BACKGROUND: Previous studies have shown that in vitro exposure to ultraviolet B(UVB) radiation resulted in a dose-dependent inhibition of natural killer activity(NK activity) of normal human peripheral blood mononuclear cella(PBMC), and that in vivo exposure to snlight also induced NK activity suppression. The precise meehanism of the UV-regulation on the riat iral killer system(NK system) is not established. Objective & METHOD: The purpose of this study is to examine whether the addition of interleukin-2(IL-2) and/or free oxygen radical scavengers, superoxide dismutas(SOD) or sodium azide(SA), is effective in reducing the UVJ3-induced suppression of NK activity of FBMC. RESULTS: The results are as follows 1. The suppressive effect of UVB radiat,ion on NK activity could successfully be prevented in the presence of SOD(100 and 1,000U/ml) during the radiation. 2. SA( LO and 10 M/ml) did not prevent the suppression of NK activity. 3. IL-2(100U/ml) markedly enhanced the NK activity of nonirradiated PBMC, but had no effect on irradiated PBMC. 4. Combination treatment with both IL-2 and free radical scavengers on UVB-irradiated PBMC resulted in no additive or synergistic effect on the prevention of the suppression of NK activity compared with a single treatment with either IL-2 or free radical scavengers. CONCLUSION: In the presserit study, we found that SOD providec a protective effect on NK activity during the UVB radiation and we suggest that superoxide anion(O ) might play a major role in the UV-regulatory mechanisms of the NK system.
Free Radical Scavengers ; Humans* ; Interleukin-2* ; Oxygen ; Sodium ; Superoxides

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 investigate DPPH radical scavenging activities of 31 flavonoids and phenolic acids and 10 extracts of Chinese materia medica.

METHODThe antioxidant activities of the above samples were evaluated by a DPPH method, the half-wave oxidation potentials (E1/2) of the 31 compounds were determined by an HPLC-CoulArray method, at the same time, phenolic contents of the the total compounds in the 10 extracts of Chinese materia medica were analyzed by Folin-Ciocalteu method.

RESULTThe 31 compounds showed a 50% inhibition of DPPH radical in the concentration range of 6.7-3 500 micromol x L(-1), in which (-) -EGCg demonstrated the strongest activity with the IC50 value of 6.7 micromol x L(-1). The E1/2 of 31 compounds spanned a wide potential range of more than 0.6 V. Myricetin had the lowest E1/2 value (20 mV) whereas apigenin and vitexin-2"-O-rhamnoside had the highest E1/2 value (620 mV). Among the 10 herb extracts, having 82% phenolic acid, tea extract showed the strongest DPPH radical scavenging activity with the IC50 value of 0.011 7 mg x mL(-1) whereas safflower demonstrated the weakest DPPH radical scavenging activity with the IC50 value of 1.250 mg x mL(-1), in which only 7% phenolic acids was tested.

CONCLUSIONThe DPPH radical scavenging activities of the 31 compounds were founded to be related to their chemical structures, such as the number and position of hydroxyl groups. And a qualitative relationship was found between DPPH radical scavenging activities and E1/2 values of the 31 compounds, the lower the E1/2 values, the higher the DPPH radical scavenging activities. A quantitative relationship was obtained to describe the DPPH radical scavenging activity of the herb extracts: Y = 7.779X(-0.48), r = 0.929 5, where Y stands for the concentration for 50% inhibition of DPPH radical, and X stands for the concentration of total phenolic compaunds, namely the extracts with higher content of flavonoids and phenolic acid exhibited the stronger DPPH radical scavenging activity.

Drugs, Chinese Herbal ; chemistry ; Flavonoids ; chemistry ; Free Radical Scavengers ; chemistry ; Hydroxybenzoates ; chemistry ; Materia Medica ; 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

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

Using bioactive compounds 7-hydroxy flavone, salicylaldehyde, cinnamic acid and 4-amino-5- mercapto-1,2,4-triazoles as starting materials, three new types of flavone derivatives containing 1,2,4-triazole structure were synthesized via different step reactions. These new compounds were characterized by 1IHNMR, ESI-MS, IR and elemental analysis. Their scavenging effects on the superoxide radical (O2·-), hydroxyl radical (·OH), DPPH · radical and their total reduction activities were tested. The results showed that all of the compounds possessed some antioxidative activity at the concentration of 0.5 mg · mL(-1), but the scavenging ability of the target compounds was lower than that of the standard compound Vc.
Cinnamates ; chemistry ; Flavones ; chemical synthesis ; chemistry ; Flavonoids ; chemistry ; Free Radical Scavengers ; chemical synthesis ; chemistry ; Triazoles ; chemistry

OBJECTIVETo study the pharmacologic action of Artemisia burning products.

METHODSThe extractions of Artemisia burning products were determined by spectrophotometry. The scavenging ability of Artemisia burning products on DPPH was evaluated. The chemical components and structures of Artemisia burning products were analyzed by Gas Chromatography and Mass Spectrometry (GC-MS).

RESULTSThe scavenging ability of extractions from Artemisia burning products was the strongest. Thirty-six chemical components were detected, and the 5-tert-Butylpyrogallol among them had a stronger anti-oxygen capacity, its scavenging free radical ability was 1.55 times and 1.21 times as strong as VitC and BHT, respectively.

CONCLUSIONThe scavenging free radical ability of 5-tert-Butylpyrogallol extracted from Artemisia burning products is stronger than the natural antioxidant of VitC and artificial synthetic of BHT.

Artemisia ; chemistry ; Free Radical Scavengers ; chemistry ; Gas Chromatography-Mass Spectrometry ; Spectrophotometry

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

AIM: Artemisia amygdalina Decne. (Asteraceae) is a critically endangered and endemic herb of Kashmir Himalayan sub-alpine region and Pakistan. Scientific research throughout the world has evidence to support the tremendous medicinal utility of the genus Artemisia. The natural resources of medicinal plants are being reduced day by day. This study provides the alternative way for medicinal resource utilization and conservation of A. amygdalina. METHODS: In vitro-raised plants and greenhouse acclimatized plants were obtained by culturing wild explants on Murashige and Skoog's medium. Plant extracts were obtained and subjected to different antioxidant assays: DPPH assay, riboflavin photo-oxidation assay, deoxy ribose assay, ferric thiocyanate assay, thiobarbituric acid assay, post mitochondrial supernatant assay and DNA damage on agarose gel. RESULTS: In vitro grown plants, as well as those acclimatized in the greenhouse reveals antioxidant activity against hydroxyl, superoxide, and lipid peroxyl radicals. CONCLUSION This preliminary study revealed the free radical scavenging potential of tissue culture-raised plant extracts of A. amydalina.
Acclimatization ; Artemisia ; chemistry ; growth & development ; physiology ; Free Radical Scavengers ; chemistry ; Plant Extracts ; chemistry ; Tissue Culture Techniques