African Journal of
Pharmacy and Pharmacology

  • Abbreviation: Afr. J. Pharm. Pharmacol.
  • Language: English
  • ISSN: 1996-0816
  • DOI: 10.5897/AJPP
  • Start Year: 2007
  • Published Articles: 2111

Full Length Research Paper

A comparative anti-inflammatory evaluation of fresh ginger extracts from China and Ghana identifies L-valine as a diagnostic biomarker

Raphael N. Alolga
  • Raphael N. Alolga
  • State Key Laboratory of Natural Medicines, Department of Pharmacognosy, China Pharmaceutical University, No. 639 Longmian Road, Nanjing 211198, China.
  • Google Scholar
Enos Mais
  • Enos Mais
  • State Key Laboratory of Natural Medicines, Department of Pharmacognosy, China Pharmaceutical University, No. 639 Longmian Road, Nanjing 211198, China.
  • Google Scholar
Vitus Onoja
  • Vitus Onoja
  • Department of Pharmaceutics and Pharmaceutical Technology, University of Jos, Plateau State, Nigeria.
  • Google Scholar


  •  Received: 16 November 2017
  •  Accepted: 12 December 2017
  •  Published: 22 December 2017

Abstract

The quality of botanicals has been reported to be influenced by their places of cultivation. Although, ginger remains a common health remedy both in Ghana and China, no comparative study exists to the best of the authors’ knowledge, on the anti-inflammatory properties of ginger from these two countries. The aim of this study was to comparatively assess the anti-inflammatory effect of the methanolic extracts of fresh ginger samples from Ghana and China and identify biomarker(s) that is/are diagnostic of acute inflammation via untargeted metabolomics. A phytochemical assessment of the ginger extracts was initially performed with high performance liquid chromatography- quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS). Low (200 mg/kg) and maximum (400 mg/kg) doses the ginger extracts from each country were assessed using Sprague-Dawley (SD) rats against groups for positive (indomethacin, 10 mg/kg) and negative controls (no drug). Blood samples were taken from the retro orbital vein at four time points: 1, 4, 8 and 24 h after induction of inflammation. The levels of tumor necrosis factor-α (TNF-α) and prostaglandin E2 (PGE2) were determined in the plasma samples. The metabolomics study was also performed with HPLC-QTOF/MS and the data analyzed with MetaboAnalyst 3.0 and SIMCA 14.1. Phytochemical evaluation revealed marked differences in terms of the compounds deemed to have anti-inflammatory activities in the ginger samples from the two countries. Ginger extract from Ghana showed superior anti-inflammatory effects over that from China. In the metabolomics study, L-valine was identified as the diagnostic biomarker of acute inflammation from 8 differential metabolites identified. 
 
Key words: Anti-inflammatory effects, biomarker, ginger, China, Ghana, L-valine, metabolomics.

Abbreviation

SD, Sprague-Dawley; TNF-α, tumor necrosis factor-α; PGE2, prostaglandin E2; HPLC/QTOF-MS, high performance liquid chromatography-quadrupole time-of-flight mass spectrometry; ELISA, enzyme-linked immunosorbent assay; OPLS-DA, orthogonal partial least-squares discrimination analysis; VIP, variable importance in projection; ANOVA, analysis of variance; ACN, acetonitrile; NR, normal rats; NC, negative control; SIMCA, soft independent modelling by class analolgy.