Investigation Of Anticancer Properties Of Philenoptera Violacea (Klotzsch) Schrire And Xanthocercis Zambesiaca (Baker) Dumaz-Le-Grand

Abstract

The aim of this study was to assess Philenoptera violacea (Klotzsch) Schrire and Xanthocercis zambesiaca (Baker) Dumaz-le-Grand as anticancer agents, to determine the mutagenic and anti-mutagenic properties, anticancer activity, antibacterial and antioxidant activity of these plant extracts, radioprotective effects of X.zambesiaca and phytochemical screening of both plant extracts in order for them to be used in developing novel anticancer drugs. The extracts of medicinal plants were prepared using the maceration with methanol as solvent. Methanol extracts were tested for their growth inhibitory effects in vitro using the Sulforhodamine B assay. Mutagenic properties were determined by the Ames test, using Salmonella typhimurium strains TA98 and TA100 without S9. Antibacterial activity was determined using p-Iodonitrotetrazolium chloride assay. The antioxidant activity was determined using 2, 2- diphenyl-1-picrylhydrazyl assay. X.zambesiaca and P.violacea were classified as inactive (TGI >50 μg/ml) against breast (MCF7), colon (HCT116), renal (UACC-62), melanoma (TK-10) and prostate (PC3) cancer cell lines. Results of test for the mutagenic properties of P.violacea and X.zambesiaca plant extracts revealed that neither plant has mutagenic effects. Antibacterial activity results revealed that both plants‘ extracts had no antimicrobial activity against Staphylococcus aureus, S. epidermidis, S. saprohyticus, Bacillus subtilis, Enterobacter cloacae, Escherichia coli or Pseudomonas aeruginosa. P.violacea plant extract showed low antioxidant activity, while X.zambesiaca extract exhibited moderate dose-dependent antioxidant activity and can be considered a weak source of antioxidant. In view of these antioxidant results, the free radical scavenging ability of X.zambesiaca was confirmed by determining the radioprotective effects of this extract on human prostate cancer cells (DU145), which were irradiated to 2 Gy. Results showed a significant radiation protection effect that can lead to over 50% reduction in cell death. Qualitative phytochemical analysis of these plant extracts confirmed the presence of tannins, flavonoids, steroids, terpenoids, alkaloids and cardiac glycosides from P.violacea extract, while X.zambesiaca extract showed the presence of flavonoids, saponins, terpenoids and glycosides. The gallic acid equivalents (GAEs) of the estimated phenolic concentrations ranged from 0.152 ± 0.0269 to 0.0895 ± 0.006 mg/GAE. Liquid chromatography-mass spectrometry analysis of these plant extracts showed the presence of nine compounds (including two unknown compounds) from P.violacea, and seven compounds from X.zambesiaca. The results thus indicate the possibility of using X.zambesiaca (methanol mixture of leaf, twig and flower) extracts as a radioprotector and an antioxidant agent to counteract and prevent cell damage by free radicals. These results were encouraging, despite the need for clinical studies to determine the real effectiveness and potential toxic effects of this extract in vivo. Our results led us to raise questions about the effect of P.violacea (methanol mixture of leaf, twig and flower) extracts, which proved to possess a number of active compounds that were somehow inactive, regardless of how many times we re-analyzed them. Finally, results revealed the importance of X.zambesiaca as a possible anticancer drug.