Asfaw Debella

Antipyretic properties of the aqueous and ethanol extracts of the leaves of Ocimum suave and Ocimum lamiifolium in mice

Numerous plant species are used to treat ailments associated with pyrexia in the indigenous health care delivery system of Ethiopia. Notable among these are Ocimum suave and Ocimum lamiifolium. The objective of the present study was thus to evaluate the antipyretic effects of the aqueous and ethanol extracts of the leaves of Ocimum suave and Ocimum lamiifolium in mice. Rectal temperatures were recorded before and after inducing pyrexia as well as after administration of the respective extracts every half an hour for 3h. Parallel experiments were run with a standard antipyretic (acetylsalicylic acid) and the vehicle (distilled water). All the plant extracts showed antipyretic property with reasonable onset and duration of action. Both ethanol and aqueous extracts of Ocimum suave were observed to be more potent than those of Ocimum lamiifolium. Aqueous extract of Ocimum suave and ethanol extract of Ocimum lamiifolium were more potent than their other counterpart extracts. Time dependent antipyretic effect was also observed with some extracts; reduced with time with aqueous extract of Ocimum suave and increased with time with both extracts of Ocimum lamiifolium.

Steroidal saponins from Asparagus africanus

The structures of two new monodesmosidic spirostanosides and a new bisdesmosidic furostanol glycoside isolated from the roots of Asparagus africanus Lam. (Liliaceae) have been elucidated as (25R)-3 beta-hydroxy-5 beta-spirostan-12-one 3-O-{beta-D-glucopyranosyl-(1-->2)-[alpha-1-arabinopyranosyl-(1--> 6)]-beta- D-glucopyranoside} (1), (25R)-5 beta-spirostan-3 beta-ol 3-O-{beta-D-glucopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1--> 6)]-beta- D-glucopyranoside} (2) and 26-O-beta-D-glucopyranosyl]-22 alpha-methoxy-(25R)-furostan-3 beta,26-diol 3-O-{beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranoside} (3), respectively, by the combined use of one and two dimensional NMR experiments. The complete 13C and 1H assignments of the peracetyl spirostanosides and the furostanol oligoside were derived. The interconversions between the methoxyl and hydroxyl group at C-22 of the furostanol glycoside was investigated and the genuine furostanol oligoside of A. africanus appears to be the hydroxyl type based on the comparative study of the methanol, pyridine and dioxane extracts.

Evaluation of in vivo wound healing activity of methanol extract of Achyranthes aspera L.

ETHNOPHARMACOLOGICAL RELEVANCE The leaves of Achyranthes aspera L. (Amarenthacea) has been used traditionally for the treatment of wound in various parts of Ethiopia. However, the plant has not been explored scientifically for its wound healing activity. Therefore, this study was designed to investigate the wound healing activity of methanol extract of Achyranthes aspera L. leaves in rats. MATERIALS AND METHODS Incision and excision wounds were inflicted on albino rats of either sex, under diethyl ether anesthesia. Group I served as positive control and was treated with 1% silver sulphadiazine, group II, III, IV treated with simple ointment containing 2.5%, 5% and 10% (w/w) methanol extract of the leaves of Achyranthes aspera L., respectively, whereas group V served as negative control and was treated with simple ointment. All the animals were treated topically once a day. Wound healing potential was assessed with excision and incision wound model. Excision wound model was used to assess the change in percentage contraction of wound, epithelization time, DNA content and histological features whereas rats inflicted with the incision wounds were used to determine breaking strength. RESULTS Based on the results of percentage wound contraction, the DNA content and epithelization time, all groups of rats treated with methanol extract of the leaves of Achyranthes aspera L. showed significant (p<0.05) wound healing activity compared to group of rats treated with simple ointment (negative control) group. The difference in breaking strength was, however, significant (p<0.05) only for the 5% and 10% methanol extract of Achyranthes aspera (w/w) ointment treated groups. Histological evaluation showed well organized epidermal layer, increased number of fibrocytes, remarkable degree of neovascularization and epithelization which was comparable to the standard on the 21st day after treatment; especially in the 5% and 10% (w/w) extract treated group. CONCLUSION The present study provides a scientific rationale for the traditional use of the leaf extracts of Achyranthes aspera L. in the treatment of wound.

