet and given distilled water, 100, 200, or 400 mg/kg of extract, respectively, for 28 days. On day 28, 8 rats from each group were subjected to the forced swimming test with tail load (10% of body weight). The remaining 8 rats per group were subjected to the 90-minute free swim. Maximum swimming time, glycemia, lactamia, uremia, triglyceridemia, hepatic and muscle glycogen, hematological parameters, and oxidative stress parameters (superoxide dismutase, catalase, reduced glutathione, and malondialdehyde) were measured. Results. M. oleifera extract increased maximum swimming time, blood hemoglobin, blood glucose, and hepatic and muscle glycogen reserves. The extract also increased the activity of antioxidant enzymes and decreased the blood concentrations of malondialdehyde. Furthermore, it decreased blood concentrations of lactate, triglycerides, and urea. In conclusion, the antifatigue properties of M. oleifera extract are demonstrated by its ability to improve body energy stores and tissue antioxidant capacity and to reduce the tissue build-up of lactic acid.

Twenty seven mixed-breed growing rabbits (1.2-1.3 kg body weight) aged 10-12 weeks were used to study the effects of the dietary replacement of maize with sun-dried cocoa pod husks on the performance of growing rabbits in a 6-week trial. Three treatment diets were compounded whereby sun-dried cocoa pod husks replaced maize at 0, 50, and 100 %, respectively. The animals were divided among the three treatment diets so that each diet had 3 replicates of 3 animals each. Feed intake and weight gain were recorded; faeces were also collected for digestibility trials, and cost analysis was also carried out. Results showed a significant difference (P < 0.05) in daily feed intake between the dietary treatments. However, there was no significant difference (P > 0.05) in the final metabolic weights, total metabolic weight gain, daily growth rate, and feed conversion ratio between the treatments. The digestibility study showed a decrease in the digestibility of dry matter and metabolisable energy with the increase in cocoa pod husk inclusion. Cost analysis indicate that significant net gains can be made by incorporating 200 g sundried cocoa pod husks per kg of the diet of growing rabbits compared with the same proportion of maize. These results suggest that sun-dried cocoa pod husks can totally replace maize and provide a cheap source of energy in the diets of growing rabbits.

Objective. The objective of this study was to find out the possible antiulcer mechanism of action of Eremomastax speciosa. Method. Carbachol- and histamine-induced hypersecretion, associated with the pylorus ligation technique, were used in rats. Gastric mucosal ulceration, mucus production, pH, gastric volume, and acidity were measured. Results. Histamine and carbachol raised gastric acidity to 86.50 and 84.80 mEq/L, respectively, in the control rats, and the extracts (200 mg/kg) reduced gastric acidity to 34.60 and 39.00 mEq/L, respectively. Intraduodenal aqueous extract (400 mg/kg) in histamine- and carbachol-treated rats produced significant (P < 0.001) decreases in acid secretion to 28.50 and 28.80 mEq/L, respectively, and 100 percent inhibition of gastric ulceration. Augmented histamine-induced gastric acid secretion (90.20 mEq/L) was significantly reduced to 52.60 and 27.50 mEq/L by the 200 and 400 mg/kg doses of the aqueous extract, respectively. The extract significantly reduced (P < 0.001) the volume of gastric secretion and significantly increased mucus production. The ulcer inhibition potential of the extract significantly dropped to 25-44% (oral extract) and to 29-37% (duodenal extract) in carbachol/indomethacin-treated rats. Conclusion. The aqueous extract of E. speciosa has both cytoprotective and antisecretory effects. The antisecretory effect may involve a mechanism common to both cholinergic and histaminergic pathways.

The aqueous extract of Enantia chlorantha Oliver (Annonaceae) stem bark, a plant widely used in Cameroon for the traditional treatment of gastritis and stomach problems, was assessed for in vitro and in vivo anti-Helicobacter/Campylobacter properties using the well diffusion assay, agar dilution assay, and killing rate determination. The in vitro activity was dose-dependent, and the same antimicrobial parameters (MAQ = 0.63 mg; MIC = 0.39 mg/mL; MBC = 1.56 mg/mL; ET(100) = 8 h) were obtained for both H. pylori and C. jejuni/coli. When the plasma active principle concentration equivalence was determined in vitro using plasma from rats exposed to a single dose (3000 mg/kg) of the extract, the peak absorption of E. chlorantha active principle against H. pylori occurred at 2 h. Plasma activity was nil 8 h after extract administration. The in vivo H. pylori eradication potency of the extract was assessed using mice infected with H. pylori. Antral mucus sample cultures from mice treated with E. chlorantha extract (500 and 1000 mg/kg for 3 days) did not yield any growth. The results suggest that in addition to its in vitro activity, E. chlorantha water extract also possesses in vivo antibiotic effects against H. pylori.

