Comparative Antibacterial Analysis and Synergistic Potency of the Leaf Extracts of Ocimum gratissimum Linn. and Gongronema latifolium Benth. on Some Enteric Bacterial Isolates

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D. A. Awomukwu
C. K. Anumudu
A. J. Ogbolosingha


The research was undertaken to investigate the comparative phytochemical and in-vitro antibacterial activity of the single and combined strengths of the leaf extracts of Ocimum gratissimum Linn and Gongronema latifolium Benth. on some enteric bacterial isolates. The sensitivity test and minimum inhibitory concentration (MIC) were carried out using a modified agar-well diffusion method.  The enteric bacterial isolates tested included Escherichia coli, Shigella dysenteriae, Salmonella Typhi and Enterobacter aerogenes.  Standard methods were applied to obtain the ethanol and aqueous leaf extracts. The ethanol extracts of O. gratissimum and G. latifolium produced highly significant inhibitory activity against all the enteric bacterial isolates tested.  Comparatively, the ethanol plant extracts were more potent than the commercially available drug, Ciprofloxacin and the aqueous plant extracts. The isolates were sensitive at a minimum inhibitory concentration of 1.25 mg/ml for the ethanol extract but varied from 2.5 mg/ml - 5.0mg/ml in the aqueous extract.  It was also observed that the synergistic antibacterial effect of the medicinal plant extracts was greater than the singular antibacterial effect of the individual plant extracts in both the ethanol and aqueous extracts. The potency of the individual extracts and the combined effect may be due to the presence of flavonoids, alkaloids, phenols, tannins and saponins in the leaves of the plants.  This study partly validates the use of the plant extracts in the treatment of disease caused by the enteric bacterial isolates by multiple traditional medicine practitioners in Nigeria, however, strict adherence to dosage is recommended.  The leaf extract is a potential source of the new drug if the components are purified and enhanced for treating infections caused by these enteric pathogens.

Ocimum gratissimum, Gongronema latifolium, enteric bacterial isolates, antibacterial activity, plant extract

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Awomukwu, D., Anumudu, C., & Ogbolosingha, A. (2019). Comparative Antibacterial Analysis and Synergistic Potency of the Leaf Extracts of Ocimum gratissimum Linn. and Gongronema latifolium Benth. on Some Enteric Bacterial Isolates. European Journal of Nutrition & Food Safety, 11(2), 98-107.
Original Research Article


Canny GO, McCormick BA. Bacteria in the intestine, helpful residents or enemies from within? Infection and Immunity. 2008; 76(8):3360-73.

Bentley R, Meganathan R. Biosynthesis of vitamin K (Menaquinone) in bacteria. Microbiological Reviews. 1982;46(3):241.

Thursby E, Juge N. Introduction to the human gut microbiota. Biochemical Journal. 2017;474(11):1823-36.

Batt RM, Rutgers HC, Sancak AA. Enteric bacteria: Friend or foe? Journal of Small Animal Practice. 1996;37(6):261-7.

Allocati N, Masulli M, Alexeyev M, Di Ilio C. Escherichia coli in Europe: An overview. International Journal of Environmental Research and Public Health. 2013;10(12): 6235-54.

Davin-Regli A. Enterobacter aerogenes and Enterobacter cloacae; versatile bacterial pathogens confronting antibiotic treatment. Frontiers in Microbiology. 2015; 6:392.

Kaur A, Kapil A, Elangovan R, Jha S, Kalyanasundaram D. Highly sensitive detection of Salmonella typhi in clinical blood samples by magnetic nanoparticle-based enrichment and in-situ measurement of isothermal amplification of nucleic acids. PloS One. 2018;13(3): e0194817.

Hugo WB, Russell AD, editors. Pharmaceutical microbiology. Oxford: Blackwell Science; 1998.

Omaye ST. Food and nutritional toxicology. CRC Press; 2004.

Okwu DE. Phytochemicals, vitamins and mineral contents of two Nigerian medicinal plants. International Journal of Molecular Medicine and Advance Sciences. 2005; 1(4):375-81.

Edeoga HO, Eriata DO. Alkaloid, tannin and saponin contents of some Nigeria medicinal plants. Journal of Medicinal Aromatic Plant Science. 2001;23:344-9.

Edeoga HO, Okwu DE, Mbaebie BO. Minerals and nutritive value of some Nigerian medicinal plants. Journal of Medicinal and Aromatic Plant Science. 2003;25:1010-5.

Edeoga HO, Okwu DE, Mbaebie BO. Phytochemical constituents of some Nigerian medicinal plants. African Journal of Biotechnology. 2005;4(7):685-8.

