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Despite the success of antibiotic discovery, infectious diseases remain the second leading source of death worldwide, while the resistance to antibiotics is among the significant problems in the twenty-first century. Medicinal plants are very rich in phytochemicals which can be structurally optimized and processed into new drugs. Nigeria enjoys a diverse collection of medicinal plants, and joint research has ascertained the efficacy of these plants. Plants such as guava ( Psidium guajava ), ginger ( Zingiber officinale ), neem ( Azadirachta indica ), and moringa ( Moringa oleifera ) have been found to exhibit broad range of antimicrobial activities. Studies on Nigerian plants have shown that they contain alkaloids, polyphenols, terpenes, glycosides, and others with possible therapeutic potentials. The antimicrobial activities of some new compounds such as alloeudesmenol, hanocokinoside, orosunol, and 8-demethylorosunol, identified from medicinal plants in Nigeria, are not yet explored. Further investigation and optimization of these compounds will facilitate the development of new sets of pharmacologically acceptable antimicrobial agents. This review study revealed the efficacy of medicinal plants as an alternative therapy in combating and curtailing the development and survival of multidrug-resistant pathogens coupled with the toxic effects of some antibiotics. Due to enormous therapeutic possibilities buried in medicinal plants, there is a need for more research into unique fingerprints and novel compounds that can provide cure to the neglected tropical diseases (NTDs) of humans and animals facing Africa, especially Nigeria., Competing Interests: The authors declare that they have no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Harriet U. Ugboko et al.)

Background: Different decoctions of Alchornea cordifolia leaves are used by Yoruba herbalists (Southwest Nigeria) for the local treatment of ulcers, rheumatic pains, febrile convulsions, and for enhancing physical performance., Materials and Methods: In this study, the anti-arthritic effect of 100 - 400 mg/kg/day of the hydroethanolic leaf extract of Alchornea cordifolia (HEAC) was investigated in Complete Freund's Adjuvant (CFA)-induced arthritic rats as a way of evaluating its efficacy in the local management of arthritis. In addition, the effects of HEAC on liver and renal function parameters as well as its effect on the antioxidant enzyme system were investigated. Arthritis was induced using 0.1 ml of 10 mg/ml of Complete Freund's Adjuvant (CFA) following 1 h oral pretreatment and 8(th) day post-arthritic induction with 100, 200 and 400 mg/kg/day of HEAC and 3 mg/kg/day of celecoxib as the reference drug. The anti-arthritic activity of HEAC was assessed based on the ability of HEAC to alter the paw edema diameter, body weight, full blood count, renal and liver function markers, glycoprotein, lysosomal enzymes and possible antioxidant potential in the arthritic rats., Results: Oral pretreatment with 100, 200, and 400 mg/kg/day of HEAC produced significant (p<0.001, p<0.05 and p<0.01) reductions in the paw edema diameter in a non-dose dependent fashion in ACF-induced arthritic rats with the 100 mg/kg/day of HEAC producing the most significant anti-arthritic effect. Similarly, HEAC increased hepatic GSH levels, CAT and SOD activities suggesting possible antioxidant mechanism for its anti-arthritic effect., Conclusion: Overall, results of this study lend credence to the folkloric use of water decoction of Alchornea cordifolia leaves against rheumatoid arthritis. However, further pharmacological investigations would be required at isolating and determining the active anti-arthritic molecule(s) in HEAC in the nearest future.

