Evaluation of Antioxidant and Anti-Inflammatory Activities of Seed Extract of Heritiera littoralis

Plant bioactive compounds are typically distributed across leaves, stems, and fruits. The Dungun plant (Heritiera littoralis), a mangrove species, is a promising source of bioactive compounds. However, research on the bioactive properties of H. littoralis seeds remains limited and warrants further investigation. This study aimed to isolate and characterize the bioactive compounds from H. littoralis seed extracts for their antioxidant and anti-inflammatory potential, with the aim of developing functional food applications. The research methodology involved the extraction and fractionation of H. littoralis seeds, antioxidant analysis using the DPPH assay, in vivo evaluation of anti-inflammatory activity using a rat paw edema model, and in silico molecular docking studies. Ethanol extraction yielded secondary metabolites including flavonoids, tannins, saponins, and steroids. Fractionation using Vacuum Liquid Chromatography (VLC) produced three main fractions. Fraction F2 was further purified by Gravity Column Chromatography (GCC), resulting in a pure isolate (F2.3). The melting point of the isolate (175–177°C) was consistent with that of catechins, suggesting its high purity. Characterization of the isolate using UV-Vis spectrophotometry revealed two absorption peaks at 218 nm and 280 nm, indicative of hydroxyl groups and electron transitions from the carbonyl groups. FTIR analysis supported this identification, with absorption bands at 3346.55 cm⁻¹ (-OH group), 2925.67 cm⁻¹ (C-H alkane), and 1521.35 cm⁻¹ (C=C aromatic), confirming the isolate’s similarity to catechin. The anti-inflammatory activity was assessed using a rat paw edema model. The results showed that the highest inhibition percentage was achieved with Na diclofenac (80.21%), followed by a 15 mg/kg body weight (BW) extract (62.63%), and a 10 mg/kg BW isolate (53.13%). Antioxidant activity testing via the DPPH method revealed that the ethanol fraction exhibited significant activity, with an IC₅₀ value of 26.51 ppm, compared to ascorbic acid (positive control) with an IC₅₀ of 5.68 ppm. These findings demonstrate that H. littoralis seeds have substantial potential as sources of effective antioxidant and anti-inflammatory agents, highlighting their potential for future development in functional foods and therapeutic applications.