Abstract

Opuntia elatior Mill. is found in the semi-arid regions of Gujarat and is known for its blood tonic action among the local communities as a folklore belief. In the present study, aqueous and methanolic extracts of cladode and fruit of O. elatior were subjected to preliminary phytochemical characterization followed by a detailed evaluation through high resolution-liquid chromatography-mass spectroscopy analysis. The isolated molecules were profiled for their properties, and isorhamnetin, phloretin, and herbacetin were the most suitable phytochemicals for further drug discovery studies as they satisfied the Lipinski rule. The study also revealed some novel unreported molecules which were subjected to further validation and confirmation. In vitro antioxidant activity of cladode and fruit extracts over a range of concentrations was evaluated using 2, 2-diphenyl-1-picryl-hydrazine-hydrate (DPPH) assay inhibition and a free radical scavenging assay. The total phenol and flavonoid content results indicated their potent antioxidant properties. In vitro antiproliferative assays such as 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), scratch (wound healing), and colony formation have shown that fruit aqueous and methanolic extracts, cladode methanolic and aqueous extracts, could inhibit cell viability in that order by enhancing cytotoxicity potential in the human breast cancer cell line, Michigan Cancer Foundation (MCF-7). Furthermore, a mechanistic in silico study was performed to evaluate the potential of the isolated molecules of the plant for their docking actions on antiproliferative and apoptotic pathways. The results revealed that isorhamnetin, phloretin and herbacetin showed a strong binding affinity toward Bax (−7.8, −7.3, −7.8), Bcl-2 (−7.4, −6.9, −7.5), Caspase 9 (−7.3, −6.3, −7.3) and Cyclin D1 complexed with CDK4 (−7, −6.6, −6.9). The overall findings of this research work are among the first in scientific investigations into this underexplored plant.

Key words: Opuntia elatior Mill., Phytoconstituent, antioxidant activity, antiproliferative activity, molecular docking