A squalene analog 4,4′-diapophytofluene from coconut leaves having antioxidant and anti-senescence potentialities toward human fibroblasts and keratinocytes

Abstract Coconut ( Cocos nucifera) leaves, an unutilized resource, enriched with valuable bioactive compounds. Spectral analysis of purified pentane fraction of coconut leaves revealed the presence of a squalene analog named 4,4′-diapophytofluene or in short 4,4′-DPE (C 30 H 46 ). Pure squalene standard (PSQ) showed cytotoxicity after 8 µg/ml concentration whereas 4,4′-DPE exhibited no cytotoxic effects up to 16 µg/ml concentration. On senescence(definition)-induced WI38 cells, 4,4′-DPE displayed better percentage of cell viability (164.5% at 24 h, 159.4% at 48 h and 148% at 72 h) compared to PSQ and BSQ (bio-source squalene) with same time duration. Similar trend of result was found in HaCaT cells. SA-β-gal assay showed that number of β-galactosidase positive cells were significantly decreased in senescent cells (WI38 and HaCaT) after treated with 4,4′-DPE than PSQ, BSQ. Percentage of ROS was increased to 60% in WI38 cells after olaparib treatment. When PSQ, BSQ and 4,4′-DPE were applied separately on these oxidative-stress-induced cells for 48 h, the overall percentage of ROS was decreased to 39.3%, 45.6% and 19.3% respectively. This 4,4′-DPE was found to be more effective in inhibiting senescence by removing ROS as compared to squalene. Therefore, this 4,4′-DPE would be new potent senotherapeutic agent for pharmaceuticals and dermatological products.