Search

The present study isolated and characterized knipholone from the active 80% methanol rhizome extract of a traditionally used endemic antimalarial plant of Ethiopia, Kniphofia insignisRendle, using preparative thin-layer chromatography for the first time. The chemical structure of the compound was elucidated on the basis spectroscopic data and in comparison with previously reported results. The standard 4-day suppressive test againstPlasmodium bergheiinfected Swiss albino mice was used for thein vivoantimalarial assay of the extract. At all tested doses, the extract showed significant inhibition of parasitaemia. In particular, the extract demonstrated chemosuppression values of 24.35 and 43.87% at 200 and 400 mg/kg, respectively. Results of the current study revealed that the extract of the plant has moderate in vivo antimalarial effect against P. berghei in mice.

No Abstract.

No Abstract.

Ethiopian Aloe species were used for diverse traditional medicines but some species have been reported for potential toxicity. Therefore, oral acute toxicity test were done from leaf exudates of 17 Aloe species using Swiss albino mice (n = 5/cage). A single oral dose of 300 and 2000 mg/kg body weight at a rate of 1 mL/100 gm administered and major toxicity symptoms were monitored; and relative body and organs weights were measured daily until day 14. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test for multiple comparisons. Groups treated with exudates of Aloe calidophila, A. trichosantha subsp. longiflora, A. megalacantha subsp. alticola, A. megalacantha subsp. megalacantha, A. otallensis, A. pubescens, A. rivae, A. rugosifolia, A. secundiflora, A. tewoldei and A. yavellana did not showed any signs of toxicity at both dose levels. These groups showed no significance difference (P > .05) in percentage body weight, relative organs weight and food and water consumption compared to control group and Median Lethal Oral Dose (LD50-value) was estimated to be > 2000 mg/kg body weight. Groups treated with A. harlana, A. mcloughlinii, A. pirottae and unidentified/AHU53 showed overt signs of toxicity and significance difference (P 300 mg/kg body weight. This acute oral toxicity test revealed the importance of safety concern while using Aloe species in traditional medicines.

Aloesin (1) and 7-O-methyl-6′-O-coumaroylaloesin (2) were isolated from the leaf latex of Aloe monticola Reynolds, and their structures determined on the basis of NMR and mass spectroscopic analyses. The antimicrobial activities of the isolated chromones were evaluated against 21 bacterial and 4 fungal strains. Both compounds displayed antibacterial and antifungal effects against most bacterial and fungal strains tested, but their action was more prominent against Salmonella typhi, Shigella dysentery and Staphylococcus aureus (MIC = 10 μg/ml). Acute toxicity tests on mice revealed that neither the latex nor the isolated compounds possess toxicity up to a dose of 2000 mg/kg, signifying an oral LD50 greater than 2000 mg/kg. The results indicate that A. monticola possesses genuine in vitro antimicrobial effect attributed in full or in part to the presence of the isolated chromones in the latex.

Aloe adigratana Reynolds and Aloe elegans Todaro are traditionally used for the treatment of various illnesses, including wounds, infections and inflammation in northern Ethiopia. Despite their morphological differences, the leaf latexes of both Aloes showed the same chemical profile when analyzed by TLC. Further phytochemical investigation of these latexes by preparative thin layer chromatography (PTLC) afforded two anthrones, which were identified as aloin A/B and microdontin A/B on the basis of NMR and MS analysis. In the present study, in vivo anti-inflammatory activities of the leaf latexes of A. adigratana and A. elegans as well as the two isolated anthrones were evaluated using carrageenan-induced mouse paw oedema model. It was noted that the latexes as well as the isolated compounds possess anti-inflammatory activities in a dose-dependent manner. The results also showed that microdontin A/B has a better activity than aloin A/B, in both the early and late phases of inflammation. At a tested dose of 200 mg/kg, microdontin A/B showed oedema inhibition of 35.9%, one h after carrageenan injection, while the inhibition caused by the standard drug indomethacin (10 mg/kg) was 18.6%. In conclusion, the results of the present work confirmed that A. adigratana and A. elegans have genuine anti-inflammatory activities attributed at least in part to the presence of aloin A/B and microdontin A/B in the leaves supporting their use in traditional medicine. Keywords: Aloe adigratana, Aloe elegans, anti-inflammatory, microdontin A/B, aloin A/B