The extracts of nine selected Nigerian medicinal plants were investigated on Trypanosoma brucei brucei infected mice. The anti-inflammatory properties of hexane fraction of the most promising U. chamae extract was assessed by acute oedema of the mice paw model while the modulatory effect of the extract on Delayed-Type Hypersensitivity (DTH) response on in vivo leucocytes mobilization was evaluated. 'Dose-probing acute toxicity tests' established an oral and intraperitoneal LD50 for T. ivorensis stem bark as >1600 < 5000 mg/kg and 100 mg/kg respectively, while the oral LD50 of Uvaria. chamae was >5000 mg/kg. Extracts of Khaya senegalensis, Harungana madagascariensis, Terminalia ivorensis, Curcuma longa, Ocimum gratissimum and Alcornea cordifolia showed weak anti-trypanosomal effect and did not exhibit significant clearance in parasitemia at the test dose administered compared with the positive control (Diminal®). However, the leaf extract of U. chamae and its hexane fraction demonstrated a significant response (P < 0.01). The fraction at 1000 mg/kg inhibited oedema by 107%. Uvaria. chamae demonstrated both antitrypanosomal and anti-inflammatory properties by increasing the survival time of infected mice due to reduction in parasitemia caused by T. brucei brucei.

The analgesic, antipyretic and anti-inflammatory effects of the aqueous extract of Mezoneuron benthamianum (MB) were evaluated in mice, rats and rabbits using the mouse writhing, tail flick, hot plate and formalin-induced pain tests; 2-4-Dinitrophenol (DNP), D-Amphetamine and E-coli Lipopolysaccharide-induced pyrexia and carrageenan, egg albumin and xylene-induced oedema. The extract (400-1600 mg/kg) and acetylsalicylic acid (100 mg/ kg) produced a significant (P < 0.05) inhibition of the second phase response in the formalin pain model, while only the highest dose (1600 mg/kg) of the extract showed a comparable antinociceptive effect in the first phase. The extract also showed a dose-dependent inhibition of acetic acid induced abdominal writhing. The tail flick latency and the hot plate pain threshold were dose dependently enhanced by the extract but these were significantly lower than that produced by morphine (2 mg/kg). The 2,4-DNP and D-Amphetamine (10 and 5 mg/kg, i.p.respectively) increased the rectal temperatures of rats within 30 minutes of their administration. The extract at doses of 400,800 and 1600 mg/kg produced significant lowering of the elevated body temperature in rats. The extract (800 mg/ kg) administered orally to rabbits passaged with E. coil lipopolysacharride was able to relieve the pyrogen induced fever. The antipyretic effect produced by the extract was comparable to a standard antipyretic drug, aspirin. The extract (400-1600 mg/kg) administered 1h after carrageenan-induced paw swelling did not inhibit the oedema. No inhibitions were observed with the egg albumin and xylene induced oedema models. Phytochemical analysis revealed the presence of flavonoids, tannins, cardiac glycosides, anthraquinones, and saponins. Administration of the extract up to 2 g/kg (orally) did not produce any toxic effect in the acute toxicity studies in mice. The LD50 of the extract when administered intraperitoneally was 1021.31 mg/kg. The data obtained show that MB extract possesses analgesic and antipyretic activities but lacks an anti-inflammatory property.

Unlabelled: Many plants remedies have been employed in solving man's health needs especially the nutritive value which enhances health living. Aphrodisiac plants are plants with anabolic properties i.e. they help in protein synthesis and enhances sexual abilities in males. They are also known as androgenic plants because their properties are similar to that of androgen a male hormone. Cold aqueous extract of Hibiscus rosasinensis leaves is reported by local traditional practioners in Western Nigeria to be aphrodisiac., Objective: To investigate the anabolic properties of Hibiscus rosasinensis., Materials and Method: Three groups (8/group) of immature male rats of known weights were administered equal doses of aqueous (cold and hot) and alcoholic extracts of Hibiscus rosasinensis leaves for 8 weeks. The gain in body and isolated sexual organs (testis, epididymis, seminal vesicle and prostate) weights were determined after treatment and compared to the value obtained from a fourth untreated group which served as the control. Section through the testes of both the treated and untreated rats were also examined microscopically and displayed as a photomicrograph for comparism. All data were statistically analysed and displaced in graphic form., Results: Over the 8 weeks of treatment, the control, the cold aqueous extract dosed, hot aqueous extract dosed and alcoholic extract dosed rats gained 8%, 15%, 18% and 22% in body weights respectively. The increase in the weight of testis, epididymis, seminal vesicle and prostate of the alcoholic extract dosed rats was 19%, 30%, 31% and 40% respectively., Conclusion: The anabolic effect of the leaf extracts of H. rosasinensis is hereby established. More work needs to be done on these leaf extracts to know their effect on the gonadotrophin hormones which regulate the activity of the androgens in relation to spermatogenesis.

