Effects of Aloe vera components on the Renin‐Angiotensin System in human mesangial cells

Abstract

The local Renin‐Angiotensin System (RAS) is related to the development of diabetic nephropathy. Studies show that Aloe vera has hipoglicemic and antioxidant effects. Aloe emodin (AE), a component of A. vera, increases glycogen synthesis and also glucose transport via the PKI3 intracellular pathway. We evaluate if the Aloe vera components have effects on angiotensin I‐converting enzyme (ACE) activity in human mesangial cells exposed to normal (NG) and high glucose (HG) medium. Two components, P9 and P9a, were semi‐purified from A. vera by High Performance Liquid Chromatography (HPLC) and were eluated at the same retention time of the standard AE. Cells were treated with insulin, P9, P9a and AE at 1, 100 and 1000 pg/mL and ACE activity was evaluated using Z‐Phe‐His‐Leu‐OH as substrate. All treatments were compared to control. Cells under NG treated with P9, P9a and AE showed decreased ACE activity. In HG, high doses of P9 increased ACE activity and AE tend to present the same profile. These data suggest that the semi‐purified fractions contain the Aloe emodin component. Further studies are needed to elucidate the role of A. vera over RAS under physiological and pathological conditions, which may occur by sinergistic or isolated compound action. It could be important in A. vera terapeutic effects research, for instance, in diabetic nephropathy.