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.     

Characterization of homoisoflavonoids in different cultivation regions of Ophiopogon japonicus and related antioxidant activity

Homoisoflavonoids were identified in Ophiopogon japonicus of two cultivation regions in China: Hang-maidong (grown in Zhejiang province) and Chuan-maidong (grown in Sichuan province). Liquid chromatography (LC), coupled with electrospray ionization (ESI) tandem mass spectrometry (MS), was developed to analyze homoisoflavonoids in these two areas. Based on LC–MS/MS data, 24 homoisoflavonoid compounds—19 in Hang-maidong and 17 in Chuan-maidong—were identified or tentatively characterized. The homoisoflavonoids in the two regions were similar in chemical profile, but distinctive in their combination and ratio. Methylophiopogonanone A and methylophiopogonanone B were the major contributors to the total homoisoflavonoid content. Hang-maidong had a higher total homoisoflavonoid content and better DPPH (2,2-diphenyl-1-picryl-hydrazyl) radical-scavenging activity than that of Chuan-maidong. The total phenolic content showed no significant difference between the two regions. This study allows a clear chemical differentiation of Hang-maidong from Chuan-maidong.     

Antioxidant and antimicrobial properties of Teucrium arduini L. (Lamiaceae) flower and leaf infusions (Teucrium arduini L. antioxidant capacity)

Antioxidant and antimicrobial activities, as well as total phenol (TP, Folin–Ciocalteu method) and phenolic acid (UPLC–MS/MS) contents of leaf and flower infusions of Teucrium arduini L. from six different mountainous localities in Croatia (U?ka, Vošac, Sveti Jure, Snje?nica, Vaganac, Šušanj) were analysed in this study. Antioxidant capacity was evaluated using the ferric reducing/antioxidant power (FRAP) assay, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. The antioxidant potency composite index (ACI), giving equal weight to all three methods used to quantify antioxidant capacity, was the highest for the sample from Vošac (96.7) among flower infusions, while maximum ACI (100) was determined for the infusion from U?ka among leaf infusions. Strong positive correlation was found between the total phenols and ACI for leaf (r = 0.953) and flower (r = 0.977) infusions. Our results point to significantly (p < 0.05) different TP content between leaf and flower infusions, as well as across localities. Leaf infusions of T. arduini from Šušanj exhibited marked antibacterial activity against Staphylococcus aureus, while none of the tested infusions exhibited antimicrobial activity against gram-negative bacterial species, or the tested fungal species.     

Comparative study of chemical composition and antioxidant activity of fresh and dry rhizomes of turmeric (Curcuma longa Linn.)

The phytoconstituents of essential oil and ethanol oleoresin of fresh and dry rhizomes of turmeric (Curcuma longa Linn.) were analyzed by GC–MS. The major constituents were aromatic-turmerone (24.4%), alpha-turmerone (20.5%) and beta-turmerone (11.1%) in fresh rhizome and aromatic-turmerone (21.4%), alpha-santalene (7.2%) and aromatic-curcumene (6.6%) in dry rhizome oil. Whereas, in oleoresins, the major components were alpha-turmerone (53.4%), beta-turmerone (18.1%) and aromatic-turmerone (6.2%) in fresh and aromatic-turmerone (9.6%), alpha-santalene (7.8%) and alpha-turmerone (6.5%) in dry rhizome. Results showed that alpha-turmerone, a major component in fresh rhizomes is only minor one in dry rhizomes. Also, the content of beta-turmerone in dry rhizomes is less than a half amount found in fresh rhizomes. The antioxidant properties have been assessed by various lipid peroxidation assays as well as DPPH radical scavenging and metal chelating methods. The essential oil and ethanol oleoresin of fresh rhizomes have higher antioxidant properties as compared dry ones.     

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.     

Isolation and characterization of a new steroid derivative as a powerful antioxidant from Cleome arabica in screening the in vitro antioxidant capacity of 18 Algerian medicinal plants

Hydromethanolic extracts from 18 Algerian medicinal plants were screened for their phenolic contents and radical scavenging activities. The phenolic extract of Cleome arabica (Capparaceae) was found to be the most active one. Purification of this extract by semi-preparative high performance liquid chromatography led to the isolation and identification of new steroid derivative. The structure of the active principle is proposed as (17-(4-hydroxy-1,5-dimethylhexyl)-2,3,7-(acetyloxy) gona-1,3,5(10)-trien-15-ol). Compared to six other standard antioxidants which were ascorbic acid, α-tocopherol, Trolox, (+) catechin, p-coumaric acid and gallic acid, the isolated compound was found to be significantly more active in the radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Similar results were obtained in the hemolysis assay. The antioxidant capacities of the methanolic extract of C. arabica and its principle compound indicate that this plant may be an important source of chemopreventive and chemotherapeutic natural products activity.     