Background Kniphofia foliosa is a flamboyant robust perennial herb which has dense clumps and tick upright rhizomes with leaves at the base. In Ethiopia, it has several vernacular names including Abelbila, Ashenda, Amelmela, Yeznjero Ageda, Shemetmetie and Yezinjero Ageda. The plant is endemic to Ethiopian highlands, where its rhizomes are traditionally used for the treatment of malaria, abdominal cramps and wound healing. In the present study, the 80% methanol extract of K. foliosa rhizomes and its constituents are tested against Plasmodium berghei in mice. Methods Isolation was carried out using column and preparative thin layer chromatography (PTLC). The chemical structures of the compounds were elucidated by spectroscopic methods (ESI–MS, 1D and 2D-NMR). Peters’ 4-day suppressive test against P. berghei in mice was utilized for in vivo anti-malarial evaluation of the test substances. Results Two compounds, namely knipholone and dianellin were isolated from the 80% methanolic extract of K. foliosa rhizomes, and characterized. The hydroalcoholic extract (400 mg/kg) and knipholone (200 mg/kg) showed the highest activity with chemosuppression values of 61.52 and 60.16%, respectively. From the dose–response plot, the median effective (ED50) doses of knipholone and dianellin were determined to be 81.25 and 92.31 mg/kg, respectively. Molecular docking study revealed that knipholone had a strong binding affinity to Plasmodium falciparum l-lactate dehydrogenase (pfLDH) target. Conclusion Results of the current study support the traditional use of the plant for the treatment of malaria.

Background: Kniphofia foliosa Hochst is endemic to Ethiopian highlands, where its rhizomes are traditionally used for the treatment of malaria, abdominal cramps and wound healing. As a continuation of our search for antimalarial compounds from Ethiopian medicinal plants, we have tested the 80% methanol extract of K. foliosa rhizomes and its constituents against Plasmodium berghei in mice. Methods: Isolation was carried out using column and preparative thin layer chromatography (PTLC). The chemical structures of the compounds were elucidated by spectroscopic methods (ESI-MS, 1D and 2D-NMR). Peters’ 4-day suppressive test against P. berghei in mice was utilized for in vivo antimalarial evaluation of the test substances. Results: Three compounds, namely knipholone, dianellin, and 12-hydroxypentadec-9-en-1-yl methyl phthalate (HPMP) were isolated and characterized from the 80% methanolic extract of K. foliosa rhizomes. The hydroalcoholic extract (400 mg/kg) and knipholone (200 mg/kg) showed the highest activity with chemosuppression values of 61.52 and 60.16%, respectively. From the dose-response plot, the median effective (ED50) doses of knipholone and dianellin were determined to be 81.25 and 92.31 mg/kg, respectively. Molecular docking study revealed that knipholone had a strong binding affinity to Plasmodium falciparum l-lactate dehydrogenase (pfLDH) target. Conclusion: Results of the current study support the traditional use of the plant for the treatment of malaria.

Crinum abyscinicum Hochst. ExA. Rich bulb is traditionally used in Ethiopia for the treatment of various ailments including internal parasites, mastitis, rabies, colic diseases of animals, and cancer. Despite its importance in traditional cancer treatment, no research work has been reported on the antiproliferative activity of the bulb extract and its major constituents. Phytochemical investigation of the bulb extract of C. abyscinicum by PTLC over silica gel resulted in the isolation of two alkaloids, which were unequivocally identified as 6-hydroxycrinamine and lycorine on the basis of 1H- and 13C-NMR and MS analysis. The bulb extract, 6-hydroxycrinamine, and lycorine possessed significant antiproliferative activity, lycorine being the most active exhibiting GI50 values of 2.8 μg/ml and 3.4 μg/ml against A2780 and MV4-11 cells, respectively. Cell cycle analysis and annexin V/propidium iodide double staining in A2780 cells revealed that both compounds increased the percentage of cells in the S-phase at 30 μg/ml without inducing apoptosis. Our results suggest that the antiproliferative activities of the bulb extract of C. abyscinicum, 6-hydroxycrinamine, and lycorine could support the traditional claim of the plant against cancer.

There are 46 Aloe species identified from Ethiopia out of which 67.3% are endemics but comprehensive data on their ethno-medicinal and bio-cultural values are lacking. Interview, focus group discussion (FGD), and guided field walks were conducted with 210 respondents (152 men and 58 women). Relative frequency of citation (RFCs), informants' consensus factor (Fic), use value (UVs), relative importance index (RIs), and cultural value index (CV) were analyzed. Non-parametric Kruskal Wallis and Wilcoxon tests were performed using R software. Twenty-three Aloe species were recorded in the study areas with 196 use-reports and 2158 citations, grouped into six major use categories (NUC = 6). Medicinal use categories accounted for 149 use-reports (76%) with 1607 citations. The species with the highest numbers of use-reports were Aloe megalacantha subsp. alticola, A. trichosantha subsp. longiflora and A. calidophila of which 87, 75 and 61.1% respectively were medicinal uses. Aloe calidophila has highest values in all indices UV (11.72), RFC (0.68), RI (0.89), and CV (6.2). Among Aloe parts, leaf exudate accounted for 111 use-reports (49.1%) of which 92.9% were used for medicinal purposes. Aloe retrospiciens and A. ruspoliana were reported poisonous to carnivores. Fic values of the six major use categories ranged from 0.86 to 0.22. Elderly people (>60) had more knowledge than 25–40 and 41–60 age groups (Kruskal-Wallis chi-squared = 12.17, df = 3, p = 0.006), which is significant difference in depth of ethno-medicinal knowledge. Men had more knowledge of medicinal uses than women (Wilcoxon test, p = 0.002) significantly different, while women were knowledgeable than men for cultural uses like, cosmetic (Wilcoxon test, p = 0.06), not significantly different. The ways in which aloes are used and valued have implications for their future medicinal utility, which instigate detailed phytochemical and pharmacological studies., Aloe calidophila; Aloe exudate; Aloe gel; Aloe retrospiciens, Ethnomedicine, Environmental science; Veterinary medicine; Health sciences, Pharmaceutical science

