Comparison of NO-scavenging and NO-suppressing activities of different herbal teas with those of green tea

Oxidative stress caused by the production of excess nitric oxide (NO) during infection or inflammation has been implicated in the pathogenesis of several diseases, including cancer, diabetes and renal disease. Accordingly, the scavenging of NO radical or/and suppression of NO production by mitogen-activated cells may be promising indicators in screening healthy food. In this work, the NO-scavenging and NO-suppressing activities of different herbal teas were determined and compared with those of green tea. All of the tested herbal teas revealed NO-scavenging and NO-suppressing activities. The NO-scavenging activity of herbal teas can be ranked by the IC₅₀, the concentration of the tested herbal tea required to quench 50% of NO radicals released by sodium nitroprusside. The activities follow the order: green tea > rosemary, sweet osmanthus, rose and lavender > jasmine, lemongrass and daisy. The NO-suppressing activity was evaluated, based on the suppressing effect of herbal teas on the production of NO by LPS-activated RAW 264.7 macrophages. Experimental results indicated that green tea and rosemary had IC₅₀ values of less than 500 μg/ml, and were proven to be good NO-suppressors, whereas lavender, sweet osmanthus, lemongrass, rose, daisy and jasmine had IC₅₀ values that exceeded 500 μg/ml, and were classified as rather poor NO-suppressors. In conclusion, consumption of herbal teas promotes the NO-scavenging and NO-suppressing activities of the diet, even though their activities are weaker than that of green tea.     

Oxidative stability of butter with added phenolics from Lamiaceae herbs and in vitro evaluation of potential cytotoxicity of rosemary (Rosmarinus officinalis L.) extract

This study evaluated the oxidative stability of butter with added phenolics from Lamiaceae herbs. Initially antioxidant activity of crude rosemary, oregano, sage, thyme and marjoram extracts were screened through methods of inhibition of the 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radical, malondialdehyde (MDA) quantification and ferric reducing antioxidant power test. The alcoholic extract of rosemary showed the highest antioxidant activity in both assays for DPPH radical inhibition and MDA quantification. The alcoholic rosemary extract showed no cytotoxicity when assayed using MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] reduction method and had dose‐dependent cytoprotective activity at 50 and 250 μg mL^?1. These results suggest that the use of rosemary as natural antioxidant is safe in the concentrations tested. The highest oxidative stability of butter with added alcoholic rosemary extract at temperatures of 60 and 110 °C was obtained with the concentration of 400 mg of phenolic compounds per kg of butter and was reflected at the lowest formation of degraded peroxides from lipids.     

绿茶、桑叶和臭黄荆叶细粉水提液抑菌和抗氧化能力

探究绿茶、桑叶和臭黄荆叶3种植物干叶细粉水提液的抑菌和抗氧化能力。采用当量法测定3种原料中黄酮、多酚含量,二倍稀释法测定水提液对大肠杆菌、金黄色葡萄球菌的最小抑菌浓度和最小杀菌浓度,牛津杯法分析原料的抑菌活性。利用分光光度法研究3种水提液及其两两等比混合后的DPPH自由基清除率、羟自由基清除率和Fe2+螯合能力。结果表明,绿茶粉中水溶性黄酮、多酚含量最高,分别为62.22、133.82 mg/g,桑叶粉次之,臭黄荆叶粉最少。绿茶、桑叶和臭黄荆叶细粉在DPPH自由基清除率、羟自由基清除率和Fe2+螯合能力方面无协同作用,但黄酮、多酚含量与其抑菌和抗氧化活性间存在显著的量效关系(P<0.05)。因此,绿茶、桑叶和臭黄荆叶细粉水提液抑菌和抗氧化能力依次减弱,且三者抗氧化活性没有协同增效作用。     

A Comparative Study on Antioxidant and DNA Protective Activity of Different Skin Coloured Brinjal (Solanum Melongena)

