Metformin-like effect of Salvia officinalis (common sage): is it useful in diabetes prevention?

Abstract

Common sage (Salvia officinalis L.) is among the plants that are claimed to be beneficial to diabetic patients, and previous studies have suggested that some of its extracts have hypoglycaemic effects in normal and diabetic animals. In the present study, we aimed to verify the antidiabetic effects of an infusion (tea) of common sage, which is the most common form of this plant consumed. Replacing water with sage tea for 14 d lowered the fasting plasma glucose level in normal mice but had no effect on glucose clearance in response to an intraperitoneal glucose tolerance test. This indicated effects on gluconeogenesis at the level of the liver. Primary cultures of hepatocytes from healthy, sage-tea-drinking rats showed, after stimulation, a high glucose uptake capacity and decreased gluconeogenesis in response to glucagon. Essential oil from sage further increased hepatocyte sensitivity to insulin and inhibited gluconeogenesis. Overall, these effects resemble those of the pharmaceutical drug metformin, a known inhibitor of gluconeogenesis used in the treatment and prevention of type 2 diabetes mellitus. In primary cultures of rat hepatocytes isolated from streptozotocin (STZ)-induced diabetic rats, none of these activities was observed. The present results seem to indicate that sage tea does not possess antidiabetic effects at this level. However, its effects on fasting glucose levels in normal animals and its metformin-like effects on rat hepatocytes suggest that sage may be useful as a food supplement in the prevention of type 2 diabetes mellitus by lowering the plasma glucose of individuals at risk.

Ursolic acid and luteolin‐7‐glucoside improve lipid profiles and increase liver glycogen content through glycogen synthase kinase‐3

“…Previous studies have demonstrated Salvia offi cinalis tea to decrease fasting blood glucose levels in healthy animals (Lima et al, 2006a). Moreover, methanolic and ethanolic extracts of S. offi cinalis as well as an infusion of S. fruticosa have been shown to have hypoglycaemic effects in diabetic experimental animals (Perfumi et al, 1991;AlarconAguilar et al, 2002;Eidi et al, 2005).…”

Kinetics of α-glucosidase inhibition by different fractions of three species of Labiatae extracts: a new diabetes treatment model

“…Otostegia persica is traditionally used in some regions of Iran as antidiabetic medicinal plant. Thus, its addressed potential has been investigated by some research groups (Lima et al 2006;Ebrahimpoor et al 2009;Tofighi et al 2009;Hajzadeh et al 2011;Manzari-Tavakoli et al 2013;Mohammadi et al 2014;Sepehri et al 2014). As the review literature reveals no documents about the effects of different fractions of Zm, Op, and Sm extracts on inhibition of a-glucosidase have been presented.…”

Activation of the nuclear receptor PPARγ by metabolites isolated from sage (Salvia officinalis L.)

“…2000; Alarcon-Aguilar et al, 2002;Eidi et al, 2005;Lima et al, 2006). Aqueous ethanol extracts of Salvia officinalis have been found to significantly reduce blood glucose in healthy rats and to significantly diminish hyperglycaemia in mildly type 1 diabetic rats (Alarcon-Aguilar et al, 2002).…”