Antioxidant, anti-inflammatory, and antiproliferative activity of extracts obtained from Tabebuia Rosea (Bertol.) DC

Abstract

Background: Tabebuia rosea (Bertol.) DC. is a neotropical tree used in traditional medicine in the Northern coast of Colombia as well as Latin America for infectious diseases treatment. Few studies have evaluated the biological activity of this species. Objective: The objective of this study is to determine the antioxidant, anti-inflammatory, and antiproliferative potential of leaf and inner bark extracts from T. rosea. Materials and Methods: The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) methods. The anti-inflammatory activity was evaluated in lipopolysaccharide-stimulated murine macrophages. In vitro antiproliferative effect was determined in HepG2, HeLa, MCF-7, and B16F10 cell lines. Results: The highest DPPH radical scavenging activity was observed for T. rosea ethyl acetate leaf extract (IC50of 157.5 ± 2.4 μg/mL). This extract also induced the best antioxidant activity as determined by ORAC (11,112.2 ± 1,255.3 μmol TE/g of extract). Moreover, T. rosea leaf n-hexane, chloroform, and aqueous extracts, in addition to inner bark aqueous extract did inhibit nitric oxide production by over 90%. In addition, inner bark extracts markedly inhibited prostaglandins E2 and tumor necrosis factor alpha (>90%). The best antiproliferative activity was displayed by the inner bark chloroform extract against HepG2 (selectivity index [SI] = 5.50) and B16F10 (SI = 3.18) cell lines. Conclusion: These results demonstrate the potential biological activity of T. rosea extracts. Abbreviations used: DPPH: 2,2-diphenyl-1-picrylhydrazyl; ORAC: Oxygen radical absorbance capacity; LPS: Lipopolysaccharide; NO: Nitric oxide; TNF-a: Tumor Necrosis Factor Alpha; PGE2: Prostaglandin E2; TAC: Total antioxidant content; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.