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  • Author: Amar Zellagui x
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Abstract

The current study investigated the protective effect of Hertia cheirifolia L. n-butanol extract on oxidative stress in vitro by measuring lipid peroxidation (MDA) level and superoxide anion (O2 •-) production in liver and heart mitochondria of rat. In addition, the antioxidant potential of H. cheirifolia n-butanol extract was evaluated by using five methods: ABTS•+, O2 •-, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. The results indicated that n-butanol extract contained large amounts of total phenolics (203.52±1.81 mg GAE/g) and flavonoids (104.86±0.57 mg QE/g), and had an interesting antioxidant activity and protective effect on mitochondrial oxidative stress. Therefore, H. cheirifolia n-butanol extract may serve as potential source of natural antioxidant for pharmaceutical applications.

Abstract

Guava (Psidium guajava L.) is a fruit tree largely used in folk medicine in tropical and subtropical areas. This exotic species was introduced in a botanical garden in the northeast of Algeria in the 1950’s. The aim of this study is to estimate, for the first time, the antioxidant and anticholinesterase activities of chloroform, ethyl acetate and n-butanol extracts of P. guajava growing in Algeria. Six antioxidant assays were tested, results showed very important efficiency in free radical scavenging, reducing power and β-carotene bleaching of tested extracts. Values of IC50 or A0.5 of some samples were lower than those of standards. With regard to anticholinesterase activity, the inhibitory of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was investigated. The extracts exhibited interesting capacity to inhibit these enzymes with low values of IC50 and even less than that of galanthamine. These activities were correlated with total phenolic content which was more important compared to the one found in extracts from trees growing in tropical and subtropical region. This could be due to resistance and adaptation of P. guajava grown in Algeria. The data obtained suggest the use of bioactive compounds from P. guajava leaves as antioxidant and drugs for symptomatic treatment of Alzheimer disease.

Abstract

The essential oils obtained by hydrodistillation of aerial parts of Centaurea dimorpha Viv. were analyzed by means of gas chromatography-mass spectrometry (GC-MS). The main constituents were Caryophyllene oxide (09.88%), limonene (5.73%), tetradecanoic acid (5.68%), spathulenol (5.44%), methyl hexadecanoate (4.45%), and α-pinene (03.08%). To our best knowledge this is the first study of essential oils from the aerial parts of Centaurea dimorpha growing in Algeria. Moreover the essential oil and methanolic extract were screened for their possible in vitro antioxidant activity by DPPH free radical-scavenging test. The findings showed that the percentage inhibition is 10.67 and 77.01 respectively at a concentration of 1mole/L.

Abstract

In this study, phenolic compounds from Crithmum maritimum L. n-butanol soluble fraction were quantified and identified spectrophotometrically and by using HPLC-DAD technics. They equally investigated for their antioxidant potential utilizing six in vitro assays: DPPH, ABTS•+, O2 •−, Bleaching of β-carotene in linoleic acid, CUPRAC and Ferric reducing power. High amounts of total phenolics and flavonoids were recorded: 161.57± 0.479 μg GAeq.mg−1 and 31.56± 0.291 μg Qeq.mg−1 respectively. Nine compounds among them hydroxicinnamic acid and hydroxybenzoic acid derivatives, coumarins and flavonoids were identified. Chlorogenic acid known for their various pharmacological properties was detected as major compound of the extract. Rutin, vanillin, trans-2-hydroxycinnamic acid, ellagic acid, ferrulic acid, 6,7 dihydroxy coumarin, methyl 1,4 benzoquinone and trans-cinnamic acid were also detected. The extract was found to exhibit strong antioxidant capacities in all systems. Based on these results, it is right to conclude the n-butanol extract is promising source of natural antioxidants.

Abstract

The aerial parts of T. gallica collected from three different locations (arid, humid and semi-arid) were extracted using ethyl acetate. The crude extracts were subjected to phenolic appraisal and antiproliferative activity using ELISA and xCELLigence assays. The total phenolic and flavonoids were evaluated using appropriate techniques to give a yield of total phenolics ranging between 238.46 and 348.56 mg GAE (Gallic acid equivalent)/g dry weight extract. The flavonoids yield was found to vary from 36.6 to 103.14 mg QE (quercetin equivalent)/g dry weight extract. Moreover, the extracts were tested against rat brain tumor (C6) and human cervix carcinoma (HeLa) cell lines and displayed important differences in activity. These disparities highlighted the effect of climatic factors as quality determinants of secondary metabolites and therefore as a key control of the biological therapeutic effect.

Abstract

This study was carried out to determine the phenolic contents as well as to evaluate the antioxidant and antimicrobial activities of Genista microcephala. Total phenolic and flavonoid compounds were quantified. Antioxidant activity was evaluated by various in vitro tests, including Ferric Ion Reducing Activity (FRP), Cuprac Ion Reducing Antioxidant Capacity (CUPRAC), and total antioxidant capacities (TAC). The antimicrobial activity of ethyl acetate and butanolic extracts of G. microcephala in addition of fatty acids content of different parts of the studied plant was evaluated against human pathogenic bacteria, fish bacteria and two yeast. The used methods were agar diffusion method and the determination of minimal bactericidal and fungicidal concentrations (MBC and MFC). No significant difference was found between the two used solvents on total phenolic content (TPC). While, difference in total flavonoid content (TFC) were found to be significant. Ethylene acetate extract was the most actif regarding antioxidant assay. The tested activity seems to be due to the high content of this extract on isoflavonoids. The tested extracts demonstrated the lowest inhibition concentration for B.cereus RSKK 863.

Abstract

The aerial parts of Tamarix gallica L. taken from three different climatic stages in Algeria (Oum El Bouaghi: Semi-arid, ElTaref: Humid, and Ouargla: Arid) were extracted using boiling distilled water. The crude extracts were subjected to total phenolics and flavonoids quantifications in addition to anti-proliferative assessment against two tumor cell lines namely rat brain tumor (C6) and human cervix carcinoma (HeLa) using BrdU (bromo-deoxyuridine) ELISA(Enzyme-linked immune-sorbent assay) and xCELLigence assay. The total phenolics yield was found to range between 16.14 and 39.32 mg GAE (Gallic acid equivalent)/g of extract and a flavonoids yield ranging between 16.51 and 20.35 mg QE(quercetin equivalent)/g of extract. The various phenolics were identified using HPLC-TOF/MS to highlight hesperidin and rosmarinic Acid as major components. Moreover, the extracts exhibited different levels of antitumor potency against C6 and HeLa cell lines depending upon the climatic stage and the concentration. A good cytotoxic effect was recorded with the species collected from the humid region at 250 μg/mL. On the contrary, the other extracts revealed a weak activity for both tests.