Glycosylceramides (GlyCers) are precursors of ceramides (Cers) that are major components of the outer layer of human skin, the stratum corneum. A Cer deficiency is associated with skin diseases such as psoriasis and atopic dermatitis and can be treated with Cer-containing semisolid formulations. Plants may serve as alternative sources for expensive semisynthetic Cer production. Since the GlyCer contents of plants vary widely, there is a need to develop a rapid, simple, selective, and precise method for GlyCer quantification in plants. In the present study, an effective and validated automated multiple development‒high-performance thin-layer chromatography (AMD‒HPTLC) method has been developed for GlyCer quantification in 9 different plant materials. An 18-step gradient elution program (n-hexane, chloroform, ethyl acetate, methanol) led to a clear separation of bands from complex matrices and allowed densitometric analysis for quantification purposes. Apple pomace and wheat germs yielded 26.8 and 39.5 mg o...

Essential oils from the aerial part of Salvia officinalis L., grown in Addis Ababa and Wondo genet regions of Ethiopia, were isolated by hydrodistillation to yield 0.99 and 1.2 mL/100 g on dry weight, respectively. Fifty-one compounds representing 96.36 and 91.47 % of the oils, respectively, were identified by GC-FID and GC-MS. The major constituents in both samples were trans-thujone (19.98-26.42 %), 1,8-cineole (16.63-21.65 %) and camphor (12.98-17.58 %). The oils were assessed for their in vitro antimicrobial activities against 21 bacterial and 4 fungal strains using the disk diffusion method. Escherichia coli strains were most susceptible (MIC = 10-25 mg/mL) with viable cells dropping to zero CFU/mL after 13.5-14 hours of exposure to 200 mg/mL of the oils. Furthermore, the oils demonstrated potent radical scavenging potential (IC50 = 4.47-4.65 μg/mL) in 2,2-diphenyl-1-picyryhydrazil (DPPH) assay. In light of the above results, the essential oil from S. officinalis grown in Ethiopia may have th...

Aloesin (

The currently available antileishmanial drugs are either toxic or too expensive for routine use in developing countries where the disease is most common. Local people in the Somalia region of Ethiopia use the leaves ofAloe macrocarpaTodaro for the treatment of malaria, jaundice, and skin diseases. In our ongoing search for new, efficient, and safe antileishmanial drugs, we investigated the leaf latex ofAloe macrocarpaand its acid-hydrolyzed product aloin A/B (1), as well as the semisynthesized derivatives of aloin A/B, namely, aloe-emodin (2) and rhein (3) against promastigotes and axenically cultured amastigotes ofLeishmania aethiopicaandL. donovaniclinical isolates. Activity study was carried out based on the fluorescence characteristic of resazurin added to drug-treated cultures. Oxidative hydrolysis of aloin A/B by ferric chloride and concentrated hydrochloric acid afforded aloe-emodin (2), which was further oxidized using sodium nitrite and concentrated sulfuric acid to furnish rhein (3). Cytotoxicity study of test substances was performed against humanmonocyticcell lineTHP-1 usingAlamar Blue and cell viability was measured fluorometrically. The test compounds showed lower activity (IC50= 6.7 to 12.1μM for promastigotes and IC50= 3.6 to 10.2μM for axenic amastigotes) than the reference drug amphotericin B (IC50= 1.3 to 2.7μM). However, amphotericin B (LC50= 11.1μM) was much more toxic than the test compounds (LC50= 369.2 – 611.6μM) towards human monocytic cell line (THP-1) despite its efficiency. As demonstrated in the current study, high selectivity indices (SIs) of the test compounds represent a remarkable advantage over the reference drug and highlight their potential use as templates for further development of safe leishmanicidal drugs.

