Essential Oil Composition, Antioxidant, Antidiabetic and Antihypertensive Properties of Two Afromomum Species

This study was designed to assess the antioxidant, antidiabetic and antihypertensive effects of essential oils from A. melegueta and A. danielli seeds. The essential oils were extracted via hydrodistillation, dried with anhydrous Na2SO4 and characterized using gas chromatography-mass spectrometry (GC-MS). Antioxidant properties and inhibition of some pro-oxidant induced lipid peroxidation in rats' pancreas and heart homogenates were also determined. The results revealed that eugenol, eucalyptol, α-terpineol, α-caryophyllene and β-caryophyllene were the most abundant components in A. melegueta and A. danielli seeds. The essential oils inhibited α-amylase, α-glucosidase and angiotensin-I-converting enzyme in vitro. A.melegueta oil showed a higher α-amylase and α- glucosidase inhibitory activities with EC50 values of 139.00 µL/mL and 91.83 µL/mL respectively than A. danielli. However, A. danielli oil (EC50 = 48.73 µL/mL) showed the highest ACE inhibitory acivity. The highest NO radical scavenging ability was observed in A. melegueta oil while A. danielli had the highest OH radical scavenging and Fe2+- chelating ability. Furthermore, both essential oils inhibited SNP and Fe2+- induced lipid peroxidation in rats' pancreas and heart respectively in a dose dependent manner. This study reveals the biochemical principle by which essential oils from A. danielli and A.melegueta seed elicits their therapeutic effects on type-2 diabetes and hypertension.