The aim of this study was to investigate the in vitro antioxidant activity and DNA damage inhibition potential of aqueous extract of S. melongena with different skin colours. Water extracts of brinjal with four different skin colours: moderately purple (S1), light purple (S2), dark purple (S3) and purple with green lines (S4) were tested for their antioxidant and radical scavenging activities. The total phenolic content (TPC) was quantified using Folin-Ciocalteau's method. The effectiveness of brinjal extracts in preventing radical induced DNA damage was also determined. There was a significant difference (p<0.0001) between the skin colour andantioxidant activity. Brinjal with S3skin colour showed the highest TPC and antioxidant activity measured by FRAP while, S2 showed the least. S1 displayed the highest percentage of DPPH radical scavenging activity with an IC₅₀ value of 3.51±0.62 mg/ml while, S3 demonstrated the strongest total antioxidant capacity with an inhibition percentage of 40.45±1.17. In the FTC (Ferric Thiocyanate) and egg yolk model, S1 and S3 showed better antioxidantactivity than S2 and S4. The in vitro freeradical quenchingand antioxidant results well correlated with the in vitro lipid peroxidation assays. All extracts were able to effectively retain DNA against AAPH induced radical damage at the concentration levels (25 and 75 mg/ml) tested. All the extracts showed moderate to potent antioxidant activity, among which S3 and S1, intensely coloured skins, demonstrated better antioxidant activity which may be attributed to the higher phenolic content since a linear relation was observed between the TPC and the antioxidant parameters.     

秦岭山脉野生蒲公英提取物的抗氧化活性及其对胡麻油氧化稳定性的影响

以秦岭山脉野生蒲公英全草为原料,采用超声波纤维素酶同步法提取总活性成分。对蒲公英提取物的DPPH自由基清除能力、超氧阴离子自由基清除能力、羟自由基清除能力和总还原能力进行了测定,并与人工合成VC进行了比较,同时采用加速氧化的方法评价蒲公英提取物对胡麻油氧化稳定性的影响,并与BHT、迷迭香提取物进行比较。结果表明:蒲公英提取物比人工合成VC有更高的抗氧化活性; 3种抗氧化剂抗氧化能力大小为迷迭香提取物(700 mg/kg)蒲公英提取物(700 mg/kg) BHT(200 mg/kg),并且蒲公英提取物添加量与胡麻油的氧化稳定性呈正相关。因此,秦岭山脉野生蒲公英全草总活性成分提取物可作为天然抗氧化剂用于延缓食用油氧化。     

Antioxidant activity and total phenolics of edible mushroom extracts

Methanol and water crude extracts from Shiitake mushroom (Lentinus edodes) and straw mushroom (Volvariella volvacea) were investigated for their antioxidant capacity in three different assays, namely, the β-carotene and linoleic acid system, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and inhibition of hemolysis of rat erythrocyte induced by peroxyl radicals. Among the four mushroom extracts, the water extract from L. edodes showed the most potent radical scavenging activity in each assay, showing 75.9% (at 20 mg/ml) in the β-carotene bleaching method, 55.4% in the DPPH radical scavenging method (at 6 mg/ml) and 94.9% of inhibition of erythrocyte hemolysis (at 5 mg/ml). Total phenolics in the water extracts were higher than that of the methanol ones. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants.     

Tea and herbal infusions: Their antioxidant activity and phenolic profile

Tea and herbal infusions have been studied for their polyphenolic content, antioxidant activity and phenolic profile. The total phenolics recovered by ethyl acetate from the water extract, were determined by the Folin–Ciocalteu procedure and ranged from 88.1 ± 0.42 (Greek mountain tea) to 1216 ± 32.0 mg (Chinese green tea) GAE (Gallic acid equivalents)/cup. The antioxidant activity was evaluated by two methods, DPPH and chemiluminescence assays, using Trolox and quercetin as standards. The EC₅₀ of herbal extracts ranged from 0.151 ± 0.002 mg extract/mg DPPH (0.38 quercetin equivalents and 0.57 Trolox equivalents), for Chinese green tea, to 0.77 ± 0.012 mg extract/mg DPPH (0.08 quercetin equivalents and 0.13 Trolox equivalents), for Greek mountain tea. Chemiluminescence assay results showed that the IC₅₀ ranged from 0.17 ± 3.4 × 10⁻³ μg extract/ml of the final solution in the measuring cell (1.89 quercetin and 5.89 Trolox equivalents) for Chinese green tea, to 1.10 ± 1.86 × 10⁻² g extract/ml of the final solution in the measuring cell (0.29 quercetin and 0.90 Trolox equivalents) for Greek mountain tea. The phenolic profile in the herbal infusions was investigated by LC-DAD-MS in the positive electrospray ionization (ESI⁺) mode. About 60 different flavonoids, phenolic acids and their derivatives have been identified.     