U The leaf latex of Aloe yavellana Reynolds is traditionally used for the treatment of various illnesses of humans and domestic animals in Ethiopia. In the present study, the latex and two major compounds isolated from it, namely, aloin A/B and microdontin A/B were assessed for their larvicidal activity against Amblyomma variegatum tick larvae using a larval packet test (LPT). The LC50 and LC99 of the latex were found to be 35.82 ± 2.27 and 83.48 ± 3.95 mg/ml, respectively. Although microdontin A/B showed better larvicidal activity (LC50 = 89.40 ± 4.45 mg/ml) than aloin A/B (LC50 = 257.69 ± 6.31 mg/ml), neither of the isolated compounds was as active as the latex suggesting that the compounds acted synergistically or minor compounds with potent larvicidal activity may exist in the latex. The results confirmed that the leaf latex of A. yavellana and its isolated compounds could have the potential to be used as larvicidal against A. variegatum ticks.

The leaves of Lippia javanica are used for the treatment of several skin diseases in Ethiopia. Forty-two components were identified and quantified, by GC–MS and GC–FID, comprising 98.9% of the total oil with cis-sabinene hydrate (20.3%) and limonene (13.9%) as major components. cis-Sabinene hydrate is reported here for the first time as a constituent of L. javanica leaf oil (Ethiopia). The essential oil and its two fractions were assessed for their possible antimicrobial activities against two bacterial strains (Bacillus cereus and Klebsiella pneumoniae) and one fungal pathogen (Cryptococcus neoformans) using the disc diffusion method. K. pneumoniae was found to be the most susceptible bacteria to the oxygenated fraction (MIC < 5 g/mL). The antioxidant property of the oil was assessed by free radical scavenging (DPPH) assay, with IC50 = 16.6 L/mL. These findings may support the traditional uses of the plant for the treatment of skin diseases.

The oleo-gum-resin of Commiphora myrrha (Nees) Engl (syn. Commiphora molmol (Engl.) Engl. ex Tschirch) is used in the Ethiopian folkloric medicine for wound management. The present study was aimed at evaluating the wound healing properties of the essential oil and resin of C. myrrha using in vivo and in vitro models. Ointments of the essential oil 4% (v/w) and resin 5% (w/w) were applied topically to study wound healing property, and their toxicity was assessed according to Draize skin irritation test. Agar diffusion and micro-dilution methods were used to evaluate antimicrobial activity. Thirty-seven components, representing 97.48% of the total essential oil, were identified by GC–MS analysis, with furanoeudesma-1,3-diene (26.09%), isofuranodiene (18.23%) and curzerene (16.52%) as the major constituents. The ointments were found to be non-irritant at the concentrations used, but they exhibited significant (p < 0.05-0.001) wound healing effect as evidenced by increased wound contraction rate, shorter epithelization time and higher skin breaking strength as compared to the control. Both the oil and resin showed potent antibacterial activity, comparable with that of ciprofloxacin against some Gram-negative bacterial strains. However, the fungal pathogens tested showed limited susceptibility. The results demonstrated that the essential oil and resin of C. myrrha enhance wound healing, in part or in full, due to their antimicrobial effects, supporting the traditional use of this plant as a wound healing agent. Keywords : Commiphora myrrha ; antibacterial; antifungal; wound healing; oleo-gum-resin

Leishmaniasis is a major protozoal disease threatening the lives of 350 million people throughout the world. However, the therapeutic options for the disease are limited. In the present study, the antiprotozoal activity of the latex obtained from the Ethiopian plant Aloe calidophila Reynolds was evaluated by in vitro testing against Leishmania aethiopica and Leishmania major. It was found that the latex possesses moderate activity against both parasites with IC50 values of 64.05 and 82.29 µg/mL, respectively. Phytochemical investigation resulted in the isolation of three anthrones identified as aloinoside, aloin, and microdontin on the basis of IR, MS, 1H NMR, and 13C NMR spectral data. The isolated compounds showed strong antileishmanial activity with IC50 values ranging from 1.76 to 6.32 µg/mL against L. aethiopica and from 2.09 to 8.85 µg/mL against L. major. Although these values were higher than those of amphotericin B (IC50 = 0.109 and 0.067 µg/mL), the selectivity indices (813.35 and 694.90, respectively, against L. aethiopica and L. major) of aloinoside were much better than those of the standard drug (423.49 and 688.96). The results indicate that the isolated compounds have the potential to be used as a scaffold for the development of safe and cost-effective antileishmanial agents. Copyright © 2014 John Wiley & Sons, Ltd.

