Bridelia ferruginea is a woody shrub that grows in the Savannah or rain forests of Africa and has traditionally been used to treat diabetes, arthritis and boils. Despite all these uses, extensive toxicological evaluation has not been carried out. The aim of the present investigation was to evaluate the sub-chronic toxicological effects of the stem bark aqueous extract of Bridelia ferruginea in rats. The lethal dose (LD50) was determined using probit analysis and graded doses of the extract (250–4000 mg/kg) were administered to the animals via oral and intraperitoneal routes and observed for mortality, behavioral changes and signs of toxicity. Sub-chronic toxicity study was carried out at doses of 1 000, 2 000 and 4 000 mg/kg administered daily for 60 days. The animals were sacrificed after 60 days. Blood was collected for biochemical (renal and hepatic), hematological, oxidative stress, sperm and histopathological examinations, using standard methods. LD50 of the extract was estimated as >4 000 mg/kg orally; neither significant visible signs of toxicity nor mortality were observed. There were no significant differences in the animals and organ weights, hematological and biochemical parameters in the treated groups compared to the control group. However, a significant increase (p<0.05) in the level of lipid peroxidation and a significant (p<0.05) decrease in sperm count were observed in the treated animals compared with the control group. The stem-bark aqueous extract of Bridelia ferruginea was found to be relatively safe, though it has the potential to cause lipid peroxidation and damage sperm quality and should thus be used with caution.

This study investigated the protective effects of carvedilol alone and coadministered with prednisolone and diltiazem on doxorubicin (DOX) and 5‐fluorouracil (5‐FU)‐induced toxicity. Each of 2 pools of 70 female rats were randomly allotted into 10 groups of 7 animals each and treated as follows: Group 1: normal saline (10 mL/kg); Group 2: normal saline and DOX (40 mg/kg)/5‐FU (20 mg/kg) alone; Group 3: gallic acid (200 mg/kg) and DOX/5‐FU; Group 4: carvedilol (0.075 mg/kg) and DOX/5‐FU; Group 5: carvedilol (0.15 mg/kg) and DOX/5‐FU; Group 6: carvedilol (0.30 mg/kg) and DOX/5‐FU; Group 7: diltiazem (3.43 mg/kg) and DOX/5‐FU; Group 8: diltiazem (3.43 mg/kg), carvedilol (0.15 mg/kg), and DOX/5‐FU; Group 9: prednisolone (0.57 mg/kg) and DOX/5‐FU; and Group 10: prednisolone (0.57 mg/kg), carvedilol (0.15 mg/kg), and DOX/5‐FU. Treatments were done p.o. for 16/14 days for the DOX/5‐FU models. DOX/5‐FU was administered i.p. to the rats in Groups 2‐10 on day 14/10‐14. On day 17/15 (DOX/5‐FU), blood samples were collected, and liver and kidneys of rats were harvested for antioxidant and histopathological assessments. Carvedilol alone and coadministered with prednisolone significantly (P < .05) decreased alanine aminotransferase level compared with administration of DOX alone. Carvedilol alone and coadministered with diltiazem significantly (P < .05) decreased creatinine level compared with administration of DOX/5‐FU alone. Carvedilol alone and coadministered with diltiazem and prednisolone significantly (P < .05) increased the level of hepatic superoxide dismutase and catalase, and decreased malondialdehyde compared with DOX administration alone. Histopathological observations correlated with results of biochemical and antioxidant analyses. Carvedilol administered alone and coadministered with diltiazem and prednisolone reduced the effect of DOX/5‐FU‐induced hepatic and renal toxicities due to enhanced in vivo antioxidant activity. The protective effect was more prominent in the doxorubicin model compared with the 5‐fluorouracil test. Coadministration of carvedilol with either diltiazem or prednisolone did not show better protection relative to carvedilol alone.

There is need for the Federal Ministry of Health to harmonize the varying opinions on traditional medicine and policy as documented in this study through collaboration and workshops on traditional medicine. These proposed approaches may guarantee the safety and regulation of herbal medicine use in Nigeria.