Comparative antihemolytic and radical scavenging activities of strawberry tree (Arbutus unedo L.) leaf and fruit

The present study reports the antioxidant properties of Arbutus unedo L. leaf and fruit extracts using different in vitro assays including (i) reducing power, (ii) scavenging effect on DPPH free radicals, and (iii) inhibitory effect on AAPH-induced hemolysis and lipid peroxidation in human erythrocytes. All assays demonstrated antioxidant efficiency for A. unedo L. aqueous extracts, being consistently higher in the leaf. EC₅₀ values for reducing power and DPPH radical scavenging activities were, respectively, 0.318 ± 0.007 and 0.087 ± 0.007 mg/mL for leaf, and 2.894 ± 0.049 and 0.790 ± 0.016 mg/mL for fruit extracts. Under the oxidative action of AAPH, A. unedo leaf and fruit extracts protected the erythrocyte membrane from hemolysis (IC₅₀ of 0.062 ± 0.002 and 0.430 ± 0.091 mg/mL, respectively) and decreased the levels of malondialdehyde, a breakdown product of lipid peroxidation (IC₅₀ of 0.075 ± 0.014 and 0.732 ± 0.452 mg/mL, respectively). In accordance with antioxidant activity, phenolic content was found to be significantly higher in leaf extract. To our knowledge, this is the first time that the antioxidant activity of A. unedo species is evaluated using human biological membranes. Overall, our results suggest that A. unedo leaves are a promising source of natural antioxidants with potential application in diseases mediated by free radicals.     

In vitro antioxidant capacities and fatty acid compositions of three Centaurea species collected from Central Anatolia region of Turkey

Antioxidant capacities of methanolic extract and fatty acid composition of three Centaurea species were investigated. The antioxidant capacity of the extracts was evaluated by different assays, including total phenolic content, phosphomolybdenum assay, free radical scavenging activity (DPPH assay), β-carotene/linoleic acid bleaching assay, iron (III) and cupric reduction assay. The findings showed that the methanolic extract of Centaurea pulchella has the strongest antioxidant capacity compared to other two Centaurea species. The order of the antioxidant properties of Centaurea species were C. pulchella > C. patula > C. tchihatcheffii. Thirty fatty acids were identified in the oils of three Centaurea species. The major fatty acids of these species were found to be linoleic acid from C. pulchella and C. tchihatcheffii, and α-linolenic acid from C. patula. The study concluded that the Centaurea species can be used as a source of natural antioxidants and essential fatty acids.     

In vitro and in vivo antioxidant activity of Symplocos cochinchinensis S. Moore leaves containing phenolic compounds

Methanol extract of Symplocos cochinchinensis S. Moore leaves was evaluated for its in vitro and in vivo antioxidant activity. The total phenolic content of the extract was 230 mg of gallic acid equivalents/g extract. The extract showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 620.30 ± 0.14 μg/ml), hydroxyl (IC₅₀ 730.21 ± 1.05 μg/ml), nitric oxide (IC₅₀ 870.31 ± 0.19 μg/ml) radicals, as well as high reducing power. The extract also showed strong suppressive effect on lipid peroxidation. In in vivo study CCl₄ induced oxidative stress produced significant increase in SGOT, SGPT and LDH levels along with reduction in liver SOD, CAT, GSH and GPx levels. Pre-treatment of rats with the extract (250 and 500 mg/kg) for 7 days showed significant reduction in the levels of SGOT, SGPT and LDH compared to CCl₄ treated rats. SOD, CAT, GSH and GPx levels were increased significantly due to treatment with the extract. The activity of the extract was comparable to the standard drug, silymarin (25 mg/kg). The results suggest that the leaves of S. cochinchinensis are a source of natural antioxidants.     

