Moringa Oleifera leaves’ exract induces Apoptosis in “A549” a human lung adenocarcinoma cell line

Abstract

Moringa Oleifera (MO) or the “Miraculous tree” is a highly valuable plant, consumed in populations of India, Asia Minor, Pakistan, Arabia, and Africa. Owing to its high nutritive values, World Health Organization (WHO) has endorsed its cultivation and consumption in malnourished populations. The different edible parts of the tree (leaves, pods, flowers, and seeds) contain a rich profile of essential amino acids, vitamins, minerals, and antioxidants. It has been extensively used in folk medicine to cure more than 300 diseases. Evidence-based in vitro and in vivo (animal models) research into the proclaimed effectiveness of MO, though limited, confirmed its medicinal quality. Few studies, however, have highlighted the anti-cancerous effect of MO extracts prepared from the distinct tree parts. This study delineates the in vitro anti-cancerous effect of Moringa leaves’ extract on A549 cells, and explores some of the underlying mechanisms.MO extract was prepared by soaking leaves powder in hot water. Its effect was determined by monitoring changes in: viability, mitochondrial membrane potential, cellular energetics, oxidative stress, expression of apoptotic and necrotic markers, as well as cell cycle phases. The methodology involves: enzymatic assays; western blot analysis; and immunofluorescence techniques.MO extract (24hrs) induced in A549 a dose-dependent (0.01percent-0.25percent) decrease in viability, ATP, and glutathione levels along with increase in reactive oxygen species (ROS) levels. The obtained cytotoxic effect was time-dependent where MO extract (EC50, 0.05percent) induced early depolarization of mitochondrial membrane (1hr) leading to a decrease in ATP levels (3hr) and subsequent increase (6hr) in: a) oxidative stress; b) active caspases; and c) expression levels of proapoptotic proteins: Cytochrome c; Smac; p53; AIF; and PARP. Activated P53, in turn, induced G0G1 cell cycle arrest (12hr) indicating irreparable genotoxic damage that led to 28percent decrease in viability. PARP activation (18hr) further decrea