Title : Phytochemical screening and antioxidant capacity of 48 plants from the chocó department, colombia: A correlative study between bioactive compounds and radical scavenging activity
Abstract:
Reactive oxygen species (ROS) are continuously generated during normal cellular metabolism, and an imbalance between their production and the body’s endogenous antioxidant defenses leads to oxidative stress, a condition implicated in cancer, cardiovascular disorders, neurodegenerative diseases, and premature skin aging. Plants constitute a valuable source of phenolic compounds and flavonoids capable of scavenging free radicals, and there is growing interest in replacing synthetic antioxidants such as BHA and BHT with natural alternatives. Colombia, and in particular the department of Chocó, remains largely unexplored despite its megadiverse flora. The objective of this study was to evaluate the antioxidant activity of plant species from Chocó using DPPH, FRAP, and ORAC assays, and to establish their correlation with total phenolic content (TPC) and total flavonoid content (TFC). The plant material was obtained from the Quibdó market in the department of Chocó, and the ethanolic extracts were prepared by maceration in 96% ethanol. Antioxidant activity was evaluated using the DPPH radical scavenging assay, the FRAP, ORAC, and ABTS assays, while total phenolic and flavonoid content was determined using the Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively, as well as through statistical analysis. Regarding DPPH radical scavenging, approximately one-fifth of the extracts exceeded 90% inhibition, and approximately one-third exceeded the 70% threshold considered indicative of good antioxidant activity, while a comparable proportion showed low activity (<50%). For FRAP, the most active extracts reached values above 400 µmol Trolox/g, while the least active extracts fell below 100 µmol Trolox/g, demonstrating wide variability in iron(III) reduction capacity across the collection. The total flavonoid content (TFC) ranged from 227.0 to 3,011.9 mg QE/g, and the total phenolic content (TPC) ranged from 0.2 to 137.6 mg GAE/g. The most bioactive extracts consistently belonged to families such as Malvaceae, Meliaceae, Hypericaceae, and Arecaceae, among others represented in the collection. Pearson’s correlation analysis (N = 45 extracts) revealed statistically significant associations (p < 0.001) among all pairs of assays, with the strongest correlations observed between DPPH-FRAP (r = 0.845) and FRAP-ORAC (r=0.772), confirming that phenolic and flavonoid content is the primary determinant of free radical scavenging capacity. Principal component analysis and hierarchical cluster analysis independently converged on the same classification of four groups (“Elite,” “High,” “Moderate,” and ‘Low’), with the “Elite” cluster (n=4) occupying an isolated region of the ordination space and comprising the extracts with the highest overall antioxidant potential and the highest phenolic and flavonoid content. These findings position the biodiversity of the department of Chocó as an exceptional and largely unexplored reservoir of natural antioxidants with strategic potential for the pharmaceutical, cosmetic, and food preservation industries. This study was funded by Colombia’s General Royalties System under project BPIN 2023000100047. Research activities on Colombian biodiversity were conducted under Genetic Resource Access Agreement No. 121 of January 22, 2016, and its Amendment No. 21, signed between the Ministry of Environment and Sustainable Development and the National University of Colombia, in compliance with the amnesty established in Law 1955 of 2019.
