| Urtica is a perennial herbaceous plant with a wide range of species and worldwide distribution.Nettles(stinging hairs)on the surface of the urtica pierced the skin of a person or animal as bees.The whole urtica plant can be used as medicine and is rich in nutrition.Previous studies by our team had shown that extracts of urtica ground above promoted the movement of isolated intestinal smooth muscle in mice,but the main parts and components of the plants are still unknown.In the present study,the main chemical components of urtica and the effects of water extract on intestinal movement in vitro in mice were investigated,and the possible mechanisms of receptors and ion channels were discussed.Moreover,the effects of feeding urtica on the growth and health of mice were investigated,so as to provide references for the development of the medicinal and feeding value of urtica.(1)Polysaccharides,flavonoids.and alkaloids from urtica were extracted by water extraction,alcohol extraction and acid extraction,respectively,and were preliminarily purified and identified.Then,the effects of polysaccharides,flavones and alkaloids of urtica on intestinal movement in vitro and the possible mechanism were studied by using biological signal processing system.The results showed that compared with before administration,the alkaloid at a dose of 0.4 mg/mL significantly increased the amplitude and peak of intestinal smooth muscle contraction(P<0.01),while the flavone only significantly increased the peak of intestinal smooth muscle contraction(P<0.05).Eight mg/mL of the three main components of urtica significantly increased the peak contraction of intestinal smooth muscle(P<0.01),but the alkaloid significantly increased the contraction amplitude(P<0.05),polysaccharide and flavonoids significantly increased the contraction tension(P<0.05)and significantly increased the contraction tension(P<0.01).Compared with the three main components of urtica,when the M-receptor blocker atropine was combined with alkaloid,the intestinal contraction peak and contraction amplitude were significantly reduced(P<0.01),and the contraction tension was significantly reduced(P<0.05).Combined with flavonoids,intestinal contractile tension was significantly reduced(P<0.01).Intestinal contractile tension was significantly reduced when the Ca2+ channel blocker verapamil was combined with flavonoids(P<0.05).(2)The effects of 0.8 g/mL water extraction from prickle and inner stem on intestinal smooth muscle movement in vitro in mice were studied by using biological signal processing system.The results showed that the range and peak of intestinal contraction were significantly increased at 10 s after administration of prickles(P<0.05),and the contraction tension was extremely significantly increased(P<0.01),while the inner stem had no effect on intestinal contraction(P>0.05).The intestinal contractile amplitude was significantly reduced after M-receptor blocker atropine was combined with prickle at 10 s compared with prickle alone(P<0.05).(3)Mice fed with 25%or 50%urtica powder decreased feed intake,body weight,blood glucose concentration,total number of white blood cells,while increased granulocyte ratio,and induced death.The present results indicate that the urtica plant three main components of polysaccharide,flavonoids and alkaloids can promote the movement of intestinal smooth muscle in mice,and the ability of action is alkaloid>flavone>polysaccharide,alkaloids mainly by activating the M-receptor,flavone is mainly promote extracellular Ca2+ internal flow;The prickle water extract can promote the intestinal smooth muscle movement in vitro in mice,and the effect may be partly realized by activating M-receptor.The pellet feed prepared by urtica plant powder has adverse effects on the growth and health of mice,and may even be toxic.The above results provide reference for the development of the medicinal value or feeding value of different parts and components of urtica plants. |
