Despite wide application of sodium nitrite (SN) as food additive, it exhibits considerable side effects on various body organs at high dose or chronic exposure. The aim of this study was to test whether Glycyrrhizic acid (GA) could ameliorate SN-induced toxicity in lung and submandibular salivary gland (SMG). A sample size of 30 adult male albino rats was randomly allocated into 3 groups. Group 1 served as control group. Rats were treated orally with 80 mg/kg of SN in group 2 or SN preceded by (15 mg/kg) GA in group 3. Lung & SMG tissues were used for oxidative stress assessment, examination of histopathological changes, fibrosis (MTC, TGF-β and α-SMA) and inflammation (TNF-α, IL-1β and CD-68). Concurrent administration of GA ameliorated pulmonary and salivary SN-induced toxicity via restoring the antioxidant defense mechanisms with reduction of MDA levels. GA reduced the key regulators of fibrosis TGF-β and α-SMA and collagen deposition. In addition to reduction of inflammatory cytokine (TNF-α, IL-1β) and macrophages recruitments, GA amended both pulmonary and salivary morphological changes. The present study proposed GA as a promising natural herb with antioxidant, anti-inflammatory and antifibrotic effects against pulmonary and salivary SN-induced toxicity.

尽管亚硝酸钠 (SN) 作为食品添加剂得到广泛应用，但在高剂量或长期暴露下，它对各种身体器官表现出相当大的副作用。本研究的目的是测试甘草酸 (GA) 是否可以改善 SN 诱导的肺和下颌下唾液腺 (SMG) 毒性。将 30 只成年雄性白化大鼠的样本量随机分为 3 组。第1组作为对照组。第 2 组大鼠口服 80 mg/kg SN 或第 3 组先用 SN (15 mg/kg) GA。肺和 SMG 组织用于氧化应激评估、组织病理学变化检查、纤维化（MTC、TGF -β 和 α-SMA）和炎症（TNF-α、IL-1β 和 CD-68）。同时服用 GA 可通过降低 MDA 水平恢复抗氧化防御机制来改善肺和唾液 SN 诱导的毒性。GA 减少了纤维化 TGF-β 和 α-SMA 以及胶原沉积的关键调节因子。除了减少炎性细胞因子（TNF-α、IL-1β）和巨噬细胞募集外，GA 还修正了肺和唾液的形态变化。本研究提出 GA 作为一种有前途的天然草药，具有抗氧化、抗炎和抗纤维化作用，可对抗肺和唾液 SN 诱导的毒性。