Urtica cannabina L. water extract exhibits anti-inflammatory activity by regulating inflammatory cytokines: In vitro and in vivo evidence

Urtica cannabina L. (U. cannabina) is a medicinal plant used in traditional Chinese and Kazakh medicine for treatment of various ailments such as rheumatoid arthritis, rheumatic pain, high blood pressure, and snake bites. However, very few studies have focused on the anti-inflammatory effects and of U. cannabina and the mechanisms underlying these effects. This study to investigate the in vitro and in vivo anti-inflammatory effect of U. cannabina, the underlying mechanisms, and its phytochemical profile. We investigated the anti-inflammatory effects of the U. cannabina water extract on lipopolysaccharide-stimulated RAW264.7 macrophages and paw edema in rats and analyzed its chemical components using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). U. cannabina water extract effectively inhibited the secretion of multiple inflammatory factors, and its corresponding mRNA expression in LPS-induced RAW264.7 cells (p < 0.05). Tincture of U. cannabina water extract significantly reduced carrageenan-induced rat paw edema and levels of inflammatory factors (p < 0.05). A total of 31 compounds, which mainly include organic acids, were tentatively identified based on the comparison of their mass spectrum profiles with those recorded in a mass spectra database. The results of this study elucidated the anti-inflammatory effect of U. cannabina water extract in vitro and in vivo and showed that the extract elicits the anti-inflammatory effects by regulating the activity of inflammatory cytokines. The results prove that U. cannabina is a valuable source of active compounds with anti-inflammatory activity.