Enhanced Anticancer Activity and Apoptosis Effect of Bioactive Compound Quercetin Extracted from Ocimum sanctum Leaves

Abstract

Background: The occurrence of cancer results in cellular changes that cause the uncontrolled growth and division of cells. Apoptosis removes cells during development and eliminates potentially cancerous cells. The bioactive compounds present in the herbal plant show cytotoxic activity that results in apoptosis. The traditional herbal plants are used worldwide both in allopathy and other traditional ways. Objective: The main objective of this study was to extract the bioactive compound Quercetin from the medicinally significant plant Ocimum sanctum and also to develop nanomedicine as Qu-PEGNiGs. Materials and Methods: Leaf extract of the medicinally significant plant Ocimum sanctum (O. sanctum) has been used for the synthesis of nickel nanoparticles (NiGs) and extraction of quercetin (Qu). The ethanolic extract of Ocimum sanctum was added to 1 mM Nickel nitrate (Ni(NO3)2) and stirred for 3 hrs at room temperature and dried at 60°C for 3hrs and calcinated at 400°C for 2hrs and characterized using Uv-Vis Spectrophotometer, FT-IR, SEM, DLS and zeta potential. The quercetin was isolated from Ocimum sanctum leaf extract using the reflux condenser method. The bio-polymer was PEG-coated over NiGs and quercetin was loaded into it. The apoptosis activity using MCF-7 cells was performed with Qu-PEG-NiGs. The purity of quercetin was characterized using HPLC. In order to analyse apoptosis efficiency, MTT assay, and reactive oxygen species (ROS), cell cycle analysis has been performed. Results: The NiGs absorption spectrum gives a peak at 408nm. The FT-IR confirms the presence of particular functional groups shifting from the compound NiGs and then coated with PEG-Qu- NiGs. The SEM images show the size of NiGs ranging from 27.3 nm to 40.4 nm with varied morphology such as hexagonal and other irregular shapes. The presence of quercetin extracted from the leaf powder is approximately 1.5 mg/g. The ROS results show the Qu-PEG-NiGs induced efficiency of the apoptosis, while the increased concentrations promote ROS and lead to activation of the apoptosis. The cell cycle analysis has shown the cytotoxic effect. Conclusion: The Quercetin loaded PEG coated nickel nanoparticles can be used as a promising chemotherapeutic agent against MCF7 breast cancer cells. Further studies are required for evaluating Qu-PEG-NiGs anticancer activity on different types of cancer cells.