The toxicological assessment of ethanolic whole-plant extract of Eleucine indica in Wistar albino rats

Introduction: Eleucine indica is a medicinal plant used by the Ibibios of Nigeria in the treatment of malaria but its safety with chronic use has not been determined. This study was to evaluate the toxicological effects of the extract in adult albino Wistar rats.Methods: The rats of both sexes were randomized into 5 groups of 6 animals per group and orally administered with extract (200, 400 and 600 mg/kg) for groups 2–4, respectively. Group 1 received distilled water (10 mL/kg) orally and served as negative control while group 5 was administered with 100 mg/kg of silymarin orally. Drugs were administered on alternate days for 28 days at 09.00 am. Toxic manifestations and mortality were monitored daily and weight changes of animals were recorded every week. On day 29, after an overnight fast, the animals were weighed, anaesthetized with light chloroform. An autopsy was performed during which any macroscopic abnormalities were noted. The brain, heart, liver, spleen, kidney and lungs were weighed immediately after removal. Samples of these organs were fixed in 10 formalin and kept in that solution for further histopathological examination. Data were analysed using one-way analysis of variance (ANOVA) followed by Tukey Kramer multiple comparison post-test.Results: The results showed that organ weights were not affected but animal weights increased significantly (P < 0.01-0.001). Relative organ weights were not affected. The extract caused, at low doses, slight inflammation of the liver, spleen, lungs, kidneys and brain. With high dose of the extract, the spleen and lungs showed moderate inflammation. The lungs also showed moderate interstitial fibrosis.Conclusion: Based on these results, the plant has a potential to damage the lungs when used on the long term. Its use as herbal remedy should be for short periods at a time

Antiplasmodial activity of methanol leaf extract of Citrus aurantifolia (Christm) Swingle

Introduction: Citrus aurantifolia (Christm) is a plant used for the treatment of various ailments including malaria. This study aimed to evaluate the in vivo antiplasmodial efficacy of methanol leaf extract of C. aurantifolia in Swiss albino mice. Methods: The median lethal dose (LD50) was determined by intraperitoneal administration of different doses of the extract (100–4000 mg/kg) to 6 groups of 3 mice each and the animals were observed for 24 hours for physical signs of toxicity. To evaluate the antiplasmodial activity of the extract, three models were used: suppressive, curative and repository. Doses of the extract used were 320, 640 and 960 mg/kg/d in mice, with Chloroquine (5 mg/kg/d) as standard drug. Pyrimethamine (1.2 mg/kg/d) was used as the standard drug for the repository test and distilled water (10 mL/kg/d) as control in all models. Results: In all models, the low dose (320 mg/kg) of the extract produced the highest chemosuppressive effects in all models (P < 0.001). Mice treated with extract lived longer than those in the control group (P < 0.001). Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, tannins and cardiac glycosides and the LD50 of 3280 mg/kg ± 0.01 shows that the extract has low toxicity. Conclusion: The result of this study shows that C. aurantifolia has antiplasmodial properties which support its use in ethnomedicine in the treatment of malaria

Larvicidal and Antifungal Properties of Picralima nitida (Apocynaceae) Leaf Extracts

