Evaluation of the Cutaneous Toxicity of the Aqueous Extract of the Aerial Parts of Mitracarpus scaber (Rubiaceae) in Rats (Rattus norvegicus Strain Wistar)

Mitracarpus scaber is a known plant in the Ivorian pharmacopoeia where it is used in various ways for the treatment of different diseases and ailments, including skin problems. The present study aims at evaluating the cutaneous toxicity of the aqueous extract of the aerial parts of M. scaber in the Wistar rat following exposure to a single dose or repeated doses. In the acute dermal toxicity experiment, a total of six (6) female rats were divided into two (2) groups, with three (3) rats per group. While a total of 32 male and female rats were divided into four (4) groups, each group consisted of eight (8) rats, four (4) males and four (4) females in the subacute dermal toxicity experiment. For the acute dermal toxicity study, rats in one group received a single application of the extract at the concentration of 2000 mg/ml on the first day of the experimental period. While the rats in the subacute study received topical application of the extract at the concentrations of 200, 400 and 800 mg/ml once a day for 28 days. The various applications were made to the dorsal shaved area of the skin. Throughout the respective fourteen (14) and twenty-eight (28) day study periods, all rats were monitored for any changes in physical appearance and behavior that might occur due to the toxic effects of the plant. No mortality or abnormal physical appearance was observed, and physiological and behavioral changes were not observed in all rats in either study. Body weight, kidney and liver weights, and hematology and biochemistry results did not show significant differences (p > 0.05) between all groups in the subacute study. Similarly, histopathological examinations of the liver, kidney and skin revealed no structural alterations. This study suggests that topical application of the aqueous extract of the aerial parts of M. scaber does not induce acute and subacute adverse effects on the skin or systemic toxicity in Wistar rats.