Inhibition of Escherichia coli nitroreductase by the constituents in Syzygium aromaticum / 中国天然药物

Gut bacterial nitroreductases play an important role in reduction of various nitroaromatic compounds to the corresponding N-nitroso compounds, hydroxylamines or aromatic amines, most of which are carcinogenic and mutagenic agents. Inhibition of gut nitroreductases has been recognized as an attractive approach for reducing mutagen metabolites in the colon, so as to prevent colon diseases. In this study, the inhibitory effects of 55 herbal medicines against Escherichia coli(E. coli) nitroreductase (EcNfsA) were examined. Compared with other herbal extracts, Syzygium aromaticum extract showed superior inhibitory potency toward EcNfsA mediated nitrofurazone reduction. Then, the inhibitory effects of 22 major constituents in Syzygium aromaticum against EcNfsA were evaluted. Compared with other tested natural compounds, ellagic acid, corilagin, betulinic acid, oleanic acid, ursolic acid, urolithin M5 and isorhamnetin were found with strong to moderate inhibitory effect against EcNfsA, with IC50 values ranging from 0.67 to 28.98 mol·L-1. Furthermore, the inhibition kinetic analysis and docking simulation demonstrated that ellagic acid and betulinic acid potently inhibited EcNfsA (Ki < 2 μmol·L -1) in a competitively inhibitory manner, which created strong interactions with the catalytic triad of EcNfsA. In summary, our findings provide new scientific basis for explaining the anti-mutagenic activity of Syzygium aromaticum, where some newly identified EcNfsA inhibitors can be used for developing novel agents to reduce the toxicity induced by bacterial nitroreductase.

Bioactivities of Alchemilla mollis, Alchemilla persica and Their Active Constituents

Abstract The aim of this study was to determine antimicrobial activities of Alchemilla mollis, Alchemilla persica as well as ellagic acid and miquelianin against Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans by using microbroth dilution method and anti-inflammatory activity by using human red blood cell (HRBC) membrane stabilization method. Microbroth dilution method was used to determine the antimicrobial activities. Extracts possessed activity having MIC values of 2.5-5-10mg/ mL, compounds possessed activity having MIC values of 1.25-2.5-4-5mg/mL. A.mollis aerial parts displayed the highest anti-inflammatory activity (IC50=1.22±0.07mg/mL). Ellagic acid and miquelianin were also determined as anti-inflammatory agents with 0.57±0.01mg/mL and 1.23±0.02mg/mL IC50 values, respectively. Total phenolic content and tannin content of the A.mollis and A.persica were determined as 357.00±75.80mg, 282.50±28.70mg PGE/g plant material and 18.02%, 18.63% respectively according to the method described by European Pharmacopoeia. Ellagic acid, miquelianin and catechin were analyzed by HPLC. The highest catechin content was detected in A.persica roots (6.69±0.05g/100g plant material). A.mollis aerial parts contain higher miquelianin (0.39±0.02g/plant material) and ellagic acid (1.56±0.01g/ plant material) than A.persica.

The effect of ellagic acid on the repair process of periodontal defects related to experimental periodontitis in rats

Abstract Objective This study aims to evaluate the effect of ellagic acid (EA) by measuring the levels of alveolar bone resorption and inflammatory and oxidative stress markers in the periodontal tissues and serum on the periodontal repair process related to experimental periodontitis in rats. Methodology Forty Wistar rats were divided into four study groups as follows: Group 1=healthy control (n=10); Group 2=EA control (15 mg/kg)(n=10); Group 3=periodontitis (n=10); Group 4=periodontitis+EA (15 mg/kg) (n=10). The periodontitis model was established by ligating bilateral mandibular first molars for 14 days. Then, rats were given normal saline or EA for another 14 days by gavage administration. Serum and gingiva myeloperoxidase (MPO) activity, 8-hydroxydeoxyguanosine(8-OHdG), and glutathione (GSH) levels were analyzed by ELISA. İmmunohistochemical analysis was used to detect Interleukin (IL)-6, IL-10, and tumor necrosis factor-alpha (TNF-α) immunoreactivities in the periodontal tissues. Alveolar bone loss (ABL) and attachment loss (AL) was evaluated by histomorphometry analysis. Results ABL and AL were statistically higher in group 3 than in groups 1, 2 and 4 and in group 4 than in groups 1 and 2 (p<0.05). MPO activities in gingival tissue and serum were significantly increased in group 3 compared to groups 1 and 2 (p<0.05). Significantly higher serum GSH levels, lower gingiva, and serum 8-OHdG levels, and MPO activity were observed in group 4 compared to group 3 (p<0.05). Rats with periodontitis (group 3) expressed significantly higher immunoreactivities of IL-6 and TNF-α and lower IL-10 immunoreactivity compared to those other groups (p<0.05). IL-6 and TNF-α immunoreactivities significantly decreased and IL-10 immunoreactivity increased in group 4 after the use of EA compared to group 3 (p<0.001). Conclusions Our findings showed that EA provides significant improvements on gingival oxidative stress and inflammatory markers and alveolar bone resorption in the repair process associated with experimental periodontitis. Therefore, EA may have a therapeutic potential on periodontitis.

