In vitro anticancer activity of “Methanolic extract of papaya blackseeds” (MPB) in Hep G2 cell lines and its effect in the regulation of bcl-2, caspase-3 and p53 gene expression

Papaya (Carica papaya) is a fruit that grows mainly in tropical areas with significant commercial worth due to its extraordinary nutritional and therapeutic value. Its fruit, leaves, and seeds are used as a traditional medicine in India for various ailments, including cancer. Papaya fruit was always a treatment choice among traditional ayurvedic practitioners for various ailments. The usage of papaya leaf extract for curing dengue fever had gained popularity at the time of severe dengue outbreak in various Asian countries, including India. Studies had proved that papaya leaf extract can increase platelet count and improve dengue patients' health conditions. However, the usage of papaya seeds for treatment has not gained much popularity even though it has been widely recommended in ancient Ayurvedic texts. In this study, we have tried to assess the anticancer potential of papaya black seeds, which are present in the ripe papaya fruits. The “methanolic extract of papaya black seeds” (MPB) ¹have been studied for the in vitro cytotoxicity against the human liver cancer Hep G2 cell lines. The half maximal inhibitory concentration (IC₅₀) value was quantified using the 3-(4,5-dimethylthiazoline-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Along with this, the apoptotic changes on the cancer cells induced by MPB have been assessed with the help of Acridine Orange-Ethidium Bromide (AO-EB) staining. The regulation of gene expression has been evaluated by targeting B cell Lymphoma -2 (Bcl-2), p53, and Caspase-3 genes by relative gene expression studies via quantitative Real Time Polymerase Chain Reaction (qRT PCR). From this study, we have concluded that papaya black seeds may be a prospective therapeutic agent in liver cancer therapy with an IC₅₀ value of 24.35 ​μg/mL along with the potential to induce apoptotic changes by downregulating the Bcl-2 and upregulating p53 and Caspase-3 genes.