The aqueous extract from the leaves of Ocimum suave was evaluated for acute and sub chronic toxicity and teratogenic effects. Swiss mice were administered single oral doses of 2000, 4000, 6000 and 8000 mg/kg and monitored for death and body weight gained for 7 days (acute toxicity). In sub-acute toxicity, experimental rats, received daily doses of 250, 500 and 1000 mg/kg for 42 consecutive days and the toxic effects were assessed using biochemical and haematological data and histology of vital organs. In a teratogenic study, 1-day pregnant rats were administered orally 500 and 1000 mg/kg of extract daily for 21 consecutive days and 14th day corpora lutea and foetal implants and litter size at birth were noted. Reproductive performance of F(1) generation rats was studied by crossing them at maturity and recording the number, birth weight and physical presentation of the young offspring. Acute intake of extract up to 8000 mg/kg did not produce mortality or significant changes in general behaviour. Sub chronic treatment did not show any change in body and organ weights, feeding habits or behaviour between the control and the treated groups of both sexes. Haematological analysis and blood biochemistry revealed no toxicity effects of the extract. No gross abnormalities or histological changes were observed. Teratogenic and fertility studies did not reveal any toxic manifestations or foetal abnormalities. The leaf aqueous extract of Ocimum suave is non toxic in acute and sub chronic intake.

Sclerocarya birrea (Anacardiaceae) is used as a traditional treatment of diabetes in Cameroon. In this study, we investigated the possible antidiabetic effect of the stem bark extract in diabetic rats. Diabetes was induced by intravenous injection of streptozotocin (STZ, 55 mg/kg) to male Wistar rats. Experimental animals (six per group), were treated by oral administration of plant extract (150 and 300 mg/kg body weight) and metformin (500 mg/kg; reference drug) for comparison, during 21 days. The stem bark methanol/methylene chloride extract of Sclerocarya birrea exhibited at termination, a significant reduction in blood glucose and increased plasma insulin levels in diabetic rats. The extract also prevented body weight loss in diabetic rats. The effective dose of the plant extract (300 mg/kg) tended to reduce plasma cholesterol, triglyceride and urea levels toward the normal levels. Four days after diabetes induction, an oral glucose tolerance test (OGTT) was also performed in experimental diabetic rats. The results showed a significant improvement in glucose tolerance in rats treated with Sclerocarya birrea extract. Metformin, a known antidiabetic drug (500 mg/kg), significantly decreased the integrated area under the glucose curve. These data indicate that Sclerocarya birrea treatment may improve glucose homeostasis in STZ-induced diabetes which could be associated with stimulation of insulin secretion.

Terminalia superba is highly regarded in some parts of Cameroon in traditional medical practice. We have studied the vasorelaxant effects of the stem bark methanol extract of T. superba on rat vascular smooth muscle. The results demonstrated that T. superba extract provoked a time-dependent relaxation of aortic rings precontracted with norepinephrine (10(-6) M). The vasorelaxant effect of the plant extract was not affected by endothelium removal or by pretreatment with indomethacin or N(W)-nitro-Larginine methyl ester (L-NAME). T. superba extract did not significantly, affect the contraction induced by 30 mM or 60 mM KCl as compared to those induced by NE. Relaxations elicited by T. superba extract were markedly reduced by glibenclamide, a putative blocker for K(ATP) channels and by tetraethylammonium, the non-specific K+ channel inhibitor. T. superba caused a time- and concentration-dependent relaxation of the rat aortic rings that were inhibited by charybdotoxin and iberotoxin but not by apamin. These finding indicate that T. superba extract at least partially relaxes the rat aorta by activating K+ channels, mainly KATP channels and large-conductance Ca2+ -activated K+ channels in rat aorta.