Malaria remains a critical problem in global public health and continues to remain among the top three infectious diseases (along with tuberculosis and HIV) due to resistance of the pathogen to antimalarial drugs. Aloe percrassa Tod is an indigenous species of Ethiopia traditionally used for the treatment of malaria, wounds and gastric problems. The present study focused on isolation and characterization of antiplasmodial constituents from the latex of A. percrassa using Peter's 4-day suppressive test. After a four day treatment of Plasmodium berghei infected mice with the latex at doses of 100, 200 and 400 mg/kg/day, chemosuppression of 45.9%, 56.8% and 73.6% was observed, respectively. Further phytochemical examination of the latex by preparative TLC over silica gel resulted in the isolation of two anthrones, viz. aloin A/B and microdontin A/B, whose structures were determined on the basis of UV, MS, 1H, and 13C NMR spectral data. Antimalarial activities of both aloin A/B and microdontin A/B were lower than that of the latex suggesting that the two compounds may have acted synergistically. No adverse sign of toxicity and mortality was observed in mice within the first 24 h as well as for the following 14 days after the test substances were orally administrated up to a dose of 2 g/kg for the pure compounds and 5 g/kg for the latex. The strong antimalarial activities coupled with a relative safety of the leaf latex and isolated compounds of A. percrassa may confirm the claim by traditional practitioners for the use of the plant against malaria infection.

Discopodium Penninervum Hochst is among the Ethiopian medicinal plants traditionally used for wound healing activity. However, to date, there is no scientific report on its wound healing activity. Thus, the main aim of this study was to investigate the wound healing activity of 80% methanol leaf extract of D. penninervum in mice. Wound healing activity was investigated using excision and incision wound models. Mice were randomly assigned and treated with simple ointment (negative control), nitrofurazone (positive control), 5%, and 10% of D. Penninervum extract. Parameters such as wound contraction, period of epithelialization and tensile strength were evaluated. In addition, anti-inflammatory test using carrageenan-induced hind paw oedema model, in vitro antibacterial activity using agar well diffusion technique against several common bacterial strains that cause wound infection and antioxidant activity studies were performed at different doses of the extract. Both 5% and 10% (w/w) ointments exhibited significant (p < 0.001) increase in wound contraction and shorter epithelization period in excision wound model. Animals treated with 5% and 10% (w/w) ointments showed about 97% and 98% wound closure, respectively, on day fifteen, while the closure of negative control was 88%. In addition, both preparations of the crude extract showed significant increase (p < 0.001) in wound tensile strength as compared to negative controls. Mice treated with 100 mg/kg, 200 mg/kg and 400 mg/kg extract showed significant (p < 0.001) reduction in paw oedema starting from the 2nd h as compared to negative controls with maximum inhibition of 56.27%, 57.36% and 58.18%, respectively. The crude extract also showed antibacterial activity against both Gram- positive and Gram-negative bacteria, with the former being more sensitive than the latter. The lowest MIC values were observed for S. aureus, (2.6 µg/µl) and the highest (350 µg/µl) for all the studied Gram-negative organisms. The MICindex of the extract was found to be 2. The extract was effective in scavenging DPPH radicals and its IC50 value was 2.77 mg/ml. In addition, quantification of total flavonoid content revealed the presence of 43.03 mg quercetin equivalent flavonoids in the extract. In conclusion, the extract of D. penninervum is endowed with significant wound healing activity that could be attributed to antibacterial, anti-inflammatory and antioxidant activities of the plant.Keywords: Discopodium penninervum, wound healing, excision and incision models, antibacterial activity, anti-oxidant activity

Discopodium penninervium Hochst (Solanaceae), locally known as Ameraro (Amharic), is traditionally used in Ethiopia for the treatment of various ailments including schistosomiasis, stomachache, eczema, leprosy, diarrhea, liver disease and cancer. The chemical composition and biological activities of D. penninervium essential oil has not been reported. The objectives of the present study were therefore, to determine the chemical composition and evaluate the in vitro antileshmanial activity of the essential oil of D. penninervium. Fresh leaves of D. peninnervium were subjected to hydrodistillation using Clevenger-type apparatus. Chemical composition of the essential oil obtained was determined by gas chromatography-mass spectrometry (GC-MS). In vitro antileishmanial activity of the oil was evaluated against the promastigote stage of L. aethiopica and L. donovani. Hydrodistillation of the leaves of D. penninervium afforded a colourless essential oil with yield of 0.01% (w/w). GC-MS analysis revealed the presence of 65 components comprising 98.6% of the total oil. Majorly, the oil is composed of hydrocarbons such as 1,4-diethyl benzene (11.49%), 1,2-diethyl benzene (11.86%) and m- xylene (8.45%) and terpenoids including 1,8-cineole (9.8%), geranic acid (8.28%) and dihydrocitronellol (5.0%). The oil possesses antileishmanial activity against L. aethiopica and L. donovani with IC50 values of 12.62 and 19.93 µl/ml, respectively. The results show that the essential oil of the leaves of D. penninervium is mainly composed of aromatic hydrocarbons and terpenoids, and exhibits antileshmanial activity on both L. aethopica and L. donovani .Keywords: Discopodium penninervium, essential oil, antileshmanial activity, chemical composition, traditional medicine