Phenolic composition and biological activities of Juniperus drupacea Labill. berries from Turkey

The present study was designed to define the phenolic profile and the biological potential of berries methanol extract of Juniperus drupacea Labill. from Turkey.The total phenolic content (Folin-Ciocalteau assay) was 48.06 ± 0.99 mg GAE/g extract. The HPLC-DAD-ESI-MS analysis allowed the determination of the complete phenolic profile of J. drupacea berries. Phenolic acids represented more than 60% of the total phenolics, and tyrosol was the major one (1324 ± 0.64 μg/g extract); within the flavonoids amentoflavone was detected as the main constituent (927 ± 0.35 μg/g extract).The extract exhibited good antioxidant properties, as determined by different in vitro models: DPPH test (IC₅₀ 0.38 ± 0.02 mg/mL), reducing power (12.63 ± 0.14 ASE/mL), Fe²⁺ chelating ability (IC₅₀ 2.26 ± 0.06 mg/mL), and TBA test (IC₅₀ 2.47 ± 1.13 μg/mL).Cytotoxicity against Artemia salina was highlighted (LC₅₀ 489.47 ± 27.8 μg/mL), and a significant decrease (p ? 0.05; p ? 0.01) in HepG2 cells viability was observed at the higher concentrations (5-10 μg/mL).The extract displayed good antibacterial activity towards Gram-positive bacteria and in particular Staphylococcus aureus was the most susceptible strain (MIC 78.12 μg/mL).     

月季花化学成分及药理作用的研究进展

月季花化学成分丰富多样,主要包括黄酮类、黄酮苷类、酚酸类化合物、芳香油、鞣质和色素等成分,其提取物或某些化学成分在抗肿瘤、抗真菌、抗病毒、抗氧化等方面显示了较好的生物活性。本文综述了月季花植物中化学成分及药理作用的研究进展,并对今后月季花的应用前景做了展望。     

Chemical composition and antioxidant activities of the essential oil and methanol extracts of Psammogeton canescens

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of the essential oil and methanol extracts of Psammogeton canescens. The chemical composition of the hydrodistilled essential oil of the aerial parts of P. canescens was analyzed by GC and GC/MS. The main constituents of the oil were found to be β-bisabolene (33.35%), apiole (28.34%), α-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, β-carotene/linoleic acid, and reducing power assay. In DPPH system, the highest radical-scavenging activity was seen by the polar subfraction of methanol extract (49.5 ± 1.21 μg/ml). Furthermore, in the second case the inhibition capacity (%) of the polar subfraction (92.40% ± 0.72) found to be the stronger one. However, in the reducing power assay, a reverse activity pattern more than in the first two systems was observed, and the essential oil was stronger radical reducer than was the methanol extract in all of the concentration tested. Our findings demonstrate that the essential oil and methanol extracts of P. canescens possess significant antioxidant activities and may be suggested as a new potential source of natural antioxidant.     

Comparative analysis of the antioxidant and DNA protection capacities of Anadenanthera colubrina, Libidibia ferrea and Pityrocarpa moniliformis fruits

This study aimed to explore the antioxidant and DNA protection abilities of hydroalcoholic extracts from fruits of Anadenanthera colubrina (ACHE), Libidibia ferrea (LFHE) and Pityrocarpa moniliformis (PMHE). These extracts were tested by five antioxidant methods (phosphomolibdenium and reducing power assays; superoxide, hydrogen peroxide and nitric oxide scavenging) and DNA protection capacity. Total phenolic content was measured by Folin-Ciocalteu method. ACHE exhibited the highest phenolic content (578 mg/g GAE), followed by LFHE (460 mg/g GAE) and PMHE (448 mg/g GAE). In phosphomolibdenium assay, ACHE showed 24.81% of activity in relation to ascorbic acid, whereas LFHE and PMHE had 21.08% and 18.05%, respectively. These plants showed high ability to inhibit reactive species tested with IC50 values ranged from 10.66 to 14.37 μg/mL for superoxide radical; 26.05 to 45.43 μg/mL for hydrogen peroxide; 178.42 to 182.98 μg/mL for reducing power; and 199.2 to 283 μg/mL for nitric oxide. Furthermore, these extracts had capacity to break the DNA damage induced by hydroxyl radicals. The antioxidant activity of these plants is related with their higher phenolic content and show that they may be used as source of bioactive compounds, relevant to the maintenance of oxidative stability of the food matrix, cosmetics and/or pharmaceutical preparations.     