The glucose-lowering efficacy of the aqueous stem bark extract of Trema orientalis (Ulmaceae) was evaluated both in normal and streptozotocin-induced diabetic rats. In normoglycemic rats, the single oral administration of the aqueous extract of T. orientalis failed to reduce blood glucose levels while in STZ-diabetic rats, the plant extract (38-300 mg/kg) exhibited significant hypoglycaemic activity with a maximum effect of 29.67%, 5 hours after administration of the 75 mg/kg dose when compared with the diabetic untreated group. Glibenclamide was not able to lower blood glucose in STZ-diabetic rats, while it significantly lowered the blood sugar in normoglycemic rats. The hypoglycaemic property of T. orientalis was also assessed by an oral glucose tolerance test (OGTT) in STZ-diabetic rats. The aqueous extract of T. orientalis and the reference drug, glibenclamide, (10 mg/kg) produced significant blood glucose lowering effects in the diabetic rats when compared to the diabetic controls. One week after repeated administration of T. orientalis extract, blood glucose levels were significantly decreased (p < 0.05) and still remained low after 2 weeks (p < 0.01). The results indicated that T. orientalis stem bark extract significantly reduces blood glucose in STZ-induced diabetic rats by a mechanism different from that of sulfonylurea agents. The present investigation provides pharmacological evidence that the use of this plant extract in traditional medicine for cardiovascular disease can be of benefit particulary in diabetic patients.

The long-lasting antihypertensive effect of a neutral extract of Bidens pilosa has been suggested to be due to vasodilation. The present work was undertaken to assess this hypothesis. The vasorelaxant effect of a neutral extract (NBp) of the leaves of B. pilosa was evaluated in vitro on isolated rat aorta contracted with KCl or norepinephrine. NBp induced a concentration-dependent vasorelaxation of the rat aorta precontracted with KCl (60 mM) by 25%-105% at the respective concentrations of 0.25-1.5 mg/mL. The maximal concentration of 1.5 mg/mL provoked 88% relaxation of norepinephrine-induced contractions. There were no significant differences between the effects of the extract on the aorta strips with or without endothelium. In the presence of indomethacin or pyrilamine maleate, the relaxant response induced by the plant extract was significantly inhibited at the lower concentrations. The plant extract was able to reduce the aorta resting tone, inhibit the KCl-induced contractions (90% at 1.5 mg/mL) and the CaCl2-induced contractions by 95% at a concentration of 0.75 mg/mL. These results demonstrate the vasodilating properties of the neutral extract of Bidens pilosa and indicate that it may act as a calcium antagonist.

An atmospheric pressure (AP) infrared (IR) laser ionization technique, implemented on a quadrupole ion trap mass spectrometer, was used to analyze underivatized, N-linked oligosaccharides in solution. Experiments were conducted on an atmospheric pressure infrared ionization from solution (AP-IRIS) ion source which differed from previous AP IR matrix-assisted laser desorption/ionization (MALDI) interfaces in that the ion source operated in the absence of an extraction electric field with a higher power 2.94 microm IR laser. The general term 'IRIS' is used as the mechanism of ionization differs from that of MALDI, and is yet to be fully elucidated. The AP-IRIS ion source demonstrated femtomole-level sensitivity for branched oligosaccharides. AP-IRIS showed approximately 16 times improved sensitivity for oligomannose-6 and the core-fucosylated glycan M3N2F over optimal results obtainable on a AP UV-MALDI with a 2,4,6-trihydroxyacetophenone matrix. Comparison between IR and UV cases also showed less fragmentation in the IR spectrum for a glycan with a conserved trimannosyl core, core-substituted with fucose. A mixture of complex, high-mannose and sialylated glycans resulted in positive ion mass spectra with molecular ion peaks for each sugar. Tandem mass spectrometry of the sodiated molecular ions in a mixture of glycans revealed primarily glycosidic (B, Y) cleavages. The reported results show the practical utility of AP-IRIS while the ionization mechanism is still under investigation., (Copyright 2004 John Wiley & Sons, Ltd.)

The coupling of atmospheric pressure matrix-assisted laser desorption/ionization (AP MALDI) with Fourier transform mass spectrometry (FTMS) is described, and its significance for the high-resolution analysis of complex peptide mixtures is demonstrated. High kinetic energy and extensive metastable decay characteristic of ions generated by vacuum MALDI have been known to constitute a possible obstacle to high-resolution analysis by FTMS. Since the initial coupling of laser desorption techniques with FTMS was realized two decades ago, several different solutions have been proposed to control the energy of the ions and fulfill the promise of high sensitivity and high resolution offered by this analytical method. Initial results obtained on quadrupole time-of-flight and ion trap analyzers have shown that ions generated by MALDI at atmospheric pressure are intrinsically less energetic than those provided by vacuum MALDI. Our report indicates that this characteristic is particularly beneficial for FTMS applications in which a sharp reduction of metastable decay can make larger ion currents available for detection and possible tandem experiments. In our hands, AP MALDI-FTMS has enabled the analysis of complex peptide mixtures with resolution and accuracy comparable to those obtained by analogous electrospray ionization-FTMS experiments, with no evidence of either metastable decomposition or significant formation of matrix adducts. Analysis of a trypsin digest of bovine serum albumin provided signal-to-noise ratios and limits of detection similar to those obtained by ion trap analyzers, but with unmatched resolution and accuracy. AP MALDI has been shown to provide stable precursor ions in amounts that allowed for informative tandem experiments. Finally, the potential of AP MALDI-FTMS for the high-resolution screening of complex mixtures was demonstrated by the analysis of isobaric peptides differing in mass by less than 0.04 Da.

