Investigation of Antibacterial Effect of Ferula macrocolea Extract and Quantity Determination of Inhibitory Effect on 4 Standard Strains of Gram Positive and Gram Negative Bacteria

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.

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 1000 ppm of formaldehyde, respectively; and groups 4-7 were exposed to 1000, 2000, 4000, and 8000 ppm of extracts, respectively, for 96 hours.

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), 4000 ppm (70%), and 8000 ppm (100%).

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.