Phytomedicine Plus (Feb 2022)
Anti-Helicobacter pylori potential, antioxidant capacity, and anti-inflammatory activity of Xylopia sericea A. St.-Hil. (Annonaceae) leaves
Abstract
Background: : Xylopia sericea A. St.-Hil. (Annonaceae), a Brazilian pepper, popularly known as “pindaíba,” has ethnopharmacological relevance as a useful remedy for gastric disorders; however, few reports are available in the literature to explain its therapeutic effects. Purpose: : This study aimed to evaluate the in vitro effects of X. sericea leaf ethanol extract (EE) on Helicobacter pylori (HP) growth, cytokine production, antioxidant capacity, and cytotoxicity in human gastric adenocarcinoma cell line (AGS). Study design: : Using a cell model system (murine macrophage LPS-stimulated) and in vitro assays, EE bioactivity, with regard to antioxidant capacity, inhibition of cytokine production, and urease inhibition, was assessed. The EE chemical profile was obtained using chromatography and biomarker quantification. Methods: : Antioxidant and urease assays were performed using colorimetric methods, H. pylori growth was evaluated using the minimal inhibitory concentration assay, cytokine production was measured using enzyme-linked immunosorbent assay, cytotoxicity was determined using the MTT method, EE chromatographic profile was obtained using HPLC-DAD-UV analysis, and biomarker quantification was obtained using calibration curves. Results: : Our findings demonstrated that EE has an antioxidant capacity similar to that of gallic acid in the hypochlorous acid inhibition assay (EC50 = 61.09 µg/ml) and higher activity (p <0.05) in the superoxide radical assay (EC50 = 25.56 µg/ml) compared to the same antioxidant standard. In RAW 264.7 LPS stimulated cells, EE (100 µg/ml) inhibited the production of NO (76%) and IL-6 (85%) but did not reduce TNF-α and superoxide levels at all tested concentrations (6.25 to 100 µg/ml). EE demonstrated urease enzyme inhibition similar to boric acid, the standard inhibitor, and inhibited H. pylori non-resistant strain growth at 512 µg/mL. EE did not reduce the AGS cell viability at the tested concentrations (6.25 to 100 µg/ml). The EE flavonoid content was 198.50 µg of rutin equivalents in each mg of extract, and the HPLC analyses showed four majoritarian components as quercetin glycosides. Conclusions: : This study partially explains the role of X. sericea in defense mechanisms associated with gastric diseases, and provides support for further research on the potential of X. sericea in gastric disease treatments.