Spigelia anthelmia Linn is used as a herb and is a common annual weed of cultivation in open re-growths, on unused land in towns as well as on road sides. The plant can grow to approximately 30 cm in height. The aim of this study was to screen extracts of Spigelia anthelmia for their anthelmintic activity against an experimental Nippostrongylus braziliensis infection in rats. Acute oral toxicity occurred at a dose of 1,140 mg/kg, while anthelmintic trials against Nippostrongylus braziliensis in rats using the aqueous fraction showed a progressive decrease in worm count with increasing dose (10, 13, 16, 20 and 25 mg per kg body weight) (p < 0.05). At 25 mg per kg body weight, the worm count was significantly lower than that at 10 mg per kg body weight (p < 0.05).

Background: Persistent diarrhea is a common endemic disease with high incidence among the Africans including Nigerians. It also represents a frequent opportunistic disease in people living with HIV. Diarrhea represents one of the most distressful and persistent symptoms of HIV/AIDS, which may or may not be accompanied by an infection. The leaves decoction of Baissea axillaries Hua (Apocynaceae) is used by traditional herbalists in Edo state, Nigeria for the management of people living with HIV/AIDS. Determination of its antimicrobial activity and toxicological profile will provide supportive scientific evidence in favour of its continuous usage., Method: Chemical and chromatographic tests were employed in phytochemical investigations. Inhibitory activities of aqueous and ethanolic extracts against clinical strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus faecalis were compared with Togamycin (Spectinomycin). Our report includes minimum inhibitory concentration (MIC) against the test organisms. Toxicological evaluation was determined by administering 250 mg/kg and 500 mg/kg of extracts on male Wister rats for 14 days with normal saline as control. The kidneys, liver, heart and testis tissues were examined., Results: Phytochemical studies revealed the presence of alkaloids, tannins, and cyanogenetic glycosides. The extracts inhibited the growth of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus to varying extents, but only the ethanolic extract inhibited growth in Streptococcus faecalis. The LD50 of the extract in mice was above 5000 mg/kg body weight when administered intraperitoneally. Toxicological evaluation showed mere ballooning degeneration of the liver at 250 mg/kg while at 500 mg/kg there was tissue necrosis. The low and high doses showed ill-defined leydig cells in the testis and no remarkable changes in the heart and kidneys., Conclusion: Extracts of Baissea axillaries have demonstrated antimicrobial activity against clinical strains of selected microorganisms. While there is toxicity at the dose of 500 mg/kg, the therapy shows potential for application in the treatment of diarrhoea associated with AIDS/HIV. Further studies of Baissea axillaries on diarrhoea and toxicity are necessary to evaluate its mechanism of action and to fully establish its safety profile.

