Cardioprotective anti-inflammatory activities of Artemisia lactiflora Wall. ex DC. extract and fractions in a rat cardiomyoblast (H9c2) model of inflammatory sepsis

Context: Sepsis is a progressive inflammatory response commonly caused by gram-negative bacteria via activation of the NF-κB-dependent pathway. Severe sepsis can cause cardiac dysfunction and increases the risk of death. Artemisia lactiflora is a Chinese medicinal plant that contains phenolics and flavonoids with probable anti-inflammatory activities. Aims: To investigate the anti-inflammatory activities of A. lactiflora leaves extract in a cardiac sepsis model. Methods: A. lactiflora leaves were extracted and fractioned using solvents of different polarities. The total phenolic and flavonoid content was quantified. The antioxidants were quantified in vitro using DPPH and ABTS radicals. The cytotoxicity of the extract and fractions was evaluated and calculated using the neutral red assay and curve-fitting analysis in cardiomyoblasts (H9c2). The anti-inflammatory activities of A. lactiflora were observed by treating H9c2 with extract and fractions in the presence of Escherichia coli. Expression of pro-inflammatory genes (TNF and IL6) and secretion of pro-inflammatory cytokines (TNF-α and IL-6) were measured by RT-qPCR and ELISA. Results: Extract and fractions of A. lactiflora contained noticeably high quantities of phenolics and flavonoids with considerably high anti-DPPH and anti-ABTS activities. Co-treatment with A. lactiflora extract and all fractions significantly downregulated the expression of TNF and IL6 as well as decreased the secretion of TNF-α and IL-6 (p<0.0001) compared with E. coli-stimulated cardiomyoblasts. The butanol fraction had the highest potency in reducing pro-inflammatory cytokine secretions in cardiomyoblasts under in vitro sepsis conditions. Conclusions: A. lactiflora leaf extract demonstrated therapeutic potential in a cardiac sepsis model by alleviating the inflammatory responses. This plant can potentially be developed as an alternative medicine for inflammation and sepsis.