keywords: Crotalaria species, fabaceae, hepato-toxicity, pyrrolizidine alkaloids
A Phytochemical analysis of four species from the genus Crotalaria (known as Bi-rana or Biya-rana in Hausa) was carried out to determine the presence of toxic pyrrolizidine alkaloids (PAs) – chemical compounds known to have medicinal as well as toxic properties to human and veterinary animals. The analysis was conducted on the leaves and aerial parts of C. lachnosema, C. microcarpa, C. naragutensis, and C. retusa (Family: Fabaceae) by extracting the alkaloids with 1% H2SO4 in 50 % aqueous ethanol. General alkaloid tests were carried out on the extracts as well as specific PA test using Ehrlich reagent [4-dimethylaminobenzaldehyde (5 g) dissolved in a mixture of acetic acid (60 ml), water (30 ml), and 60% perchloric acid (10 ml)]. Thin layer chromatographic analysis was conducted by extracting the PAs with dichloromethane and developed on silica gel plate using hexane-ethyl acetate (1:1). The plate was treated with Ehrlich spray reagent (1 g p-dimethylaminobenzaldehyde in 100 ml ethanol + 15 ml concentrated hydrochloric acid) heated at 950C for 15 min. to reveal the presence of PA as purple and blue spots in all the extracts. The results of the study suggest the presence of potentially hepatotoxic PAs in the leaves and aerial parts of the four plants samples.
Bildfell R 2016. Overview of Pyrrolizidine Alkaloidosis (Seneciosis, Senecio poisoning, Ragwort toxicity), www.msdvetmanual.comDate accessed September, 2017 Bras G, Brooks SE & Watler DC 2006. Cirrhosis of liver in Jamaica. J. Pathol.Bacteriology, 82: 503–512. Dharmananda, S. (2001). Safety Issues Affecting Herbs: Pyrrolizidine Alkaloids, Institute for Traditional Medicine, Portland, Oregon, www.itmonline.org/arts/pas.htm. Accessed: September, 2017. Evans WC 2009. Trease and Evans Pharmacognosy, 16th Edition Elsevier Limited, Edinburgh, United Kingdom, pp. 353 – 357. Kar A 2007. Pharmacognosy and Pharmaco-biotechnology. 2nd edition, New Age International (Ltd.) Publishers, New Delhi, India, pp. 375 – 395. Kone WM & Kande B 2012. Qualitative Analysis of the pyrrolizidine alkaloids from 11 asteraceae and boraginaceae used in traditional medicine in Cote d’Ivoire. Res. J. Phytochemistry, 6: 75 – 83. Mattocks AR & Jukes R 1987. The Simple Detection of Potentially Toxic PAs under Field Conditions. In: Poisonous Plants: Proceedings of the Third International Symposium. Editor Keeler, J. Iowa State University Press, pp. 553 – 555. Nuhu H, Abdurahman EM & Shok M 2009a. Ethnomedical studies of crotalaria species found in Zaria, northern Nigeria. Nig. J. Pharm. Sci., 8(2): 46 – 53. Nuhu H, Abdurahman EM & Shok M 2009b. Comparative analysis of the alkloids of crotalaria species. Nig. J. Pharm. Sci., 8(2): 54 – 58. Rosemann GM 2006. Analysis of Pyrrolizidine Alkaloids in Crotalaria Species by HPLC-MS/MS in Order to Evaluate Related Health Risks, University of Pretoria, Republic of South Africa, pp 14 – 17. WHO 1989. Pyrrolidine Alkaloids Health and Safety Guide, International Program on Chemical Safety, Health and Safety Guide, No. 26. (World Health Organization, Geneva).