Phenolic constituents in the polar extracts of Lawsonia inermis mitigate antimycin A-induced mitochondrial degenerative cascades in Hep3B cells

Degenerative conditions are associated with free radical-induced oxidative damages in the mitochondrial paraphernalia. Antimycin A (AMA) treatment of cells mimics such conditions in vitro by augmentation in ROS levels, thus causing injury to mitochondrial DNA (mtDNA), proteins and lipids, along with depolarization of mitochondrial membrane, activation of pro-apoptotic factors, resulting in apoptosis. This study investigates the potential of aqueous and methanolic extracts of Lawsonia inermis in prevention of such oxidative damage to the cell homeostasis. The extracts significantly mitigated membrane damages induced by peroxide, along with substantial decline in AMA-induced degeneration of mitochondrial proteins and lipids in hepatic carcinoma (Hep3B) cells. mtDNA analyzed for oxidative damage by assaying for 8-OHdG revealed considerable protective effect of both extracts against AMA-induced mtDNA damage. SQ-PCR of selected mtDNA genes confirmed that both extracts alleviated amplitudes of mtDNA injury. FACS analysis with JC-1 dye established that both extracts maintained homeostasis of mitochondrial membrane potential in AMA-treated cells. Extract treatments caused decline in AMA-induced discharge of cytochrome c and AIF into the cytoplasm along with consequent subjugation of apoptosis. All activities of the extracts reported in the present study significantly (P < 0.05) correlated to their total phenolic contents, thereby proving that polyphenolic constituents of the extracts alleviate cells from oxidative stress-induced injury.