Applications of Chromatographic Techniques for Fingerprinting of Toxic and Non-toxic Euphorbia Species.

ABSTRACT

BACKGROUND AND OBJECTIVE: Euphorbia species have historically been used as medicinal plants to treat different ailments. However, some species have been reported to exhibit various degrees of toxicity. It becomes critical to distinguish toxic species from those that are non-toxic, for a particular application. The aim of the study was to determine the method for fingerprinting the chemical constituents of the selected toxic and non-toxic Euphorbia species to identify markers of toxicity. MATERIAL AND METHODS: Hexane, DCM, methanol, ethyl acetate and water plant extracts of Euphorbia ammak, clavarioides, caerulescens, polygona and trigona were investigated for their cytotoxic activities towards the mammalian Vero cell line using MTT cell viability test assay. The presence of secondary metabolites and proteins were assessed in the plant extracts. Moreover, the study used chromatographic methods to fingerprint the plant extracts to identify toxicity markers. RESULTS: The DCM extract of E. ammak exhibited the highest cell growth inhibition at all concentrations tested. The non-polar extracts of E. clavarioides exhibited the highest cell growth inhibition activity with hexane extract reaching IC50 at 1 µg mL-1. The DCM extract of E. caerulescens reached IC50 at a concentration of 10 µg mL-1, while other extracts didn't show any activity. The hexane and DCM extracts of E. polygona exhibited the highest cell growth inhibition activity, reaching IC50 at a concentration of 10 µg mL-1. All 4 extracts of E. trigona didn't show cell growth inhibition. All Euphorbia species showed the presence of secondary metabolites. The biuret and xanthoprotein methods indicated that there were no proteins detected in all 5 Euphorbia species. TLC profiles of toxic extracts revealed additional bands which were absent in non-toxic species. CONCLUSION: It is concluded that the TLC method developed in this study can be used as a quick screen method to possibly distinguish toxic from non-toxic species, as well as in identifying the studied species.