Green tea preparation and its influence on the content of bioactive compounds

The effect of different extraction conditions and storage time of prepared infusions on the content of bioactive compounds of green teas and their antioxidant capacity were investigated. The content of total phenols, total flavonoids and total non-flavonoids in green teas was determined spectrophotometrically, while 7 flavan-3-ols, 6 phenolic acids and 3 methylxanthines were identified and quantified by using high performance liquid chromatography (HPLC–PDA). Among the tested green teas bagged green tea Twinings of London was recognized as the richest source of phenolic compounds (3585 mg/L GAE of total phenols). The most abundant phenolic constituents of green tea were flavan-3-ols, of which EGCG was prevailing in all teas (94.54–357.07 mg/L). The highest content of caffeine, as the most abundant methylxanthine, was determined in powdered green tea. The findings of this investigation suggest that extraction efficiency of studied bioactive compounds from green tea depends on the extraction conditions and that maximum extraction efficiency is achieved during aqueous extraction at 80 °C, for 5′ (powder), 15′ (bagged) and 30′ (loose leaf). In order to determine the antioxidant capacity of teas the DPPH, ABTS and FRAP assays were applied. Regardless of the extraction conditions all green teas exhibited significant antioxidant capacity in vitro, which was in correlation with their phenolic content, confirming that green tea is one of the best dietary sources of antioxidants.     

Antioxidant activity and antimicrobial properties of phenolic extracts from acerola (Malpighia emarginata DC) fruit

The antioxidant activity and antimicrobial property of phenolic extracts from acerola (Malpighia emarginata DC) fruit were assessed. The contribution of ascorbic acid and phenolic compounds in the total antioxidant capacity of the extracts was also evaluated. The extracts showed high total phenolic values and possessed high antioxidant activity as expressed by 2,2′‐diphenylpicrylhydrazyl (DPPH) and oxygen radical absorbance capacity assays (ORAC). The ascorbic acid content ranged from 405 to 1744 mg/100 g of fruit on a fresh weight basis. The antioxidant capacity of the phenolic fractions was in the following order: anthocyanins<phenolic acids<flavonoids. The phenolic fractions contributed 7.1–36.5% of the antioxidant activity expressed by ORAC, whereas the contribution of ascorbic accounted for 18–39% of the total activity. Selected extracts from the flavonoids fraction showed some activity against Staphylococcus aureus.     

The composition of polyphenols and methylxanthines in teas and herbal infusions

The popularity of tea is increasing on the global aspect because of its role as a significant source of phenolic compounds in human diet. The purpose of this study was to determine and compare the phenolic and methylxanthine composition as well as the antioxidant capacity of white, green, Oolong and black teas, and chamomile and linden infusions depending on the extraction conditions (water temperature and multiple extractions). The content of total phenols and total flavonoids in teas and herbal infusions was determined by using UV/vis spectrophotometric methods, whilst individual polyphenols (phenolic acids and flavan-3-ols) and methylxanthines were identified and quantified by using high performance liquid chromatography coupled with photodiode array detection. In order to determine the antioxidant capacity of teas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays were applied. The highest content of phenolic compounds was determined in green tea, which also demonstrated the highest antioxidant capacity, whilst herbal infusions were characterised with the lowest content of phenolic compounds, as well as the lowest antioxidant capacity. The highest content of caffeine, as the most abundant methylxanthine, was determined in black tea. Extraction at 100 °C is the most effective to extract the highest content of polyphenols and methylxanthines in all studied teas.     

Compositions, antioxidant and antimicrobial activities of Helichrysum (Asteraceae) species collected from Turkey

The methanolic extracts of 16 Helichrysum species were investigated for their in vitro antioxidant, radical scavenging and antimicrobial activities. All the extracts showed strong antioxidant and radical scavenging activity. The highest total antioxidant capacity as ascorbic acid equivalents (AAE) of 194.64 mg/g dry extract was obtained for Helichrysum noeanum in the phosphomolybdenum assay. The highest IC₅₀ value (7.95 μg/ml) was observed for the extract of Helichrysum stoechas subsp. barellieri in the DPPH assay. The total phenolic contents of the extracts ranged from 66.74 to 160.63 mg gallic acid equivalents (GAE)/g dry extract. The major component present in the extracts was identified as chlorogenic acid followed by apigenin-7-glucoside and apigenin by HPLC analysis. All the extracts showed significant antimicrobial activity against microorganisms containing 13 bacteria and two yeasts in the agar diffusion method.     

