Anti-inflammatory actions and Salmonella typhimurium-bacteraemia clearance by methanol extract of Curcuma longa Linn. (Turmeric)

ABSTRACT

Aims@#Rhizome of turmeric is known to possess therapeutic activities and has been used in medical practice as an anti-diabetic, hypolipidemic, hepatoprotective, anti-diarrheal, and anti-asthma agent. This study was designed to investigate the anti-inflammatory and antimicrobial activities of Curcuma longa. @*Methodology and results@#Rhizomes of Curcuma longa (Turmeric) purchased from markets in Ado-Ekiti, Nigeria, were analysed for anti-inflammatory and anti-microbial properties, as well as phytochemical constituents. The in vitro anti-inflammatory activities of the C. longa methanol extract (CLME) were evaluated by albumin denaturation, proteinase inhibitory activity, membrane stabilization, and anti-lipoxygenase activity, at different concentrations using Aspirin, Diclofenac sodium and Indomethacin as standard drugs. The in vitro antimicrobial activities of CLME were carried out on five pathogenic microbes namely Escherichia coli ATCC 29929, Staphylococcus aureus ATCC 29293, Salmonella typhimurium ATCC 14028, Klebsiella pneumoniae ATCC 4252 and Candida albicans ATCC 10231, using both agar well diffusion and broth dilution techniques. A S. typhimurium infected rat model was used for in vivo antimicrobial studies. Phytochemical analyses showed that C. longa rhizomes contain high concentrations of alkaloids, flavonoid and saponins, with moderate levels of phenols, tannin and ferric reducing antioxidant power. CLME was found to be rich in alkaloids, tannins, phenols, steroids, saponins, terpenoids, flavonoids and reducing sugars. CLME showed potent anti-inflammatory activities, and the results compared favourably with the standard anti-inflammatory drugs used. C. longa methanol extract significantly inhibited albumin denaturation and proteinase activity, stabilized membrane of red blood cell from haemolysis in heat and hypotonic conditions, as well inhibited lipoxygenase activity; all of which are associated with inflammatory processes. CLME was found to possess high in vitro antimicrobial activities against the five microorganisms tested. Rats orally infected with S. typhimurium, demonstrated bacteraemia five days post infection, with a total clearance of bacteraemia within 3-5 days following oral administration of CLME. The infected rats treated with CLME equally showed significant improvement in some haematological indices compared to infected rats that were not treated with CLME. @*Conclusion, significance and impact of study@#The results also showed that methanol extract of C. longa rhizome effectively cured with S. typhimurium infected rats. The overall results suggest that Curcuma longa is a potential source of anti-inflammatory and antimicrobial agents.