Triterpenoid saponins and sapogenin lactones from Albizia gummifera.

The structures of two new monodesmosidic and bisdesmosidic triterpenoid saponins (1 and 2) and the known compound delta 5-stigmasterol-3-O-beta-D-glucopyranoside (3) as well as two new oleanane type triterpene lactone glycosides 4, 5 and a new sapogenin lactone 6 isolated from the stem bark of Albizia gummifera C.A. Smith (Mimosaceae) have been elucidated as 3-O-¿beta-D-glucopyranosyl(1-->2)-[alpha-L-arabinopyranosyl(1-->6) ]-beta-D- glucopyranosyl¿-oleanolic acid (1), beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl 3-O-¿beta-D-glucopyra-nosyl(1-->2)-[alpha-L-arabinopyrano syl(1-->6)]-beta-D- glucopyranosyl¿-oleanolate (2), 3 beta-¿O-D-glucopyranosyl-(1-->2)-[O-alpha-L-arabinopyranosyl(1-->6 )] beta-D-glucopyranosyloxy¿-machaerinic acid gamma-lactone (4), 3 beta-O-beta-D-glucopyranosiduronic acid (1-->2)-beta-D-glucopyranosyloxy]-machaerinic acid gamma-lactone (5), and A-homo-3a-oxa-5 beta-olean-12-en-3-one-28-oic acid (6), respectively. The complete assignment of the 1H and 13C resonances of 1, 2, 4 and 6 and of the peracetate of 5 were achieved by means of 2D-NMR studies.

Effect of essential oils on Aspergillus spore germination, growth and mycotoxin production: a potential source of botanical food preservative

OBJECTIVE To investigate effect of essential oils on Aspergillus spore germination, growth and mycotoxin production. METHOD In vitro antifungal and antiaflatoxigenic activity of essential oils was carried out using poisoned food techniques, spore germination assay, agar dilution assay, and aflatoxin arresting assay on toxigenic strains of Aspergillus species. RESULTS Cymbopogon martinii, Foeniculum vulgare and Trachyspermum ammi (T. ammi) essential oils were tested against toxicogenic isolates of Aspergillus species. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 µl/mL by essential oils of T. ammi. The oil also showed, complete inhibition of spore germination at a concentration of 2 µl/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting aflatoxin production from Aspergillus niger and Aspergillus flavus at 0.5 and 0.75 µl/mL, respectively. Cymbopogon martinii, Foeniculum vulgare and T. ammi oils as antifungal were found superior over synthetic preservative. Moreover, a concentration of 5 336.297 µl/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity and strengthening its traditional reputations. CONCLUSIONS In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by storage fungi.

Antihyperglycemic Effect on Chronic Administration of Butanol Fraction of Ethanol Extract of Moringa Stenopetala Leaves in Alloxan Induced Diabetic Mice

Abstract Objective The present study was conducted to evaluate the antihyperglycemic activity on chronic administration of the butanol fraction of the ethanol extract of Moringa Stenopetala leaves in alloxan induced diabetic mice. Methods The mice were grouped in four groups; Normal control, Diabetic control, Butanol fraction treated and standard drug treated groups. The Diabetic mice received the butanol fraction of Moringa stenopetala daily for 28 days. Results The butanol fraction of Moringa stenopetala treatment resulted in significant reduction of fasting blood glucose level, serum total cholesterol and triglycerides level. This fraction also showed a tendency to improve body weight gain in diabetic mice. Its oral LD50 was found to be greater than 5000mg/Kg indicating its safety in mice. Conclusions Though the mechanism of action of Moringa stenopetala seems to be similar to that of sulfonylureas, further studies should be done to confirm its mechanism of antidiabetic action. Furthermore the active principle(s) responsible for the antidabetic effects should also be identified.

In vivo anti-inflammatory activities of Ocimum suave in mice.

