OBJECTIVE: To investigate the eliminating ability of catechin to eliminate O2-* and *OH. METHODS: The ability of catechin to clear away O2-* and *OH was respectively measured by faintness chemiluminescence and spin trapping assay. RESULTS: IC50 that catechin eliminated O2-* and *OH was 6.16, 0.59 g/mL respectively, and the eliminating ability of catechin was much stronger than that of the extract from liquorice, rosemary, grape pip, giant knotweed and ginkgo leaf. CONCLUSION Compared with several important natural plants of antioxidants, the eliminating ability of cathechin is the best.
Antioxidants ; pharmacology ; Catechin ; pharmacology ; Free Radical Scavengers ; pharmacology ; Hydroxyl Radical ; metabolism ; Luminescent Measurements ; Superoxides ; metabolism

The mechanism responsible for the formation of sunburn cells in mammalian skin is unknown. However it is suggested that the reactive free radicals and oxygen species generated by UV radiation are causing oxidative reactions in certain keratinocytes that are manifestated in the form of dyskeratotic cells and free radical scavengers such as a-tocopherol acetate or p-carotene were thought to be photoprotective against sunburn radiation. In the present study, we evaluated the effect of single and multiple applications of n-tocopherol acetate(a-TCA) and p-carotene on the formation of sunburn cells. We also determined the effect of these two antioxidants on the sunburn reartion by UVB irradiation. The results were as follows : 1. Both a-tocopheroJ acetate and p-carotene were photoprotective and prevented the formation of sunburn cells and sunburn reaction. 2. Topical p-carotene was less photoprotective than u-tocopherol acetate. 3. Topical use of a-tocopherol acetate and p-carotene in dose range exceeding 1,000 pgcm could provide photoprotective effect if the UVB exposure doses were less than 300 mJ/cm'( 3 MED)
Animals ; Antioxidants ; Carotenoids* ; Free Radical Scavengers ; Free Radicals ; Guinea Pigs* ; Guinea* ; Keratinocytes ; Oxygen ; Skin ; Sunburn ; Tocopherols*

OBJECTIVETo compare and elucidate the antioxidant efficacy of ethanolic and hydroethanolic extracts of Indigofera tinctoria Linn. (Fabaceae family).

METHODSVarious in-vitro antioxidant assays and free radical-scavenging assays were done. Quantitative measurements of various phytoconstituents, reductive abilities and chelating potential were carried out along with standard compounds. Half inhibitory concentration (IC50) values for ethanol and hydroethanol extracts were analyzed and compared with respective standards.

RESULTSHydroethanolic extracts showed considerably more potent antioxidant activity in comparison to ethanol extracts. Hydroethanolic extracts had lower IC50 values than ethanol extracts in the case of DPPH, metal chelation and hydroxyl radical-scavenging capacity (829, 659 and 26.7 μg/mL) but had slightly higher values than ethanol in case of SO2- and NO2-scavenging activity (P<0.001 vs standard). Quantitative measurements also showed that the abundance of phenolic and flavonoid bioactive phytoconstituents were significantly (P<0.001) greater in hydroethanol extracts (212.920 and 149.770 mg GAE and rutin/g of plant extract respectively) than in ethanol extracts (211.691 and 132.603 mg GAE and rutin/g of plant extract respectively). Karl Pearson's correlation analysis (r2) between various antioxidant parameters and bioactive components also associated the antioxidant potential of I. tinctoria with various phytoconstituents, especially phenolics, flavonoids, saponins and tannins.

CONCLUSIONThis study may be helpful to draw the attention of researchers towards the hydroethanol extracts of I. tinctoria, which has a high yield, and great prospects in herbal industries to produce inexpensive and powerful herbal products.

Antioxidants ; analysis ; Free Radical Scavengers ; analysis ; Humans ; Indigofera ; chemistry ; Plant Extracts ; chemistry

The average life expectancy in Macau is ranking the second in the world, the consumption of fresh medicinal plants is a profound culture in Macau. The paper focus on the distribution of the antioxidant herbs, a comprehensive investigation and analysis the amount of the plant resources was carried out. The antioxidant activity of alcohol extracts was determined by using the DPPH method, and six kinds fresh herbs with high antioxidant free radical activity were screened out. Reference to adult daily dose of vitamin C, it is calculated that the daily dose amount of fresh herbs is less than 200 g. For the expected shortage of resources and the ecological status of Macau, we give some suggestions of herbal introduction in population ecology reconstruction.
Antioxidants ; pharmacology ; Ecosystem ; Free Radical Scavengers ; pharmacology ; Macau ; Plant Extracts ; pharmacology

