In-Vitro Cytotoxic and Proliferative Activity of Three Plant Extract on Human Peripheral Blood Mononuclear Cells (PBMCs)

Plant products provide a vast source of therapeutics, but not without toxicity. This study evaluated the in vitro cytotoxic and proliferative activity of selected plant extracts on human peripheral blood mononuclear cells (PBMCs). The PBMCs from healthy donors were exposed to varying concentrations (25 µg/ml, 50 µg/ml, 100 µg/ml and 200 µg/ml) of aqueous extracts of young leaves of Mangifera indica (MI) and stem barks of Commiphora kerstingii (CK), and Lannea acida and Acacia sieberiana formulation (LAASF). Trypan blue assay was used to determine the viability of human PBMCs after isolation. Cytotoxicity and proliferation of PBMCs were determined using WST-8 assay. The total viable cell count of the isolated PBMCs in this study was 8000 x 104 cells/ml while viability was 96.15%. The extract of LAASF showed the lowest percentage cytotoxicity (2.63%) at 25 µg/ml concentration, followed by CK (2.70%), then MI (7.71%). There was significant decrease in PBMCs mean absorbance scores across the different concentrations of MI (p=0.008), CK (p<0.0001) and LAASF (p=0.01). There was statistically significant proliferation of PBMCs for MI (p=0.003) and CK (p=0.005) compared to control. However, no significant difference was observed in LAASF on proliferation. Mean absorbance scores significantly decreased with an increase in the concentration of the extracts. The extracts have potential cytotoxicity on the PBMCs at higher concentrations. The extract of MI and CK exhibited higher cytotoxic and proliferative activity on the PBMCs than LAASF. An in-depth study to identify specific immune cells proliferated by the extracts will improve the credence of this study’s findings. Keywords: Herbal medicine, cytotoxicity, cell proliferation, humans, mononuclear leukocytes