The atmospheric pressure (AP) matrix-assisted laser desorption/ionization (MALDI) technique described to date has proven to be a convenient and rapid method for soft ionization of biomolecules. However, this technique, like other AP ionization methods, has so far suffered from a low efficiency in transmitting ions from atmospheric pressure into the vacuum of the mass spectrometer (MS). In this work, a novel technique we termed pulsed dynamic focusing, or PDF, which improves the ion transmission efficiency and sensitivity of AP-MALDI by over an order of magnitude, is described. Pulsed dynamic focusing operates on the basis of pulsing a high-voltage extraction field to zero, when ions are just outside of the MS entrance, to allow the intake gas flow of the MS to effectively entrain the ions into the MS. Results from application of the PDF technique to an AP-MALDI ion trap MS demonstrated that in comparison to static AP-MALDI operation (1). up to 2.1 times more ions from a given laser shot could be transferred into the MS, (2). applying higher voltages in combination with the switching scheme yielded up to 1.6-times-higher ion intensities, and (3). a 3-times-larger laser spot area could be utilized. The combination of these factors produced an enhancement in throughput and sensitivity, as measured by the ions detected per unit time, of over 12 times for a digest sample of bovine serum albumin. In addition, the PDF technique proved to make AP-MALDI less sensitive to laser positioning, creating a more robust ion source in comparison to static AP-MALDI.

Mitragyna ciliata is commonly used in traditional medicine for the treatment of inflammation, hypertension, headache, rheumatism, gonorrhoea and broncho-pulmonary diseases. In the present study, the vascular relaxant effect in the rat and guinea-pig was investigated. The extract induced aortic relaxation in a concentration-dependent manner, with an EC(50) of 1.3 and 7 microg/mL for the noradrenaline- and KCl-induced contractions, respectively. The relaxant effect of the extract on KCl-induced contractions was fi ve times greater than on noradrenaline-induced contractions. Moreover, the relaxant effect of the extract was higher in rat aortic rings with endothelium (104.67%) than without endothelium (49.44%). Chemical analysis of the extract showed the presence of alkaloids and flavonoids which may be responsible for the antihypertensive properties., (Copyright 2004 John Wiley & Sons, Ltd.)

The aim of this study was to investigate the hypotensive and cardiac effects of the neutral extract from Bidens pilosa leaves. Intravenous administration of the extract resulted in a biphasic dose-related hypotensive activity. In normotensive rats (NTR), B. pilosa decreased systolic blood pressure by 18.26%, 42.5% and 30% at doses of 10, 20 and 30 mg/kg, respectively. In spontaneously hypertensive rats (SHR), the decrease in systolic blood pressure was 25.77%, 38.96% and 28.64% at the above doses, respectively. These doses induced hypotension by 27%, 34.13% and 18.73% respectively in salt-loaded hypertensive rats. In NTR, B. pilosa reduced heart rate by 23.68% and 61.18% at doses of 20 and 30 mg/kg, respectively. The force of contraction of the heart was only affected at 30 mg/kg. The initial phase of hypotensive response was partially inhibited by atropine while propranolol increased this effect. These results suggest that B. pilosa exhibited its fi rst hypotensive effects by acting on the cardiac pump efficiency and secondly through vasodilation.

Mitragyna ciliata is widely used in traditional medicine for the treatment of inflammation, hypertension, headache, rheumatism, gonorrhoea and broncho-pulmonary diseases. In the present study, the anti-inflammatory and analgesic properties of the stem bark extract of M. ciliata were investigated. The stem bark of this plant was extracted over Soxhlet with hexane followed by another extraction with methanol. The resulting methanol extract was used for the pharmacological test. Anti-inflammatory activity was evaluated on the basis of the inhibitory effect of the extract on 5-lipoxygenase, and carrageenin-induced hind paw oedema in the rat. The methanol extract, at a dose of 19.2 microg/ml, exhibited no inhibition on 5-lipoxygenase. However, this extract administered per os (50 mg/kg) produced about 70% inhibition of carrageenin-induced paw oedema 1 h after administration. This inhibition was maintained to about 50% 2 h after administration. The dose of 50 mg/kg of MeOH extract significantly decreased sensitivity to pain from 78.75 to 107.5 g These findings suggest that extracts of the bark of M. ciliata, possess potent anti-inflammatory and analgesic effects. Chemical analysis of the extract showed the presence of alkaloids and kaempferol derivative which may be responsible for the anti-inflammatory properties., (Copyright 2002 Elsevier Science Ireland Ltd.)

