Beneficial effects of berberine against pulmonary complications of experimental pulmonary arterial hypertension in rats and some relevant mechanisms

Pulmonary arterial hypertension (PAH) is a severe disease that leads to pulmonary vascular remodeling characterized by a rise in pulmonary vascular resistance and pressure. We assessed the effects of an herbal compound, berberine (BB), and some related mechanisms on PAH in rats. Male Wistar rats were assigned to seven groups: control, monocrotaline (MCT), MCT+vehicle, and MCT+BB (with doses of 10, 20, 30, and 40 mg/kg) groups. Three weeks after induction of PAH by MCT, treatment groups received daily intraperitoneal injections of vehicle or BB for 3 weeks. On Day 43, the right ventricular systolic pressure (RVSP, as an index of pulmonary arterial pressure) and the ratio of RV to LV+septum weight (as RV hypertrophy index, right ventricle hypertrophy [RHVI]) were measured. Inflammatory and oxidative stress indices and histopathology of the lungs were also assessed. RVSP (89.4 +/- 8.2 vs. 23 +/- 3.3), RVHI (0.63 +/- 0.08 vs. 0.26 +/- 0.04), and lung inflammatory cytokines TNF-alpha (2.03 +/- 0.25 vs. 1.21 +/- 0.3) and IL-6 (8.8 +/- 0.59 vs. 6.3 +/- 0.95) significantly increased in the MCT group compared to the control group. MCT also raised the level of Malondialdehyde (0.11 +/- 0.01 vs. 0.09 +/- 0.01) and diminished total antioxidant capacity (6.5 +/- 0.51 vs. 8.3 +/- 0.62), the activity of superoxide dismutase (1.19 +/- 0.22 vs. 1.93 +/- 0.2), glutathione peroxidase (0.02 +/- 0.002 vs. 0.03 +/- 0.005), catalase (2.1 +/- 0.29 vs. 2.8 +/- 0.20) and Bax/Bcl-2 ratio (0.41 +/- 0.07 vs. 0.61 +/- 0.09) in the lungs. Treatment with BB significantly recovered all of these alterations. BB ameliorated pulmonary vascular remodeling by decreasing inflammation and fibrosis and increasing apoptosis and antioxidant/oxidant balance. Therefore, this herbal derivative may be considered a therapeutic goal against PAH.