Syringic acid through reduction of inflammation, oxidative injury, and downregulation of NF-κB-IL-6 pathway ameliorates HFD-induced pulmonary toxicity in male Wistar rats.

Pulmonary inflammation is a condition that can result from different diseases such as asthma, chronic obstructive pulmonary disease, and influenza as well as other antigenic substances including a high-fat diet. The potency of syringic acid (SYR), a bioactive substance with therapeutic properties, was evaluated on high-fat (HF) diet–induced pulmonary inflammation in male Wistar rats. Thirty male rats were randomly grouped into five: control, SYR (50 mg/kg), HF only, HF + SYR (25 mg/kg), and HF + SYR (50 mg/kg). Animals were sacrificed after 7 weeks of SYR treatments. Blood, bronchoalveolar lavage fluid (BALF), and lungs were collected for biochemical and histopathological analyses. SYR at 50 mg/kg significantly reversed the HFD-induced dyslipidemia. Furthermore, the observed alterations in both the enzymic and non-enzymic oxidative indicators (MDA, SOD, CAT, and GST) due to intake of HF were ameliorated by SYR. A further dose-dependent increase in GSH was observed following treatments. The increased levels of inflammatory cytokines (NF-κB, IL6, TNF-α, and COX-2) quantified in the BALF and lung tissue were significantly lowered when treated with SYR. Furthermore, exposure to HF lowered the inflammatory indices (albumin) quantified in the BALF, while the levels of LDH and globulin were significantly increased. Also, inflammatory indices including platelet/lymphocytes and (neutrophils × platelets)/lymphocytes quantified in the BALF were significantly lowered with SYR treatments, while over twofold increase in albumin/globulin ratio was recorded by 50 mg/kg SYR. SYR demonstrated antioxidative and anti-inflammatory effects via inhibition of HF-induced activation of pro-inflammatory cytokines in rats. Summary of the findings in this study [ABSTRACT FROM AUTHOR]