Chronic fructose treatment in rats has repeatedly been shown to elevate blood pressure in association with insulin resistance and hyperinsulinemia. The purpose of the current study was to investigate the effect of the leaf methanol extract of Bidens pilosa on systolic blood pressure (SBP) and plasma glucose, insulin, cholesterol, triglycerides and creatinine levels in rats with fructose-induced hypertension. Wistar rats that drank a 10% fructose solution for 3-6 weeks showed significant increase not only in plasma insulin and cholesterol levels but also in SBP. B. pilosa extract was able to prevent the establishment of hypertension and lower elevated blood pressure levels. The extract also reduced the highly elevated plasma insulin levels provoked by the high fructose diet. These results suggest that the leaf methanol extract of B. pilosa exerts its antihypertensive effect in part by improving insulin sensitivity.

The anti-ulcerogenic potential of the leaf methanol extract of Ocimum suave (Lamiaceae) was investigated using four methods of gastric lesion induction in experimental Wistar rats (150-200 g): (1) HCl/ethanol-induced gastric lesions, (2) Absolute ethanol-induced gastric lesions, (3) Indomethacin-HCl/ethanol-induced gastric lesions, (4) Pylorus ligation-induced gastric lesions. Administration of the extract of O. suave to the rats by oral route (75-500 mg/kg) dose-dependently prevented the formation of acute gastric lesions induced using the four experimental techniques. The dose-dependent reduction of lesion formation was in all cases accompanied by significant increases in gastric mucus production. At the dose of 250 mg/kg there was complete inhibition of gastric lesions induced using the HCl/ethanol solution. Pre-treatment, by intraperitoneal route, with indomethacin significantly reduced the ability of the extract to inhibit the formation of HCl/ethanol-induced lesions. When the rats were subjected to pylorus ligation, the dose of 500 mg/kg completely inhibited lesion formation but did not have any effect on gastric acid secretion compared with the controls. The mucus secretion promoting effect of the extract was most significant when the gastric environment was highly acidic. These results suggest that a new anti-ulcer therapy regimen may be formulated which does not require the use of antacids and anti-secretory agents.

A 10-day winter sampling campaign was conducted in downtown Toronto for particulate matter (PM) air pollution in the fine (<2.5 microm) size range. An aerosol laser ablation mass spectrometer (LAMS), a tapered-element oscillating microbalance (TEOM), and an aerodynamic particle sizer (APS) were operated in parallel to characterize the PM on-line. In this study, the LAMS observed differences in the chemical composition between three separate episodes with higher PM2.5 mass and APS counts. LAMS results showed that in one instance of elevated PM, organic amines were present in the particulates. Temporal analyses of this episode revealed chemical transformations as the amines, characterized by m/z peaks 58(C3HeN)+, 86(C5H2N)+, and nitrates, increased in number concentration while Ca and hydrocarbon particle classes concurrently decreased. On another day, sulfates were found to have increased significantly. The third event was only 4 h in duration and exhibited an increase in the number of submicron-sized K/hydrocarbons and sulfate-containing particles. In this last event, the hydrocarbons and a K to Fe ratio enrichment indicated there was likely a contribution from a combustion source. This work offers some of the first insights into single particle size and chemistry in a cold winter climate.

An Algorithm for Discriminant Analysis of Mass Spectra--ADAMS--was created that classified aerosol mass spectra into dominant chemically-assigned classes, and grouped rare cases in an outlier class. ADAMS was trained with ambient particulate matter (PM) mass spectra, and then validated through classification tests on known spectra with random noise added, various standard chemicals, and salt-spiked polystyrene latex microspheres. The classification results showed that ADAMS gave a reasonable chemical description of the particle populations. In contrast to adaptive resonance theory (ART-2a) classification, ADAMS could be trained to be advantageously sensitive or insensitive to selected chemical markers. Application of ADAMS to Toronto ambient PM and diesel PM (NIST 2975) demonstrated that these samples could be well described, with a low proportion of the cases falling into the outlier class. Such an algorithm may find application for source-receptor modeling of aerosol mass spectra.

