Isolation and characterization of 5-hydroxymethylfurfural, antiglycation, antihyperglycaemic, antioxidant, and cytotoxic effects of Garcinia kola Heckel roots extract and fractions

• Garcinia kola is traditionally used in the management of diabetes mellitus. • 5-Hydroxymethylfurfural isolated from G. kola roots is reported for the first time in Garcinia genus. • G. kola roots extract and ethyl acetate fraction contain high amount of polyphenols. • G. kola roots extract and fractions act as good antidiabetic, antiglycation, and antioxidant agents. • DCM fraction of G. kola roots showed no cytotoxicity to brine shrimps. Garcinia kola is a perennial medicinal plant used in ethno-medicine for the treatment of several ailments, including diabetes. The ethanol extract, dichloromethane, ethyl acetate, and butanol fractions of G. kola roots were evaluated for chemical composition, antiglycation, antidiabetic, antioxidant, and cytotoxic effects using standard procedures. 5-Hydroxymethylfurfural was isolated from the ethyl acetate fraction of G. kola roots. The chemical structure was established based on spectroscopic studies and comparison with literature data. The phytochemical test indicted high amount of flavonoids, tannins, and alkaloids in the ethanol extract, with a total phenol content in the extract (55.55 mg/g) and ethyl acetate fraction (53.55 mg/g). The extract and fractions exhibited good antiglycation activity (IC 50 , 0.10–0.70 mg/mL) and cytotoxicity to brine shrimps (LC 50 , 0.68–637.12 µg/mL). Treatment of alloxan induced diabetic rats with the ethanol extract caused a significant reduction ( P < 0.05) in fasting blood glucose level (42%) in acute study and 64% reduction in prolonged treatment (2 weeks). The extract and ethyl acetate fraction also demonstrated high antioxidant effects on 2,2-diphenyl-1-picrylhydrazyl radicals (85.82 and 85.26%, respectively at 100 µg/mL) and ferric reducing power (absorbance, 0.575 and 0.559, respectively at 100 µg/mL). Garcinia kola root is a viable resource for the management of diabetes and possesses the capacity to inhibit the glycation and oxidative processes implicated in diabetic complications. The presence of 5-hydroxymethylfurfural is reported for the first time in the Garcinia genus.