Phytochemicals enriched Punica granatum L. peel extract promotes the chondrocyte proliferation by inducing cell cycle progression and inhibiting of NO-induced cell death and ROS production

Abstract

Punica granatum L. has been used as a traditional remedy to treat sore throat, cough, digestive and skin disorders, urinary infection, arthritis and expel tape-worm. Modern research focuses on its use on arthritis, diabetes and cancer. The present study was conducted to identify the bioactive phytochemicals in the ethanolic extract of Punica granatum peel (PGP) through GC-MS to illustrate its proliferation, antioxidant and anti-apoptotic activities in an established in vitro primary cultured chondrocyte. The cells were treated with 25 μM indomethacin, positive control and different concentration of PGP in the absence or presence of different inhibitors such as (H2O2 for ROS production and sodium nitroprusside [SNP] for nitric oxide [NO] induced cell death). The cell viability assay and cell cycle analysis were performed to study the proliferation of cells. Oxidative stress was measured as intracellular ROS and anti-apoptotic activities were studied through nuclear staining assays like DAPI and PI-Exclusion staining. The GC-MS result indicates the presence various antioxidants such as kaempferol, quercetin, myricetin, luteolin, ascorbic acid, gallic acid, vitamin C and lycopene. The PGP treatment on chondrocytes shows increased proliferation and decreased apoptosis through the reduction of oxidative stress in a concentration-dependent manner. The rise in the total number of chondrocytes at higher doses of PGP was significant (p<0.05) as compared to indomethacin (positive control) treated cells. The findings suggest that PGP exhibits therapeutic antioxidant potential due to the presence of bioactive components regulating oxidative stress , promoting the chondrocytes proliferation and inhibiting apoptosis of chondrocytes.