Antimicrobial properties and action of galangal (Alpinia galanga Linn.) on Staphylococcus aureus

https://doi.org/10.1016/j.lwt.2005.06.015Get rights and content

Abstract

The ethanol extracts of the Zingiberaceae family (galangal, ginger, turmeric and krachai) were evaluated for antimicrobial action on Staphylococcus aureus 209P and Escherichia coli NIHJ JC-2 by using an agar disc diffusion assay. The galangal extract had the strongest inhibitory effect against S. aureus. The minimum inhibitory concentration (MIC) of the galangal extract was 0.325 mg/ml and the minimum bactericidal concentration (MBC) at 1.3 mg/ml using the broth dilution method. Transmission electron microscopy clearly demonstrated that the galangal extract caused both outer and inner membrane damage, and cytoplasm coagulation. The disruption of the cytoplasmic membrane properties was determined by the releasing of cell materials including nucleic acid which absorbed UV/VIS spectrophotometer at 260 nm. The major compound of the extract was d,l-1′-acetoxychavicol acetate which was identified by GC-MS and NMR.

Introduction

At present, food safety is a fundamental concern to both consumers and food industries in particular as there are an increasing number of reported cases of food associated infections. Most consumers prefer high quality, nutritious and long shelf-life food products with no preservative agents. Food preservation, however, is the basis of some of the largest and the most modern food industries in the world. Spices and their essential oils have been widely used as natural food preservatives to make the processed foodstuff safe for consumers.

Rhizomes of some members of the Zingiberaceae family such as galangal [Alpinia galanga (Linn.) Stuntz], ginger (Zingiber officinalis Roscoe), turmeric (Curcuma longa Linn.) and krachai [Boesenbergia pandurata (Roxb.) Schltr] have been extensively used as condiment for flavoring and local medicines for the stomachache, carminative and treating diarrhea. They are known to contain various antimicrobial agents. Galangal has characteristic fragrance as well as pungency; hence, its rhizomes are widely used as a condiment for foods in Thailand. Galangal is also used as a medicine for curing stomachache in China and Thailand (Yang & Eilerman, 1999). It has been shown that essential oils from both fresh and dried rhizomes of galangal have antimicrobial activities against bacteria, fungi, yeast and parasite (Farnsworth & Bunyapraphatsara, 1992). Janssen and Scheffer (1985) have reported that terpinen-4-ol, one of the monoterpenes in the essential oil from fresh galangal rhizomes, contains an antimicrobial activity against Trichophyton mentagrophytes. Acetoxychavicol acetate (ACA), a compound isolated from an n-pentane/diethyl ether-soluble extract of dried rhizomes, is active against some bacteria and many dermatophyte species (Janssen & Scheffer, 1985). In addition, the ability of ACA to act as an antiulcer and antitumor agents as well as an inhibitor of chemically induced carcinogenesis is event (Murakami, Toyota, Ohura, Koshimizu, & Ohigashi, 2000).

The staphylococcal food poisoning or food intoxication syndrome was first studied in 1894 (Jay, 2000). Staphylococcal gastroenteritis is caused by ingestion of enterotoxins produced by some staphylococcal species and strains. Staphylococcus aureus is nonspore forming Gram-positive cocci, which in some strains, are able to produce an enterotoxin (Vanderzant & Splittstoesser, 1992). In processed foods in which S. aureus should have been destroyed by processing, the reappearance of this particular bacterium can cause damages to food industries as it is a vector of food poisoning. It may be inferred that sanitation or temperature control or both were inadequate. There is no guarantee that foodstuff is safe enough for consumption, although only a trace amount of S. aureus is present. Natural preservatives such as spices and plant essential oils are used as additives, instead of chemical preservatives because food remains safe for consumers while S. aureus is eliminated.

The purpose of this study is to: (1) compare the antimicrobial effect of four genus in Zingiberaceae family against S. aureus and Escherichia coli; (2) to describe the primary mode of actions of galangal ethanol extract; and (3) to identify the main component of the galangal ethanol extract.

