Comparative in Vitro Antioxidant and Enzymatic Inhibitory Activities of Zingiber Officinale Roscoe. And Cymbopogon Nardus (L.) Rendle Essential Oils

Introduction: Diabetes mellitus affects over 400 million people worldwide. Due to the side effects of current anti-diabetic drugs, there is growing interest in natural treatments. Antioxidants help prevent diabetic complications, and inhibiting α-glucosidases and α-amylases significantly reduces post-prandial blood glucose levels. This research aims to examine the bioactive compounds in Zingiber officinale Roscoe. and Cymbopogon nardus (L.) Rendle essential oils using gas chromatography/mass spectrometry (GC/MS) and their antioxidant, as well as α-glucosidase and α-amylase inhibition activities. Methods: The chemical composition of the essential oils was determined by GC/MS analysis. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, while enzyme inhibition was assessed using α-amylase and α-glucosidase assays. Results: The major phytochemical components of Z. officinale essential oil were found to be dodecanoic acid, 1,2,3-propanetriyl ester (37.81%), dodecanoic acid, 1-(hydroxymethyl)-1,2-ethanediyl ester (9.52%), 3-(octanoyloxy)propane-1,2-diyl bis(decanoate) (4.73%), gingerol (3.62%), 1-(4-hydroxy-3-methoxyphenyl)oct-4-en-3-one (1.67%), linalool (1.46%), geranyl acetate (1.03%), zingiberene (1.08%) and farnesene (0.64%). The major phytochemical constituents in the C. nardus are dodecanoic acid, 1,2,3-propanetriyl ester (22.95%), hexadecanoic acid, 2-[(1-oxododecyl)oxy]-1,3-propanediyl ester (2.74%), D-limonene (2.49%), eudesm-11-en-1α-ol (2.01%), α-phellandrene (1.93%), D-citronellol (0.94%), geraniol (0.87%), α-terpineol (0.84%) and citronellal (0.69%). Z. officinale oil demonstrated better antioxidant (55.4%, p< 0.05), α-amylase (39.7%, p<0.05) and α-glucosidase (24.5%, p<0.05) inhibitory activity, respectively, compared to C. nardus oil. Conclusion: This finding indicates that the constituents of Z. officinale essential oil may collectively inhibit oxidative stress and enzymes linked to T2DM, and thus potentially help reduce postprandial glucose levels and diabetes complications. Further in vivo studies are required to validate these findings.