Aspilia africana is widely used in ethnomedical practice in Africa for its ability to stop bleeding, even from a severed artery, as well as promote rapid healing of wounds and sores, and for the management of problems related to cardiovascular diseases. In the present paper, the methylene chloride/methanol extract of A. africana leaves was tested for its contractile activity in vitro. Rings of rat aorta, with or without an intact endothelium, were mounted in tissue baths, contracted with norepinephrine, and then exposed to the plant extract. The effect of the extract was also assessed on the baseline tension of aortic rings in normal and calcium-free PSS. At the lower doses, A. africana slowly re-inforced contractions induced by norepinephrine and relaxed precontracted tension at the highest concentration. The relaxant activity of the extract was endothelium-independent and was not modified by pre-treatment with Nw-nitro-L-arginine methyl ester or indomethacin, suggesting that its effect was not mediated by either nitric oxide or prostacyclin. A. africana extract induced slow and progressive increase in the basal vascular tone which was partially endothelium-dependent. In calcium-free PSS, a high proportion of the contractile activity was inhibited (77%), suggesting that A. africana contractile activity in vascular tissue depends, in part, on extracellular calcium.

TN, an alkaloid from the fruit of Voacanga africana and a protoberberine-type alkaloid (7,8-dihydro-8-hydroxypalmatine) (1), obtained from the bark of Enantia chlorantha were tested for ulcer preventive and antisecretory activity in combination with ranitidine. When tested alone (50 and 100 mg/kg, p.o.), TN and 1 achieved their anti-ulcer actions through reduced gastric secretion and improved mucus production. 1:1 combinations of 1 and the antisecretory agents (25/25 and 50/50 mg/kg) resulted in significant reduction of ulceration under highly acidic conditions (50-70 mEq/l), suggesting potentiating effects. A combination of TN and ranitidine led to synergistic antisecretory effects.

Laser ablation/ionization mass spectrometry (LAMS) of particulate matter (PM) was undertaken on-line in order to extend and contrast PM characterization. Qualitative on-line LAMS results for certified materials and Toronto source materials demonstrated the versatility and limitations of the technique. The observation of organic and inorganic components of certified materials verified the proper working condition of the in-house on-line LAMS. Organic and inorganic components of Toronto source materials were also observed with the on-line LAMS. Common components identified from both types of materials were Na, Al, Ca, Fe, and K. Other recognized components were compared with marker elements reported for some common PM emission sources. An in-house off-line LAMS was used to analyze urban Toronto PM deposited on glass substrates, while the on-line LAMS analyzed individual urban Toronto PM particles that were introduced directly into the instrument. Scanning electron microscopy (SEM), X-ray spectrometry and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used for confirmatory purposes. Organic and inorganic components of urban Toronto PM at their typical ng/m3 concentrations were successfully observed in mass spectra using both off-line LAMS and on-line LAMS. Identified ions unique to each analyzed material were compared to identified ions of urban Toronto PM. The ability of LAMS to analyze individual respirable PM particles (viz. < 2 microns), both for inorganic trace elements and for organic components, greatly extended our capability to characterize PM and also to achieve estimates of concentration contributions of each material.

Primary sources of particulate matter (PM) were analyzed by suspending powdered samples into an aerosol laser ablation mass spectrometer (LAMS). PM sources studied included vehicle exhaust particulates, dust from a non-ferrous smelter, cement powder, incinerator fly ash, two coal fly ash samples, and two soils. Marker peaks signified certain PM source sectors: construction particles could be distinguished by abundant Ca and Ca compounds, fuel combustion was marked by elemental carbon clusters, and nonferrous industrial particles showed inorganic As, Cu, Pb, Zn, and SOx. In addition to the distinction between particles from these different source sectors, mass spectral results also showed that for a single source, different particle types existed, and among different sources within a sector, similar spectra were present. The aerosol LAMS results show the difficulty in differentiating among separate fly ash sources as well as among different soil samples. A particle class balance receptor model that measures the amount of specific particle types rather than the amount of a chemical component is suggested as a means of source apportionment when particle spectra with overlapping source possibilities occur. The assumptions and limitations of receptor modeling aerosol LAMS data are also described. In particular, methods need to be developed to account for the contribution of secondary sources.