In vitro antioxidant,antidiabetic and antilipidemic activities of Symplocos cochinchinensis (Lour.) S. Moore bark

Symplocos cochinchinesis is used in Indian system of traditional medicine to treat diabetes mellitus. The present study investigates the in vitro antioxidant, antidiabetic and antilipidemic activities of S. cochinchinensis bark methanolic extract (SCBe) in streptozotocin (STZ) induced diabetic rats. In in vitro studies SCBe showed very good scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 820.34 ± 1.74 μg/ml), hydroxyl (IC₅₀ 884.19 ± 0.45 μg/ml) and nitric oxide (IC₅₀ 860.21 ± 1.18 μg/ml) radicals, as well as high reducing power. SCBe (250 and 500 mg/kg) was administered to STZ (40 mg/kg) induced diabetic rats for 28 days. SCBe showed a significant decrease in blood glucose and significant increase in plasma insulin and liver glycogen levels in treated diabetic rats. Further, SCBe showed antilipidemic activity as evidenced by significant decrease in serum TC, TG, LDL-C levels and significant increase in HDL-C level in treated diabetic rats. SCBe also restored the altered plasma enzymes (SGOT, SGPT and ALP), total protein, urea and creatinine levels to near normal. The action of SCBe was comparable to the antidiabetic drug glibenclamide. Results of this experimental study indicated that SCBe possessed antioxidant, antidiabetic and antilipidemic activities.     

Antimicrobial and antioxidant activities of Russula delica Fr.

Russula delica Fr. is a well known macrofungi which is used as a food in Turkey. The ethanolic extract of R. delica exhibited antimicrobial activity against some of the tested foodborne and spoilage bacteria. The phenolic composition of R. delica ethanolic extract was analyzed by high performance liquid chromatography (HPLC). The major component in R. delica ethanolic extract was catechin (5.33 mg/L). Antioxidant activities of the ethanolic extract of R. delica was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging and chelating ability on ferrous ions assays. Scavenging effect on DPPH radicals was 26% at 10 mg/ml and chelating effects on ferrous ions was 58% at 5 mg/ml. In addition, the amounts of total phenol content (6.23 mg/g), ascorbic acid (2.93 mg/g), β-carotene (0.11 mg/g) and lycopene (0.03 mg/g) in the macrofungi ethanolic extract were determined.     

Antioxidant and antidermatophytic activities of essential oil and extracts of Metasequoia glyptostroboides Miki ex Hu

This study was undertaken to assess the antioxidant and antidermatophytic potential of the essential oil and extracts (hexane, chloroform, ethyl acetate and methanol) of Metasequoia glyptostroboides Miki ex Hu. Antioxidant activity was evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The free radical scavenging activities of the oil and ethyl acetate extract were found to be superior (IC₅₀ = 9.1 and 14.24 μg/ml, respectively) as compared to butylatedhydroxyanisole (BHA), (IC₅₀ = 18.27 μg/ml). Also the ethyl acetate extract revealed the highest phenolic contents (93.26 mg/g of dry wt) as compared to the other extracts. Further, oil (1250 μg/disc) and extracts (1750 μg/disc) revealed 35.33–67.66 and 18.0–53.3% antidermatophytic effect, respectively, along with their respective MIC values (62.5–500 and 250–4000 μg/ml) against Trichophyton rubrum KCTC 6345, T. rubrum KCTC 6375, T. rubrum KCTC 6352, T. mentagrophytes KCTC 6085, T. mentagrophytes KCTC 6077, T. mentagrophytes KCTC 6316, Microsporum canis KCTC 6591, M. canis KCTC 6348 and M. canis KCTC 6349. The oil also had a strong detrimental effect on spore germination as well as concentration and time-dependent kinetic inhibition of M. canis KCTC 6591.     

