Antimicrobial properties of Ginger, Zingiber officinale. Marion Dwain T. Siady # 1065747 Biology 493 Advisor: Dr. Goodwill
ABSTRACT Ginger (Zingiber officinale) has been used as a digestive and circulatory medicine. The intent of this research is to further investigate the antimicrobial properties of ginger. Ginger juice was extracted from the root of the plant. The Kirby-Bauer technique using Mueller-Hinton agar was used to test ginger juice (Zingiber officinale) for antimicrobial properties. Zones of inhibition were measured for the tetracycline disk (positive control), blank disk (negative control), and the ginger disk. The ginger extract indicated a significant anti-microbial effect on the gram-negative (E. coli and P. aeruginosa) bacterial strains tested, but no significant antimicrobial effect on the gram-positive (S. aureus) bacterial strain. INTRODUCTION Ginger (Zingiber officinale) is native to Southeast Asia but also grows in many tropical regions (Heywood 1982). Zingiber officinale is a member of the Zingiberaceae family, of which many have been used as food and medicine throughout the world (Cost 1989). Commonly known as a spice for flavoring, ginger is also widely used as a herbal medicine (Chevallier 1996). An African ginger, Zingiber officinale, is reported to have antifungal, antiemetic, antibacterial, antiprotozoal, antioxidant, antirhinoviral, anti-inflammatory, antihepatotoxic and insecticidal activity (Ficker et al. 2003). Reported pharmacological activities of ginger include: antipyretic, analgesic, antitussive, in addition to hypotensive effects (Thompson et al. 2002). Zingiber officinale, is commonly used as a digestive and circulatory medicine (Carr et al. 1987 and Chevallier 1996). Ginger is reported to sooth indigestion and relieve motion sickness (Lien et al. 2003). Ko (1999) states that it may be beneficial for nausea and vomiting resulting from pregnancy. Ginger's - 1 -
antiseptic properties make it highly beneficial for gastrointestinal infections (Chevallier 1996). As a mild stimulant that promotes the circulation of blood, Ginger helps lower blood pressure and reduce fever (Carr et al. 1987). Other medicinal claims attributed to ginger are that it relieves nausea, pain and cramps of the stomach, headache, fevers, colds, and disordered menstruation (Felter and Lloyd 1898). Ginger has been widely used by people all around the world. In Indonesia, they use ginger to cure coughs, colds and fevers (Ficker et al. 2003). In Fiji and Papua New Guinea, it is used to relieve muscle aches and sprains (Ficker et al. 2003). In China, India, and Africa, it is reported to relieve nausea and stomach pain (Ficker et al. 2003). Ginger s efficacy is believed to stem from its aromatic, carminative, and absorbent properties (Portnoi et al. 2003). The intent of this research is to further investigate the antimicrobial properties of the African ginger (Z. officinale) outside the digestive and circulatory environment. - 2 -
METHODS Zingiber officinale rhizome was obtained from the fresh produce section of a grocery store in Laie, Hawaii. The skin of the ginger was removed using a scalpel. The peeled ginger was blended in a juice blender. The pulp and the juice were strained using a piece of cheesecloth and the pure juice extract was stored in a dark bottle at 4 C. The Kirby-Bauer technique was used to test the juice for antimicrobial properties on three standard bacteria provided by the BYU-H microbiology culture collection: Staphylococcus aureus (Ward s 85W1941), Escherichia coli (Ward s 85W0400), and Pseudomonas aeruginosa (Ward s 85W1903). A positive control consisted of the antibiotic tetracycline (30 mcg disks). A blank disk provided a negative control. The test bacteria were aseptically spread onto Mueller-Hinton agar. Antimicrobial disks were soaked with 20 microliters of the strained root juice extract. The disks were added to the plates and the plates were incubated at 35ºC for 18 hours. The plates were parafilmed and placed in the refrigerator at 4ºC for storage. The diameter of the zones of inhibition were measured and recorded in millimeters and compared to the positive and negative controls. The same procedure was repeated for each of the test bacteria. Statistical analyses were performed using a standard t-test. The mean and the standard deviation were calculated. - 3 -
