ETHNOPHARMACOLOGICAL RELEVANCE Thalictrum minus L., which is widespread across Eurasia, is utilized as a folk medicine for treating dysentery, bedsore, fungal infection and lung inflammation in China, Mongolia and Iran .
AIM OF THE STUDY A Mongolian folk medicinal plant named Thalictrum minus L. (TML) has been extensively used for the treatment of lung inflammation, bacterial and fungal infection and tuberculosis . Our present study aims to investigate the effectiveness of TML against particulate matter (PM) -induced acute lung injury (ALI) and the potential underlying mechanisms . MATERIALS AND
METHODS Initially, HPLC-Q-TOF was applied for the qualitative analysis and HPLC was used for quantitative analysis of main components in TML . Then, the mice model of ALI was induced by PM via intratracheally instilled with 50 mg/kg body weight of Standard Reference Material1648a (SRM1648a), and TML (10 , 20 , 40 mg/kg) were administered orally 1 h prior to PM . The efficacy and molecular mechanisms in the presence or absence of TML were elucidated .
RESULTS Eleven main ingredients were detected in TML and the contents of homoorientin and berberine were quantified . Additionally, the results demonstrated that TML profoundly inhibited weight loss in mice and ameliorated lung pathological injury induced by PM . Furthermore, we also found that TML significantly decreased the lung wet to dry weight (W/D) ratios, reduced total protein in bronchoalveolar lavage fluid (BALF), and effectively attenuated PM-induced increased leukocyte and macrophages in BALF . Meanwhile, TML could pronouncedly inhibited myeloperoxidase (MPO) activity in lung tissues, decreased the PM-induced inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β), reduced nitric oxide (NO) and increased superoxide dismutase (SOD) in BALF . In addition, TML markedly facilitated the expression of p-AMPK-Nrf2 and suppressed the expression of KEAP, prohibited the activation of the MAPKs-NLRP3/caspase-1 and cyclooxygenase-2 (COX2), and inhibited apoptotic pathways .
CONCLUSION These findings indicated that TML attenuated PM-induced ALI through suppressing the release of inflammatory cytokines and alleviating oxidative damage correlated with the AMPK-Nrf2/KEAP signaling pathways, MAPKs-NLRP3/caspase-1 signaling pathways, as well as apoptotic pathways.