The larvicidal and antifungal activities of ethanolic and aqueous leaf extracts of Picralima nitida were evaluated in static bioassays on 4th instar larvae of Anopheles gambiae and three fungal species: Aspergillus flavus, Candida albicans and Microsporum canis. All extractions were done using distilled water and 50% ethanol. Larvicidal assays were carried out at extract concentrations of 0.15, 0.30, 0.45, 0.60 and 0.75% w/v, for 72h. For the antifungal studies extract concentrations used were 200, 100, 50 and 25mg/ml. At the end of larvicidal assay the highest concentration recorded mortality of 57.60% and 38.40% for ethanolic and aqueous leaf extracts respectively. 72h LC50 values obtained from Probit analysis, using SPSS version 17 were 0.660% and 1.057% w/v for ethanolic and aqueous leaf extracts respectively. Larvae in the control experiments registered no death throughout the period of experiment, rather they were actively wriggling and some even metamorphosed into pupae. For the antifungal studies the agar well diffusion technique was employed. Antifungal effects were determined using measurements of inhibition zone diameter (IZD). Results obtained revealed that both the aqueous and ethanolic leaf extracts exerted antifungal effect on A. flavus and C. albicans, but no antifungal effect was exhibited against M. canis, at the extract concentrations used in this study, rather a steady growth in the test plates seeded with M. canis was observed. The same was applicable with the negative controls. The drug, ketoconazole exerted antifungal effect on all test organisms. Phytochemical screening of the leaf revealed the presence of alkaloids, cardiac glycosides, saponins and terpenes. The leaf of P. nitida possesses larvicidal and antifungal potential and therefore warrants a more thorough exploitation

In vivo antiplasmodial potential of aqueous seed extract of Ricinus communis

Introduction: Ricinus communis is used by the people of Niger-Delta region of Nigeria, for the treatment of various ailments, especially malaria. This study evaluated the antiplasmodial potentials of the aqueous seed extract of R. communis, using Plasmodium berghei berghei. Methods: Acute toxicity study was carried out to determine the median lethal dose (LD50) of the extract. Antiplasmodial effect of the extract was assessed in suppressive, repository/ prophylactic and curative models, using Swiss albino mice (15-29 g). Mice were infected intraperitoneally with 0.2 mL of parasitized blood. Extract doses administered were 54.77, 109.54 and 164.32 mg/kg/d of the seed extract and each dose had 6 replicates. Artesunate (5 mg/kg/d) and pyrimethamine (1.2 mg/kg/d) were used as standard drugs, while distilled water (10 mL/kg/d) served as control. Results: Acute toxicity study produced LD50 of 547.72 mg/kg. The extract demonstrated a dosedependent reduction in parasitaemia in all tests. At the end of 4-day test, suppressive effect of 20.80, 49.00, 75.00 and 88.40% were obtained for doses 54.77, 109.54 and 164.32 mg/kg/d of the seed extract and artesunate, respectively. In the repository test pyrimethamine was more potent (72.26%) than the seed extract (9.47%–51.42%). The extract also exhibited appreciable curative effect. The activity of the seed extract was significant when compared with the control (P < 0.05). Mice treated with the seed extract and drugs survived for longer duration than the control group. Conclusion: The aqueous seed extract of R. communis has antiplasmodial potential and its active principle should be elucidated and further investigated to help in the ongoing fight against malaria

Brine shrimp lethality and antimicrobial studies on the seeds of Garcinia kola (Heckel)

Garcinia kola (Family, Guttiferae) is employed in a variety of therapies ranging from skin, gastrointestinal, chest to tumour problems. Preparations of the stem and roots are used as antitumour in traditional medicine but the potential of the seeds as antitumour had not yet been investigated hence the brine-shrimp lethality and as well as the antimicrobial studies on the seed were carried out. The crude ethanolic extract and methanol fraction elicited good antibacterial activity against S. aureus, B. subtilis and, to some extent, E. coli but gave minimal activity against Ps. Aeruginosa and none against fungal isolates (Aspergillus spp and C. albicans). The brine shrimp lethality assay, analysed using the Finney probit method, showed that the aqueous and crude ethanolic extracts and methanol fraction displayed ‘marginal' LD50 values at 565ppm, 349ppm and 316ppm respectively compared with literature values below 200ppm which are generally considered “significant”. These findings indicate the potential of the seeds as panacea for infectious ailments and therefore scientific justification to some of the folkloric uses of the plant. Key words: Brine-shrimp lethality; Antimicrobial; Seeds; Garcinia kola Journal of Pharmacy and Bioresources Vo. 2 (1) 2004: 29-3