Resistance to pyrethroid insecticides and DDT caused by the kdr gene in the malaria vector Anopheles gambiae Giles s.s. (Diptera: Culicidae) has been reported in several West African countries. To test for pyrethroid resistance in two more countries, we sampled populations of the An. gambiae complex from south-western Ghana and from urban and rural localities in Ogun State, south-west Nigeria. Adult mosquitoes, reared from field-collected larvae, were exposed to the WHO-recommended discriminating dosage of exposure for 1 h to DDT 4%, deltamethrin 0.05% or permethrin 0.75% and mortality was recorded 24 h post-exposure. Susceptibility of An. gambiae s.l. to DDT was 94-100% in Ghana and 72-100% in Nigeria, indicating low levels of DDT resistance. Deltamethrin gave the highest mortality rates: 97-100% in Ghana, 95-100% in Nigeria. Ghanaian samples of An. gambiae s.l. were fully susceptible to permethrin, whereas some resistance to permethrin was detected at 4/5 Nigerian localities (percentage mortalities 75, 82, 88, 90 and 100%), with survivors including both An. arabiensis Patton and An. gambiae s.s. identified by PCR assay. Even so, the mean knockdown time was not significantly different from a susceptible reference strain, indicating absence or low frequency of kdr-type resistance. Such low levels of pyrethroid resistance are unlikely to impair the effectiveness of pyrethroid-impregnated bednets against malaria transmission. Among Nigerian samples of An. gambiae s.l., the majority from two urban localities were identified as An. arabiensis, whereas the majority from rural localities were An. gambiae s.s. These findings are consistent with those of M. Coluzzi et al. (1979). Differences of ecological distribution between molecular forms of An. gambiae s.s. were also found, with rural samples almost exclusively of the S-form, whereas the M-form predominated in urban samples. It is suggested that 'urban island' populations of An. arabiensis and of An. gambiae s.s. M-form in the rainforest belt of West Africa might be appropriate targets for elimination of these malaria vectors by the sterile insect technique.

Vernonia amygdalina and Annona senegalensis, two plants used by local/smallholder livestock farmers in Nigeria as anthelmintic were screened for in vitro anthelmintic activity using Haemonchus contortus eggs. The extract of V. amygdalina did not show any significant activity at concentrations up to 11.2mg/ml. The extract of A. senegalensis showed significant (P<0.001) reduction in egg hatch at a concentration of 7.1mg/ml. The in vitro fecal culture of eggs with A. senegalensis showed significant (P<0.001) reductions in larval recovery with increasing concentrations from 1 to 10% ((w/w) in fecal culture) when whole ground plant material was used. Although traditional veterinary healers and local livestock farmers claim both plants are effective as anthelmintics, our result indicate that only A. senegalensis showed promising anthelmintic activity especially with use of ground whole plant materials as used by some farmers.

The contraceptive potential of an aqueous crude extract of the bark of Carica papaya administered orally is reported at the dose regime of 5 and 10 ml/animal/day for 4 weeks. Although the body weight or the weights of reproductive organs, kidneys, adrenals remained unaltered during the course of treatment, there was significant alteration in the histology of the testis and semen analysis when compared to the intact control group. The seminiferous tubules of rats treated with low doses of Carica papaya for 4 weeks showed no significant histological changes compared with the control. At the high dose concentration of the extract there was disorganisation in some of the seminiferous tubules with arrest of spermatogenesis beyond the level of spermatocytes. There was also widening of the lumen of the tubules. Seminal analysis showed some of the motile spermatozoa with abnormal feature in all the experimental groups. There was a dose-dependent suppression of sperm progressive forward motility which coincided with a decrease in sperm count, viability and a dose-dependent increase in percentage abnormal spermatozoa during the 14-28 days experimental period. Taken together, the present experiment showed that complete loss of fertility is attributed to decline in sperm motility and alteration in their morphology and suggest that the aqueous extracts of Carica papaya bark is safe and could serve as an effective male contraceptive in animals.

Objective: To determine the efficacy of a multi-herbal preparation extract of 'Agbo-Iba' on rodent malaria induced in mice., Design: An experimental design in which mice were divided into four groups A,B,C,D representing control, prophylactic, chloroquine and 'Agbo-Iba' groups respectively. Each mouse was intraperitoneally inoculated with Plasmodium yoelii nigeriensis and treated with oral herbal extract or chloroquine syrup depending on group., Setting: College of Medicine of the University of Lagos Medical Microbiology and Parasitology Laboratory., Subjects: One hundred and twenty male and female albino mice aged 10-12 weeks with an average weight of 25 grams., Main Outcome Measures: The herbal extract was effective, preventing the development of parasitaemia in the prophylactic group of mice., Results: After intraperitoneal inoculation of Plasmodium yoelii nigeriensis, a prepatent period of two days was observed before parasitaemia was established in all but the prophylactic group of mice. Induced infection was promptly aborted with oral chloroquine treatment in group C, while in groups A and D, infection terminated fatally. Group B mice appeared normal throughout the duration of investigation with 100% survival rate., Conclusion: 'Agbo-Iba' extract has some prophylactic action against malaria induced in mice with no apparent significant side effects.