The phenolic compounds and the antioxidant potential of infusion of herbs from the Brazilian Amazonian region

The consumption of tea increased significantly in the past few years as a result of its health benefits as potent antioxidants in the diet. However, studies on the antioxidant compounds from Brazilian tea are scarce. Thus, the aim of this work was to evaluate the total phenolic compounds (TPC) and total flavonoids (TF) contents and the antioxidant capacity (DPPH and β-carotene/linoleic acid system) of nine herb infusions from the Amazonian region, namely agirú (Chrysobalanus icaco), açoita-cavalo (Luehea speciosa), capim-santo (Cymbopogon citratus), erva-cidreira (Lippia alba), graviola (Annona muricata L.), jucá (Libidibia ferrea), pata-de-vaca (Bauhinia ungulata), parirí (Fridericia chica) and sacaca comum (Croton spp.). These herbs were chosen based on popular knowledge and consumption. C. ferrea (68.13 mg GAE/g), L. speciosa (47.54 mg GAE/g) and C. icaco (51.30 mg GAE/g) presented the highest TPC contents, while L. speciosa (12.85 mg CE/g) and L. alba (15.42 mg CE/g) showed the highest TF contents. The highest antioxidant capacity, using both assays, was shown by L. ferrea. The three herbs with the highest TPC contents were selected to be analyzed by high performance liquid chromatography (HPLC) coupled to a diode array detector (DAD). A commercial green tea (Camellia sinensis) was also analyzed as a reference. The main compounds tentatively identified were gallic acid (0.45 mg/g), myricetin (0.78 mg/g) and quercetin (0.14 mg/g) in C. icaco; (+)-catechin (1.20 mg/g) and quercetin (0.14 mg/g) in L. speciosa; gallic acid (0.59 mg/g) and quercetin (0.13 mg/g) in C. ferrea; and gallic acid (0.24 mg/g), (−)-epicatechin (2.44 mg/g), (+)-catechin (0.68 mg/g) and quercetin (0.66 mg/g) in green tea. Among the nine studied herbs, the importance of L. ferrea should be pointed out since it presented the highest TPC content and antioxidant capacity and its gallic acid content was much higher than that of green tea.     

Screening of free radical scavenging capacity and antioxidant activities of Rosmarinus officinalis extracts with focus on location and harvesting times

Methanolic extracts from the leaves of Rosmarinus officinalis (rosemary) harvested from different locations of Turkey at four different times of the year were analyzed by HPLC, and their radical scavenging capacities and antioxidant activities were studied by various assays. The amounts of carnosol, carnosic acid and rosmarinic acid, active constituents of rosemary, varied in different geographical regions of growth, and also showed a seasonal variation. The levels of the constituents were higher in the warm months of June 2004 and September 2004. The antioxidant activities of 12 extracts were determined by in vitro DPPH radical scavenging activity, by Trolox equivalent antioxidant capacity (TEAC), and by reversing H₂O₂-induced erythrocyte membrane lipid peroxidation (EMLP). The two antioxidant enzyme activities of human erythrocyte, namely superoxide dismutase (SOD) and catalase (CAT), after in vitro incubation with the extracts, were also examined in order to see whether the observed effects are related to altered enzymatic efficiency. The resulting values were correlated with active metabolite and total phenol contents of the extracts. The results indicated that the plants harvested in September possessing higher levels of active constituent had superior antioxidant capacities compared to the ones collected at other times. With respect to the location, plants harvested from the Izmir region had lower total phenol and active constituent levels resulting in poorer antioxidant activity.     

