Antimicrobial Activity, Toxicity Profile And Phytochemical Composition Of Fagaropsis Hildebrandtii (engl.) Milne-redh. Root Extracts (rutaceae Juss.)

Abstract

Alternative and herbal medicine has contributed greatly in treatment, management and control of diseases in both developed and developing countries. According to (WHO 2008) approximately 75% - 80% of world‟s population especially in developing countries use complementary medicine for basic health care. Herbal medicines are preferred because they are cheap, readily available, are accepted easily in various cultures, and are efficacious. However, due to limited research, their safety is questionable and there are limited reports of severe adverse effects following their use. Fagaropsis hildebrandtii is a plant commonly used in the treatment of chronic pain, pneumonia, arthritis, ulcers, stomach pains, malaria epilepsy and women‟s infertility. The ethnomedical claims and safety for use have not been proved despite the continued use. The study will form a basis for continued use of the plant and further validation. This study was carried out on the crude extracts of the Fagaropsis hildebrandtii roots for their phytochemical composition, toxicity profile and antimicrobial activity. Oral acute toxicity studies were done and its effects on the vital organs were determined macroscopically and their weights recorded. Dose levels of 300mg/Kg and 2000mg/Kg body weights of aqueous and organic root extracts. In the toxicity study, female albino mice were used according to the Organization for the Economic Co-operation and Development (OECD) guidelines 423 which recommends the use of one sex animals preferably females which are more sensitive to drug reactions/effects. The control group for the organic extract was administered with extra virgin oil and for the aqueous extract was administered with distilled water. A 28-day sub-acute study of oral administration of both aqueous and organic extracts was done on six groups of both male and female albino mice at doses of 250mg/Kg, 500mg/Kg and 1000mg/Kg body weights. The phytochemical analysis procedures showed the presence of alkaloids, xvii terpenoids, flavonoids, steroids, tannins, saponins, cardiac glycosides and phenolics. The median lethal dose of Fagaropsis hildebrandtii extracts was estimated to be greater than 2000mg/Kg body weight. The vital body function parameters were observed keenly for any changes after 30 minutes, 4 hours, 24 hours, 48 hours, 1 week and 2 weeks. After the sub-acute studies, haematological parameters and biochemical parameters were determined as shown in the results. The major organs were harvested and any changes determined histopathologically. The 1000mg/kg aqueous and hexane extracts doses used caused deaths of 6 females and 2 males. After physical and histopathological studies, the liver, kidney, lungs and spleen were congested. Their biochemical and haematological parameters were increased compared to the controls, P-value <0.05. The body weights in mice on 1000mg/Kg Bwt doses on both aqueous and hexane extracts decreased significantly. For those on 250mg/Kg and 500mg/Kg Bwt, their body weight increased gradually in both the treated and control groups. There was no significant difference in the mean body weight in the treated and control groups of these two doses with P values >0.05. The antimicrobial activity of both aqueous and hexane extracts was determined using Staphylococcus aureus (Gram-positive), Salmonella typhimurium (Gram-negative) and Candida albicans (fungal). The most susceptible organism was Staphylococcus aureus and the most resistant was Candida albicans. The MIC and MBC for Staphylococcus aureus for both aqueous and hexane extracts were 100 mg/ml and 200 mg/ml. The MIC and MBC for the Salmonella typhimurium for both aqueous and hexane extracts was 200 mg/ml and 400 mg/ml; 100mg/ml and 200mg/ml. The study revealed its safety in a single dose (less than 2000mg/kg Bwt) oral administration. However, if administered at doses above 500mg/kg Bwt for more than 28 days can result in deleterious dose-dependent effects especially on the kidneys, the liver and alters biochemical and haematological parameters on prolonged administration. xviii Isolation, characterization and identification of the phytochemicals are recommended. AST, ALT, urea, creatinine and total proteins levels, WBCs, RBCs and platelets should be closely monitored in prolonged use.