Therapeutic effects of ellagic acid on L-arginin induced acute pancreatitis

ABSTRACT PURPOSE: To investigate the therapeutic effects of ellagic acid on L-arginin ınduced acute pancreatitis in rats. METHODS: Thirty-two were split into four groups. Group 1 (control) rats were performed only laparotomy, no drugs were administered. Group 2 (control+EA) rats were administered 85mg/kg EA orally. Rats were sacrificed by cardiac puncture 24 hours after the administration. Group3 (AP) 24 hours after intraperitoneal L-arginine administration, rats were sacrificed by cardiac puncture. Group 4 (EA)-(AP): 85mg/kg EA was administered orally after the L-arginine administration. 24 hours later, rats were sacrificed by cardiac puncture. Serum TNF-α, IL-1β, IL-6, total oxidative status (TOS), total antioxidant capacity (TAC), amylase levels were determined in all groups. RESULTS: Group 3 (AP) rats showed significantly raised TOS level as compared to Group1 (control) rats (p<0.001). Following the EA therapy, a decrease in TOS was observed in Group 4 (AP+EA). TAC levels were significantly raised in the Group 4 (AP+EA) compared to the Group 3 (AP) (p=0.003). Group 3 (AP) showed significantly increased TNF-α, IL-1β and IL-6 serum levels as compared to Group 4 (AP+EA). Histopathological changes were supported our result. CONCLUSION: The healing effects of ellagic acid on inflammatory and oxidative stress were confirmed by histopathological and biochemical evaluations of the pancreatic tissue.

Ellagic acid inhibits proliferation and induces apoptosis in human glioblastoma cells

PURPOSE: To investigate the anticancer activity of ellagic acid (EA) in U251 human glioblastoma cells and its possible molecular mechanism. METHODS: The cells were treated with EA at various concentrations for different time periods. Cell viability and cell proliferation were detected by cell counting kit-8(CCK-8) assay and live/dead assay respectively. Cell apoptosis were measured with Annexin V-FITC/PI double staining method by flow cytometry and Mitochondrial membrane potential assay separately. Cell cycle was measured with PI staining method by flow cytometry. The expressions of Bcl-2, Survivin, XIAP, Caspase-3, Bax, JNK, p-JNK, ERK1/2, p-ERK1/2, p38, p-p38, DR4, DR5, CHOP and GRP78-related proteins were detected by western blot after EA treatment. RESULTS: Cell viability and proliferation of glioblastoma cells treated with EA were significantly lower than the control group. EA caused robust apoptosis of the glioblastoma cells compared to the control group. EA significantly decreased the proportion at G0/G1 phases of cell cycling accompanied by increased populations at S phase in U251 cell lines. And the expressions of anti-apoptotic proteins were dramatically down-regulated. CONCLUSION: Ellagic acid potentially up-regulated DR4, DR5 and MAP kinases (JNK, ERK1/2 and p38). EA also caused significant increase in the expressions of CHOP and GRP78. Our findings suggest that EA would be beneficial for the treatment of glioblastoma.

Produtos derivados do camu-camu: efeito da secagem sobre elagitaninos e flavonoides, atividades antioxidante e antimicrobiana / Camu-camu ingredients: effect of drying on ellagitannins and flavonoids, and their antioxidant and antimicrobial activities

