Evaluation of the Antimalarial Activity of the Hydroalcoholic Extract of Leaf of Leonotis ocymifolia (Burm. f.) Iwarsson (Lamiaceae) against Plasmodium berghei in Mice.

Malaria's global impact, fueled by resistance to several antimalarial drugs, has necessitated a quest to new antimalarial drugs from several sources with traditional medicinal plants being one of them. This study was conducted to assess the antimalarial activity of a traditionally used medicinal plant, Leonotis ocymifolia, against Plasmodium berghei. The plant has been extracted using maceration technique, and doses ranging from 100-800 mg/kg of Leonotis ocymifolia were used to test its antimalarial activity. Tween 80 (2% in water) and chloroquine 25 mg/kg were used as negative and positive controls, respectively. The antimalarial activities of the plant were determined by measuring parasitemia, survival time, packed cell volume, temperature, and weight. The plant's hydroalcoholic extract, as compared to negative control, maximally decreased parasite load by 41.4% at 800 mg/kg (p < 0.001). This parasite suppression was followed by longer survival time in the groups taking 400 mg/kg (p < 0.05) and 800 mg/kg (p < 0.05) in a four-day suppressive test and in those taking 800 mg/kg (p < 0.05) in Rane's test. The plant did not prevent weight and PCV reduction but prevented temperature reduction at 400 mg/kg (p < 0.05) and 800 mg/kg (p < 0.05) in a four-day suppressive model, and at 800 mg/kg (p < 0.05) in Rane's model. The average but consistent antimalarial activity of the plant across the test models corroborates the folkloric antimalarial use of the plant. The study recommends further pharmacological screenings, isolation, and identification of active compound(s) of the plant Leonotis ocymifolia.

Evaluation of Antidiabetic Effect of Ethanolic Leaves Extract of Becium grandiflorum Lam. (Lamiaceae) in Streptozotocin-Induced Diabetic Mice.

BACKGROUND: Becium grandiflorum has been used traditionally for treatment of different ailments including diabetes mellitus although it lacks scientific evidence. Thus, the present study was aimed at evaluating the antidiabetic effect of Becium grandiflorum in streptozotocin (STZ)-induced diabetic mice. METHODS: The antidiabetic activity of hydro-ethanolic (30:70) leaf extract of Becium grandiflorum was evaluated in STZ (45 mg/kg)-induced diabetic and normal mice. Antihyperglycemic, hypoglycemic, oral glucose tolerance and body weight change effects of the extract were assessed after administering three doses of the extract (200, 400 and 600 mg/kg), glibenclamide 5 mg/kg (reference drug) and 2% Tween 80 (vehicle). One-way analysis of variance and Tukey's post hoc test were used for data analysis. RESULTS: All doses of the extract (200 mg/kg (p<0.05), 400 mg/kg (p<0.05) and 600 mg/kg (p<0.01)) and glibenclamide 5 mg/kg (p<0.001) showed statistically significant blood glucose level reduction in normal mice as compared to Tween 80. The hydroalcoholic extract at a dose of 200 mg/kg (p<0.05), 400 mg/kg (p<0.01) and 600 mg/kg (p<0.001) showed better blood glucose tolerance after 60, 120 and 180-minute treatment duration in normal mice as compared to negative control. In diabetic mice, Becium grandiflorum doses and the reference drug caused maximum reduction in blood glucose level at the end of the 15th day of treatment by 17.61%, 22.52%, 24.62% and 34.12%, respectively. The extract's doses and the standard drug showed significant (p<0.05) improvement in body weight while the diabetic control continued to lose their body weight. CONCLUSION: Thus, Becium grandiflorum exhibits antihyperglycemic activity in STZ-induced diabetic mice, and shows improvement in oral glucose tolerance and body weight, which justifies the claimed use of the plant in ameliorating diabetes mellitus in Ethiopian folk medicine.

In Vivo Wound Healing and Anti-Inflammatory Activities of Leaf Latex of Aloe megalacantha Baker (Xanthorrhoeaceae).

BACKGROUND: Aloe megalacantha Baker (Xanthorrhoeaceae) is one of the Aloe species widely distributed in Ethiopia. The leaf latex of the plant is used for treatment of wounds, inflammation, and other multiple ailments in Ethiopian traditional medicine. PURPOSE: The aim of this study was to evaluate in vivo wound healing and anti-inflammatory activities of the leaf latex of Aloe megalacantha in mice. METHODS: The wound healing activity of the leaf latex of the plant was studied topically by incorporating the latex in simple ointment base in a concentration of 5% (w/w) and 10% (w/w) using excision and incision models. In these models, wound contraction, period of epithelialization, and breaking strength of the wounded skin were determined. Carrageenan induced inflammation of paw model was also used to assess the anti-inflammatory activity of the leaf latex at doses of 200 mg/kg, 400mg/kg, and 600 mg/kg. The level of inflammation suppressions were measured at 1, 2, 3, and 4 hrs after carrageenan injection, and then the percentages of inflammation inhibition were computed as compared with the negative control. RESULT: In both wound models, mice treated with 5% (w/w) and 10% (w/w) latex ointment showed a significant (p<0.05) increment in the rate of wound contraction, reduction in epithelialization time, and higher skin breaking strength. Besides, the latex also exhibited a dose-dependent significant (p<0.05) reductions of inflammation as compared to negative control groups. CONCLUSION: The overall results of this study demonstrate that the leaf latex of A. megalacantha possesses wound healing and anti-inflammatory activities which can scientifically substantiate the traditional use of the plant as a wound healing agent.