Abstract 1867: Liver and urinary bladder cancers: The modifying role of aqueous leaf extract ofTerminalia glaucescensPlanch. ex Benth

Abstract

Background: The aggressive and asymptomatic nature of liver cancer etiology in blacks is well documented. Furthermore, in Egypt, bladder cancer accounts for as many as 31% of all cancer cases, while in the US, the incidence in whites is higher than in blacks. There has been an increased search for phytochemicals, such as capsaicin (a bioactive component of hot peppers), which are easily available, and possess chemopreventive and chemotherapeutic activities. We therefore investigated the potential scientific relevance of aqueous leaf extract of Terminalia glaucescens (ALET) in cancer management. Terminalia glaucescens has been ethnomedicinally associated with various biological and therapeutic properties. Methods: Total flavonoid and phenolic contents of ALET were assessed spectrophotometrically using gallic acid and quercetin as standards, in addition to its free-radical-scavenging activity involving 2,2-diphenyl-1-picrylhydrazyl assay with butylated hydroxytoluene and vitamin C as reference compounds. The hydroxyl-radical-scavenging and reducing-power activities were correspondingly assessed. In addition, antiproliferative activities of ALET in comparison with capsaicin on normal and cancer cell lines of human liver (THLE-3 and HepG2) and urinary bladder (HUC-PC and MC-T11) were evaluated using fluorometry. Luminometry was used to determine ATP concentrations, caspase 3/7 activities, glutathione status, and mitochondrial functions. Results: Quantitative phytochemical assessments indicate the predominance of phenolic compounds (599.61 ± 6.14 µg gallic acid equivalents per mg of ALET) as compared with flavonoids (144.27 ± 3.44 µg quercetin equivalents per mg of ALET). ALET possesses comparable free-radical-scavenging, antioxidant and reducing-power activities in comparison to the standards. Treatment of the four cell lines with ALET for three days results in the following percent total cells: THLE-3 (30.13% at 24 h; 5.65% at 48 h; 5.43% at 72 h), HepG2 (31.09% at 24 h; 4.75% at 48 h; 1.41% at 72 h), HUC-PC (7.33% at 24 h; 2.35% at 48 h; 1.74% at 72 h), and MC-T11 (19.79% at 24 h; 9.20% at 48 h; 0.29% at 72 h). Assessment of the ATP levels after 24 h treatment with ALET resulted in a concentration-dependent depletion with a remarkable effect on HUC-PC and MC-T11 urinary bladder cells. ALET specifically caused a concentration-dependent decrease in caspase 3/7 activities and glutathione levels in HepG2 cells. ALET seems more toxic to the mitochondria at higher concentrations as compared with capsaicin. Conclusions: ALET could be a natural source of mitocans for the treatment of cancers. Citation Format: Jeremiah Olorunjuwon Olugbami, Robert Damoiseaux, James Kazemier Gimzewski, Oyeronke Adunni Odunola. Liver and urinary bladder cancers: The modifying role of aqueous leaf extract of Terminalia glaucescens Planch. ex Benth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1867.