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 its use on arthritis, diabetes, and cancer. The present study is conducted to identify the bioactive phytochemicals in the ethanolic extract of Punica granatum peel (PGP) through GC-MS and illustrates its proliferation, antioxidant and anti-apoptotic activities in an established in-vitro primary cultured chondrocytes. The cells were treated with 25μM indomethacin, positive control and different concentration of PGP in absence or presence of different inhibitors (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 of bioactive phytochemicals with antioxidant activity like kaempferol, quercetin, myricetin, luteolin, ascorbic acid, gallic acid, vitamin C and lycopene. The PGP treatment on chondrocytes shows increased proliferation and decreased apoptosis through reduction of oxidative stress in a dose-dependent manner. The increase in the number of chondrocytes at higher doses of PGP was significant (p<0.05) than indomethacin (positive control) treated cell. The findings suggest that PGP exhibits therapeutic antioxidant potential due to the presence of bioactive components regulating oxidative stress and promoting the proliferation and inhibiting apoptosis of chondrocytes.