<em>In vitro </em>anti-inflammatory activity of Mongolian horse faecal hotwater extract

Abstract

133-139In Mongolia, horses mostly consume herbal plants that are abundant in pastures. Some pharmaceutical substances that are not absorbed can be excreted in the faeces. Therefore, the faeces of Mongolian horses contain various pharmaceutical substances and have been traditionally used as a home remedy to treat back pain and inflammatory diseases. The present study investigated the anti-inflammatory effect of Mongolian horse faecal hot water (HFW) extracts on lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages. Anti-oxidant activity was screened using an established DPPH assay. Viability and nitric oxide (NO) release of cells treated with 50, 100, 200, and 400 μg/mL HFW were measured using CCK-8 and Griess reagents, respectively. Finally, RT-PCR and Western blot analyses were used to respectively assess the mRNA and protein expression of inflammation-related genes including iNOS, COX-2, NF-κB, and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). HFW extracts displayed pronounced anti-oxidant activity, which increased in a dose-dependent manner. HFW treatment had no effect on non-stimulated RAW264.7 cells at any concentration, while the treatment dose-dependently inhibited cell proliferation as well as NO production in LPS-stimulated cells. Moreover, mRNA and protein expressions of NF-κB and downstream target genes (iNOS, COX-2, IL-1β, IL-6, and TNF-α) were decreased in a dose-dependentmanner. The collective results indicate that hot water extract of Mongolian horse faeces has anti-oxidant activity and exhibits anti-inflammatory activity via inhibition of the NF-κB pathway. HFW should be further explored for the management of inflammatory pathogenesis