Study On The Antioxidant And Molluscicidal Activities Of The Extracts From Chimonanthus Nitens Flowers

Chimonanthus nitens Oliv.is widely distributed and rich in resources.It is a unique Chinese herbal medicine.Its roots,stems,leaves,buds and fruits can be used as medicine,which is a traditional garden flower and folk medicine and has great development prospects.Pomacea canaliculata Lamarck is one of the 100 malignant invasive alien species in the world,which is seriously harmful to agriculture,economy and human health.How to effectively prevent and control the harm caused by P.canaliculata has become a concern of the whole society.In this paper,C.nitens flowers was used as the experimental material.Firstly,it was placed in the shade of the outdoor and dried.After being pulverized,it was passed through a 60mesh sieve.Finally,weighing dry powdery plant materials,performing ultrasonic-assisted cold extraction with 70%ethanol by volume,sequentially extracting the ethanol extract with petroleum ether,ethyl acetate and water-saturated n-butanol in the same volume ratio to obtain petroleum ether extract?PEEE?,ethyl acetate extract?EAEE?and water-saturated n-butanol extract?SBEE?.We studied the antioxidant activity and molluscicidal activity of C.nitens different extracts on P.canaliculata.The components with the best molluscicidal activity were selected to study the degree of hepatopancreas tissue damage and its effects on physiology and biochemistry when killing 25%,50%and 75%P.canaliculata,so as to provide scientific theoretical basis for further development and utilization of C.nitens.The results of antioxidant activity in vitro showed that PEEE,EAEE and SBEE of C.nitens flowers have scavenging effect on DPPH radical and ABTS⁺radical and have certain inhibitory effects on?-glucosidase and tyrosinase,of which EAEE has the strongest antioxidant activity.Through the determination of total phenol and total flavonoids,PEEE,EAEE and SBEE of C.nitens flowers all contain phenols and flavonoids,the contents of phenols and flavonoids in EAEE were the highest,with total flavonoids of 9.33 mg/g and total phenols of 2.93 mg/g.The molluscicidal activity indicated that PEEE,EAEE and SBEE of C.nitens flowers also had toxic effects on P.canaliculata but PEEE had the greatest molluscicidal activity(24 h,IC₅₀=0.287 mg/mL).After exposure to PEEE of different concentrations for 24 h,the hepatopancreas surface of P.canaliculata was loose,causing extensive necrosis and serious damage to the hepatopancreas tissue.The number of rough endoplasmic reticulum and mitochondria in the hepatopancreas cells of P.canaliculata decreased,and the rough endoplasmic reticulum appeared swelling,breaking and degranulation.Mitochondria showed swelling and irregular shape.The levels of soluble sugar,soluble protein and albumin?Alb?in the hepatopancreas of P.canaliculata decreased with increasing PEEE concentration,while the activities of glutamic pyruvic transaminase?GPT?,glutamic oxaloacetic transaminase?GOT?and acetylcholinesterase?AchE?increased with increasing PEEE concentration.A total of29 compounds were identified from the PEEE of C.nitens by gas chromatography-mass spectrometry analysis.The main components were esters?48.13%?,alcohols?18.43%?and the compound Chimonanthine?14.70%?.