Antioxidant activities of citrus herbal product extracts

Total phenolic content, DPPH free radical-scavenging activity, hydrogen peroxide-scavenging activity, ferrous ion-chelating activity and ferric-reducing antioxidant power (FRAP) of four citrus herbal products, Citri Reticulatae Pericarpium (CRP), Citri Reticulatae Viride Pericarpium (CRVP), Aurantii Immaturus Fructus (AIF) and Aurantii Fructus (AF) extracts were determined. EC₅₀ values of DPPH radical-scavenging activities ranged from 0.1 mg/ml (AF) to 1.59 mg/ml (AIF). EC₅₀ values of hydrogen peroxide-scavenging activities ranged from 0.08 mg/ml (AF) to 0.9 mg/ml (CRP). EC₅₀ values of ferrous ion-chelating activities ranged from 0.8 mg/ml (AF) to 2.08 mg/ml (AIF). The differences in DPPH free radical-scavenging activity, hydrogen peroxide-scavenging activity, and ferrous ion-chelating activity of all citrus herbal product extracts were significant. AF had the highest antioxidant activity. In this study, citrus herbal product extracts did not have good reducing power.     

Biochemical,biological and histological evaluation of some culinary and medicinal herbs grown under greenhouse and field conditions

BACKGROUND: Increasing evidence supports the potential health benefits of herbal extracts displaying antioxidant, anti‐inflammatory and antitumour activities. Environment can have a pronounced effect on phenolic content and antioxidant capacity. The objectives of this study were to evaluate the total phenolic contents and antioxidant capacities of five different herbs grown under greenhouse and field conditions and to assess their potential anti‐inflammatory effects. RESULTS: High total polyphenolic (TPP) content (measured by the Folin‐Ciocalteu reagent method) and high Trolox equivalent antioxidant capacity (TEAC) were observed in all herbs evaluated. Leaves from thyme, sage, spearmint and peppermint grown in the greenhouse showed significantly higher TPP content and TEAC than those grown under field conditions, with a threefold difference being observed in peppermint. Rosemary, spearmint and peppermint extracts showed stronger inhibition of cyclooxygenase COX‐2 than of COX‐1. CONCLUSION: The results show that producing herbs under greenhouse conditions can improve their biological activities by increasing TPP contents and antioxidant capacities. The selective inhibition of COX‐2 activity by rosemary, spearmint and peppermint suggests that they may be useful as anti‐inflammatory agents with fewer side effects than regular non‐steroidal drugs. Copyright © 2010 Society of Chemical Industry     

Comparative Flavonoids Contents of Selected Herbs and Associations of Their Radical Scavenging Activity with Antiproliferative Actions in V79-4 Cells

ABSTRACT:  To elucidate the health benefit of herbal teas on the cytotoxicity induced by H₂O₂ in V79-4 cells, herbal extracts and its flavonoids were tested using lactate dehydrogenase release and determining intracellular reactive oxygen species generation and antioxidant activity with superoxide radical scavenging assay. Significant decrease in cell viability was observed on V79-4 cells treated with H₂O₂ (1 mM), while herbal extracts and its flavonoids including catechin and epigallocatechin gallate prevented the LDH release from H₂O₂ cytotoxicity. Total catechin contents of green tea (65.6 mg/g of dry matter) were significantly higher than other herbal teas (35.8 to 1.2 mg/g of DM). The relative concentration of the 4 major tea catechins ranked EGCG > EGC > EC > C. Green tea exhibited the lowest IC₅₀ values (2 g fresh herb/100 mL) of superoxide radical scavenging activity among the tested herbal tea, which indicates powerful antioxidant activity in O₂^·− radicals scavenging, followed by black tea, dandelion, hawthorn, rose hip, chamomile.     

Effect of Extraction Techniques and Solvent Systems on the Extraction of Antioxidant Components from Peanut (Arachis hypogaea L.) Hulls

This research work was carried out to investigate the effect of different extraction techniques on antioxidant potential of peanut (Arachis hypogaea) hulls. The antioxidant extracts of peanut hulls (PH) were prepared using different extraction methods such as soaking, stirring, shaking, and sonicated-assisted stirring with methanol/water (80:20) and ethanol/water (80:20) solvents systems. The antioxidant potential of extracts was measured using different in vitro antioxidant assays like estimation of total phenolic contents (TPC), estimation of total flavonoids contents (TFC), DPPH-scavenging capacity, percentage inhibition of linoleic acid peroxidations, and bleachability of ?-carotene in linoleic acid system. TPC and TFC of different PH extracts were found in range of 1.23–8.43 mg/g of dry plant material, measured as gallic acid equivalent, 0.33–5.06 mg/g of dry plant material, measured as catechin equivelent (CE), respectively. All the PH extracts exhibited good free radical scavenging potential and moderate inhibition of linoleic acid peroxidation. Significant (p ≤ 0.05) variations were observed in the antioxidant potentials of various extraction methods and solvent systems. Among all the extraction methods, sonicated-assisted stirring showed better yield and antioxidant capacity. In view of the present findings, it is reasonable to say that different extracts of peanut hulls exhibited varying degree of antioxidant activity, which might be attributed to various mechanisms involved in extraction procedures.     

