In vivo Toxicity Evaluation of Ethanolic Extract From Two Mangrove Plants

Background: Mangrove plants, often possessing a unique collection of metabolites, have extensively been used for the primary healthcare of coastal residents. Objectives: To determine the safety level and enrich the scientific data, the present study aimed to investigate the toxicity of Avicennia officinalis and Excoecaria agallocha.  Methods: Ethanolic leaf and stem extracts were evaluated for cytotoxicity by brine shrimp lethality assay. The obtained extracts were administered to Swiss albino in a single dose (200, 400, 800, 1600, & 3200 mg/kg body weight) by oral-gavage for acute toxicity assay. Furthermore, systematic observation was performed by close monitoring for any toxic manifestations and mortality after dosing for the first 4 h, at 24 h and twice daily for 6 days. Evaluating the adverse effects were estimated by comparing the test groups with the controls. After sacrificing all group animals, relative organ weight was measured and histopathological analysis was conducted.  Results: Having Lethal Concentration (LC50) of 44.66 µg/mL, E. agallocha leaf was found with the highest toxicity against brine shrimp nauplii. The toxicological study data demonstrated no death and noticeable change in behavioral patterns in the test mice groups, compared with the control group. Moreover, no significant (P>0.05) differences were found in body weight and relative organ weights, compared to the controls. The histological structures of the liver in the treated mice displayed regular tissue configurations similar to the control group. Conclusion: In this study, the mice model exhibited no harmful effects; thus, the reported results indicated that the ethanolic extracts of leaf and stem of these two mangrove plants are safe for therapeutic use. Further long-term toxicological impact of the extracts should be determined for well-founded confirmation.