The Effect of the Emulsion of Echinophora cinerea Boiss. on Paraquat-Induced Lung Fibrosis in Male Rats

Abstract

Introduction: Paraquat (PQ) induces pulmonary fibrosis through mechanisms involving oxidative stress, inflammatory responses, and fibrotic reactions. During this process, the overexpression of alpha-smooth muscle actin (α-SMA) promotes the differentiation of fibroblasts into myofibroblasts, leading to excessive protein accumulation in the extracellular matrix (ECM). Echinophora cinerea Boiss. (E. cinerea) is an herb known for its antioxidant effects. The goal of this study is to assess the protective effects of E. cinerea in PQ-induced lung injury.

Methods: Fifty adult male Sprague Dawley rats, weighing 220–250 g, were randomly assigned to five groups: (1) Sham received daily gavage of Tween 20, 3% for 6 weeks, along with inhalation of nebulized sterile distilled water (10 mg/m³ for 30 min, three times a week) during Weeks 3 and 4 of treatment. (2) PQ was administered via inhalation of nebulized PQ in sterile distilled water at a concentration of 10 mg/m³ for 30 min, three times a week, during Weeks 3 and 4 of treatment. (3) PQ and emulsion 100 were administered via daily gavage at a dosage of 100 mg/kg emulsion in a 3% Tween 20 solution for 6 weeks, alongside inhalation of PQ, similar to Group 2. The animals in Groups 4 (PQ + E200) and 5 (PQ + E400) were administered with higher doses of emulsion. At the end of the study period, the animals’ lungs were excised for histological analysis.

Results: PQ exposure caused lung injury and an elevation in α-SMA relative to the sham group. The administration of emulsion at doses of 400 and 200 mg/kg, along with PQ, reduced lung injury and α-SMA levels relative to the PQ group. No significant differences were observed in the protective effects of the emulsion at doses of 400 and 200 mg/kg.

Conclusion: Echinophora cinerea essence emulsion attenuates PQ toxicity and mitigates lung injury, with more studies needed to confirm these effects further.