ABSTRACT
Objective: To evaluate the anti-angiogenic and anticancer activities of Psidium guajava leaf extracts against angiogenesis-dependent colorectal cancer. Methods: Three extracts were produced using distilled water, ethanol, and n-hexane as solvents. The extracts were physically characterised through gas chromatography-mass spectrometry, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. Their antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl, total phenolic content, and total flavonoid content assays. To assess their anti-angiogenic activity, cell viability and rat aortic ring assays were conducted, while cell migration, tube formation, colony formation, and VEGF ELISA assays were conducted to elucidate their effects on different aspects of angiogenesis. Molecular docking was used to assess the anti- angiogenic potential of some possible compounds in the extracts. Tumour spheroid assay was used to assess the extracts' potential as a treatment for colorectal cancer. Results: The ethanol extract showed the best antioxidant activity. The distilled water and ethanol extracts exhibited more inhibitory activity against EA.hy926 cell viability and aortic ring microvessel growth. In addition, the ethanol extract performed significantly better than the distilled water extract against cell migration and colony formation, and VEGF expression of the cells was suppressed by the ethanol extract. Both the distilled water and ethanol extracts showed significant inhibitory effect on EA.hy926 tube formation and tumour spheroids consisting of EA.hy926 and HCT116 cells. The ethanol extract contained β-caryophyllene and β-elemene by phytochemical analysis and subsequent docking studies, which may contribute to its anti-angiogenic activity. Conclusions: The ethanol extract of Psidium guajava has potential in the treatment of colorectal cancer through the inhibition of angiogenesis.
ABSTRACT
Objective To decompose and reformulate Banxia Baizhu Tianma Decoction (BBT) in order to optimize its ratio for vasodilatory effect. The fingerprints of these six component herbs were also studied via Tri-step FTIR analysis. Methods The herbal components of BBT were extracted separately with different solvents, such as 95% ethanol, 50% ethanol, and distilled water. The vasodilatory effect of the extracts was studied using the in vitro pre-contracted aortic ring model. Among these extracts, the water extracts of Pinellia ternata [PT(W)] and Citri reticulatae [CR(W)], 50% ethanol extracts of Gastrodia elata [GE(50)] and Glycyrrhiza uralensis [GU(50)], and 95% ethanol extracts of Atractylodes macrocephala [AM(E)], and Poria cocos [PC(E)] were selected for the orthogonal stimulus-response compatibility group study due to their high effectiveness in vasodilation. Results The best combination ratio (G2) was GE(50), GU(50), AM(E), PC(E), CR(W), and PT(W) at EC0, EC5, EC5, EC5, EC5, and EC5, with EC50 of (0.06 ± 0.01) mg/mL. Comparison between the vasodilatory effects of extracts derived from G2 and BBT were also studied. From the results, the 50% ethanol extract following G2 ratio was found to be most potent extract with the highest vasodilatory effect compared with other extracts derived from G2 or BBT, with EC50 of (0.05 ± 0.005) mg/mL. Conclusion The optimum ratio and appropriate extraction method for the new BBT formulae are obtained. G2 is determined as the best formulae with the highest potency in producing the vasodilatory effect on isolated rat aortic rings. The results obtained suggest that 50% ethanol is found to be the best solvent to extract the vasoactive compounds of G2 in order to exhibit the highest efficacy of vasodilatory effect.