A bioactivity monitored phytochemical examination of the morphological parts of Mallotus oppositifolium utilizing the hole-in-plate bioassay procedure against gram-positive, gram-negative bacteria and fungal isolates resulted in the location of significant antimicrobial activity in the acidic fraction (HAF) of the hexane extract of the powdered leaves. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were 32.5 microg/ml and 65 microg/ml against Pseudomonas aeruginosa NCTC 6750 and 25 microg/ml and 50 microg/ml against Staphylococcus aureus NCTC 6571 respectively. These activities were found comparable with standard drugs.

The anti-diarrhoeal and gastro-intestinal protective potentials of aqueous extract of leaves of Phyllanthus amarus were investigated in mice. Graded doses of the aqueous extract (100-800 mg/kg) administered orally produced a dose-related inhibition of gut meal travel distance in normal mice. The highest intestinal transit inhibition of 31.65% was obtained with 400 mg/kg. In castor oil induced diarrhoea in mice, P. amarus extract (400 mg/kg) delayed the onset of diarrhoea, reduced frequency of defecation and reduced gut meal travel distance significantly resulting in intestinal transit inhibition of 79.94% compared to 86.92% produced by morphine (100 mg/kg). In addition, the activities of some intestinal mucosa enzymes (maltase, sucrase, lactase and alkaline phosphatase) in mice pretreated with extract before castor oil were not as severely depressed as those in the control (castor oil treated mice). Phytochemical screening revealed the presence of many secondary metabolites. The results are discussed with a view to establishing the basis of the use of this plant in traditional medicine for treatment of diarrhoea and other gastrointestinal disorders.

Crude extracts from eight Nigerian medicinal plants, used traditionally in the treatment of infectious and septic diseases in both humans and animals were screened in vitro for antibacterial activity, using the hole-plate diffusion method. Most of the extracts were active against gram-positive bacteria. Two of the plant, Angeiossus schimperi and Anacardium occidentale, had good antibacterial activity against Escherichia coli and Pseudomonas aeruginosa which are gram-negative bacteria.

The potency status and efficacy of measles vaccines were studied in three immunization (EPI) centres in the suburban area of Lagos, Nigeria. A total of 14 vials of measles vaccine were collected and subjected to potency testing while, 203 measles-vaccinated children were recruited for this study. Only 85 (41.87%) of the vaccinees reported back for the post-vaccination follow-up screening. The seroconversion pattern showed that 51(60%) had potent antibody titres ranging from 1:40 to 1:1280, while the remaining 34 (40%) had a low antibody titres between < 1:20 and 1:20. The vaccine potency test showed that only 1 (7.14%) of the 14 vaccine vials collected at these centres had virus titre of 3.5 Log while the remaining 13 (92.86%) had virus titres lower than 3.0 Log: the recommended human dose by the World Health Organisation (WHO) for measles vaccine. The administration of these subpotent and/or impotent vaccines vis-à-vis the status of immune response elicited in the vaccinees may be one of the reasons for the occurrence of measles infection in vaccinated children in the recent time in Nigeria. We herein suggested the subjection of all vaccines to a thorough standard laboratory screening before use in Nigeria.

This report is on the antimicrobial potential of Bridelia micrantha, Alchornea cordifolia and Boerhavia diffusa sourced from traditional healers through an ethnobotanical survey of antiinfective plants in Egbado South in Ogun State, Nigeria. Extracts of B. micrantha and A. cordifolia exhibited significant inhibitory activity against the pathogenic organisms. In some cases, the antibacterial activity was comparable to those of ampicillin and gentamycin. However, only the leaf of A. cordifolia showed reasonable antifungal activity when compared with Trosyd. The study shows that there is justification for the use of these medicinal plants in traditional medicine.

