Citrullus colocynthis is widely distributed in the desert regions of the world. C. colocynthis has shown to improve constipation, liver diseases, jaundice, typhoid fever, diabetes and asthma in traditional use. As a kind of exterritorialy medicinal material, C. colocynthis has been used in China and introduced successfully. The main active ingredients of C. colocynthis are cucurbitacin, flavonoids, alkaloids and phenolic acids, which have been proven to have antioxidant, anti-diabetic, anti-pathogenic microorganisms and anti-cancer activities in modern pharmacological research. This paper reviews the traditional application, chemical composition and pharmacological effects of C. colocynthis, and provides reference for the in-depth study for the efficacy and mechanism of different components of C. colocynthis.
China ; Citrullus colocynthis/chemistry* ; Drugs, Chinese Herbal/pharmacology* ; Phytochemicals/pharmacology*

Three new cucurbitane-type triterpenoid glycosides were separated from the ethyl acetate extract of Citrullus colocynthis by a variety of chromatographic techniques. According to the data of NMR, HR-ESI-MS, and/or comparison with the reported data, the three novel cucurbitane-type triterpenoid glycosides were identified as colocynthenin E(1), colocynthenin G(2), and colocynthenin H(3). The cell inflammation model was established with RAW264.7 macrophages exposed to lipopolysaccharide and then used to determine the anti-inflammatory activities of the three compounds. Compounds 2 and 3 showed mild anti-inflammatory activities with the IC_(50) of 48.21 and 40.11 μmol·L~(-1), respectively, compared with that(IC_(50)=7.57 μmol·L~(-1)) of the positive control dexamethasone.
Citrullus colocynthis/chemistry* ; Triterpenes/chemistry* ; Glycosides/chemistry* ; Plant Extracts/chemistry* ; Anti-Inflammatory Agents/pharmacology*

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