The Possible Protective Role of Basil Leaf Extract on Chronic Intermittent Hypoxia Induced Pulmonary Vascular Remodeling in Adult Male Rat (Histological and Biochemical Study)

Introduction: Chronic Intermittent hypoxia (CIH) is a common clinicopathological process in several diseases causing pulmonary vascular remodeling with enlarged smooth muscle mass surrounding the pulmonary arterioles. We hypothesized that basil leaf extract (BLE) administration may be useful for preventing the cellular and vascular damage induced by CIH on pulmonary arterioles and its fatal sequelae. Aim: This work aimed to study the possible protective role of basil leaf extract on pulmonary arterial response to chronic intermittent hypoxia in adult male rat. This was based on biochemical, histological, immunohistochemical, morphometrical and statistical studies. Materials and Methods: 38 healthy adult male (Sprague-Dawley) rats were divided into 4 groups; control, BLE (200mg/kg/d orally), CIH group (CIH induced in a hypoxic chamber (10% O2) 8hours/day), protective group (BLE 200mg/kg/d orally before induction of CIH). Body weight was measured and blood samples were collected from abdominal aorta for the biochemical assessments. After scarification of rats, tissue MDA and Glutathione peroxidase were assessed, DNA fragmentation was evaluated through agarose gel electrophoresis, and the lungs were subjected to histological and immunohistochemical studies. Results: In the CIH group, significant decreases in body weight, arterial PH, arterial PaO2 and tissue glutathione peroxidase level were recorded while arterial PaCO2 and tissue MDA level were significantly increased. The protective group revealed apoptotic bands in DNA gel electrophoresis lesser than that in CIH group. Histologically, CIH group showed congested pulmonary arterioles with massive destruction of the lining endothelium and thickening of the tunica media. Immunohistochemical study of CIH group showed significant up-regulation of INOS, α-SMA, CD68, and VEGF-1 immunoreactions. While the protected group with BLE showed improvement of histological architecture of lungs, as well as biochemical and immunohistochemical results. Conclusion: Basil leaf extract affords protection against pulmonary vascular remodeling.