In-vitro Antioxidant, In-vitro and In-silico Ovarian Anticancer Activity (Ovarian Cancer Cells-PA1) and Phytochemical Analysis of Cissus quadrangularis L. Ethanolic Extract

Comb Chem High Throughput Screen. 2023 Oct 10. doi: 10.2174/0113862073255558230926114444. Online ahead of print.

Abstract

Background: Cissus quadrangularis is a valuable natural source of traditional medicines.

Objective: An in vitro investigation was performed to determine whether the ethanolic extract from the whole portions of C. quadrangularis had anticancer and free radical scavenging activities against ovarian cancer cells-PA1. C. quadrangularis is a herb collected from rural areas in Andhra Pradesh, India.

Materials and methods: C. quadrangularis was air-dried and crushed, and the powder and ethanol (0.5 kg) were used in a Soxhlet device for continuous extraction. Phytochemical analysis of the extracts was performed using a standard procedure. The antioxidant activity of the ethanolic extract of C. quadrangularis was evaluated using DPPH. An in vitro anticancer study used an ethanolic extract against the PA1 cell line. Apoptosis of ovarian cancer cells was studied using DAPI and carboxy-H2DCFDA staining. From LC-MS analysis, quercetin-3-O-alpha-Lrhamnopyranoside and erucic acid were docked with the threonine tyrosine kinase (TTK) enzyme using auto docking.

Results: The ethanolic extract of C. quadrangularis demonstrated significant dose-dependent antioxidant activity compared to ascorbic acid. The ethanolic extract of C. quadrangularis was found to have high anticancer activity against ovarian cancer cell lines (PA1), with an IC50 value of 482.057 ± 113.857 μg/ml. DAPI and carboxy-H2DCFDA staining confirmed that C. quadrangularis ethanolic extract induced apoptosis in ovarian cancer cells (p < .001). Molecular docking studies helped identify the binding affinities between the protein and ligand complexes, such as Quercetin-3-O-alpha-Lrhamnopyranoside binding sites of target proteins 5N7V (MET602, GLN672) and erucic acid 5N7V (GLY354). Quercetin-3-O-alpha-L-rhamnopyranoside was reported to bind with 5N7V by hydrogen bonding at MET602 and GLN672 amino acids with 2.02, 2.99 Å bonding length distance and binding affinity of -7.9 kcal/mol. Erucic acid was reported to bind with 5N7V by hydrogen bonding at GLY354 amino acid with 3.18, 2.93 Å bonding length (Å) distance and binding affinity of -4.3 kcal/mol. The current analysis showed that the ethanolic extracts of C. quadrangularis L. exhibited antioxidant and anticancer properties against ovarian PA1 cells.

Conclusion: The experimental results confirmed that C. quadrangularis L. is a promising, safe chemotherapeutic plant for ovarian cancer PA1 cells. The docking results demonstrated that Quercetin-3-O-alpha-L-rhamnopyranoside strongly binds threonine tyrosine kinase at the MET602 and GLN672 positions. This study showed that the C. quadrangularis ethanolic extract has Quercetin-3-O-alpha-L-rhamnopyranoside, which can be used as an anticancer agent.

Keywords: Anticancer activity; Antioxidant activity; C. quadrangularis L; Ethanolic extract; LC-MS analysis; Ovarian cancer PA1 cells.