Ficus pumila fruit polysaccharide attenuate ovalbumin-induced allergic asthma in mice associated with changes in microbiota involving the lung-intestinal axis

Abstract

Allergic asthma accounts for more than 50 percent of adult asthma in life. Glucocorticoids and leukotriene receptor antagonists are commonly used to treat asthma, but these drugs not only have high side effects but also cannot cure the disease. In contrast, natural active ingredients are relatively safe to the organism and show great potential for improving the organism. Polysaccharides, as the main active ingredient in aqueous extract, may be equally beneficial for biological activity. The aim of this study is to investigate the alleviating effect and mechanism of action of Ficus pumila fruit polysaccharide (FPP) and aqueous extract of Ficus pumila fruit (FPW) on mice with allergic asthma. The results showed that FPP and FPW could regulate the secretion of the cytokines IL-4, IL-5, IL-13, and IFN-γ. FPP and FPW also reduced the inflammation, mucus secretion, and collagen deposition in mouse lung tissue, and down-regulated the expression of matrix metallopeptidase-9 (MMP-9), tissue inhibitor of metalloproteinases-1 (TIMP-1), and α-smooth muscle actin (α-SMA) proteins. In addition, FPP and FPW modulated the intestinal microbiota by augmenting the alpha diversity and adjusting the taxonomic composition at the phylum and family levels, thereby ensured the sustenance of regular physiological processes in the body. This study demonstrated that FPP and FPW may attenuate asthma by inducing beneficial microbiota in the gut-lung axis and provide an effective basis for the future clinical treatment of allergic asthma with Ficus pumila and the development and utilization of new anti-asthma drugs.