The hypoglycemic effect of Telfaria occidentalis was studied in mice. The effect of the aqueous extract of the leaves on blood glucose level were assessed in normoglycaemic, glucose induced hyperglycaemic and streptozotocin (STZ) induced diabetic mice. The aqueous extract given orally in 1 g/kg did not alter the blood glucose level in normoglycaemic mice. In glucose-induced hyperglycemia, antidiabetic activity was seen when the extract and glucose were administered simultaneously and when the extract was giving to the mice 60 minutes before glucose. In STZ-induced diabetic mice, a reduction in the blood glucose level was seen from day two of the administration of the extract. The hypoglycemic effect of the aqueous extract was compared with that of an oral dose of chlorpropamide (200 mg/kg) under the same conditions. The results of this study indicate that the aqueous extract of the leaves of Telfaria occidentalis possess hypoglycaemic activity.

Objective: To investigate the disinfectant/antiparasitic activities of Jatropha curcas as a first step in providing a cheap, readily available disinfectant and malaria vector control agent., Design: Bacteriological and parasitologic tests were carried out on laboratory bench surfaces using the sap and crushed leaves of Jatropha curcas. Four rectangular areas labelled A, B, C and D were first swabbed and streaked onto McConkey and Nutrient agar plates. Section A was treated with "Hibiscrub", D with exterma germcloth, B and C with full strength sap and leaf extracts respectively. Effect of the sap was also tested on helminth ova, vector control on mosquito eggs and toxic effects of the sap on mice., Setting: The study was carried out in the medical microbiology laboratory of the College of Medicine, University of Lagos, Lagos., Results: Observation showed that the sap extracted germicidal actions on the growth of common bacteria of Staphylococcus, Bacillus and Micrococcus species on contact and retained such effects on treated laboratory bench surface for close to six hours after initial application. Ova of Ascaris Lumbricoides and Necator americanus incubated in 50% and 100 concentrations of the sap at room temperature showed either no evidence of embryonation after 21 days in the case of A. Lumbricoides, negation of hatchability in hookworm, or complete distortion in both. The sap also exhibited strong inhibitory effect on normal larval growth of mosquito, but was highly toxic to mice when administered through oral or intraperitoneal routes., Conclusion: J. curcas would provide a very cheap, readily available disinfectant and malaria vector control agent and should be commercially exploited.

Male toads, weighing 70-123 g, were divided into 13 groups with 8 toad in each group. Animals in each group were fasted overnight before the experiments. Toads in groups 1 to 4 were infused for 30 minutes with adrenaline, 5 ugkg-1 min-1, glucose, 5.5 mg kg-1 min-1; glucagon 2 ugkg-1 min-1; and insulin 2000 uU kg-1 min-1, respectively. Blood samples for blood glucose measurement were taken before, during and after each infusion. The experiment was repeated in groups 5 and 6 using 3.5 mg kg-1 min-1 and 7.5 mg kg-1 min-1 of glucose respectively. Toads in groups 7 to 9 were pretreated with prazosin, 0.2 mg/kg and those in groups 10 to 12 were pretreated with propranolol, 0.5 mg/kg. After pretreatment, glucose, glucagon and insulin infusions were repeated in the alpha-blocked and beta-blocked toads, respectively. Group 13 was infused with 0.7% saline and served as the control. The results showed that infusions of adrenaline, glucose and glucagon resulted in significant hyperglycaemia while insulin caused hypoglycaemia. The hyperglycaemic response to glucose was dose-dependent. The experiments using blockers showed that the glycaemic effects of glucagon and insulin are mediated via beta adrenoceptors, that for glucose is via alpha adrenoceptors and from an earlier study, the glycaemic response of adrenaline is through both alpha and beta adrenoceptors.

