phytochemicals

Diabetes mellitus is a chronic metabolic disorder characterized by sustained hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Enzyme inhibition of α-amylase and α-glucosidase is a proven therapeutic strategy to attenuate postprandial glucose surges. Although synthetic inhibitors such as acarbose are widely used, their gastrointestinal side effects have stimulated interest in natural dietary alternatives. The present study investigates the phytochemical composition and in vitro antidiabetic activity of ethanolic extracts from five rice varieties: Mapillai Samba, Red Rice, Karuppu Kavuni, Karudan Samba, and Ponni Rice. Extracts were prepared using Soxhlet extraction and evaluated for α-amylase and α-glucosidase inhibition across concentrations ranging from 10 to 500 µg/mL, with acarbose serving as the reference inhibitor. Qualitative phytochemical screening revealed that all varieties contained alkaloids and flavonoids, while pigmented rice types exhibited higher diversity of secondary metabolites. In enzyme assays, Karuppu Kavuni showed the strongest inhibitory activity (91.40% for α-amylase and 91.10% for α-glucosidase at 500 µg/mL), closely comparable to acarbose (93.25% and 95.16%, respectively). Red Rice and Mapillai Samba demonstrated moderate activity, whereas Ponni Rice showed the least inhibition. Statistical analysis confirmed significant differences between rice varieties (p < 0.05). These findings suggest that pigmented rice varieties, particularly Karuppu Kavuni, may serve as functional foods or nutraceutical sources for managing postprandial hyperglycemia. Future in vivo validation and phytochemical characterization are warranted.

Phytochemical characterization of plants is an important task in medicinal botany and drug discovery. In the current study, Catharanthusroseus is considered as medicinal plants by evaluation of phytochemical composition. Methanolic extract of the leaves of C. roseus was prepared by soxhlet extraction. The extract was used to detect the presence of different phytochemicals like alkaloids, phenols, flavonoides, tannin, lignin, steroids, glycosides, saponins, terpenoides and anthraquinone by their biochemical tests. Alkaloids, tannin, steroids, glycosides were found to be present in methanolic extract of C.  roseus.

Green beans contain high concentration of polyphenols, carotenoids, ascorbic acids, tocopherol and flavonoids which fight against oxidative damage. Free radicals have been implicated in the pathogenesis of most diseases. Thus, the consumption of dietary antioxidants from vegetables and fruits is beneficial in preventing these diseases. The present study was undertaken to evaluate antioxidant potential of ethanolic extracts of four different species of green beans. Ethanolic extract of Phaseolus vulgaris (french bean), Vicia faba (broad bean), Cyamopsis tetragonoloba (cluster bean) and Vigna unguiculata (cowpea) were studied for antioxidant properties by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, H2O2 decomposition, reducing power ability assay. Total phenolic content was measured by Folin Coilteau reaction and flavonoid contents were determined by AlCl3 assay. Efforts were made to study the iron chelation. Total phenol content ranged from 17.00 ± 0.004 to 53± 0.007 µg GAE/mg while total flavonoid ranged 22 ± 0.003 to 36 ± 0.006 µg QE/ mg. All the extracts scavenged DPPH radical, decomposed H2O2 and had significant reducing potential. The IC50 for DPPH scavenging activity was highest for Vigna unguiculata as 2.27 ± 0.19 mg/ml while lowest for Vicia faba as 0.18± 0.02 mg/ml. All the extracts chelated Fe2+ form of iron but not Fe3+. A positive and strong correlation (r2 = 0.9) between total phenolic content & antioxidant activity suggests that green beans have enormous potential to enhance antioxidant capacity of our daily food supply and may provide health benefits in oxidative stress as neutraceuticals.