Toxicological Evaluation of Phytochemicals and Heavy Metals in Ficus exasperata Vahl (Sandpaper) Leaves obtained in Birnin Kebbi, Nigeria

TL;DR

This study evaluates the toxicity and chemical content of Ficus exasperata leaves, revealing high levels of certain phytochemicals and heavy metals, with toxicity observed at high extract doses in a shrimp model.

Contribution

It provides the first detailed analysis of heavy metal contamination and toxicity levels of Ficus exasperata leaves from Nigeria, informing safe usage.

Findings

High flavonoids and saponins in leaves

Non-tolerable levels of cadmium, copper, and lead

Toxicity at high extract doses in shrimp model

Abstract

Objective: Ficus exasperata Vahl (Sandpaper tree) is extensively used in Nigeria to treat diseases, but a dearth of documentation about its toxicity exists. This information is crucial because pollutants can contaminate medicinal plants. This study determined the heavy metal and phytochemical content of methanolic leaf extract of F exasperata obtained in Birnin Kebbi, Nigeria. Material and Methods: The lethality of the plant was also assessed using 70 wild shrimps divided equally into seven groups. Group 1 (negative control), groups 2 and 3 (positive controls) were exposed to 500 and 1000ppm of formaldehyde, respectively; and groups 4-7 were exposed to 1000, 2000, 4000, and 8000ppm of extracts, respectively, for 96 hours. Results: The phytochemistry revealed high levels of flavonoids and saponins and moderate levels of tannins and phenols. The heavy metal analysis revealed non-tolerable levels of cadmium, copper, and lead, while zinc was within the tolerable limit. The negative control recorded 10% mortality, 1000 and 2000 ppm (20% each), 4000ppm (70%), and 8000 ppm (100%). Conclusion: These results inferred safe doses of the plant's extract in low and medium concentrations but toxic and fatal at high doses over a period of time. Consumers are advised to seek an expert's guidance before using it.