European Journal of Medicinal Plants

Aim: To investigate the safety of a popular polyherbal decoction, consisting of Alstonia boonei stem bark and Fagara zanthoxyloids stem bark, used in the management of arthritis and rheumatism in Nigeria.

Place and Duration of Study: Department of Pharmacology and Toxicology, Nnamdi Azikiwe University, Agulu, Anambra State, Nigeria between the months of June and November, 2013.

Study Design: In acute toxicity study, 2 -10 ml/kg were administered to rats and mice and obvious toxic signs and mortality were observed for 24 hours post-administration. In sub-chronic toxicity study, 1.29, 2.97 and 5.14 ml/kg, of the herbal preparation were orally administered to three groups (five animals per group) of Wistar rats daily for 90 days. The control group of animals received       10 ml/kg of normal saline. Body weight changes were determined weekly, while hematological parameters, biochemical parameters, ulcer index and liver and kidney histologies were evaluated on 31, 61 and 91^st days. Post-treatment studies were also carried out.

Results: All the animals survived after twenty four (24) hours of observation in acute toxicity study and the LD₅₀ was estimated to be above 10 ml/kg. In sub-chronic toxicity studies, there were insignificant (P>.05) changes in body weight and hematological parameters. However, some blood chemistry indices were significant (P<.05). The histologies of the liver and kidney showed irreversible toxicities especially at high doses and duration of administration.

Conclusion: These findings indicate that the herbal preparation may be nephrotoxic and hepatotoxic especially at high doses on long term use, suggesting that it may not be safe in the treatment of arthritis and rheumatism and other chronic diseases.