Mitigation of starch and glucose-induced postprandial glycemic excursion in rats by antioxidant-rich green-leafy vegetables′ juice

Abstract

Objective:Consumption of green-leafy vegetables is being advocated beneficial for type 2 diabetes mellitus individuals possibly because they are cost effective source of potent biological antioxidants. This research analyzed various phytochemicals, free radicals scavenging antioxidant potentials and starch digesting enzymes inhibitory activities in fresh juice of nine green-leafy vegetables. Furthermore, this study also investigated influence of these vegetables juice on starch and glucose induced postprandial glycemic load.Materials and Methods:Phytochemical constituents, in vitro free radicals scavenging antioxidant and enzymes inhibitory activities were evaluated applying various reported methods. Post-prandial glycemic excursion was induced in rats pretreated with vegetables juice by oral administration of starch and glucose.Results:All the leafy vegetables juice displayed potent free radicals scavenging activities. Juice of amaranthus, rumex, palak and raphanus displayed potential anti-oxidative property by reducing H2O2 induced hemolysis in rats red blood cells RBCs. Ajwain and rumex juice showed pancreatic α-amylase inhibitory activity. Alternanthera, ajwain, methi, amaranthus and sowa leaves juice displayed intestinal α-glucosidase inhibitory activity. Juice of raphanus, ajwain and sowa significantly mitigated starch-induced postprandial glycemic load. Amaranthus leaves juice potently mitigated glucose-induced postprandial glycemic load and also reduced hemoglobin glycation induced by glucose in vitro.Conclusions:This investigation finds that juice of leafy vegetables is potent source of biological antioxidants. In addition, juice of raphanus, ajwain and sowa leaves possess capacity to mitigate starch induced postprandial glycemic burden and amaranthus leaves’ juice can reduce glucose induced postprandial glycemic excursion.

In vitro studies on the effect of watercress juice on digestive enzymes relevant to type 2 diabetes and obesity and antioxidant activity

“…Similar inhibitory effects towards digestive enzymes have been demonstrated by other vegetable juices (Kumar et al, ; Tiwari et al, ), while other studies (Abirami, Nagarani, & Siddhuraju, ; Lee et al, ; Simsek et al, ) documented stronger inhibitions by vegetables and fruit juices than WJ.…”

“…TPC value of WJ (Table ) was comparable to that of a commercial juice (2.5 mg mL −1 ) (Tabart, Kevers, Pincemail, Defraigne, & Dommes, 2009). Lower TPC and TFC values were found in vegetable juices studied by other authors (0.11–0.58 and 0.08–0.48 mg mL −1 , respectively) (Simsek et al, ; Tiwari et al, ).…”

“…demonstrated by other vegetable juices Tiwari et al, 2013), while other studies (Abirami, Nagarani, & Siddhuraju, 2014;Lee et al, 2013;Simsek et al, 2014) documented stronger inhibitions by vegetables and fruit juices than WJ. The increased free-radical production by oxidative stress is associated with the initiation and progression of diabetes and related complications (Podse R dek et al, 2014;Tiwari et al, 2013). Therefore, supplementation with radical scavenging antioxidants can be useful for prevention and/or reduction of oxidative stress involved in this metabolic disorder.…”

“…The increased free‐radical production by oxidative stress is associated with the initiation and progression of diabetes and related complications (Podsędek et al, ; Tiwari et al, ). Therefore, supplementation with radical scavenging antioxidants can be useful for prevention and/or reduction of oxidative stress involved in this metabolic disorder.…”

“…A diet rich in fruits and vegetables has been associated with several health benefits in humans, not only due to the presence of large amounts of fiber but also to substances with antioxidant activity (Isabelle et al, ; Simsek et al, ; Tiwari et al, ; Vinha, Alves, Barreira, Costa, & Oliveira, ). Vegetable juices are a natural dietary source of polyphenols, often used as a low‐sugar alternative to fruit juice.…”