We investigated the effects of the aqueous (150-350 mg/kg) and methylene chloride (150-300 mg/kg) extracts of Bidens pilosa on fructose-induced hypertension in rats. Food and liquid intake were measured as well as systolic blood pressure and plasma levels of glucose, insulin, cholesterol, triglycerides and creatinine. Fructose feeding for 6 weeks induced hypertension, hyperinsulinemia and increased plasma triglyceride levels in male Wistar rats. The aqueous and methylene chloride extracts of B. pilosa reversed the high blood pressure and hypertriglyceridemia developed due to fructose feeding but did not have any effects on plasma levels of insulin and glucose. High doses of the extracts reduced plasma creatinine levels and tended to increase plasma cholesterol. These results suggest that the extracts of B. pilosa possess hypotensive effects whose mechanism of action is not related to insulin sensitivity.

We examined the effect of methanol/methylene chloride extract of Dorstenia psilurus given by gastric intubation on systolic blood pressure, plasma glucose, insulin, cholesterol, triglycerides and creatinine in rats with fructose-induced hypertension. Male Wistar rats in groups of 6 animals each were fed fructose-rich diets or standard chow for 3 weeks and treated with 100 mg/kg/day or 200 mg/kg/day of plant extract or vehicle for 3 subsequent weeks. Systolic blood pressure was measured every three days using the indirect tail cuff method. Systolic blood pressure was higher in fructose-fed rats (142+/-2 mm Hg, p < 0.01) compared with the controls (112+/-2 mm Hg), and was lower in Dorstenia psilurus-treated groups (127+/-2 and 119+/-1 mm Hg for the dose of 100 and 200 mg/kg, respectively) compared with the fructose-fed rats. Plasma insulin, cholesterol and triglycerides were higher on the fructose-rich diet compared with the controls. Plasma insulin and cholesterol were lower in the Dorstenia psilurus-treated groups. These results suggest that, Dorstenia psilurus treatment could prevent and reverse high blood pressure induced by a diet rich in fructose probably by improvement of plasma insulin levels. The plant extract might prove useful in the treatment and/or prevention of hypertension.

Ethnobotanical studies have revealed that Bidens pilosa is used in the traditional management of wounds and chronic gastro-duodenal ulcers. This led us to screen the methanol, cyclohexane and methylene chloride extracts of the plant for anti-ulcerogenic activity using the HCl/ethanol gastric necrotizing solution. The methylene chloride extract, which showed the highest activity (100% inhibition) at a dose of 750 mg/kg compared with the methanol and cyclohexane extracts (41 and 46% inhibition, respectively), was further tested using the indomethacin-HCl/ethanol-, absolute ethanol- and pylorus ligation-induced ulcer methods. Pre-treatment with indomethacin significantly reduced the protective effect of the extract against HCl/ethanol solution to 31%. The extract had very little gastric mucosal protection against absolute ethanol (9.8% inhibition at 750 mg/kg) compared with the controls and neither reduced gastric acid secretion in vivo nor the acidity of gastric juice following in vitro incubation.

The antiulcerogenic effects of the bark methanol extract of Voacanga africana were studied using various experimental ulcer models in rats. The effects of the extract on the volume of gastric juice, gastric pH, acid output, mucus production and peptic activity were recorded, as well as the preventive action against lesions caused by HCl/ethanol and indomethacin. Oral administration of the extract (500-750 mg/kg) inhibited the formation of gastric lesions induced by HCl/ethanol (40-63% inhibition). The inhibitory effect against HCl/ethanol was significantly (P<0.01) suppressed by pre-treatment of the rats with indomethacin (30 mg/kg, i.p.). The extract significantly reduced gastric lesion formation in pylorus ligated rats, but this was not associated with an increase in gastric mucus production or with a reduction in acid content, volume of gastric secretion or pepsin activity of the gastric juice.

Voacanga africana is used in Cameroonian ethnomedicine for the treatment of peptic ulcers. We have tested the cytoprotective, anti-secretory and ulcer healing actions of an alkaloid (TN) obtained from the fruit extract. Oral administration of TN (50-100 mg/kg) dose-dependently prevented ulcer formation by HCl/ethanol (36-75%), absolute ethanol (43-75%), HCl-ethanol/indomethacin (58-84%), Pylorus ligation (31-100%), cold restraint stress (68-100%) and histamine (49-100%). The inhibitory effect at 50 and 100 mg/kg against HCl/ethanol was not suppressed by pre-treatment with indomethacin (20 mg/kg, i.p.). TN reduced Shay-ligated gastric acid secretion from 77 mEq/l in the controls to 46 and 25 mEq/l for the 50 and 100 mg/kg doses. Augmented histamine-induced gastric acid secretion was reduced from 84 mEq/l in the controls to 45 and 21 mEq/l for the two doses of TN, with total inhibition of gastric and duodenal ulcers by the 50 mg/kg dose. Healing rate of chronic acetic acid-induced ulcers was 62 and 83%, respectively, for the dose of 50 and 100 mg/kg of TN compared with the controls. TN has gastric anti-secretory effects similar to histamine receptor blockers. Its cytoprotective and ulcer healing properties are related to its ability to strengthen gastric mucosal defenses through enhanced gastric mucus production.