RESULTS Zones of inhibition were observed for the antimicrobial property of ginger. The zones of the tetracycline (positive control), blank disk (negative control), and the ginger disk were recorded (Table 1). The zones of the ginger disk were compared to the zones of the blank disk (negative control). Results were analyzed using a student s t-test. The values were calculated for the mean and the standard deviation (Table 2). For E. coli, the ginger extract yielded a 11.2 ± 1.92 mm zone of inhibition, compared with 6.6 ± 0.55 mm for the negative control (P<0.05) (Figure 1). Likewise, with P. aeruginosa, the ginger yielded a 11.6 ± 4.13 mm zone of inhibition, compared with 6.0 ± 0 mm zone, as observed for the negative control (P<0.05) (Figure 2). Conversely, with S. aureus, yielded a 8.4 ± 2.06 mm zone of inhibition, compared with a 6.6 ± 0.49 mm zone for the negative control (P>0.05) showing no significant antimicrobial effect of ginger extract to S. aureus (Figure 3). - 4 -
T able 1. Zones of inhibitio n for tetracycl ine (positive control), blank disk (negativ e control) and ginger disk with E.coli, S. aureus, and P. aeruginosa. Zone Diameter (millimeters) Organism Tube Tetracycline Blank disk Ginger E. coli 1 25 7 8 2 29 6 12 3 30 7 13 4 29 6 11 5 29 7 12 S. aureus 1 25 6 9 2 28 6 6 3 32 7 7 4 32 7 12 5 33 7 8 P. 1 10 6 6 aeruginosa 2 20 6 17 3 20 6 15 4 20 6 8 5 21 6 12 Table 2. Mean, standard deviation, and P-value. The zones of inhibition for the - 5 -
blank disk (negative control) and the ginger disk when run against E.coli, S. aureus, and P. aeruginosa. Average Figure 1. Tetracycline, Blank disk and ginger disk showing their standard deviations for E. coli E. coli 35 30 25 20 15 10 5 0 T etracycline blank ginger E. coli Organism Mean Mean for Standard Standard Ginger for ginger Deviation Deviation test, blank disk for blank for ginger P- disk disk Value E. coli 6.6 11.2 0.55 1.92 0.001 S. aureus 6.6 8.4 0.55 2.30 0.127 P. 6.0 11.6 0 4.62 0.027 aeruginosa 25 P. aeruginosa 20 Average 15 10 5-6 - 0 Tetracycline blank ginger P. aeruginosa
Figure 2. Tetracycline, Blank disk and ginger disk showing their standard deviations for P. aeruginosa. 40 S. aureus Average 30 20 10 S. aureus 0 Tetracycline blank ginger Figure 3. Tetracycline, Blank disk and ginger disk showing their standard deviations for S. aureus DISCUSSION Results suggest a significant antimicrobial effect of ginger extract against E. coli and P. aeruginosa (P<0.05). On the other hand, S. aureus showed no significant antimicrobial effect (P>0.05). Escherichia coli and Pseudomonas aeruginosa are both gram-negative bacteria while Staphylococcus aureus is gram-positive. While further testing would need to be performed before a conclusive correlation could be made, it seems possible that ginger extract may demonstrate its antimicrobial effect primarily against gram-negative bacteria. A conclusive correlation could not be made because of having only one gram-positive strain being tested. - 7 -
SOURCES CITED Carr, A., C. Kowalchik, and W.H. Hylton. 1987. Illustrated Encyclopedia of Herbs. Pennsylvannia: Rodale Press, p. 223. Chevallier, A. 1996. The Encyclopedia of Medicinal Plants. New York: DK Publishing Inc., p. 153. Cost, B. 1989. Ginger East to West: the Classic Collection of Recipes, Techniques, and Lore. California: Aris Books Editorial Offices and Test Kitchen, p. 198. Felter, H.W. and J.U. Llyod. 1898. Zingiber (U.S.P.) Ginger. King s American Dispensatory. http://www.ibiblio.org/herbmed/eclectic/kings/zingiber.html Ficker, C., M.L. Smith, K. Akpagana, M. Gbeassor, J. Zhang, T. Durst, R. Assabgui and J.T. Arnason. 2003. Bioassay-guided isolation and identification of antifungal compounds from ginger. Phytotherapy Research 17: 897-902. Heywood, V. H. 1982. Popular Encyclopedia of Plants. New York: Cambridge University Press, p. 157. - 8 -
Ko, R. 1999. Adverse reactions to watch for in patients using herbal remedies. Western Journal of Medicine 171(3): 181-185. Lien, H.C., W.M. Sun, Y.H. Chen, H. Kim, W. Hasler and C. Owyang. 2003. Effects of ginger on motion sickness and gastric slow-wave dysrhythmias induced by circular vection. American Journal Gastrointestinal Liver Physiology 284: G481-G489. Portnoi, G., L. Chng, L. Karimi-Tabesh, G. Koren, M.P. Tan and A. Einarson. 2003. Prospective comparative study of the safety and effectiveness of ginger for the treatment of nausea and vomiting in pregnancy. American Journal Obstetrician Gynecology 189(5): 1374-1377. Thompson, M., K.K. Al-Qattan, S.M. Al-Sawan, M.A. Alnaqeeb, I. Khan and M. Ali. 2002. The use of ginger (Zingiber officinale Rosc.) as a potential antiinflammatory and antithrombotic agent. Prostaglandins, Leukotrienes, and Essential Fatty Acids 67(6): 475-478. ACKNOWLEDGEMENTS Dr. Roger Goodwill (Advisor) o Dr. Roger Goodwill helped me as my advisor. He gave suggestions on how to do revise my papers and also on the methods section on my paper. Dr. Shane Gold o Dr. Shane Gold helped me analyze my data and fitted it in a standard t-test. BYU-H Biology Faculty o For all the help and suggestions that was given to help and train me on how to write a good scientific paper. Harold Spencer T. Siady o For the initial microbiological methods involved in the research. - 9 -