Anticancer Potential and Cytotoxic Activity of NN-32, a Snake Venom Peptide, Against A549, Lung Cancer Cell Line

Abstract

Lung cancer is the prime cause of death after breast cancer among non-infectious diseases and is highly prevalent across the world. Several chemotherapies, immunotherapies, radiation therapies, and combination therapies have been employed, but their side effects, low efficiency, and off-target effects necessitate the exploration of other sources of therapeutic agents. The A549 lung cancer cell line was procured from NCCS, Pune, and treated for 48 h with increasing concentrations from 2 to 20 µg/mL of NN-32, a snake venom peptide obtained from the Naja naja cobra species. The MTT assay was done to assess the working concentration of NN-32. Apoptosis, Reactive Oxygen Species (ROS) production, mitochondrial membrane potential (MMP), and cell cycle arrest analysis were carried out and analysed using flow cytometry. The results were analysed using GraphPad Prism 8. The MTT assay revealed that the cytotoxic effect of NN-32 is limited to cancer cells at concentrations ranging from 2 to 20 µg/mL, and for subsequent experiments, 5 µg/mL and 10 µg/mL $\left( {\frac{1}{ 2 }{\text{IC}}_{{{50}}} \;{\text{and IC}}_{{{5}0}} \;{\text{respectively}}} \right)$ were used. Early apoptosis was significantly observed at 5 μg/mL and 10 μg/mL when compared with the control (P < 0.05). Phase contrast microscopy and Scanning Electronic Microscopy (SEM) were used to detect apoptotic bodies within the cells. NN-32 showed a higher percentage of cells in the S phase of the cell cycle when compared with the control. It also induced ROS production and disrupted MMP. NN-32, a snake venom peptide, has a cytotoxic effect on lung cancer cells, making it a promising anti-cancer agent.