The usage of vast amount of synthetic dye causes pollution that disturbs the ecological balance and health hazards for human beings. Indeed there is a growing trend towards the usage of natural colorants of plant origin in various food industries. One of such plant that falls in this category is Bixa orellana (Annatto) whose seed aril extracts are used as a natural food colorants. Aril of seeds of B. orellana was subjected to extraction using three different solvent mixtures (CHCl3/EtOH; CHCl3/Acetone; Hexane/EtOAc) and a base extraction (5% KOH) to yield a reddishorange semi-solid, with percentage yield of 9.02% (w/w; CHCl3/EtOH), 4.90% (w/w; CHCl3/Acetone), 2.98% (w/w; Hexane/EtOAc) and 26.66% (w/w; alkali extraction). The total carotenoids were found to be 3.14% (CHCl3/EtOH), 1.42% (CHCl3/Acetone), 0.51% (Hexane/EtOAc) and 1.76% (Alkali extraction) in the seed extracts. Phytochemical investigation of the CHCl3/EtOH seed extract over silica gel preparative thin layer chromatography led to the isolation of two compounds, of which one compound BO-2 was identified as Bixin by using spectroscopic techniques (UV, IR, MS and NMR). Compound BO-3 was partially characterized. Bixin is one of the most important constituents of the seed, which was gravimetrically determined to be 1.62% (w/w) from the seed. It is important to note that the antioxidant activity of the seed extract was showed a weak free radical scavenging with an IC50 value of 3124.31 μg/ mL, which is about 50 times less than that offered by the standard ascorbic acid (IC50=577.04 μg/mL). The CHCl3/ EtOH seed extract exhibited moderate inhibitory effect against the tested bacterial pathogens at a concentration of 50 mg/mL. The Gram-negative bacterium Escherichia coli was found to be the most susceptible to the seed extract, with zone of inhibition of 14.0 mm (MIC=0.25 mg/mL), while the least antibacterial activity against the Gram-positive bacteria, S. aureus, was observed, with zone of inhibition of 9.2 mm (MIC=1.0 mg/mL). In general, the activity of the tested substances on the tested fungal pathogens were relatively weaker with the exception of seed extract against A. niger, which showed a zone inhibition of 9.2 mm (MIC=12.5 mg/mL). In conclusion, the present findings support the huge potential of B. orellana as a natural food colorant.

In Ethiopian traditional medicine, the leaves of Otostegia integrifolia Benth. are used for the treatment of several diseases including malaria. In an ongoing search for effective, safe and cheap antimalarial agents from plants, the 80% methanol leaf extract O. integrifolia was tested for its in vivo antimalarial activity, in a 4-day suppressive assay against Plasmodium berghei. Activity-guided fractionation of this extract which showed potent antiplasmodial activity resulted in the isolation of a labdane diterpenoid identified as otostegindiol. Otostegindiol displayed a significant (P

Background Health seeking behavior of people around the globe is affected by different socio-cultural and economic factors. In Ethiopia, people living in rural areas in particular, are noted for their use of medicinal plants as a major component of their health care option. This study was conducted to document ethnopharmacological information of the Hamer semi-pastoralists ethnic group in southwestern Ethiopia. Methods A cross-sectional study was carried out whereby information on demographic characteristics, prevalence of perceived illnesses, factors associated with preference of health care seeking options, medicinal plants used and hoarded as well as some healers’ socio-economic characteristics were collected using two sets of semi-structured questionnaires – one for household (HH) heads and the other for traditional healers supplemented by focus group discussions (FGDs). Households were selected using a cluster sampling followed by systematic sampling techniques; whereas healers and FGD participants were purposively selected with the assistance of local leaders and elders from the community. Results The study revealed that the use of traditional medicine among the Hamer ethnic group is very high. Females preferred traditional medicine more than males. The main reasons for this preference include effectiveness, low cost and ease of availability. Malaria (gebeze) was the most frequently occurring illness in the area identified by all FGD participants. A total of 60 different medicinal plants were reported [34 by HH respondents, 14 by traditional healers and 12 by both]. Fifty-one medicinal plants were fully identified, 3 at generic level and 6 have not yet been identified. Conclusion It can be concluded that traditional medical practices, particularly herbal aspect, is widely used by the Hamer ethnic group, although health seeking behavior of the community is affected by different socio-economic and cultural factors. Electronic supplementary material The online version of this article (doi:10.1186/s13002-016-0107-x) contains supplementary material, which is available to authorized users.