Ijeh II, Omodamiro OD, Nwanna IJ. Antimicrobial effects of aqueous and ethanolic fractions of two spices, Ocimum gratissimum and Xylopia aethiopica. African Journal of Biotechnology. 2005; 4(9):953-6.

Eleyinmi AF. Chemical composition and antibacterial activity of Gongronema latifolium. Journal of Zhejiang University Science B. 2007;8(5):352-8.

Jimoh OR, Olaore J, Olayaki LA, Olawepo A, Biliaminu SA. Effects of aqueous extract of Ocimum gratissimum on haematological parameters of Wistar rats. Biokemistri. 2008;20(1)33-7.

Ugochukwu NH, Babady NE. Antioxidant effects of Gongronema latifolium in hepatocytes of rat models of non-insulin dependent diabetes mellitus. Fitoterapia. 2002;73(7-8):612-8.

Morebise O. A review on Gongronema latifolium, an extremely useful plant with great prospects. European Journal of Medicinal Plants. 2015;10(1):1-9.

Osuagwu GG, Nwosu M. The effect of inorganic fertilizer (N: P: K) on alkaloid, cyanogenic glycosides, saponin and tannin contents of Ocimum gratissimum (Nchanwu) and Gongronema latifolium (Benth)(Utazi). Journal of Sustainable Agriculture and the Environment. 2006; 8(2):148-55.

Hutchinson J, Dalziel MD. Flora of West Tropical Africa. Crowns Agents, London, UK. 1963;2.

Chen Y, Xie MY, Gong XF. Microwave-assisted extraction used for the isolation of total triterpenoid saponins from Ganoderma atrum. Journal of Food Engineering. 2007;81(1):162-70.

Harborne AJ. Phytochemical methods: A guide to modern techniques of plant analysis. Springer Science & Business Media; 1998.

Trease E, Evans WC. Pharmacognosy, Williams Charles Evans. Balliere; 2004.

Cheesbrough M. District laboratory practice in tropical countries. Cambridge university press; 2006.

Atlas RM, Parks LC. Principles of Microbiology. WCB McGrill-Hill, New York, NY; 1997.

Usman H, Haruna AK, Akpulu IN, Ilyas M, Ahmadu AA, Musa YM. Phytochemical and antimicrobial screenings of the leaf extracts of Celtis integrifolia Lam. J. Trop. Biosci. 2005;5(2):72-6.

UNESCO. Culture and health, orientation texts-world decade for cultural develop-ment 1988-1997. Document CLT/DEC/ PRO-1996; 1996.

Akinmoladun AC, Ibukun EO, Afor E, Obuotor EM, Farombi EO. Phytochemical constituent and antioxidant activity of extract from the leaves of Ocimum gratissimum. Scientific Research and Essays. 2007;2(5):163-6.

Nweze EI, Eze EE. Justification for the use of Ocimum gratissimum L in herbal medicine and its interaction with disc antibiotics. BMC Complementary and Alternative Medicine. 2009;9(1):37.

Talabi JY, Makanjuola SA. Proximate, phytochemical, and In vitro antimicrobial properties of dried leaves from Ocimum gratissimum. Preventive Nutrition and Food Science. 2017;22(3):191.

Macready AL, George TW, Chong MF, Alimbetov DS, Jin Y, Vidal A, Spencer JP, Kennedy OB, Tuohy KM, Minihane AM, Gordon MH. Flavonoid-rich fruit and vegetables improve microvascular reactivity and inflammatory status in men at risk of cardiovascular disease—FLAVURS: A randomized controlled trial. The American Journal of Clinical Nutrition. 2014;99(3):479-89.

Udochukwu U, Omeje FI, Uloma IS, Oseiwe FD. Phytochemical analysis of Vernonia amygdalina and Ocimum gratissimum extracts and their antibacterial activity on some drug resistant bacteria. American Journal of Research Communication. 2015;3(5):225-35.

Sakharkar P, Chauhan B. Antibacterial, antioxidant and cell proliferative properties of Coccinia grandis fruits. Avicenna Journal of Phytomedicine. 2017;7(4):295.

Usoh IF, Akpan HD. Antioxidative efficacy of combined leaves extracts of gongronema latifolium and ocimum gratissimum on Streptozotocin-induced diabetic rat models. International Invention Journal of Medicine and Medical Sciences. 2015;2(6):88-95.

Tariq MO, Gore M, Aruna K. Antibacterial and synergistic activity of ethanolic ajwain (Trachyspermum ammi) extract on ESBL and MBL producing uropathogens. International Journal of Pharmacy and Pharmaceutical Science. 2014;6(6):278-84.