Exploring the antioxidant, anticancer, and cytotoxic effects of Caesalpinia digyna (Rottl.) fruit extracts along with GC-MS profiling: Combined in vitro and computational modeling studies

Background Caesalpinia digyna Rottl. is an evergreen shrub traditionally used as an astringent, phthisis, antipyretic, nervine tonic, and diabetes remedy. Aim Our main goal is to determine the fruit extract’s antioxidant, anticancer, and cytotoxic effects through in vitro and computational studies. Methods Firstly, methanol extract was prepared, and the fractionation was carried out using petroleum ether, dichloromethane, ethyl acetate, and distilled water. Preliminary screening was done using qualitative techniques, while Folin-Ciocalteu and AlCl ₃ techniques were used to measure the total phenol (TPC) and flavonoid content (TFC), respectively. The total antioxidant capacity, DPPH scavenging, and Fe ³⁺ reducing power were used to calculate the antioxidant activity using a spectrophotometric technique. Besides, Trypan Blue Exclusion and MTT methods were used to measure cytotoxic and anticancer activities against Vero and different cancer cell lines. GC-MS profiling was also carried out to identify the plant's phytochemicals. Results The phytochemical screening revealed various phytoconstituents, and the GC-MS analysis discovered 40 bioactive compounds in the ethyl acetate extract (ECDF). The ECDF showed the highest TPC (258.16 ± 4.84 mg GAE/g), TFC (174.25 ± 8.33 mg QCE/g), and potent antioxidant capacity. In the in vitro anticancer and cytotoxicity studies, the lowest viability was shown by the ECDF at doses of 800 µg/mL against lung cancer (43.97 ± 2.95%) and Vero cell (53.58 ± 3.20%) lines. Besides, ECDF extract has strong anticancer effects against breast cancer cell lines MCF-7 and MDA-MB-231 (IC ₅₀ : 23.53 ± 1.61 and 15.57 ± 3.74 µg/mL). Moreover, the docking results showed that the selected compounds have a strong binding affinity for various proteins and bind to amino acid residues via hydrogen bonds and non-covalent and Van Der Waals interactions. Molecular dynamics simulations revealed that the 1,3-dihydroxyanthraquinone (C14) compound forms stable complexes with respective proteins. Conclusion Our findings suggest that C. digyna fruit extracts might be a potential source for discovering cancer medicine. However, further analysis is required to isolate and identify the compounds responsible for these effects.