Phytochemical screening and free radical scavenging activity of Citrullus colocynthis seeds extracts

Objective:To 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.Methods:Phytochemical 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.Results:None of these extracts contained detectable amount of alkaloid,quinone,antraquinone,or reducing sugar.Catechic tannins and flavonoids were abundant in E1,MM 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 2000μg/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 IC_(50)of 350,580and 500μg/mL as compared to 1.1μg/mL for ascorbic acid.Conclusions:These 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.

Anomeric specificity of D-glucose metabolism study in rat and human erythrocytes

The anomeric specificity of D-glucose metabolism in erythrocytes has been since 1985 the matter of extensive investigations reported in about ten publications. The present report aims at providing an integrated review of the major findings on this issue.

Physiopathology of parotid cell energetics

Attention was recently drawn to the production of D-glucose by salivary glands and its concentration in the saliva of both normal and diabetic subjects. Likewise, the identity and expression of selected transporters involved in the handling of the hexose by salivary glands were recently investigated in both normal and diabetic rats. In consideration of this information, the present report aims at providing an integrated review on the physiopathology of parotid cell energetics.

Effects of Citrullus colocynthis Seed Aqueous Extracts upon Sodium Transport across A6 Kidney Cell Monolayers

Background:Various extracts from Citrullus colocynthis seeds were recently examined for their possible favorable effects on glucose homeostasis,other metabolic variables,and pancreatic islet size in streptozotocin-induced diabetic rats.Objective:Considering the effectiveness of insulin upon target cells as another process susceptible to be influenced by plant extracts,the present study is used to compare the effects of either crude or defatted aqueous extracts from C.colocynthis seeds upon Na+transport in A6 kidney cells.Method:The intensity of electrical currents,taken as the potential difference divided by the epithelial resistance was measured in monolayers of A6 kidney cells exposed at the basolateral side to either crude untreated aqueous(EI)or defatted aqueous(EII)extracts,as well as their fractions EI1 and EII1 containing components with high molecular weight(>5 kDa),and EI2 and EII2 containing components with low molecular weight(<5 kDa).The effect of insulin was to assess the functional integrity of the A6 monolayer.Results:All extracts caused a rapid and sustained increase in current intensity.The defatted aqueous extract(EII)was more efficient than the non-defatted aqueous extract(EI)in terms of increasing the intensity of current in the A6 monolayer.The components of the defatted aqueous extract responsible for such a greater efficiency were located in the fraction containing components with low molecular weight and acted in a time-related progressive fashion upon Na+transport.Conclusion:These data suggest that colocynth seed extracts mainly containing components with low molecular weight increased the current intensity in A6 cells,thus suggesting that colocynth may affect Na+transport in kidney cells.