Effect of garlic component s-allyl cysteine sulfoxide on glycated human serum albumin induced activation of endothelial cells: an in vitro study.

OBJECTIVE

Alternative medicine or herbal therapies have been in use for blood glucose control in patients with diabetes for considerable time. Effect of garlic, more specifically its biologically active component s-allyl cysteine, on amelioration of hyperglycemia has also been reported. However, the cellular or molecular target of this compound is little known. This study was designed to determine the action of s-allyl cysteine sulfoxide (SACSO) at the cellular and molecular level in the widely reported HUVEC model when activated with advanced glycation end products (AGEs).

METHODS

AGE-HSA was derived from non-enzymatic glycation of human serum albumin in the presence of 20 mM glucose. AGE-HSA induced expression of receptors of AGEs, namely RAGE and galectin-3 has been assayed. Activity of endothelial nitric oxide synthase (NOS) denoting normal endothelial function and expression of AGE-RAGE triggered inflammatory marker sICAM-1 is also evaluated in the presence or absence of SACSO.

RESULTS

In presence of SACSO, AGE-HSA induced expression of RAGE was down-regulated, galectin-3 was significantly up-regulated, NOS activity was enhanced and sICAM-1 expression was reduced.

CONCLUSIONS

The data suggest that SACSO exerts an attenuating effect on 20 mM glucose derived AGE-HSA induced inflammation, by selectively inhibiting RAGE while stimulating galectin-3 expression. The former triggers inflammatory pathways while the latter sequesters AGE molecules and prevents AGE-RAGE engagement. This may form the basis for its therapeutic action.