Decoctions prepared from Enantia chlorantha are used in the traditional treatment of some forms of ulcers. We have tested the anti-ulcer actions of a novel protoberberine-type alkaloid (7,8,-dihydro-8-hydroxypalmatine (1)) obtained from the bark of E. chlorantha using the HCl/ethanol, absolute ethanol and pylorus ligation techniques. The healing effect on chronic acetic acid-induced gastric ulcer was also tested. 1 (50 and 100 mg/kg) dose-dependently inhibited the formation of gastric ulcers induced by HCl/ethanol (35-52% inhibition), absolute ethanol (46-53% inhibition) and pylorus ligation (38-62% inhibition). The prophylactic actions were associated with significant increases in gastric mucus production compared with the controls. The significant inhibition of pylorus-ligated ulcers occurred at gastric acid concentrations (83 mEq/l) previously known to induce severe gastric ulceration in rats. The ulcer-healing test showed significant macromorphological and histological acceleration of healing following 10-day treatment with 1 (40 - 80 mg/kg). The results show that 1 has no anti-secretory effects. The prophylactic anti-ulcer effects are associated with enhanced mucus production, which is an important factor in the mechanism of the local healing process of chronic gastric ulcers.

The chemical analysis of urban Toronto airborne particulate matter (PM), size segregated into respirable PM10/2.5, is presented. The characterization of PM by use of proton-induced X-ray emission analysis (PIXE), and inductively coupled plasma-atomic emission spectrometry revealed elemental information; a newer laser ablation-ionization mass spectrometry approach has the potential to expand the chemical information from PM by analyzing both the inorganic and organic species. These PM analytical approaches will be continued in the future for studying (1) emission source identification, (2) inhalation health hazards, and (3) urban smog chemistry.

An investigation into the fate of elements during residential composting was conducted by studying an Envirocycle residential-type aerobic composter unit that was set up and operated at the University of Toronto's greenhouse facility. Source materials consisting of various fruits and vegetables were combined with Metropolitan Toronto Works Department's finished leaf compost (MWFLC), and composted over a 2-month period. Instrumental neutron activation analysis (INAA) was used to determine the concentrations of Al, As, Ba, Ca, Co, Cr, Fe, K, Mg, Mn, Na, Sb, Sr, Ti, V, and Zn in the source materials and the 2-month greenhouse finished compost (GHFC). Results indicate that the ratio of final element mass to input element mass was approximately 1, suggesting that elements are conserved during the composting process. One tailed t tests (0.05 level of significance) on element concentrations between the MWFLC and GHFC revealed that supplementing MWFLC with fruits and vegetables does not significantly change concentrations >25%. One-way analyses of variances conducted on Toronto residential compost samples revealed good homogeneity within an individual composter, although significant elemental variances occurred between separate composters. Incidentally, it was noticed that several of the Toronto residential compost samples had Cr levels that exceeded Ontario Ministry of Environment and Energy guideline values for municipal compost.

The effect of leaf aqueous extract of Bidens pilosa Linn. on KCl- and norepinephrine-induced contractions of rat aortic strips was studied. In aortic strips with endothelium intact, contractions induced using 60 mM KCl and 10(-5) M norepinephrine were dose-dependently relaxed by the extract, a more significant effect being seen with norepinephrine-induced contractions. Following mechanical damage to the aortic endothelium, inhibition of contractions was more prominent (105%) with the norepinephrine-induced contractions compared with KCl-induced contractions (15%) when the maximal dose (8 mg/ml) of the extract was used. The results suggest that the relaxation effect of the extract may be due to the blockade of the influx of extracellular Ca2+ into the cell.

The anti-ulcerogenic potential of the aqueous extract of Eremomastax speciosa leaves was investigated using two methods of ulcer induction: HCl/EtOH-induced ulceration and pylorus ligation. With both methods, the extract inhibited gastric ulceration in a dose-related manner. The highest oral dose tested (190 mg/kg) completely inhibited gastric ulceration and significantly reduced gastric acidity compared with the controls. Incubation of gastric juice with the plant extract (190 mg/kg) significantly reduced the acidity of the incubated gastric juice compared with the controls.