O camu-camu (Myrciaria dubia Mc. Vaugh) tem demonstrado ser um fruto promissor devido ao potencial funcional, principalmente pelo alto teor de vitamina C e compostos fenólicos, em especial elagitaninos. Este trabalho teve como objetivo avaliar os efeitos sobre os compostos fenólicos dos processos de secagem de polpa comercial de camu-camu, por leito de jorro e atomização (spray-drying), em diferentes temperaturas e concentrações de agentes carreadores, comparando-os com os do processo de liofilização. Os pós obtidos foram comparados em relação ao teor total de compostos fenólicos, ácido ascórbico e proantocianidinas. Além disso, avaliou-se o potencial benéfico à saúde através da determinação da capacidade antioxidante in vitro , atividade antimicrobiana e inibição das enzimas α-amilase, α-glicosidase e enzima conversora da angiotensina (ECA). Avaliou-se também proteção e regeneração celulares em modelo de planárias (Dugesia trigrina). Complementarmente, os pós de camu-camu foram adicionados em leite de soja, que foram fermentados com bactérias produtoras de ácido láctico (L. helveticus ATCC 12046 e L. plantarum NCDO 1193), para verificar sua funcionalidade quando incorporados como ingredientes em alimentos funcionais. Os resultados mostraram que a secagem da polpa acarretou em perdas significativas de compostos bioativos, na ordem ácido ascórbico>fenólicos totais> proantocianidinas, e spray-drying>leito de jorro>liofilização. Os compostos fenólicos detectados nos pós de camu-camu foram elagitaninos, ácido elágico, derivados de quercetina, ácido siríngico e miricetina, por LC-TOF-MS. A liofilização foi a melhor técnica de secagem para a preservação dos compostos fenólicos, e também da capacidade antioxidante e de inibição enzimática. Além disso, os pós liofilizados e atomizado (contendo 6% goma arábica a 120 °C) foram mais efetivos contra Staphylococcus aureus que a ampicilina. Os extratos desses pós demostraram potencial para proteção celular e rejuvenescimento no modelo de planárias. E por último, o leite de soja enriquecido com o pó de camu-camu resultou em um produto com maior teor de fenólicos, alta capacidade antioxidante e propriedades anti-hiperglicêmica e anti-hipertensiva. Portanto, os pós de camu-camu são ricos em compostos fenólicos e tem potencial para serem acrescentados como ingredientes em alimentos para o controle dos estágios iniciais de diabetes tipo 2 e complicações associadas

Camu-camu (Myrciaria dubia Mc. Vaugh) has demonstrated promising perspectives as a functional food, mainly due to high vitamin C and phenolic compounds contents, in particular ellagitannins. This study aimed to evaluate the effect of different drying processes (spouted bed drying, spray-drying) at selected temperatures and carrier concentrations, comparing to freeze-drying, on the contents and composition of phenolic compounds. The pulp powders were compared in relation to phenolic profiles, ascorbic acid and proanthocyanidins contents. Further, functional health potential was evaluated such as in vitro antioxidant capacity, antimicrobial activity and inhibition of α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). It was also investigated cellular protection and regeneration in planaria (Dugesia trigrina) model. Additionally, camu-camu powders were added into soymilk and were fermented by lactic acid bacteria (L. helveticus ATCC 12046 and L. plantarum NCDO 1193) to verify their functionality as a functional food ingredient. The results showed that drying of the pulp led to significant losses of bioactive compounds, in the order ascorbic acid>total phenolics>proanthocyanidins, and spray-drying>spouted bed drying>freeze-drying. Phenolic compounds, such as ellagitannins, ellagic acid, quercetin derivatives, syringic acid and myricetin were detected in camu-camu by LC-TOF-MS. The freeze-drying was the best technique to preserve phenolic compounds, and also antioxidant capacity and enzyme inhibition. Besides that, freeze-dried and spray-dried (6% arabic gum at 120 °C) powders were more effective against Staphylococcus aureus than ampicillin. The extracts of those powders have desmonstrated potential to cellular protection and rejuvenation in planaria model. Finally, soymilk enriched with camu-camu powders resulted in more phenolic contents, high antioxidant capacity and anti-hyperglycemia and anti-hipertension properties product. To sum up, camu-camu powder is rich in phenolic bioactive profiles has potential as part of dietary strategies in the management of early stages of type 2 diabetes and associated complications

Physicochemical properties, in vitro release and skin permeation studies of a topical formulation of standardized pomegranate rind extract

The aim of the present study was to develop a stable formulation containing standardized pomegranate rind extracts [SPRE] for topical use in the treatment of dermal diseases. Ellagic acid [EA] as the major active constituent of SPRE [not less than 13%] was quantified by HPLC as an indicator for studies on the stability, in vitro drug release, and skin penetration/retention. The formulation prepared with polyethylene glycols [PEG 400 and PEG 4000] containing 5% SPRE has been found to be stable and provide a release rate of 36.6741 +/- 5.0072 micro g/cm2 /h that was best fitted to the zeroorder kinetic model. EA from SPRE did not penetrate the full-thickness rat skin but the skin retention of EA was determined to be 2.22 +/- 0.16 micro g/cm2 with a total recovery of 95.14 +/- 5.51%. The results indicated that this 5% SPRE PEG ointment was of satisfactory physicochemical properties and worth further in vivo investigations

Protective effect of ellagic acid and pumpkin seed oil against methotrexate-induced small intestine damage in rats.