Malaria is one of the three major global public health threats due to a wide spread resistance of the parasites to the standard antimalarial drugs. Considering this growing problem, the ethnomedicinal approach in the search for new antimalarial drugs from plant sources has proven to be more effective and inexpensive. The leaves of Aloe pulcherrima Gilbert and Sebsebe, an endemic Ethiopian plant, are locally used for the treatment of malaria and other infectious diseases. Application of the leaf latex of A. pulcherrima on preparative silica gel TLC led to the isolation of two C-glycosylated anthrones, identified as nataloin (1) and 7-hydroxyaloin (2) by spectroscopic techniques (UV, IR, 1H- and 13C-NMR, HR-ESIMS). Both the latex and isolated compounds displayed antimalarial activity in a dose-independent manner using a four-day suppressive test, with the highest percent suppression of 56.2% achieved at 200 mg/kg/day for 2. The results indicate that both the leaf latex of A. pulcherrima and its two major constituents are endowed with antiplasmodial activities, which support the traditional use of the leaves of the plant for the treatment of malaria.

In the search for new antimicrobial and antioxidant compounds from plants, the latex of the medicinal plant Aloe harlana Reynolds from Ethiopia was subjected to bioassay‐guided fractionation, which led to the isolation of two known compounds, anthrone (aloin) and chromone (7‐O‐methylaloeresin A). The latex and its two constituents were assessed for their possible antimicrobial activities against 23 bacterial and four fungal strains using the disc diffusion method and their antioxidant activity by two complementary test systems, namely 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2‐deoxyribose degradation assay methods. The isolated compounds showed promising results against various pathogenic bacterial and fungal strains in comparison with standard drugs. Moreover, 7‐O‐methylaloeresin A exhibited good activity against multiple drug resistant Staphylococcus aureus (NCTC 11994) and Salmonella typhimurium (ATCC 1255) with MIC values of 0.72 and 0.18mM, respectively. Among the fungal strains tested, Candida albicans (ATCC 10231) was the most susceptible organism to the latex and the two isolated compounds. The latex and isolated compounds also showed significant activities on both antioxidant assays with the highest activity being observed for 7‐O‐ methylaloeresin A, which gave IC50 values of 0.026mM and 0.021mM for DPPH and 2‐deoxyribose degradation assay, respectively. These findings support the traditional uses of the plant for the treatment of various infectious and inflammatory diseases. Copyright © 2011 John Wiley & Sons, Ltd.

Most commercially available repellents of mosquitoes and other biting arthropods are synthetic and have a severe toxic effect to human. Moreover, these chemicals cause an irreversible damage to the ecosystem as some of them are non-degradable in nature. Therefore, there is a need to develop safe and effective alternatives to the currently available chemicals used to control vectors. In southern Ethiopia, the smoke obtained from burning the stem of Kleinia squarrosa Cufod. is used as a fumigant to ward off mosquitoes. In the present study hydrodistillation of the powdered stem of K. squarrosa gave a pale yellow oil (0.04%; w/w) with a characteristic pungent odor. A total of twenty-seven compounds have been identified by GC-MS analysis, accounting 48.71% of the total oil. The main constituents of the oil were ( E )-iso-γ-bisabolene (9%), α-pinene (5.74%), caryophyllene (5.36%) and sabinene (5.55%). The powdered stem of K. squarrosa was also burned, and the smoke extracted to yield a trace amount brownish oil. Analysis of the oil by GC-MS afforded 36 compounds comprising 94.56% of the total peak area. Terpene-4-ol (18.09%), ( E )-iso-γ-bisabolene (14.07%), 5-epi-7-epi-α-eudesmol (12.45%), and caryophyllene (8.35%) figured as major compounds. Mosquito repellent activity of the essential oil was tested on guinea pigs against Anopheles gambiae by a modified Kunming mice technique under laboratory testing conditions. The essential oil exhibited a dose-dependent repellent action in the dose range tested (0.03 - 5%; v/v) with ED 50 and ED 99.9 values of 1.49% and 4.74% (v/v), respectively. The study further revealed that that the essential oil possesses a 3 h complete protection time. The similarity in the chemical profiles of the essential oil and the oil extracted from the smoke obtained by burning K. squarrosa stem supports the traditional use of the plant as a fumigant to kill mosquitoes. Keywords: Kleinia squarrosa ; fumigant; essential oil; mosquito repellent; Anopheles gambiae

Sweet pepper (Capsicum annuum) leaves at the mature stage have strong ovipositional deterrence against Liriomyza trifolii (Burgess) (Diptera, Agromyzidae), whereas the cotyledons are fiercely attacked by the fly. Treatment of the cotyledons with 50 microM and 100 microM of a jasmonic acid (JA) solution caused the plant to acquire strong oviposition deterrence against the leafminer. An HPLC analysis of the JA-treated cotyledons revealed the inducible accumulation of a compound. Based on spectroscopic analysis and chemical methods, the induced compound was identified to be caffeoylputrescine (CP). The accumulated amounts of CP in the cotyledons treated with 0, 10, 50 and 100 microM of JA were 6.0, 43.0, 105 and 140 microg/g fr. wt., respectively. Treatment of the cotyledons with CP resulted in a significant decrease in the number of punctures made by L. trifolii, indicating that the JA treatment enhanced the deterrence against the leafminer by inducing CP accumulation.

