In vitro and in vivo evaluation of hypoglycemic potential and acute toxicity of microencapsulated turmeric instant powder

Curcuma longa L. (turmeric), traditionally used to treat various ailments including diabetes, has demonstrated beneficial health effects. However, its potential in food formulations requires further investigation. This study examined the hypoglycemic effects of an instant powder containing microencapsulated turmeric oleoresin both in vitro and in vivo, alongside an acute toxicity assessment in Holtzman rats. This study encompassed both in vitro and in vivo evaluations. In vitro, the α-glucosidase (a digestive enzyme) inhibition assay was employed to determine the powder's effectiveness. In vivo assessments included: (1) evaluation of the hypoglycemic effect in mice; (2) conducted safety testing following international guidelines, administering a 2000 mg/kg dose to rats with subsequent monitoring of biochemical parameters; and (3) histological examination of liver, kidney, and spleen tissues for potential harmful effects. The instant powder with turmeric oleoresin microencapsulation demonstrated significant α-glucosidase inhibition in vitro and hypoglycemic effects in vivo. The acute toxicity test at 2000 mg/kg showed no mortality but revealed significant alterations in erythrocyte parameters and hemoglobin percentage. Histological examinations of liver, kidney, and spleen tissues did not differ from those of the control group, though pancreatic tissue was not evaluated in this study. According to this study, the microencapsulated turmeric oleoresin instant powder exhibited antidiabetic effects without signs of overt toxicity at doses up to 2000 mg/kg in rats.