Abstract

Oxidative stress and advanced glycation end-products (AGEs) contribute to cellular damage and the progression of chronic diseases. Kratom (Mitragyna speciosa (Korth.) Havil.) has been traditionally used for various therapeutic purposes; however, its antioxidative and cytoprotective properties remain inadequately characterized. This study evaluated the antioxidant, antiglycation, and cytoprotective activities of kratom leaf extracts, including aqueous (KW), methanol (KM), alkaloid (KA), and its major alkaloid, mitragynine (MG), using chemical and cell-based assays. Total tannin, flavonoid, phenolic, and MG contents were quantified. MG exhibited strong radical scavenging activity in 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) (IC50 = 12.02 ± 0.43 μg/ml) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 = 677.50 ± 55.24 μg/ml) assays. In the ferric reducing antioxidant power assay, KW and KM rapidly reduced ferric ions within 5 minutes. KM showed the highest antiglycation activity in the BSA-glucose model (IC50 = 4.98 ± 0.76 μg/ml). Notably, KW significantly reduced intracellular reactive oxygen species by 27.72%–98.45% and malondialdehyde levels by 2.9–10.4-fold, protecting HepG2 cells from H2O2-induced cytotoxicity. These findings suggest that KW is a promising natural source for mitigating oxidative damage. Further studies should characterize its bioactive constituents to clarify potential synergistic mechanisms and assess their therapeutic relevance in oxidative stress-related disease models.

Key words: Mitragyna speciosa, Kratom, Mitragynine, Antioxidant, Antiglycation, Cytoprotective