ABSTRACT
Trigonella foenum-graecum has been extensively used for centuries in traditional medicine systems for the cure of health ailments including diabetes. Improving the medicinal attributes of plants through the elicitation strategy is gaining great interest in the recent past. In the current study, an attempt is made to reveal the role and possible mechanism of action of vitamin C elicit phytochemical-rich aqueous extract of 4th day germinated IM6 genotype fenugreek sprouts in the form of lyophilized powder (IM6E) under both in vitro and in vivo conditions. The IM6E demonstrated strong α-glucosidase activity (95.24 %) and moderate α-amylase and invertase inhibition activities under in vitro conditions. The High Performance Thin Layer Chromatography (HPTLC) based analysis demonstrated that IM6E possess significantly higher concentration of phenolic phytochemical quercetin (0.148 %) as compared to diosgenin and trigonelline bioactive anti-diabetic nutraceuticals. In normal rats after loading with glucose and sucrose, the IM6E administration in a dose-dependent manner significantly reduced the post-prandial hyperglycemia, in a similar fashion as the anti-diabetic drug voglibose as evident from the area under curves (AUC) of oral glucose tolerance test (OGTT) and oral sucrose tolerance test (OSTT) tests. The administration of IM6E in streptozotocin (STZ) induced diabetic rats drastically improved the antioxidant activity of plasma in them as determined by Ferric Reducing Ability of Plasma (FRAP) and the effect was found to be dose-dependent. The oral administration of IM6E in diabetic rats normalized almost all the deregulated biochemical markers like liver enzymes, lipids and significantly decreased higher blood glucose levels with increasing insulin levels as compared to diabetic control. The best concentration of IM6E was found to be 300 mg/kg b.w after 21 days of experimentation. The intra-peritoneal glucose tolerance test (IPGTT) in diabetic rats responded very well to IM6E treatment and 100 mg/kg.b.w. behaved almost like the administration of 0.5U insulin/kg bw, and thus indicating the insulinotropic nature of IM6E. Our findings clearly reveal the use of IM6E for diabetes management and at the same it possesses great potential when combined with voglibose to ameliorate diabetes and its associated complications to a greater extent due to synergistic effects as compared to monotherapy. However, more clinical trials need to be performed before recommending IM6E as an anti-diabetic alternative medicine.
ABSTRACT
Taraxacum officinale (T. officinale), a wild vegetable with a number of health claims, has been mostly ignored and unexplored. The study aims to compare the nutritional, phytochemical as well as antidiabetic potential of fresh as well as shade-dried leaves of T. officinale, in order to recommend its best form as a dietary antidiabetic product. The results revealed that as compared to fresh leaves, the shade-dried leaves, in addition to possessing higher levels of carbohydrates, crude protein, crude fat, crude fiber, etc., also contain appreciable amounts of total phenols (5833.12 ± 4.222 mg/100), total flavonoids (188.84 ± 0.019 mg/100 g), ascorbic acid (34.70 ± 0.026 mg/100 g), ß-carotene (3.88 ± 1.473 mg/100 g) and total chlorophyll (239.51 ± 0.015 mg/100 g) antioxidants. The study revealed the presence of medicinally important antidiabetic flavonoid quercetin present in T. officinale leaves. Among the three solvent systems used, the aqueous extract of shade-dried T. officinale leaves comparatively demonstrated potent antidiabetic activity under in vitro conditions in a dose-dependent manner via targeting α-amylase and α-glucosidase, the two potent enzymes of carbohydrate metabolism. Therefore, in addition to being a nutritious herb, the shade-dried leaves of T. officinale have great potential to suppress post-prandial glucose rise and can be better exploited through clinical trials to be used as a dietary intervention for better management of diabetes.
