A Phenolic Fraction from Catharanthus roseus L. Stems Decreases Glycemia and Stimulates Insulin Secretion

Abstract

Catharanthus roseus (L.) G. (C. roseus) is a medicinal plant used traditionally for diabetes mellitus control. Several compounds of an alkaloidal nature have been proposed as hypoglycemic principles. However, little attention has been paid to other compounds in this plant that could also participate in this hypoglycemic activity. This study aimed to analyze the hypoglycemic effect of a polyphenolic fraction from C. roseus, as well as its action on insulin secretion and expression in RINm5F cells. Methods. An alkaloid-free aqueous extract was obtained from C. roseus stems. The hypoglycemic effect of different doses of this extract was evaluated in normal and streptozotocin-induced diabetic mice. This extract was fractionated by bipartition, and the resultant fractions were assessed by their hypoglycemic effects. Subsequently, the fraction with the greater hypoglycemic activity was added to the RINm5F cells, and the expression and secretion of insulin were analyzed. The antioxidant activity was determined by the DPPH method and through chromatographic analysis of the most active fraction by HPLC, using an Econosphere C18 column. Results. The aqueous alkaloid-free extract of C. roseus stems significantly reduced blood glucose in normal and diabetic mice. The fractionation of this extract provided three fractions, one of which (a precipitate) showed significant reductions in glycemia at 6 h (48.1 and 64.5% in normal and diabetic mice, respectively). This precipitate contained phenolic compounds and saponins. Its chromatographic analysis showed that it is formed by several phenolic compounds; gallic acid (0.053%) and chlorogenic acid (0.216%) were identified and quantified. Conclusion. The phenolic fraction of C. roseus containing gallic acid and chlorogenic acid had a hypoglycemic effect that may be explained by an increase in insulin secretion.

<p>Consumption of Cooked Common Beans or Saponins Could Reduce the Risk of Diabetic Complications</p>

“…Indeed, control of blood glucose, plasma cholesterol, and nutrient absorption through dietary saponins could provide substantial health and nutritional benefits in humans, as well as reduce diabetic complications. Had a hypoglycemic effect that may be explained by an increase in insulin secretion [28] Panax noto ginseng…”

Spray-Drying Microencapsulation of Bauhinia ungulata L. var. obtusifolia Aqueous Extract Containing Phenolic Compounds: A Comparative Study Using Different Wall Materials

“…The chlorogenic acid content determined in the samples (1.740 to 1.975 mg/g Extract) is close to that observed in a polyphenolic fraction obtained from Catharanthus roseus stems (2.16 mg/g). This sample was effective in reducing the glycemia of normal or diabetic mice 6 h after its administration, in addition to stimulating insulin secretion in RINm5F cells [ 86 ]. Similarly, an aqueous extract of Cecropia obtusifolia leaves standardized in chlorogenic acid (5.2 µg/g) promoted, among other effects, an increase in insulin secretion in vitro and acute and subacute reductions in glucose levels in diabetic mice.…”

Ethnomedicinal survey of traditional antidiabetic plants in Baturraden and Sumbang

“…50 Furthermore, its phenolic fraction that was rich with gallic acid and chlorogenic acid demonstrated a reduction in blood glucose level in mice as well as stimulation in insulin secretion and expression in RINm5F cell line. 51 There was no other report on the traditional use of Melia azedarach for treating diabetes mellitus in Indonesia to date. However, its antidiabetic-related activity has been reported in rats, in which its leaves extract showed blood glucose level decreasing, peripheral glucose uptake improvement, gastric emptying rate reduction, and insulin demand lowering effects.…”