The antimalarial activity of boiled water extracts of two medicinal plants (Cymbopogon giganteus and Enantia chlorantha) against chloroquine resistant Plasmodium yoelii nigeriensis in albino mice was assessed. Twenty-five mice were used for each extract. Each mouse was inoculated with approximately 10(5) erythrocytes infected with chloroquine-resistant P.y. nigeriensis. At five to seven percent parasitaemia, the mice were randomly divided into five groups of five mice each. The first four groups were treated intraperitoneally for three consecutive days with different doses of the stock solution per mouse. The two extracts cleared the infection in a dose-dependent manner.

The petroleum ether, chloroform, methanol, and water extracts of the leaves, stem bark, and root of Diospyros mespiliformis were studied for their antimicrobial activities. The crude extracts showed broad spectrum antimicrobial activities against 9 Gram-positive bacteria, 8 Gram-negative bacteria, and 6 fungal strains. Of the four extracting solvents, chloroform produced extracts with the best antimicrobial activities, while the chloroform extract of the root exhibited the highest antimicrobial activity. Some tetracycline resistant strains of Staphylococcus aureus and gentamicin resistant strains of Pseudomonas aeruginosa were sensitive to some of the extracts tested. Preliminary phytochemical screening revealed the presence of the following metabolites: anthraquinones, tannins, triterpene, saponins, steroids, and sugars and the absence of alkaloids. The antimicrobial activities observed are discussed in relation to the chemical constituents reportedly isolated from several species of this plant and their traditional uses.

The antihypertensive effect of aqueous extracts of the calyx of Hibiscus sabdariffa (HS) has been investigated in anaesthetized rats. Hibiscus sabdariffa caused a dose-dependent decrease in mean arterial pressure (MAP) of the rats. Sectioning of the right and left vagi nerves did not have a significant effect on the fall in MAP produced by HS. Cholinergic blockade with 0.2 mgkg-1 atropine and histaminergic blockade with 1 mgkg-1 cimetidine and 15 mgkg-1 promethazine significantly attenuated the hypotensive response to HS. Pretreatment of the rats with 20 mgkg-1 HS extract did not have a significant effect on increase in blood pressure induced by bilateral carotid occlusion (48.05 +/- 6.83 mmHg vs 46.53 +/- 7.49 mmHg). The cumulative addition of HS to noradrenaline precontracted aortic rings produced dose-dependent relaxation of the rings. The maximum relaxation response was 86.96 +/- 5.20% and this was observed at the dose of 1.70 mgml-1. These findings suggest that the antihypertensive effect of the extracts of calyx of HS is not mediated through inhibition of the sympathetic nervous system but it could be mediated through acetylcholine-like and histamine-like mechanisms as well as via direct vaso-relaxant effects.

In an attempt to induce chloroquine resistance in Plasmodium yoelii nigeriensis by the method of drug pressure, it was found that the mice continued to be infected until the fourth passage when they became refractory or immune to the infection. When the immune mice were challenged at four weekly intervals, they remained refractory to the infection until week 12 when one of them became infected. However, by the sixteenth week, the rest of the mice became susceptible to the infection. Four of the mice which received a booster dose of the parasite which had been exposed to chloroquine in three passages, that is, chloroquine-attenuated at the sixteenth week, did not pick up a challenge infection two weeks later while the controls did.

A bioactivity-directed fractionation of the root-and stem-barks of Enantia chlorantha resulted in the isolation of palmatine chloride 1 and jatrorrhizine chloride 2 as the major antimicrobial constituents. MIC determinations indicated that these compounds were superior to those of well established broad spectrum antibiotics against some of the organisms used.

The methanol extracts of the leaves and stem bark of four Bignoniaceae plants Jacaranda mimosifolia D. Dol., Tecoma stans Linn., Tabebuia rosea (Bertol) D.C., and Crescentia cujete Linn. were studied for their antimicrobial activity using a wide range of Gram-positive and Gram-negative bacteria and fungi. Extracts of both the leaves and stem bark of majority of plant species studied showed variable but remarkable broad spectrum antimicrobial activity. However, methanol extracts of Tecoma stans leaves was found to be effective against only Candida albicans at the concentrations employed. It was observed that the extracts of stem bark generally showed better antimicrobial activity than those of the leaves and some organisms were selectively more sensitive to the extracts than others. Preliminary phytochemical screening of these plants revealed the presence of tannins, flavonoids, alkaloids, quinones and traces of saponins. The antimicrobial activity observed are discussed in relation to the chemical constituents reportedly isolated from these plants and their traditional uses.

