The vascular protective effects of Anoectochilus roxburghii polysaccharose under high glucose conditions

Anoectochilus roxburghii has been used as a health food and a herb for treatment diabetes in China for hundreds years. Anoectochilus roxburghii polysaccharose (ARP) is the major active component of the plant.

The present study investigated the vascular protection of ARP in vivo and in vitro experiments.

Hypoglycemic activity of ARP was examined in diabetic mice. Moreover, the further vascular protective effects in vitro were investigated in human umbilical vein endothelial cells (HUVECs) stimulated by high glucose (HG, 35mM).

Compared with untreated diabetic mice, ARP (100 or 300mg/kg) caused a significant decrease in blood glucose levels. Histological examination showed that ARP ameliorated endothelial damage to some extent, especially ARP at dosage of 300mg/kg. In vitro assay, pretreatment with ARP (10, 20 and 30μg/mL) markedly inhibited generations of reactive oxygen species (ROS), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) in HG-induced HUVECs. ARP pretreatment not only suppressed HG-induced matrix metalloproteinases (MMPs) activity via increasing the expression of the tissue inhibitors of MMPs (TIMPs), but also adjusted the MMPs/TIMPs balance to maintain homeostasis of vascular structure. Moreover, pretreatment with ARP could significantly reduce p-NF-κB p65, p-p38 MAPK expression levels in HG-induced HUVECs.

The vascular protective effects of ARP might be associated with NF-κB and p38 MAPK pathway. ARP might be used as useful substance in the treatment of vasculopathy in diabetic patients.