Effect of different brewing methods on antioxidant properties of steaming green tea

The extracts were prepared from cold or hot brewed steaming green tea at different concentrations (2, 6, and 10%), its antioxidant properties studied and potential antioxidant components determined. The yields of hot water extracts (17.49–28.27%) were significantly higher than those of cold water extracts (11.72–14.70%). EC₅₀ values in antioxidant activity determined by the conjugated diene method and reducing power were 2.19–3.10 and 0.22–0.28 mg/ml, respectively. EC₅₀ values in scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals were 29.45–43.80 and 2.88–3.22 mg/ml, respectively. EC₅₀ values in chelating ability on ferrous ions were 6.45–13.51 mg/ml. Contents of total phenols were 221.71–330.22 mg/g whereas those of total catechins in cold and hot water extracts were 135.05–193.14 and 161.57–195.05 mg/g, respectively. Based on the results obtained, hot water extracts were more effective in antioxidant activity and reducing power. However, cold water extracts were more effective in scavenging ability on DPPH and hydroxyl radicals, and chelating ability on ferrous ions. Summarily, the cold brewing method would be a new alternative way to make a tea.     

Rose Petal Tea as an Antioxidant-rich Beverage: Cultivar Effects

ABSTRACT Twelve rose cultivars were selected by field tasting as potential sources of edible flowers. Hot water infusions (teas) of air‐dried petals of these cultivars were assayed for antioxidant activity, total phenols, and total anthocyanins contents. Their composition was analyzed by high‐performance liquid chromatography (HPLC). Green tea was tested in parallel as a reference antioxidant‐rich beverage. Rose petal teas from different cultivars exhibited scavenging capacity toward 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonate cation radical (ABTS+) ranging between 712.7 and 1770.7 μM Trolox equivalents (TE) per gram of dry petals, as compared with 1227.6 μM TE/g dry weight in the green tea. The range of total phenols content in rose teas was 50.7 to 119.5 mg gallic acid equivalents (GAE) per gram of dry matter, as compared with 62.1 mg GAE/g dry weight in the green tea. The rose teas were rich in free gallic acid. The highest values of antioxidant activity, total phenols, and gallic acid contents were found in the cultivars San Francisco, Katharina Zeimet, and Mercedes and in the essential‐oil‐bearing rose Rosa damascena. The correlation coefficients between antioxidant activity, on the 1 hand, and the contents of total phenols and of gallic acid in various rose cultivars, on the other hand, were 0.79 and 0.81, respectively. No clear relationship between anthocyanin level and radical‐scavenging activity was revealed. Teas from different rose cultivars significantly differed in their sensory properties. It was concluded that dried rose petals may be used for preparing antioxidant‐rich caffeine‐free beverages, either separately or in combination with other herbal materials.     

ANTIOXIDANT ACTIONS OF FRUIT, HERB AND SPICE EXTRACTS

The antioxidant properties of extracts of five fruits (apple, pear, peach, plum and grapefruit), three herbs (rosemary, tarragon and basil) and one spice (black pepper) were evaluated in a series of assays involving reactive oxygen species (ROS). In general, the crude extracts possessed potent antioxidant properties in vitro . Rosemary extract was 50-times more effective at preventing microsomal lipid peroxidation of human liver microsomes induced by NADPH/iron compared to peroxidation induced by iron/ascorbate, but tarragon was more effective in the iron/ascorbate dependent peroxidation. Analysis of the content of hydroxycinnamic acids of the pear, apple, plum and peach extracts measured after hydrolysis with sodium hydroxide showed that caffeic acid, p-coumaric and ferulic acids were the principal hydroxycinnamic acids present. Although the hydroxycinnamic acids and naringin do not contribute to the inhibition of lipid peroxidation by fruit extracts, they were able to inhibit deoxyribose degradation by 30% suggesting ability to weakly scavenge hydroxyl radicals (OH). Nevertheless, extracts of herbs and spices are increasingly of interest in the food industry because they retard oxidative degradation to lipids.