Comparison of Antioxidant Levels and Anti‑Inflammatory Activities of Kelulut Honey Harvested at Different Month of Intervals and its Chemical Compositions

Objectives: This study aims to evaluate the optimum time for harvesting kelulut honey (KH) by determining its antioxidant and anti‑inflammatory activities and chemical composition at different harvesting times. Materials and Methods: KH harvested at three different intervals (1, 2, and 3 months) was supplied by Rimbunan Hijau Bee Farm, located in Sarawak, Malaysia. The total phenolic content (TPC) and antioxidant level of KH were determined using Folin–Ciocalteu reagent and 2,2‑diphenyl‑1‑picrylhydrazyl, 2,2’‑azino‑bis (3‑ethylbenzothiazoline‑6‑sulfonic acid), and ferric‑reducing ability of plasma assays, respectively. The cytotoxicity and anti‑inflammatory effects of KH were evaluated on murine macrophage cells (RAW 264.7) by 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide and lipopolysaccharide (LPS)‑induced nitric oxide (NO) production. The chemical composition of KH was analyzed by gas chromatography‑mass spectrometry (GC‑MS). Results: TPC and antioxidant levels of KH collected at different intervals showed no statistically significant difference (P > 0.05). KH at 1% concentration showed no cytotoxic activity toward RAW 264.7 cells after 24 h incubation. However, 1% KH showed no inhibition on NO production in LPS‑induced RAW cells compared to the control. GC‑MS revealed that hydroxymethylfurfural was present with the highest concentration in all samples. Conclusion: This study suggests that harvesting time does not influence the biological activities of KH.