ETHNOPHARMACOLOGICAL RELEVANCE Ocimum suave has been used in the Ethiopian traditional medicine to relieve pain, fever, inflammation and other disease conditions. AIM OF THE STUDY The aim of the present study was to investigate the anti-inflammatory activities of the aqueous and ethanol leaf extracts and some fractions of Ocimum suave in mice. MATERIALS AND METHODS The crude extracts were screened for their anti-inflammatory activities on carrageenan-induced mouse paw edema at three dose levels. The butanol and aqueous fractions of the aqueous extract were also evaluated for their anti-inflammatory activities using carrageenan, histamine and serotonin-induced mouse paw edema at three dose levels. Normal saline and aspirin were employed as negative and positive control groups, respectively. RESULTS Both ethanol and aqueous extracts significantly decreased carrageenan-induced inflammation at all the three doses used. However, greater paw edema inhibition was observed with the aqueous extract. The two fractions also showed significant reduction of inflammation against inflammatory models in which the aqueous residue exhibited the highest inhibition. CONCLUSIONS From the present findings, it can be concluded that the ethanol and aqueous leaf extracts as well as butanol and aqueous fractions of Ocimum suave have shown anti-inflammatory properties.

Effects of crude extracts and fractions of Moringa stenopetala (Baker f) Cufodontis leaves in normoglycemic and alloxan-induced diabetic mice

Moringa stenopetala leaves are traditionally employed for the treatment of diabetes mellitus in Ethiopia. Previous studies confirmed that the aqueous crude extract of the leaves of this plant and fractions isolated from these extracts have hypoglycemic and antihyperglycemic effects. Whether the active components are also present in the ethanol extract and its fractions, however, have not yet been investigated. The aim of this study was to evaluate the effects of M. stenopetala leaves ethanol crude extracts and its fractions in healthy and alloxan induced diabetic mice. For single dose hypoglycemic test, normoglycemic mice were given 300 mg/kg of ethanol extract, aqueous extract, petroleum fraction, chloroform fraction, butanol fraction, aqueous residue, glibenclamide (0.66 mg/kg) and distilled water (10 ml/kg) intraperitoneally (i.p). Similarly, for single dose anti-hyperglycemic study, alloxan induced diabetic mice were given the same dose of test substances. For the repeated dose anti-hyperglycemic investigation, diabetic mice were given 300 mg/kg of ethanol extract, aqueous extract, chloroform fraction, butanol fraction, glibenclamide (0.66 mg/kg)) and distilled water (10 ml/kg) through i.p route. The results of single dose hypoglycemic and antihyperglycemic studies indicated that extracts, chloroform fraction, butanol fraction and aqueous residue reduced blood glucose level significantly within the treatment period. The repeated dose of both extracts as well as chloroform and butanol fractions also reduced blood sugar level of diabetic mice significantly. The present findings, therefore, hints that the ethanol extract as well as its chloroform and butanol fractions might also have active principles responsible for antidiabetic effect which confirms the claim for the traditional antidiabetic use of M. stenopetala .

A Diterpene, a Flavonol Glycoside, and a Phytosterol Glycoside from Securidaca longipedunculata and Entada abyssinica

Summary. The MeOH extract of the stem bark of Entada abyssinica and of the leaves and stem bark of Securidaca longipedunculata yielded a diterpene, a flavonol glycoside, and a phytosterol glycoside. Their structures were established on basis of NMR spectroscopic analysis; the complete 13C and 1H assignment of the compounds was achieved by means of 2D NMR studies.

Is khat-chewing associated with HIV risk behaviour? A community-based study from Ethiopia

This study examines the possible association between the stimulant khat and risky sexual behaviour that might aggravate the spread of HIV. A community-based cross-sectional survey involving 4 000 individuals and focus group discussions were conducted to assess the attitudes and perceptions of an Ethiopian population towards the habit of khat-chewing and its possible association with risky sexual behaviour. All participants in the focus group discussions and 38% of the survey respondents were of the opinion that behaviours associated with the mild narcotic effects of khat are conducive to casual sex, and hence constitute an increased risk for contracting and spreading HIV. A significant shift towards casual sex practices was observed in response to the effects induced by the substance, and a strong association was observed between khat-chewing, indulgence in alcohol and recourse to risky sexual behaviours. There was no significant difference in the use or non-use of condoms among those male chewers who admitted resorting to casual sex after khat-chewing. We suggest that HIV/AIDS programmes in certain regions should address the habitual use of khat and other substances of potential abuse as part of their intervention efforts to curb the epidemic.