Protective effects of areca nut polyphenols on hypoxic damage of rat pulmonary microvascular endothelial cells.

Abstract

To investigate the protective effects of areca nut polyphenols on hypoxic damage of rat pulmonary microvascular endothelial cells (PMVECs). Malondialdehyde and superoxide dismutase (SOD) were used to determine the optimal modeling of lung hypoxic injury cells. CCK-8 method was used to detect cell viability for determining the effective dose of areca nut polyphenols. Rat PMVECs were divided into control group, hypoxia model group and areca nut polyphenols group. BCA method was used to detect the protein concentration of each group, and the oxidative stress level in PMVECs was measured. Western blotting was used to detect the expression of inflammatory and apoptosis-related proteins. Immunofluorescence staining was used to detect the expression of occludin and zonula occludens (ZO) 1. Transwell chamber was used to detect transendothelial electrical resistance, and rhodamine fluorescent dye was used to detect PMVECs barrier permeability. The hypobaric hypoxia-induced cell injury model was established by culturing PMVECs for 48 h at 1% oxygen concentration. The 20 μg/mL areca nut polyphenols significantly reversed the survival rate and the oxidative stress of PMVECs in hypoxia model group (all P<0.05). Areca nut polyphenols had significant inhibitory effect on the up-regulation of inflammation-related proteins, including nuclear factor-κB (NF-κB) and nuclear factor-E2-related factor (Nrf) 2 in hypoxia model group (all P<0.05). And areca nut polyphenols could reduce hypoxia-induced PMVECs apoptosis by down-regulating the expressions of apoptosis-related proteins, including cysteine aspartic acid specific protease (caspase) 3, Bcl-2 associated X protein (Bax) in PMVECs (all P<0.05). In addition, areca nut polyphenols effectively improves the transendothelial electrical resistance and barrier permeability of PMVECs through elevating the expression of occludin and ZO-1 (all P<0.05). Areca nut polyphenols can inhibit the hypoxic damage of PMVECs by reducing oxidative stress and apoptosis down-regulating the expression of inflammatory proteins and reducing membrane permeability.