Antioxidant Profiling of Glycosmis cyanocarpa: In Vitro Assays and Pearson's Correlation Study

Oxidative stress is a major contributor to the development of various chronic illnesses, making the evaluation of plant-derived antioxidants a crucial step in the search for novel therapeutic agents. Glycosmis cyanocarpa (Blume) Spreng., a relatively underexplored species native to South and Southeast Asia, has shown potential as a natural antioxidant source. Therefore, the current study aimed to assess the antioxidant potential of the crude methanolic extract of G. cyanocarpa (GCM) by determining its total phenolic content (TPC), total flavonoid content (TFC), evaluating its free radical scavenging and reducing power through DPPH, ABTS, and FRAP assays, and conducting Pearson's correlation analysis to explore the associations among these parameters. The extract exhibited a TPC of 44.84 ± 0.99 mg gallic acid equivalent/g and a TFC of 60.83 ± 2.60 mg quercetin equivalent/g. GCM demonstrated significant antioxidant activity with IC₅₀ values of 18.80 ± 0.42 μg/mL in DPPH and 74.54 ± 0.31 μg/mL in ABTS assays, and a ferric reducing capacity of 2.42 ± 0.33 mmol Fe²⁺ equivalent/g in the FRAP assay. Pearson correlation analysis revealed strong and positive correlations between DPPH and TPC (r = 0.998, p < 0.05) and FRAP with TFC (r = 0.999, p < 0.05) and indicated a significant association between phenolic and flavonoid compounds and antioxidant activity. ABTS values were also strongly correlated to TPC (r = 0.957) and TFC (r = 0.977). These findings highlight G. cyanocarpa as a potential source of natural antioxidants and recommend further work to isolate active compounds and explore their therapeutic importance in conditions associated with oxidative stress.