Objective: To evaluate the in vitro anti-diabetic effects of Bryonia dioica roots extracts, including water-acetone extracts and their ethyl acetate and butanol fractions, and chloroform-methanol extracts. Methods: The total phenolic, flavonoid, flavonol, and saponin contents in the Bryonia dioica root extracts (chloroform-methanol extracts, water-acetone extracts and their ethyl acetate and butanol fractions) were determined using colorimetric methods with Folin-Ciocalteu, aluminum trichloride, and vanillin reagents, respectively. The in vitro anti-diabetic activity was evaluated by measuring the half-maximal inhibitory concentration (IC50) values of these root extracts against α-amylase and α-glucosidase activities, evaluating their effects on α-amylase kinetics, quantifying the inhibition of bovine serum albumin (BSA) glycation using fluorometry to assess advanced glycation end products (AGE) production, and determining glucose uptake by isolated rat hemidiaphragm. Additionally, molecular docking analysis was conducted to investigate the binding affinity and interaction types between Bryonia dioica ligands (cucurbitacin B, bryogénin, vitexin, and isovitexin) and target enzymes, and a phytochemical-targets interaction network was constructed. Results: For α-amylase inhibition, ethyl acetate fraction demonstrated the most potent activity (IC50 = 145.95 µg/mL), followed by chloroform-methanol extract (IC50 = 300.86 µg/mL). Water-acetone root extracts and their ethyl acetate and butanol fractions inhibited the α-glucosidase activity with IC50 values ranging from 562.88 to 583.90 µg/mL. Both ethyl acetate and butanol fractions strongly inhibited non-enzymatic BSA glycation (IC50 = 318.26 and 323.12 µg/mL, respectively). The incubation of isolated rat hemidiaphragms with the ethyl acetate fraction (5 mg/mL) significantly increased glucose uptake (35.16%; P < 0.0001), exceeding the effects of insulin (29.27%), chloroform-methanol extract (24.07%), and catechin (15.27%). Molecular docking revealed that cucurbitacin B exhibited the strongest docking scores against α-amylase (– 16.4 kcal/mol), and α-glucosidase (– 14.2 kcal/mol). Compared with other ligands, isovitexin formed the maximum number of hydrogen bonds with the α-amylase active site residues (Asp300, Asp197, and Glu233), α-glucosidase residues (Ser13, Arg44, Met86, Gly10, Asp39, and Tyr131) and other residues (Arg195, Trp59, His299, and Tyr62). Network analysis identified 36 overlapping targets between Bryonia dioica phytochemicals and type 2 diabetes mellitus-associated genes, with cucurbitacins and polyphenols interacting with α-amylase, α-glucosidase, and Glut4 translocation pathway targets. Conclusion Bryonia dioica root extracts demonstrated promising in vitro anti-diabetic activity through multiple mechanisms, including the inhibitory effect on digestive enzymes, protein antiglycation potential, and enhancement of glucose uptake, suggesting their potential as a source for anti-diabetic drugs development.

OBJECTIVETo study the phytochemical screening of different extracts from Citrullus colocynthis (C. colocynthis ) seeds extracts and to assess their antioxidant activity on the DPPH free radical scavenging.

METHODSPhytochemical screening, total content of polyphenols and flavonoids of C. colocynthis seeds extracts, including a crude aqueous extract (E1), a defatted aqueous extract (E2), a hydromethanolic extract (HM), an ethyl acetate extract (EA) and a n-butanol extract (n-B) was carried out according to the standard methods and to assess their corresponding effect on the antioxidant activity of this plant.

RESULTSNone of these extracts contained detectable amount of alkaloid, quinone, antraquinone, or reducing sugar. Catechic tannins and flavonoids were abundant in E1, HM and EA, whilst terpenoids were abundantly present in E1 and n-B but only weekly in HM. Coumarins were found in E2, EA and n-B. Polyphenols, expressed as gallic acid equivalent, amounted, per 100 g plant matter, to 329, 1002 and 150 mg in EA, HM an E1 respectively. Flavonoids, expressed as catechin equivalent, amounted, per 100 g plant matter to 620, 241 and 94 mg in EA, HM and E1 respectively. Comparable values were found in n-B and E1, with lower values in E2. Quercetin, myricetin and gallic acid were found in the EA and HM extracts by thin layer chromatography, The antioxidative effect of these extracts yielded, when tested at a concentration of 2 000 µg/mL in a 1,1-diphenyl-2-picrylhydrazyl assay, a reducing percentage of 88.8% with EA, 74.5% with HM and 66.2% with E1, and corresponding IC50 of 350, 580 and 500 µg/mL as compared to 1.1 µg/mL for ascorbic acid.

CONCLUSIONSThese qualitative and quantitative analytical data document the presence in C. colocynthis extracts of such chemical compounds as flavonoids responsible for the antioxidant activity, as well as other biological activities of this plant.

Antioxidants ; chemistry ; pharmacology ; Biphenyl Compounds ; chemistry ; Citrullus colocynthis ; chemistry ; Free Radical Scavengers ; chemistry ; pharmacology ; Oxidation-Reduction ; drug effects ; Picrates ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Seeds ; chemistry