Section snippets

Spice extracts preparation

Rhizomes of galangal, ginger, turmeric and root of krachai were purchased from a local market in Nakhon Ratchasima, Thailand. The fresh rhizomes were sliced and dried in a tray-dryer oven at 50 °C for 24 h, after which they were ground in a blender (National, MX-T2GN, Taiwan) to make powder.

Microorganisms preparation

Stock cultures of S. aureus 209P and E. coli NIHJ JC-2, used throughout this study, were kindly provided by the Laboratory of Ecological Circulation, Faculty of Bioresources, Mie University, Japan.

Antimicrobial activities of spice ethanol extracts

The growth inhibition zones measured by using agar disc diffusion assay are presented in Table 1. In general, S. aureus (Gram-positive bacteria) is more sensitive to extracts than E. coli (Gram-negative bacteria). These results are in substantial agreement with many previous studies (Burt, 2004; Maillard, 2002). Turmeric showed less inhibition in growth of both S. aureus and E. coli. Galangal extract exhibited the strongest inhibitory activity against S. aureus. Extract of galangal, krachai and

Conclusions

The major constituent of galangal ethanol extract was d,l-1′-ACA, which was found in some plants in the Zingiberaceae family, especially galangal. This galangal extract had the greatest inhibitory effect against S. aureus among ginger, turmeric and krachai. Some Gram-positive bacteria and yeast were susceptible to the extract, especially Staphylococcal species. The data obtained from this study could be described as the antimicrobial effect of the extract which depended on the exposure time and

Acknowledgements

This work was supported by a research Grant from Suranaree University of Technology, Thailand.

References (27)

  • S. Burt

    Essential oils: Their antibacterial properties and potential applications in foods-a review

    International Journal of Food Microbiology

    (2004)
  • R.E. Marquis et al.

    Fluoride and organic weak acids as modulators of microbial physiology

    FEMS Microbiology Reviews

    (2003)
  • Achararit, C., Panyayong, W., & Rachatagomut, E. (1983). Study of antifungal of some Thai herbs. Research project,...
  • I.R. Booth

    Regulation of cytoplasmic pH in bacteria

    Microbiological Reviews

    (1985)
  • Caichompoo, W. (1999). Antimicrobial activities of volatile oil and curcuminoids from Curcuma longa. Master's Thesis,...
  • C.F. Carson et al.

    Mechanism of action of Melaleuca alternifolia (Tea Tree) oil on Staphylococcus aureus determined by time-kill, lysis, leakage, and salt tolerance assays and electron microscopy

    Antimicrobial Agents and Chemotherapy

    (2002)
  • P.M. Davidson

    Chemical preservatives and natural antimicrobial compounds

  • P.M. Davidson et al.

    Phyto-phenols

  • N.R. Farnsworth et al.

    Thai medicinal plants. Recommended for primary health care system

    (1992)
  • E. Freese et al.

    Function of lipophilic acids as antimicrobial food additives

    Nature

    (1973)
  • J.B. Harborne et al.

    The flavonoids

    (1975)
  • L. Huang et al.

    Influence of external pH and fermentation products on Clostridium acetobutylicum intracellular pH and cellular distribution of fermentation products

    Applied and Environmental Microbiology

    (1986)
  • Y. Horiuchi et al.

    Single mixing fixation using glutaraldehyde and osmium tetroxide for improved ultrastructure of bacteria

    Journal of Electron Microscopy Technology Medical Biology

    (2001)
  • Cited by (189)

    • A comparative study of essential oil profile, antibacterial and antioxidant activities of thirty Piper betle landraces towards selection of industrially important chemotypes

      2022, Industrial Crops and Products
      Citation Excerpt :

      Bennis et al. (2004) reported that eugenol inhibited the growth of S. cerevisiae by lysing the cell wall. Chavibetol acetate was found to neutralize and denature the proteins present inside the cell (Freese et al., 1973; Burt, 2004; Onmettaaree et al., 2006). The antimicrobial activity of the betel leaf essential oil against various multi drug resistant bacterial strains like Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Citrobacter freundii and Enterobacter cloacae was also examined by using MIC assay is presented in Table 6.

    View all citing articles on Scopus
    View full text