Polyphenolic-rich extract of Illicium verum fruit modulates inflammation in lipopolysaccharide-induced acute lung injury in rats

• Lipopolysaccharide (LPS) caused acute lung injury (ALI) in rats. • Polyphenolic-rich extract of Illicium verum (PEIV) mitigated oxidative stress related with ALI. • PEIV exerted an anti-inflammatory effect against LPS-induced ALI. • PEIV restore damaged lung histoarchitecture in LPS-induced ALI. Acute lung injury (ALI), one of the contributing factors of global mortality (about 40% of hospital deaths), is primarily associated with inflammatory responses and oxidative stress. Illicium verum , commonly called Ba jiao hui xiang (八角茴香) or Chinese star anise, is native to the subtropical provinces of Southwestern China and used in traditional Chinese medicine (TCM) to treat digestive disorders, insomnia, and colds, and as a spice in Chinese cuisines. This study investigated the protective effect of polyphenolic-rich extract of Illicium verum (PEIV) fruit against lipopolysaccharide (LPS)-induced ALI in rats. Phytochemicals in the plant was screened using high performance liquid chromatography (HPLC). Thirty-five male Wistar rats were grouped into seven as follows: Control, ALI (250 µg/kg LPS via intraperitoneal injection for 5 days), ALI + silymarin, ALI + PEIV (25, 50 and 100 mg/kg), and PEIV (100 mg/kg) via oral administration for 14 days. At the end of the experimental study, lung tissues were collected for biochemical (oxidative stress and pro-inflammatory (interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α)) and histological assays. Fourteen distinct biological compounds were identified by the HPLC analysis, with cinnamic acid being the most abundant, at a concentration of 58.99 µg/100 g. The LPS markedly ( p < 0.05) increased the tissue arginase activity and levels of malondialdehyde (MDA), TNF-α, and IL-6. Also, a significant ( p < 0.05) decrease was noted in the levels of nitric oxide (NO) and reduced glutathione (GSH), as well as the activities of enzymatic antioxidants (superoxide dismutase (SOD) and glutathione-s-transferase (GST)). However, pretreatment with PEIV protected the rats from LPS-induced ALI by a significant ( p < 0.05) reduction in the arginase activity and MDA levels and elevation ( p < 0.05) in the NO level and activities of antioxidant enzymes. Furthermore, PEIV reduced the levels of cytokines and reversed histological alterations induced by LPS. The result of this study showed that PEIV protected the rats from LPS-induced ALI by suppressing oxidative stress and inflammation and, therefore, could be considered a promising anti-inflammatory agent in managing ALI.