Antioxidant activities of the essential oils and methanol extracts from myrtle (Myrtus communis var. italica L.) leaf,stem and flower

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of α-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50 mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, β-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.     

Chemical composition and antioxidant activity of essential oils and solvent extracts of Ptychotis verticillata from Morocco

The objective of this study was to characterize the chemical composition of the essential oil and extracts of Ptychotis verticillata. The antioxidative activities of this species were also evaluated to suggest it as a new potential source of natural antioxidants. Analysis of the chemical composition of P. verticillata essential oil from Morocco was carried out using GC and GC-MS. The oil was dominated by phenolic compounds (48.0%) with carvacrol (44.6%) and thymol (3.4%) as the main compounds. Plant phenolics constitute one of the major groups of components that act as primary antioxidant free radical terminators. The amounts of total phenolics and flavonoids in the solvent extracts (diethyl ether and ethyl acetate) were determined spectrometrically. Furthermore, the antioxidant activities of the essential oil and extracts were determined using a DPPH test system. The DPPH scavenging activity of extracts increased in the order ethyl acetate > ascorbic acid > diethyl ether > essential oil. Finally, a relationship was observed between the antioxidant activity potential and total phenolic and flavonoid levels of the extract.     

Human cancer cell antiproliferative and antioxidant activities of Juglans regia L.

Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. Walnuts contain several phenolic compounds which are thought to contribute to their biological properties. The present study reports the total phenolic contents and antioxidant properties of methanolic and petroleum ether extracts obtained from walnut (Juglans regia L.) seed, green husk and leaf. The total phenolic contents were determined by the Folin–Ciocalteu method and the antioxidant activities assessed by the ability to quench the stable free radical 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and to inhibit the 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of human erythrocytes. Methanolic seed extract presented the highest total phenolic content (116 mg GAE/g of extract) and DPPH scavenging activity (EC₅₀ of 0.143 mg/mL), followed by leaf and green husk. In petroleum ether extracts, antioxidant action was much lower or absent. Under the oxidative action of AAPH, all methanolic extracts significantly protected the erythrocyte membrane from hemolysis in a time- and concentration-dependent manner, although leaf extract inhibitory efficiency was much stronger (IC₅₀ of 0.060 mg/mL) than that observed for green husks and seeds (IC₅₀ of 0.127 and 0.121 mg/mL, respectively). Walnut methanolic extracts were also assayed for their antiproliferative effectiveness using human renal cancer cell lines A-498 and 769-P and the colon cancer cell line Caco-2. All extracts showed concentration-dependent growth inhibition toward human kidney and colon cancer cells. Concerning A-498 renal cancer cells, all extracts exhibited similar growth inhibition activity (IC₅₀ values between 0.226 and 0.291 mg/mL), while for both 769-P renal and Caco-2 colon cancer cells, walnut leaf extract showed a higher antiproliferative efficiency (IC₅₀ values of 0.352 and 0.229 mg/mL, respectively) than green husk or seed extracts. The results obtained herein strongly indicate that walnut tree constitute an excellent source of effective natural antioxidants and chemopreventive agents.     

Metabolic profiling and biological capacity of Pieris brassicae fed with kale (Brassica oleracea L. var. acephala)

Phenolic and organic acid profiles of aqueous extracts from Pieris brassicae material and the host kale (Brassica oleracea L. var. acephala) leaves were determined by HPLC/UV–DAD/MSⁿ-ESI and HPLC–UV, respectively. The identified phenolics included acylated and nonacylated flavonoid glycosides, hydroxycinnamic acyl gentiobiosides, and sulphate phenolics. Kale exhibited the highest content (11 g/kg lyophilized extract), while no phenolics were identified in the butterflies or exuviae. Nine different organic acids were characterized in the materials, with kale showing the highest amount (112 g/kg lyophilized extract). With the exception of the exuviae extract, the rest were screened for bioactivity. Using spectrophotometric microassays, all exhibited antiradical capacity against DPPH and NO in a concentration-dependent way, whereas only kale and excrement extracts were active against superoxide. All displayed activity on intestinal smooth muscle, albeit with distinct relaxation–contraction profiles. Larvae and butterfly extracts were more efficacious for intestinal relaxation than was kale extract, whereas excrement extract evoked only contractions, thus evidencing their different compositions. Collectively, these results show that P. brassicae sequesters and metabolizes kale’s phenolic compounds. Moreover, the extract’s bioactivities suggest that they may constitute an interesting source of bioactive compounds whose complex chemical structures preclude either synthesis or isolation.     

