title: Microwave-assisted extraction of three bioactive alkaloids from Peganum harmala L. and their acaricidal activity against Psoroptes cuniculi in vitro.
abstract: BACKGROUND
  Peganum harmala L. is a perennial herbaceous, glabrous plant that grows in semi-arid conditions, steppe areas and sandy soils. It is used to treat fever, diarrhoea, subcutaneous tumours, arthralgia, rheumatism, cough, amnesia and parasitic diseases in folk medicines. In this paper, we aimed to develop a simpler and faster method for the extraction of three alkaloids from Peganum harmala L. than other conventional methods by optimizing the parameters of a microwave-assisted extraction (MAE) method, and to investigate the acaricidal activities of three compounds against Psoroptes cuniculi.
  
  
  METHODS
  After optimizing the operating parameters with the single factor experiment and a Box-Behnken design combined with a response-surface methodology, a MAE method was developed for extracting the alkaloids from the seeds, and a high-performance liquid chromatography was used to quantify these compounds. An in vitro experiments were used to study the acaricidal activities.
  
  
  RESULTS
  The optimal conditions of MAE method were as follows: liquid-to-solid ratio 31.3:1mL/g, ethanol concentration 75.5%, extraction time 10.1min, temperature 80.7°C, and microwave power 600W. Compared to the heat reflux extraction (HRE, 60min) and the ultrasonic-assisted extraction (UAE, 30min) methods, MAE method require the shortest time (10min) and obtain the highest yield of three compounds (61.9mg/g). Meanwhile, the LT50values for the vasicine (1.25 and 2.5mg/mL), harmaline (1.25 and 2.5mg/mL), harmine (1.25 and 2.5mg/mL) and MAE extract (100mg/mL) against Psoroptes cuniculi were 12.188h, 9.791h, 11.994h, 10.095h, 11.293h, 9.273h and 17.322h, respectively.
  
  
  CONCLUSIONS
  The MAE method developed exhibited the highest extraction yield within the shortest time and thus could be used to extract the active compounds from Peganum harmala L. on an industrial basis. As the active compounds of Peganum harmala L., vasicine, harmalin and harmine presented the marked acaricidal activities against Psoroptes cuniculi, and could be widely applied for the treatments of acariasis in animals.
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: shangxf928@126.com.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Shang
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: gx_139417@163.com.
authors.forename: Xiao
authors.initials: X
authors.lastname: Guo
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: libing@caas.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: panhu@caas.cn.
authors.forename: Hu
authors.initials: H
authors.lastname: Pan
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: zhangjiyu@caas.cn.
authors.forename: Jiyu
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Emergency, Lanzhou General Hospital of PLA, Lanzhou 730050, PR China. Electronic address: 262730291@qq.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of New Animal Drug Project, Gansu Province, Key Laboratory of Veterinary Pharmaceutical Development of Ministry of Agriculture, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Science, Lanzhou 730050, PR China. Electronic address: shangxf928@163.com.
authors.forename: Xiaolou
authors.initials: X
authors.lastname: Miao
mesh_terms: D056810:Acaricides / Q000302:isolation & purification / Q000494:pharmacology*; D000470:Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004305:Dose-Response Relationship, Drug; D006246:Harmaline / Q000302:isolation & purification / Q000378:metabolism; D006247:Harmine / Q000302:isolation & purification / Q000494:pharmacology; D006358:Hot Temperature; D008872:Microwaves; D021261:Parasitic Sensitivity Tests; D032443:Peganum / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D040042:Psoroptidae / Q000187:drug effects*; D011799:Quinazolines / Q000302:isolation & purification / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D056810:Acaricides; D000470:Alkaloids; D010936:Plant Extracts; D011799:Quinazolines; D006247:Harmine; C019592:vasicine; D006246:Harmaline
keywords: Acaricidal activity; Alkaloids; Microwave-assisted extraction; Peganum harmala L.