Anti-Helicobacter pylori, anti-inflammatory and antioxidant evaluation of crude extracts from Amomum krervanh fruits

The aim of the present study was to determine the antibacterial properties against Helicobacter pylori and the anti-inflammatory and antioxidant activities of crude A. krervanh extracts.The minimum inhibitory concentrations (MICs) of ethanolic and aqueous extracts were measured against standard strain H. pylori standard (ATCC 43504) and six clinical isolates by disc diffusion and agar dilution.Anti-inflammatory activities were evaluated by measuring the inhibition of nitric oxide (NO) production in LPS-activated RAW 264.7 macrophages using the Griess assay and the ELISA measurement of proinflammatory cytokines, tumour necrosis factor α (TNF-α), and interleukin 6 (IL-6).Their cytotoxic activities against macrophages were determined by the MTT assay.ABTS and DPPH scavenging assays measured the antioxidant activities.Only the ethanolic extract showed antibacterial activity with mean inhibition zones of 9.0-19.3mm for a corresponding MIC of 250 µg/ml; the clarithromycin MICs ranged from 0.5-1 µg/ml.This extract also inhibited production of NO (mean IC 50 98.99 ± 0.39 µg/ml) and IL-6 (mean IC 50 18.68 ± 2.16 µg/ml) and exhibited moderate antioxidant activity using DPPH and ABTS scavenging assays: mean IC 50 s 95.92 ± 1.26 and 90.35 ± 2.25 µg/ml, respectively.Thus ethanolic extract showed a greater spectrum of activity that could be exploited further as adjunct treatments of H. pylori related gastrointestinal disease.