The antibacterial effect of local honey on local isolates of bacterial agents of diarrhoea was determined by an in vitro method involving the impregnation of filter paper discs in undiluted honey and different honey concentrations ranging from 10%-50%. The discs were later placed on plates that have been seeded with the different bacteria and zones of inhibition of growth were measured after a 48 hr. period of incubation. Results presented show that undiluted honey and honey at concentrations of 40% and above were inhibitory to all enteropathogens tested. Zones of inhibition of growth around the disc margin of the various enteropathogens tested ranged from 16-18mm in diameter for the local undiluted honey and 7-12mm in diameter for concentrations of honey at 40% and 50%. The possible mechanisms of this inhibitory effect of local honey are discussed.

A water disinfectant tablet containing calcium hypochlorite as the main ingredient has been developed using a variety of excipients to improve the tablet characteristics. Avicel, polyvinylpyrrolidone, sodium hydrogen carbonate, calcium carbonate, sodium chloride and potassium chloride were used. Inclusion of polyvinylpyrrolidone together with calcium carbonate gave better tablet characteristics. Avicel though gave better tablet characteristics, promoted loss of chlorine from the tablets. Inclusion of inorganic salts were not satisfactory as they, enhanced atmospheric water absorption.

Molluscicides are crucial for the control of schistosomiasis. The need to use plant molluscicides has received increased interest as an inexpensive technology because of the high cost of synthetic compounds for snail control in the endemic areas of poor nations of the world. Laboratory screening of Nigerian medicinal plants has shown that some of these contain chemicals which are among the most potent natural molluscicides available today. Field trials have been carried out on Tetrapleura tetraptera, locally known as Aridan, which is widely distributed in West Africa and can be collected and processed locally for the control of schistosomiasis. Research efforts in identifying botanical molluscicides, such as Aridan, should be encouraged by strong support, both from the Government and the private sector, in a current period of economic depression.

Methanolic (MEOH), evaporated crude water (ECW) and unevaporated crude water (UECW) extracts of 25 Nigerian plants, used for different medicinal and domestic purposes were screened for molluscacidal activity on laboratory-reared Lymnaea natalensis Krauss. Seven of the plants were not active; extracts from 18 (72 per cent) of the plants, some of which are renowned fish poisons, had molluscicidal activity. These were Acacia nilotica, Aristolochia albida, Balanites aegyptiaca, Blighia sapida, Boswellia dalzielii, Detarium microcarpum, Gnidia kraussiana, Kigelia africana, Nauclea latifolia, Opilia celtidefolia, Parkia clappertoniana, Polygonum limbatum, Pseudocedrela kotschyi, Sclerocarya birrea, Securidaca longipedunculata, Ximenia americana, Vetiveria nigritana and Ziziphus abyssinica. The LC50 of these extracts were determined. It is strongly recommended that the toxic effects of these extracts against fish, cercariae, snail eggs and mammals be further investigated so as to determine the right concentration, especially for use in fish ponds.

Biochemical analysis of a selected sample of the Hausa (northern Nigeria) medicinal flora is presented in order to assess potential chemotherapeutic values. Laboratory investigation, supplemented by previously published phytochemical constituent analyses of pertinent taxa, suggests that a number of disorders can be effectively treated by the Hausa practitioner. The Hausa herbal pharmacopoeia is analysed first with reference to its efficacy in the treatment of oral disease. Examined subsequently are Hausa plant medicines considered to be of potential value in the treatment and/or prevention of malaria infection, with particular attention focussed on the malaria symptom complex and parasite-host cell biochemistry. Results are discussed in the context of the adaptive potential of non-Western medical systems and the significance of this aspect for medical policy development programs.