In vitro protective effects of Thymus quinquecostatus Celak extracts on t-BHP-induced cell damage through antioxidant activity

The purpose of this study was to evaluate the antioxidative activities of water and 70% ethanolic extracts from the Thymus quinquecostatus Celak (TQC) for natural antioxidant source. The antioxidant activities were compared with other natural and synthetic antioxidants. The levels of total polyphenols and flavonoids were also determined. The extracts were found to have different levels of antioxidant properties in a few kind of assay. The results showed that higher radical scavenging activity, reducing power and antioxidant capacity in FRAP than those of BHT as a positive control. In addition, the extracts from the TQC leaf and stem showed stronger antioxidant activity than that of vitamin C, α-tocopherol in ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. Cytoprotective and anti-apoptotic effect of water extracts from TQC was also prevented t-BHP-induced toxicity in Chang liver cells. Therefore, these results indicate that TQC extracts have antioxidant properties through its ability to enhance the cell viability, reduction of production of ROS, inhibition of oxidative damage, mitochondria dysfunction and ultimately inhibition of cell apoptosis. Based on the results described above, it is suggested that TQC has the potential to protect liver on t-BHP-induced cell damage and should be considered as a prospective functional food.     

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.     

Extracts of Halenia elliptica exhibit antioxidant properties in vitro and in vivo

The antioxidant properties of different extracts of Halenia elliptica was investigated by employing various established in vitro systems. The results showed that various extracts possessed strong antioxidant activity in vitro, and the 70% methanol extract (ME) had the strongest antioxidant activity. Based on our in vitro results, ME was used for investigating the antioxidant properties of H. ellipticain vivo. The liver and kidney of CCl₄-intoxicated animals exhibited a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels. Additionally, these organs exhibited a significant increase in the level of malondialdehyde (MDA). These changes were significantly reversed, in a dose-dependent manner, after treatment with ME and the standard treatment Vitamin E. Thus, it may be concluded that the ME possesses potent antioxidant properties, and might be valuable natural source of antioxidants that could be applicable to both the medical and food industries.     

Antioxidant activity and total phenolic content of ethanolic extract of Caesalpinia bonducella seeds

The aim of this study was to assess the in vitro potential of ethanolic extract of Caesalpinia bonducella seeds as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 μg/ml) was increased in a dose dependent manner, which was found in the range of 38.93–74.77% as compared to ascorbic acid (64.26–82.58%). The IC₅₀ values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 74.73 and 26.68 μg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of C. bonducella was achieved using Folin–Ciocalteau reagent containing 62.50 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC₅₀ values of 109.85, 102.65 and 89.84 μg/ml, respectively. However, the IC₅₀ values for the standard ascorbic acid were noted to be 70.79, 65.98 and 36.68 μg/ml respectively. The results obtained in this study clearly indicate that C. bonducella has a significant potential to use as a natural antioxidant agent.     

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.     

Antioxidant and antityrosinase activity of mulberry (Morus alba L.) twigs and root bark

The antioxidant and antityrosinase activities of the ethanolic extract of mulberry twigs (EEMT) were investigated. The results showed that EEMT exhibited radical scavenging and reducing activity, as well as ferrous ion-chelating activity. In addition, EEMT also protected phospholipids against free radicals, indicating that EEMT could protect biomolecules from oxidative damage. Meanwhile, in the range of 0-60 μg/ml, the tyrosinase inhibitory activity of EEMT increased with increase in sample concentration, and was superior to that of the ethanolic extract of mulberry root bark (EEMR). High-performance liquid chromatography (HPLC) analysis was employed to determine the phenolic components, revealing that maclurin, rutin, isoquercitrin, resveratrol, and morin were present in EEMT. Acting as an antioxidant and a tyrosinase inhibitor, these bioactive constituents could contribute to the protective effects of EEMT. Overall, the results showed that EEMT might serve as a natural antioxidant and tyrosinase inhibitor.     

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).     

Flavonoid characterization and antioxidant activity of hydroalcoholic extracts from Achillea ligustica All.

