Acute and Sub-chronic Toxicity Studies on Methanol Stem Bark Extract of Frankincense Tree (Boswellia dalzielii) and Leaves Extract of Kenaf (Hibiscus cannabinus)

Aim: Frankincense tree (Boswellia dalzielii) and Kenaf (H. cannabinus) are plants abundantly found in north-western Nigeria. These plants are very popular among the locals as potent sources of ethno medicine. The present study investigates the oral acute toxicity potentials of methanolic stem bark extract of frankincense tree and Kenaf leaves, as well as sub-chronic toxicity potentials of the plants extracts on the kidney and liver of Albino rats. Study Design: Laboratory-experimental design was used for this study. Place and Duration of Study: This study was carried out between September 2019 and November 2019 at Biochemistry laboratory, Sokoto State University, Sokoto, Nigeria. Methodology: For the oral acute toxicity study, the revised “Up and Down” test (Limit Dose Test) was used to determine the LD50 of the extracts. For sub-chronic toxicity study, twenty albino rats were used for each plant, and were divided into four groups of five animals each. Group I (control), Group II (received 200 mg extract/kg body weight), Group III (received 400 mg extract/kg body weight) and Group IV (received 800 mg extract/kg body weight). All administrations were given orally for 28 days. Liver and kidney markers were determined using standard methods. Result: The oral acute toxicity test of the plant extracts at 3000 mg/kg body weight showed no mortality for 24 hours and subsequent 14days of administration. LD50 for both plants is therefore greater than 3000 mg/kg. The result shows no significant differences (p > 0.05) on liver and kidney function biomarkers investigated when Group II, III and IV are compared with control. Conclusion: This suggests that Frankincense stem bark and kenaf leaves extracts may be safe in rats at doses less than or equal 3000 mg/kg.