AIM: AMany oxidative stress-related diseases occur as a result of the accumulation of free radicals in the body. Free radicals are generated by various endogenous systems, exposure to different physiochemical conditions, or pathological states. A balance between free radicals and antioxidants is necessary for appropriate physiological function. A lot of studies are going on worldwide directed towards finding natural antioxidants of plant origin. FTIR spectroscopy is used to develop a rapid and effective analytical method for studying the main constituents in medicinal plants. The chemical constituents in the plants were identified and monitored for their medicinal properties. The aim of this study was to evaluate the in vitro antioxidant activities and FTIR spectroscopic analysis of the ethanolic extract of Evolvulus alsinoides. METHOD: Free radical scavenging activity of ethanolic extract of the whole plant of E. alsinoides was evaluated by in vitro methods, including total antioxidant assay (FRAP method) and hydrogen peroxide scavenging activity using ascorbic acid as a standard. The degree of lipid peroxidation was examined by estimating the thiobarbituric acid reactive substances (TBARS) using standard methods and the functional groups were analyzed using FTIR spectroscopy. The IR spectrum in the mid-infrared region 4 000-400 cm(-1) was used for discriminatio and to identify various functional groups present in E. alsinoides. RESULTS: The findings indicated the presence of amino acids, amides, amines, carboxylic acids, carbonyl compounds, organic hydrocarbons, and halogens in the ethanolic extract of E. alsinoides, and the antioxidant activities were significantly increased, when compared with the standard antioxidant ascorbic acid, in a dose-dependent manner. CONCLUSION The findings indicated promising antioxidant activity of the crude extract of E. alsinoides, and needs further exploration for their potential effective use.
Antioxidants ; analysis ; Convolvulaceae ; chemistry ; Ethanol ; Free Radical Scavengers ; analysis ; Plant Extracts ; analysis ; Spectroscopy, Fourier Transform Infrared

Antioxidants

Vitamin C acts as a antioxidants and as free radical scavengers in biological systems. The objective of this study was to examine whether the administration of vitamin C could improve the skin flap survival. Sprague-Dawley rats (n = 40) were divided into 4 groups (n = 10); normal saline, vitamin C 200 mg/day, vitamin C 500 mg/day, vitamin C 1000 mg/day were injected subcutaneously to each group (n = 10). A classic caudally based random flap (2 X 7 cm) was elevated on the dorsum of rats and then sutured to its normal position. On the 3rd, 7th, 14th days postoperatively each animal was evaluated for percentage area of flap survival by paper template technique, thereafter rats were sacrificed and we obtained tissue from the distal ends of the flap. Following is our results. 1) The experimental group treated with vitamin C revealed an increased rate of random pattern skin flap survival compared with the control group (p < 0.005). 2) There was correlation of vitamin C dosage with flap survival rate (Spearman's correlation coefficient = 0.971). 3) The biopsy of the control group showed extensive atrophy and necrosis. However, New capillary proliferation and collagen deposition were noted in the vitamin C 200 mg and 500mg treated group. In the vitamin 1000 mg group, microscopic findings were very alike compared with normal rat skin texture. Finally, we concluded that the Vitamin C supplement increases survival rate of random pattern flap in rat skin flap model, and flap survival is correlated with vitamin C dosage.
Animals ; Antioxidants ; Ascorbic Acid* ; Atrophy ; Biopsy ; Capillaries ; Collagen ; Free Radical Scavengers ; Necrosis ; Rats* ; Rats, Sprague-Dawley ; Skin ; Survival Rate ; Vitamins*

The contents of total phenolics and extractable condensed tannins in the leaves, twigs and stem bark of Canarium album were determined. The structural heterogeneity of condensed tannins from stem bark was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and nuclear magnetic resonance (NMR) analyses. The results show the predominance of signals representative of procyanidins and prodelphinidins. In addition, epicatechin and epigallocatechin polymers with galloylated procyanidin or prodelphinidin were also observed. The tannins were screened for their potential antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) model systems. Tannins extracted from leaves, twigs and stem bark all showed a very good DPPH radical scavenging activity and ferric reducing power.
Antioxidants ; analysis ; chemistry ; pharmacology ; Burseraceae ; chemistry ; Free Radical Scavengers ; pharmacology ; Magnetic Resonance Spectroscopy ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Tannins ; analysis ; chemistry ; pharmacology

OBJECTIVETo isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa).

METHODSThe essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method.

RESULTSAbout 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene.

CONCLUSIONSThe chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.

Antioxidants ; chemistry ; pharmacology ; Free Radical Scavengers ; chemistry ; pharmacology ; Gas Chromatography-Mass Spectrometry ; Humans ; Lettuce ; chemistry ; Oils, Volatile ; chemistry ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Plant Leaves ; chemistry

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