Ethanolic extracts of Achillea ligustica All. (Asteraceae) flowering tops were evaluated. High-performance liquid chromatography–electrospray ionisation-mass spectrometry was used for the identification and quantification of phenolic compounds. 6-Hydroxykaempferol-3,6,4′-trimethyl ether, apigenin-6-C-glucoside-8-C-arabinoside, luteolin, and apigenin were the most abundant flavonoids. For the first time C-glycosylflavones were detected in A. ligustica with apigenin-6-C-glucoside-8-C-arabinoside being the most representative. The radical scavenging activity of the extracts was determined by DPPH test and ranged between 4.18 and 12.3 mM. The ability of these extracts to inhibit non-enzymatic lipid peroxidation was studied using the simple in vitro system of linoleic acid oxidation: five of the nine extracts exerted a protective effect at the lower amount tested (5 μg). Protection on CaCo-2 intestinal cells against TBH-induced toxicity was also investigated: the results showed that two of the extracts tested in this cell system had the ability to protect against oxidative stress induced by TBH starting from concentrations as low as 10 μg/ml.     

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.     

HPLC测定黔产钩藤不同部位钩藤碱和异钩藤碱的含量

目的 HPLC测定黔产钩藤不同部位中钩藤碱和异钩藤碱的含量,并比较其差异。方法 以钩藤碱、异钩藤碱为对照品,采用CAPCELL PAK C₁₈色谱柱（4.6 mm×250 mm,5μm）,以乙腈-0.1%三乙胺水溶液（1%磷酸调pH=9）为流动相,流速1 mL·min^-1,检测波长245 nm,柱温30℃,进样量10µL。结果 钩藤碱与异钩藤碱分离良好,线性、重复性以及回收率均符合要求,钩藤不同部位中的含量存在差异,由高到低依次为皮 > 茎 > 带钩茎枝 > 叶,而茎薄壁组织与木质部未检测到钩藤碱与异钩藤碱。结论 该含量测定结果为钩藤资源的充分利用提供了科学依据。     

Walnut (Juglans regia L.) leaves: phenolic compounds, antibacterial activity and antioxidant potential of different cultivars.

Different cultivars of walnut (Juglans regia L.) leaves (Cv. Lara, Franquette, Mayette, Marbot, Mellanaise and Parisienne) grown in Portugal, were investigated in what concerns phenolic compounds and antimicrobial and antioxidant properties. Phenolics analysis was performed by reversed-phase HPLC/DAD and 10 compounds were identified and quantified: 3- and 5-caffeoylquinic acids, 3- and 4-p-coumaroylquinic acids, p-coumaric acid, quercetin 3-galactoside, quercetin 3-pentoside derivative, quercetin 3-arabinoside, quercetin 3-xyloside and quercetin 3-rhamnoside. The antimicrobial capacity was screened against Gram positive (Bacillus cereus, B. subtilis, Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae) and fungi (Candida albicans, Cryptococcus neoformans). Walnut leaves selectively inhibited the growth of Gram positive bacteria, being B. cereus the most susceptible one (MIC 0.1mg/mL). Gram negative bacteria and fungi were resistant to the extracts at 100mg/mL. Lara walnut leaves were also submitted to antibacterial assays using 18 clinical isolates of Staphylococcus sp. Antioxidant activity was accessed by the reducing power assay, the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and beta-carotene linoleate model system. In a general way, all of the studied walnut leaves cultivars presented high antioxidant activity (EC(50) values lower than 1mg/mL), being Cv. Lara the most effective one.     

Antimicrobial and antioxidant properties of the essential oil of Salvia lanigera from Cyprus

The essential oil of aerial parts of Salvia lanigera Poir. (Lamiaceae) growing wild in Cyprus was obtained by hydrodistillation and was analysed by GC and GC-MS. A total of 67 compounds, representing 93.6% of the oil, were identified, and the major components were showed to be thymol (12.1%), hexadecanoic acid (6.0%), carvacrol and α-thujone (5.7%). The essential oil was assayed for its antioxidant and antimicrobial activities. Antimicrobial activity of the oil, evaluated using the broth dilution method, resulted higher against Gram-positive bacteria than the other referenced strains tested. Antioxidant activity of the oil was evaluated by using DPPH and FRAP methods together with three antioxidant standards, l-ascorbic acid, tert-butyl-4-hydroxy toluene (BHT) and gallic acid. The activity of the sample in both methods was higher than that of all of standards used at the same dose.