Chemical composition,in vitro anti-microbial,antifungal and antioxidant activities of the essential oil and methanolic extract of Hymenocrater longiflorus Benth., of Iran

In this study we identified the chemical composition, anti-microbial and antioxidant effects of essential oil and methanolic extract of Hymenocrater longiflorus Benth. Totally 87 volatile compounds from the essential oil in H. longiflorus, were identified by gas chromatography–mass spectrometry (GC–MS). These compounds are mainly monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated monoterpenes and oxygenated sesquiterpenoids compounds. The anti-microbial and antifungal activity of plants extracts against several pathogenic microorganisms was studied by disc diffusion and minimum inhibitory concentration procedures. The results revealed that the essential oil and polar sub-fraction are effective mostly against Staphylococcus aureus, Aspergillus niger and Candida albicans. The antioxidant activity was also determined by 1,1′-diphenyl-2-picryl-hydrazyl (DPPH) free radical scavenging, β-carotene linoleic acid assay and reducing power. In addition the total phenol of essential oil (54.6 ± 1.2), polar sub-fraction (50.0 ± 1.4) and non-polar sub-fraction (64.7 ± 2.0) were determined.     

Evaluation of anti-oxidant activities and total phenolic content of Chromolaena odorata

The aim of this study was to assess the in vitro potential of chloroform extract of Chromolaena odorata leaves. The DPPH activity of the extract (0.1–5 mg/ml) was increased in a dose dependent manner, which was found in the range of 23.48–91.61% as compared to ascorbic acid (33.69–94.10%). The IC50 values of chloroform extract in DPPH radical, hydroxyl radical, nitric oxide, ABTS radical were obtained to be 0.31, 0.43, 0.28 and 1.32 mg/ml, respectively. However, the IC50 values for the standard ascorbic acid were noted to be 0.24, 0.41, 0.23 and 1 mg/ml, respectively. Measurement of total phenolic content of the chloroform extract of C. odorata was achieved using Folin–Ciocalteau reagent containing 242.2 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The results obtained in this study clearly indicate that C. odorata has a significant potential to use as a natural anti-oxidant agent.     

Diverse role of microbially bioconverted product of cabbage (Brassicaoleracea) by Pseudomonassyringe pv. T1 on inhibiting Candida species

This study was carried out to evaluate the anticandidal effects of bioconverted product, obtained from the microbial conversion of cabbage (Brassicaoleracea) by a bacterial strain Pseudomonassyringe pv. T1 (Ps-T1) against various isolates of Candida species. The diameters of zones of inhibition of bioconverted product of cabbage (10 μl, corresponding to 500 μg/disc) against Candidaalbicans KACC 30003 and 30062, Candidageochares KACC 30061, Candidasaitoana KACC 41238 and Candidaglabrata P00368 were found between 10 ± 1 and 16 ± 0.8 mm. The bioconverted product was tested for the minimum inhibitory and minimum fungicidal concentration values against the tested pathogens which were found in the range of 125-500 and 125-500 μg/ml, respectively. On the viable counts of the tested fungal pathogens, the bioconverted product showed a remarkable anticandidal effect. Also the study of using scanning electron microscopy on the morphology of C.albicans KACC 30062 revealed potential detrimental effect of bioconverted product at MIC concentration. The results of this study suggest that bioconverted product of cabbage by Ps-T1 holds potential therapeutic value and medicinal significance to control Candida species.     

