Polyherbal decoction modulates redox homeostasis during Malachite green induced metabolic stress in Saccharomyces cerevisiae

Abstract

Malachite green (MG) is aquatic pollutant that induces oxidative stress when comes in contact with the living organisms. In Saccharomyces cerevisiae, MG produces intracellular reactive oxygen species (ROS) and these ROS disturb redox homeostasis and cellular functions leading to early cell death. Exogenous supply of natural antioxidants containing polyherbal decoction may play a crucial role in re-establishment of redox homeostasis by ensuring the cell survival. Exposure of MG to Saccharomyces cerevisiae resulted in a significant decrease (97.8%) in colony forming units (CFU). An Ayurvedic polyherbal formulation ‘Vayasthapana Rasayana’ (VR) which contains natural antioxidants from plants viz. Terminalia chebula, Clitoria ternatea, Boerhaavia diffusa, Centella asiatica, Phyllanthus emblica, Asparagus racemossus and Tinospora cordifolia at 1.0 mg/mL concentration could arrest the oxidative stress during MG exposure. Levels of ROS elevated up to 67.3% on MG exposure; while VR supplementation reduced it by 54.7%. MG induced cellular apoptosis in 38% and necrosis in 27% cells, while VR augmentation reduced it to 8%. Activities of antioxidant enzymes like catalase, superoxide dismutase and glutathione peroxidase in MG exposed cells were induced by 408, 144 and 140%, respectively, whereas, VR supplementation lowered the expressions to 102, 57 and 111%, respectively. Induction in caspases 3/7 activity was also found to be reduced by 65.39% after VR augmentation. Similarly, VR modulated activities of oxido-reductases like lignin peroxidase, laccase, NADH-DCIP reductase and MG reductase. VR supplementation also maintained the MG utilization potential of S. cerevisiae up to 20th exposure cycle which was otherwise arrested to 8th cycle. The treatment also decreased the ROS accumulation and nuclear damage, restoring the cell viability up to 94% and retained normal growth dynamics. Thus, VR supplementation could significantly decrease oxidative stress, enhance cell viability and ultimately protect the dying S. cerevisiae cells during MG exposure.