Antimicrobial activity and phytochemical screening of Alpinia malaccensis (Ran-kiriya) against food-borne bacteria.

AIMS: Investigation of antimicrobial activity and phytochemicals of Alpinia malaccensis (Ran-kiriya) against foodborne bacteria Staphyloccocus aureus, Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium. METHODS AND RESULTS: Antibacterial activity was tested on the above four foodborne bacteria using agar disc diffusion and broth dilution assay. Alpinia malaccensis rhizome extract chemical composition was determined using gas chromatography-mass spectrometry (GCMS). Active compound was identified using thin-layer chromatography (TLC) and confirmed by nuclear magnetic resonance spectroscopy (NMR). The A. malaccensis rhizome hexane crude extract showed significantly (P < 0·05) higher diameter of inhibition (DIZ) 40 ± 0·52, 38 ± 0·96 and 36 ± 1·45 mm for S. aureusSA113, MSSASS25D and methicillin-resistant S. aureus compared with other tested bacteria. The minimum inhibition concentration and minimum bactericidal concentration were 0·625 and 5 mg ml-1 for S. aureus 113. TLC showed DIZ 39 ± 0·12 mm only for one fraction. The crude extract showed 82·87% a major compound by GCMS which is the active fraction. This purified active fraction was confirmed as 1'acetoxychavicol acetate (1'ACA) by NMR. No significantly different inhibition was observed for crude extract and purified compound. CONCLUSIONS: Bioactive 1'ACA of A. malaccensis showed strong antibacterial activity against S. aureus strains including MRSA strain. SIGNIFICANCE AND IMPACT OF THE STUDY: This study is the first to identify 1'ACA from A. malaccensis. The crude or purified compound could potentially be developed as antimicrobials.

Definition, Derivation, and Diagnosis of Barrett's Esophagus: Pathological Perspectives.

More than 60 years have elapsed since Barrett described the condition that continues to bear his name. Despite much research, clinical and basic, the defining features and the diagnosis of columnar-lined esophagus (CLO) are still embroiled with controversy and uncertainty. For pathologists, these controversies are notorious. The disease has been defined by the pathological demonstration of "specialized intestinal metaplasia" and yet there is compelling evidence that this approach is flawed due to sampling issues, poor levels of agreement between expert pathologists as to what constitutes "goblet cells," and the fact that most glandular epithelium in the esophagus is "intestinalized," even if goblet cells are not demonstrable. We believe that reliance on such pathological features can result in erroneous diagnoses of CLO and that the endoscopic diagnosis of CLO is more reliable with pathology corroborative in uncertain cases, when there is stricturing and/or ulceration and in shorter segment disease. Intriguingly, there are recent research findings that elucidate our understanding of the pathogenesis and the derivation of CLO and the way that initial gastric metaplasia converts to the unstable and neoplasia-associated intestinal phenotype. Even so, more research is required to enable a better understanding of the pathogenesis of CLO and to further improve the current management of the disease and its neoplastic complications.

In Vivo and In Vitro Toxicity Profiles of Hexane Extract of Alpinia malaccensis Rhizome in Rat and Cell Line Models.

The objective of the study was to evaluate the potential toxicity of crude n-hexane extract of Alpinia malaccensis rhizome. The in vivo acute oral toxicity was evaluated by administering a single oral dose of the extract at 0, 300, or 2000 mg/kg body weight to female Wistar rats according to modified OECD Test Guideline 423. For the in vitro cytotoxicity study, A549, HepG2, 3T3, and COS-7 cell lines were exposed to different doses of A. malaccensis extract and cell viability was assessed adopting MTT assay followed by AO/EB staining, Hoechst staining, and comet assay with a view to compare the cellular and molecular mechanisms underlying the toxicity, if any. It was found that administration of 2000 mg/kg bw dose in in vivo oral acute toxicity study did not produce significant toxicity or mortality. No significant (p < 0.05) differences were observed for body weight and hematological and biochemical parameters compared to control after 14 days of treatment. No changes in behavior, body weight, hematological and biochemical parameters, and aspects of histopathology were observed when compared to the control. Thus, the possible oral lethal dose for A. malaccensis extract is above 2000 mg/kg body weight. The in vitro cytotoxicity analysis showed nontoxicity concentrations of the extract to be 2, 1.4, 30, and 1.4 µg/mL for A549, HepG2, 3T3, and COS-7 cells, respectively, where no apoptotic/necrotic cell death and DNA damage were observed. In conclusion, the extract of rhizome of A. malaccensis did not produce apparent cytotoxicity or acute oral toxicity, confirming the scope to use A. malaccensis as a safe food preservative and a natural therapeutic product after further subacute and chronic toxicity studies.