Gastrointestinal toxicity is one of the most serious side effects in the methotrexate (MTX) treatment. This study was designed to investigate whether ellagic acid (EA) and/or pumpkin seed oil (PSO) had a protective effect on MTX-induced small intestine damage. Forty albino rats were randomized into five groups of 8 rats each. Group I served as a normal control group. In Group II, MTX was administered as a single dose (20 mg/kg) intraperitoneally. Groups III, IV and V were pre-treated respectively with either PSO (40 mg/kg), EA (10 mg/kg) or 0.2% DMSO (vehicle control) orally every day by gavage for 5 days and then they received MTX. All animals were sacrificed 5 days after the intraperitoneal injection of MTX for histopathological examination, estimation of serum prostaglandin E2 (PGE2) level, assay of tissue malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) levels and myloperoxidase (MPO), xanthine oxidase (XO) and adenosine deaminase (AD) activities. Administration of EA and/or PSO decreased the intestinal damage, PGE2, MDA and NO levels and MPO, XO and AD activities and increased GSH level. These results suggest that EA and PSO protect the small intestine of rats from MTX-induced damage through their antioxidant and anti-inflammatory effects and thus have potential as a promising drug in the prevention of undesired side effects of MTX.

Protective effect of dietary phytochemicals against arsenite induced genotoxicity in mammalian V79 cells.

Chronic arsenic exposure causes skin diseases, gastrointestinal and neurological disorders, diabetes and cancer in various organs. Oxidative stress associated with arsenic exposure cause genetic instabilities and may initiate carcinogenesis. Phytochemicals present in vegetables, fruits, spices, tea, and medicinal plants, have shown to suppress experimental carcinogenesis in various organs. The aim of the present study was to elucidate the protective effect of some of the phytochemicals against the arsenite induced DNA damage in normal mammalian V79 cells. Comet assay was used for assessment of DNA damage and 2', 7'-dichlorofluorescein dihydroacetate for estimation of ROS generated by arsenite. The effect of the phytochemicals was observed during simultaneous treatment with arsenic, before arsenite exposure and during repair experiments. Of all the phytochemicals tested against arsenic, curcumin gave better protection during simultaneous treatment and resveratrol during pre treatment, which was evident both from comet assay and ROS generation experiments. During pre treatment a longer duration of treatment with lower dose of phytochemicals proved fruitful in reducing the genotoxicity. During repair experiments the phytochemicals enhanced recovery of DNA damage and ellagic acid gave promising results. The results indicated that natural phytochemicals may have the efficacy in reducing arsenic induced genotoxicity, in scavenging ROS and in enhancing the process of DNA repair in V79 cells.

Hepatoprotective activity of ellagic acid against carbon tetrachloride induced hepatotoxicity in rats.

Administration of CCl4 to normal rats and consequent oral feeding with ellagic acid (50 mg/kg) provided a significant protection against the biochemical alterations in serum and liver produced by CCl4. In vitro experiments showed that liver microsomes from animals treated with ellagic acid and CCl4, decreased lipid peroxidation compared to microsome prepared from rats exposed to CCl4 alone.

Protective effect of ellagic acid on t-butyl hydroperoxide induced lipid peroxidation in isolated rat hepatocytes.

Ellagic acid, a plant polyphenol, showed protective effect on isolated rat hepatocytes against destruction due to lipid peroxide formation induced by t-butyl hydroperoxide in vitro. Ellagic acid inhibited the generation of superoxide anions and hydroxyl radicals both in enzymic and non enzymic systems, thus providing protection against oxidative damage.

Protective effect of curcumin, ellagic acid and bixin on radiation induced toxicity.

Whole body irradiation of rats (10 Gy as five fractions) found to produce lung fibrosis within 2 months as seen from increased lung collagen hydroxyproline and histopathology. Oral administration of antioxidants curcumin, ellagic acid, bixin and alpha-tocopherol at a concentration 200 mumole/kg body weight significantly reduced the lung collagen hydroxyproline in these animals. In serum and liver lipid peroxidation which were found to be increased by irradiation was reduced significantly by antioxidant treatment. The liver superoxide dismutase and glutathione peroxidase activity were also found to be increased and catalase activity decreased in irradiated control. Superoxide dismutase activity reduced significantly by antioxidant treatment while catalase activity was found to be increased with alpha-tocopherol treatment. The increased frequency of micronucleated polychromatic erythrocytes after whole body irradiation of mice was found to be significantly reduced with antioxidants.