Phenolic profile and inhibitory activity of leafy vegetables against enzymes related to stress induced diseases: A comparative study

Leafy vegetables have immense medicinal properties apart from their nutrient contents. So, extracts of fourteen leafy vegetables of India were studied for their properties to inhibit enzymes that are involved in different stress induced diseases such as diabetes, obesity and associated diseases, neurodegenerative diseases, hepatic disorders. The extracts were examined for their inhibition properties against α-glucosidase, α-amylase, lipase, acetylcholinesterase and β- glucuronidase. Most of the extracts inhibited the enzymes in concentration dependent manner, except a few which showed less or no activity. Among all the tested species, only Bauhinia acuminata exhibited α-amylase inhibition with a high IC50 value of 465.578.81 g/ml. Bacopa monnieri had highest α-glucosidase inhibition property. Lipase inhibitory activities of the extracts of Ipomoea aquatica, Nyctanthes arbortristis, Moringa oleifera, Centella asiatica and Hygrophila schulli were found to be significantly higher than that of orlistat. Methanolic extracts of Nyctanthes arbortristis, followed by Ipomoea aquatica, Bauhinia accuminata, Hygrophila schuli, and Trigonella foenum-graecum showed promising activity against acetylcholinesterase. However, the activities were lower than that of the well-known acetylcholinesterase inhibitor galanthamine. Coriandrum sativum, Enhydra fluctuans, Hygrophila schulli, Ipomoea aquatica, Nyctanthes arbortristis, Paederia foetida, and Trigonella foenum-graecum were found to have higher β- glucuronidase inhibition properties than silymarin, a plant sourced β-glucuronidase inhibitor. Gas chromatography - mass spectrometry indicated the presence of different phenolic constituents having enzyme inhibition properties in the plants.