Toxicity and Phytochemical Analysis of Five Medicinal Plants

Abstract

Recent studies have shown that long-term uses of herbs have been associated with a rise in morbidity and mortality rates. While most researches are focused on bioactivity investigations, the toxicity of many plants has not been reported. There is a paucity of data on the potential toxicity of the following plants: Harungana madagascariensis (HM), Pterocarpus osun (PO), Phoenix dactylifera (PD), Annona muricata (AM), and Rutidea parviflora (RP). To evaluate the toxicity of the above-mentioned plants; two tests were employed namely: The Brine shrimp lethality test (BSLT) and the Allium cepa test. A correlation between the oral acute toxicity assay in mice and the LC50 obtained from BSLT has been established. Allium cepa test measures the potential genotoxic effects of plant extracts exerted on the root meristem of A. cepa (onions). Plant extracts were administered in concentrations ranging from 100 to 2500 µg/ml to the A. cepa for 72 h to obtain their Mitotic Indices (MI) and EC50. Results of the MI at 2500 µg/ml for HM, PO, PD, AM, and RP were 3.75, 4.96, 5.96, 6.10, and 6.71 while 281.81, 398.11, 501.19, 630.96, and 707.9 µg/ml were obtained as the respective EC50 values. Furthermore, 10-1000 mcg/ml concentrations were administered in the BSLT and the obtained LC50 values were 116.3, 250, 581.5, 581.5, and 750 µg/ml. The toxicity result demonstrated that the five plants were moderately toxic, with RP exhibiting minimal toxicity values and thus potentially having a good safety profile. The phytochemical screening of these plants revealed the presence of some pharmacologically important classes of compounds that are abundant. Several bioactive and toxic compounds were identified in the GC-MS analysis for some of the plants.