Background The incidents of drug resistant microorganisms and the need of treatments for newly emerging pathogens are of great concern to the global community. Our ability to treat infectious diseases is dependent on the development of new pharmaceuticals, and one potential source being medicinal plants with traditional claims. The leaves of Aloe trigonantha L.C. Leach, an endemic Ethiopian plant, are locally used for the treatment of infectious and inflammatory diseases. This study explores the potential of the latex of this plant and compounds isolated thereof for their in vitro antibacterial and antifungal properties. Methods Analytical RP-HPLC and silica gel preparative TLC were used for identification and isolation of active constituents, respectively. Characterization of the compounds was based on UV, IR, HR-ESIMS, 1H and 13C NMR, and 2D-NMR spectral assignments. Antimicrobial activity studies were carried out against 21 pathogenic bacterial and 4 fungal strains using the disk diffusion method. Minimum inhibitory concentrations (MICs) were determined by the broth dilution method. Results A C-glycosylated chromone identified as aloesin, and three C-glycosylated anthrones characterized as 8-O-methy-7-hydroxyaloin A/B, aloin A/B and aloin-6’-O-acetate A/B were isolated. The latex and isolated compounds exhibited in vitro antibacterial activity against the tested pathogens. In some cases the activity of the isolated compounds (MIC = 10 μg/mL) was comparable with that of the standard drug ciprofloxacin, particularly against some of the Gram-negative bacterial strains tested. However, their activity towards the fungal pathogens tested was relatively weaker showing maximum activity against Candida albicans with MIC value of 400 μg/mL. Conclusion The present findings can be used for further research aimed at the development of new antibacterial agents, and may also justify the ethnomedicinal claim of the plant for the treatment of infectious diseases.

Liriomyza trifolii (Burgess), the American serpentine leafminer fly, is a well-known serious pest in the world. This insect species attacks plants of more than 21 families including Solanaceae plants. A sweet pepper, Capsicum annuum (Solanaceae), on mature stage, however, shows resistance to this leafminer fly. This resistance is based on the ovipositional deterrent in the sweet pepper leaf against the fly species. Based on the bioassay guided fractionation, phytol [(2E)-3,7,11,15-tetramethyl-2-hexadecen-1-ol] was isolated and identified as an ovipositional deterrent against this insect species. The yield of this compound was 815 μg/g fresh leaf of C. annuum. This compound completely deterred the females from laying their eggs on host plant leaves treated at 35.2 μg/cm2.

Liriomyza trifolii (Burgess), the American serpentine leafminer fly, is well known as a serious pest throughout the world. This insect attack over 21 different plant families including solanaceae plants. The mature sweet pepper, Capsicum annuum (Solanaceae), however, shows resistance to this leafminer fly. This resistance is based on the ovipositional deterrent in the sweet pepper leaf against the fly species. Based on bioassay-guided fractionation, luteolin 7-O-beta-D-apiofuranosyl-(1--2)-beta-D-glucopyranoside was isolated and identified as the ovipositional deterrent against this insect species. This compound completely deterred L. trifolii females from laying their eggs on a host plant leaf treated at 4.90 microg/cm2.

Leishmaniasis is a major protozoal disease threatening the lives of 350 million people throughout the world. However, the therapeutic options for the disease are limited. In the present study, the antiprotozoal activity of the latex obtained from the Ethiopian plant Aloe calidophila Reynolds was evaluated by in vitro testing against Leishmania aethiopica and Leishmania major. It was found that the latex possesses moderate activity against both parasites with IC50 values of 64.05 and 82.29 µg/mL, respectively. Phytochemical investigation resulted in the isolation of three anthrones identified as aloinoside, aloin, and microdontin on the basis of IR, MS, (1) H NMR, and (13) C NMR spectral data. The isolated compounds showed strong antileishmanial activity with IC50 values ranging from 1.76 to 6.32 µg/mL against L. aethiopica and from 2.09 to 8.85 µg/mL against L. major. Although these values were higher than those of amphotericin B (IC50 = 0.109 and 0.067 µg/mL), the selectivity indices (813.35 and 694.90, respectively, against L. aethiopica and L. major) of aloinoside were much better than those of the standard drug (423.49 and 688.96). The results indicate that the isolated compounds have the potential to be used as a scaffold for the development of safe and cost-effective antileishmanial agents.