Antioxidant, Diabetic and Inflammatory Activities of Alpinia calcarata Roscoe Extract

Background: Alpinia calcarata (AC) Roscoe of Zingiberaceae popularly known as lesser galangal has a widespread occurrence in China, India, Sri-Lanka, Bangladesh, Malaysia, Indonesia and Thailand. Essential oil (Eoil) was obtained from leaves/rhizomes of AC via hydro-distillation process. Methods: To identify chemical ingredients in oil from leaves/rhizomes of AC through GC/MS technique for volatile components and their anti-oxidant, inflammatory/diabetic activities. Results: The 38 and 65 components were found to make up 99.9 and 99.6 %, respectively in total of Eoil composition of AC leaves/rhizomes. Key chemical constituents were eucalyptol (28.7 % in leaves; 25.4 % in rhizomes), camphor (12.8 % in leaves; 4.2 % in rhizomes), and carotol (9.8 % in leaves; 5.6 % in rhizomes) found in oil of AC leaves/rhizomes. Colorimetric assay showed anti-oxidant activities in leaves and rhizomes are IC50=71.01 +/- 0.71 mu g/mL and IC50=73.83 +/- 0.49 mu g/mL, respectively in the Eoils. Eoils had high anti-oxidant capabilities in IC50-values of AC-L-Eoil=43.09 +/- 0.82&AC-Rh-Eoil=68.11 +/- 0.87 in reducing power in mu g/mL was found. Albumin test of rhizome oil had IC50-values of 15.19 +/- 0.25 mu g/mL. Concentrations range of 7.81 mu g/mL and 250 mu g/mL in the Eoils of AC leaves and rhizome, respectively by alpha-glucosidase inhibition assay. Conclusion: Our findings demonstrated that leaf oil was slightly more promising results than rhizome oil of AC extract, which was ultimately showed medicinal potential of secondary metabolites with anti-oxidant, diabetic/inflammatory activities. Further, Eoils of AC have a wide range of pharmacological potential and promising anti-diabetic effects.