Effects of Thai Musa species on prevention of UVB-induced skin damage in mice

The effects of oral administration of Musa sapientum and Musa suerier on prevention of UVB induced skin damages were investigated in male ICR mice. Animals were orally administered 50 mg/day ascorbic acid, or M. sapientum or M. suerier’s fruit pulps at dose of 0.5, 1 or 1.5 mg/g body weight/day for 12 weeks. Concurrently, the shaved backs of animals were irradiated with UVB for 12 weeks. The intensity of irradiation was progressively increased, from 54 mJ/cm² per exposure at week 1–126 mJ/cm² at week 11. A significant decrease (p < 0.05) in skin elasticity (from 0.82 ± 0.02 to 0.42 ± 0.09) and total glutathione (from (193.6 ± 18.7 to 152.7 ± 7.8 ng/mg protein) as compared with the control group (water-administered UVB-irradiated mice) was observed after 12 weeks of UVB exposure. When l-ascorbic acid (0.72 ± 0.01) or 1 mg/g body weight/day M. suerier (0.84 ± 0.06) were administered to UVB-irradiated mice, the reduction in skin elasticity was significantly inhibited (p < 0.05). Moreover, the significant increase (p < 0.05) in level of total glutathione was found in these groups (220.8 ± 13.3 ng/mg protein for l-ascorbic acid and 224.9 ± 20.1 ng/mg protein for M. suerier). These findings suggest the potential effect of daily consumption of M. suerier on prevention of skin damage from repeated UVB exposure.     

Microbial conversion and anticandidal effects of bioconverted product of cabbage (Brassica oleracea) by Pectobacterium carotovorum pv. carotovorum 21

This study was undertaken to examine the anticandidal effects of microbially bioconverted product of cabbage, obtained from the microbial conversion of cabbage (Brassica oleracea var. capitata) by a bacterial strain Pectobacterium carotovorum pv. carotovorum 21 (Pcc 21) against various isolates of Candida species including a clinical isolate. The bioconverted product (10 μl, corresponding to 500 μg/disc) displayed potential anticandidal effect against Candida albicans KACC 30062, Candida geochares KACC 30061, Candida albicans KACC 30003, Candida saitoana KACC 41238 and Candida glabrata P00368 (clinical isolate) as a diameter of zones of inhibition, found in the range of 14 ± 0.9 to 19 ± 1.1 mm. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of bioconverted product against the tested isolates were found in the range of 62.5–250 and 125–250 μg/ml, respectively. Also the bioconverted product had remarkable anticandidal effect on the viable counts of the tested Candida isolates. Further, scanning electron microscopic study revealed potential detrimental effect of bioconverted product on the morphology of C. albicans KACC 30062 at MIC concentration. All these findings together indicate that bioconverted product of cabbage has potential therapeutic value of medicinal significance to control Candida species including clinical isolates.     

Biological potentials and cytotoxicity of various extracts from endemic Origanum minutiflorum O. Schwarz & P.H. Davis

The aim of the present study was to investigate antioxidative, antimicrobial and cytotoxic effects of endemic Origanum minutiflorum (O. Schwarz & P.H. Davis). Antioxidant activities of the extracts from O. minutiflorum were evaluated by using DPPH radical scavenging, β-carotene bleaching and metal chelating activity assays. In addition, the amounts of total phenol components in the plant extracts were determined. In the β-carotene bleaching test, the extracts exhibited in the range of 58.1 ± 0.2% – 98.2 ± 0.3% inhibition against linoleic acid oxidation. The antimicrobial efficiency of the plant was evaluated according to agar well diffusion and microdilution broth methods. The n-hexane extract of O. minutiflorum having an inhibition zone of 20.2 ± 0.2 mm, had the maximum antibacterial efficiency against Shigella sonnei RSKK 878. Cytotoxic effects of the extracts were determined by MTT assay. O. minutiflorum extracts (at concentration of 10–100 μg/ml) did not show any cytotoxic effect on baby hamster kidney fibroblast cell line. The results showed that O. minutiflorum could be used as a natural source in food industry.