Phytochemical, Antimicrobial and Acute Toxicity Studies on Methanolic Extracts of Citrus medica L. and Citrus hystrix D. C. Fruits

Aim: The present study aims to investigate the phytochemical, antimicrobial and acute toxicity assay of methanol extract of Citrus medica L. fruit (CMF) and Citrus hystrix D.C. fruit (CHF).

Place and Duration of Study: Fruit samples were collected between February to August 2018, at the Department of Life Sciences, Manipur University.

Methodology: Phytochemical studies were conducted using Gas Chromatography-Mass Spectrometry (GC-MS), HR-LC-MS (High Resolution-Liquid Chromatography-Mass Spectrometry), Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) respectively. The standard filtered disc-diffusion method was used for antimicrobial assay. Acute toxicity was performed using 423-OECD guidelines.

Results: GC-MS and HR-LC-MS analysis showed presence of Ranitidine, 4-Methylesculetin, Diosmin and Avobenzone in CMF whereas 9-Octadecenamide, Gamma-Sitosterol, n-Hexadecanoic acid, 2-Methoxy-4-Vinylphenol, Rhoifolin, Diosmin and Phytosphingosine in CHF. GF-AAS and ICP-OES study prominently showed Pb content in both the samples. Highest element in CMF was Pb (4.26±0.120 ppm) while in CHF was Cr (4.35±0.70 ppm). Antimicrobial study exhibited highest inhibitory effect of CMF against Staphylococcus aureus and Klebsiella pneumonia while CHF against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus than Gentamicin (p<0.05). No toxicity behaviour and mortality in mice were observed during acute toxicity study period even at a dose of 5000 mg/kg body weight. Changes in serum constituent level were observed however, no genotoxicity was recorded.

Conclusion: We concluded that CMF and CHF cultivation site selection should be the first step to avoid Pb content. The CMF and CHF have many health beneficial constituents. From this study also concluded that CMF and CHF may be a potential source of antiulcer, antimicrobial, antiarthritic, diuretic, antiinflammatory and anticancer effects. However, further study to understand whether changes in serum constituent level for prolonged period usages as medicine or nutraceuticals is highly recommended.