Trans-3,5-dicaffeoylquinic acid from Geigeria alata Benth. & Hook.f. ex Oliv. & Hiern with beneficial effects on experimental diabetes in animal model of essential hypertension.

Geigeria alata Benth. & Hook.f. ex Oliv. & Hiern (Asteraceae) is used in Sudanese folk medicine for treatment of diabetes. The study aimed to estimate the acute oral toxicity of trans-3,5-dicaffeoylquinic acid (3,5-diCQA) from G. alata roots and to assess its antihypeglycemic, antioxidant and antihypertensive effects on chemically-induced diabetic spontaneously hypertensive rats (SHRs). The structure of 3,5-diCQA was established by NMR and HRMS spectra. Type 2 diabetes was induced by intraperitoneal injection of streptozotocin. 3,5-diCQA was slightly toxic with LD50 = 2154 mg/kg. At 5 mg/kg 3,5-diCQA reduced significantly (p < 0.05) the blood glucose levels by 42%, decreased the blood pressure by 22% and ameliorated the oxidative stress biomarkers reduced glutathione, malondialdehyde, and serum biochemical parameters. The beneficial effect on antioxidant enzymes was evidenced by the elevated glutathione peroxidase, glutathione reductase, and glutathione S-transferase activitiy in the livers of diabetic animals. 3,5-diCQA prevents the histopathological changes related to diabetes and hypertension. 3,5-diCQA was more potent α-glucosidase inhibitor (IC50 27.24 µg/mL) than acarbose (IC50 99.77 µg/mL). The antihyperglycemic action of the compound was attributed to the α-glucosidase inhibition. The beneficial effects of 3,5-diCQA on streptozotocin-induced diabetic hypertensive rats support the traditional use of G.alata for the management of diabetes.