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, 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 IC 50 of 350, 580 and 500 μg/mL as compared to 1.1 μg/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. Contents lists available at ScienceDirectPeer reviewer C h e r i t i A b d e l k r i m , P r o f e s s o r , D e p a r t m e n t o f C h e m i s t r y ,

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In the light of previous findings, the major aim of the present study was to investigate the potential beneficial effects of various Citrullus colocynthis L. seed extracts on such variables as glucose tolerance, body weight gain, pancreas, liver, kidney, testis, epididymal fat and diaphragm muscle weight, as well as serum cholesterol, triglyceride, urea, creatinine, transaminases and alkaline phosphatase concentrations in an animal model of type-1 diabetes mellitus, i.e. streptozotocin-induced diabetic rats. For purpose of comparison, a comparable study was conducted in normal rats. Both the immediate and long-term effects of the plant extracts were assessed in rats injected daily, up to 3 weeks after the start of the experiments. The results of this study reinforce the view that both a crude aqueous extract and a n-butanol extract from the Citrullus colocynthis L. seeds may represent the best candidates in order to eventually identify a component suitable for the treatment of both type-1 and type-2 diabetic subjects.

Micromeria inodora (Desf.) Benth. is most studied for the antimicrobial activity of their essential oils; nevertheless there are no reports on the phenolic compounds of this species and their antioxidant activity. In this study, aqueous and organic extracts were assayed for their antioxidant activity. The polyphenol and total flavonoid content, varied between 175.50 to 332.62 mg GAE/g extract and 65.38 to 86.30 mg catechin equivalent/g extract, respectively.The results of antioxidant activity have shown that all extracts reported an important activity and the ethyl acetate extract showed the stronger effect, higher than some standards molecules. Its IC 50 value of scavenging DPPH is 1.5 ± 0.001μg/mL; β-Carotene Bleaching assay (BCB) IC 50 = 28.1± 0.001μg/mL and the Ferric Reducing Antioxidant Power (FRAP) IC 50 = 6.96 0.05 μg/mL. RP-HPLCPDA analysis of phenolic compounds revealed the presence of phenolic acids and flavonoids as: gallic acid, quercetin, rutin, vanillin and naringenin.

This study was designed to investigate the antioxidant and antiulcer activities of flavonoid‐rich fractions of Zingiber officinale extract. The fractions, obtained by solvents of increasing polarities, were subjected to 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity. The fraction which possessed the highest antioxidant activity was used to assess gastroprotective action against diclofenac sodium induced gastric ulcer in rats. Chromatographic profiling was carried out using LC‐ESI‐MS analysis. The butanol fraction (BF) showed the strongest antioxidant potential and the results of the in vivo study revealed that BF at 100 mg/kg protected against gastric lesions. At the same dose, BF prevented diclofenac sodium‐induced increase in tumor necrosis factor alpha (TNF‐α) and malondialdehyde (MDA) levels, and depletion of catalase (CAT) activity as well as glutathione (GSH) and prostaglandin E2 (PGE2) contents. LC‐ESI‐MS analysis revealed the presence of 12 phenolic compounds. BF exerted antiulcer action which could be linked to the presence of phenolic compounds. Practical applications Zingiber officinale has been widely consumed as a spice and used in folk medicine for treatment of gastric disorders. This is the first report evaluating the pharmacological effects of the butanol extract of ginger for the prevention of gastric ulcer. The results showed that the extract affords better gastroprotective activity against diclofenac sodium‐induced gastric ulcer in rats by reducing oxidative stress. Information provided in this study will be beneficial for developing applications of ginger in food biotechnology as functional and nutraceutical ingredient.

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