Antioxidant and Antimicrobial Activity of Tellurium Dioxide Nanoparticles Sols

2013 ◽  
Vol 25 ◽  
pp. 8-15 ◽  
Author(s):  
Cai Ling Zhong ◽  
Bi Yin Qin ◽  
Xin Yuan Xie ◽  
Yan Bai

In this study, the antioxidant activity and antimicrobial effect of tellurium dioxide nanoparticles (TeO2NPs) sols were evaluated by oxygen radical absorbance capacity (ORAC) and agar diffusion bioassay method, respectively. The results of ORAC demonstrated that the antioxidant activity of TeO2NPs sols was in a dose-dependent manner and TeO2NPs-gallic acid sol showed stronger antioxidant activity than TeO2NPs-acetic acid sol due to the synergistic antioxidant effect of gallic acid and TeO2NPs. On the other hand, the results of agar diffusion bioassay method demonstrated that the antimicrobial effect of TeO2NPs-acetic acid sol was stronger than that of TeO2NPs-gallic acid sol and the two kinds of TeO2NPs sols could evidently inhibit the growth of some gram negative bacteria and gram positive bacteria which lack nitrate reductase. The antimicrobial mechanism of the TeO2NPs sols might be similar to that of tellurite.

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Vinicyus Teles Chagas ◽  
Rafaella Moraes Rego de Sousa Coelho ◽  
Renato Simões Gaspar ◽  
Samira Abdalla da Silva ◽  
Mauricio Mastrogiovanni ◽  
...  

Syzygium cumini (L.) Skeels has been reported to exert anti-inflammatory and cardiometabolic activities due to its high content of polyphenols. We characterized the chemical composition and assessed the antidiabetic effects of a novel polyphenol-rich extract (PESc) obtained from S. cumini leaf. Rats were injected with alloxan (150 mg/kg, ip, ALX group) and followed up for 7 days. Some were orally treated with PESc (50 mg/kg/day) for 7 days before and after diabetes induction (ALX-PP) or only for 7 days after alloxan injection (ALX-P). ALX-P and ALX-PP decreased fasting glycemia in 37 and 43%, respectively, as compared to ALX. Triglycerides and total cholesterol serum levels were also significantly reduced in comparison to ALX. PESc presented high polyphenol concentration (71.78 ± 8.57 GAE/100 g), with flavonoid content of 8.21 ± 0.42 QE/100 g. Upon HPLC-MS/MS and MS/MS studies, five main polyphenols—gallic acid, quercetin, myricetin, and its derivatives—were identified. Myricetin was predominant (192.70 ± 16.50 μg/mg PESc), followed by measurable amounts of gallic acid (11.15 ± 0.90 μg/mg PESc) and quercetin (4.72 ± 0.06 μg/mg PESc). Kinetic assessment of total antioxidant capacity revealed PESc high potency, since maximum response was reached within 5 min reaction time in a concentration-dependent manner. Specific antioxidant activity of PESc was assessed against both DPPH• and ABTS•+, showing strong activity (IC50: 3.88 ± 1.09 and 5.98 ± 1.19 μg/mL, resp.). PESc also inhibited lipoxygenase activity (IC50: 27.63 ± 8.47), confirming its antioxidant activity also on biologically relevant radicals. Finally, PESc induced insulin secretion by directly stimulating INS-1E β cells in the absence of any cytotoxic effect. Overall, our results support that PESc is a potent antioxidant phytocomplex with potential pharmacological use as a preventive antidiabetic natural product.


2013 ◽  
Vol 781-784 ◽  
pp. 1020-1026
Author(s):  
Yu Ping Li ◽  
Li Hua Yao ◽  
Guang Jie Wu ◽  
Fu Quan Jiang ◽  
Xiang Yuan Xiong ◽  
...  

Xiao-Yan-Hua-Jie-San (XYHJS), a traditional Chinese prescription, is used as a medication recipe to clinically treat inflammation and hepatitis. In previous study, we reported the hepatoprotective effects of XYHJS by increasing an antioxidant enzyme activity in mice. In the present study, the main bioactive components of XYHJS and their antioxidant activity were further investigated by using different model systems in vitro. The total phenolics content in the extract of XYHJS was determined by the Folin-Ciocalteu method. Analysis of the major phenolic compounds in the extract of XYHYS was carried out by high-performance liquid chromatography (HPLC) and thin layer chromatographic (TLC) method. The total phenolic content of the extract was 2.84 ± 0.06 mg gallic acid equivalent (GAE)/g extract powder. The phenolic acid in XYHJS was found to be gallic acid (GA). The content of GA was 2.80 mg/ml by HPLC (n=5, RSD=1.26%). Furthermore, the antioxidant activity of XYHJS extract was determined by 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity and hydroxyl free radicals (·OH) scavenging activity assay. The radical scavenging activity of XYHJS increased significantly in a concentration-dependent manner. At a concentration of 2.5 mg/ml, the DPPH and ·OH scavenging activity was 89.94% and 91.53%, respectively. It can be concluded that the content of GA in XYHJS is very high and it is the main contributor to the antioxidant activity of XYHJS. Our study indicates that XYHJS prescription could be considered to be an effective agent in the prevention of various liver diseases associated with oxidative stress.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yijing Han ◽  
Gege Hu ◽  
Yuying Chen ◽  
Lizhu Chen ◽  
Daode Yu ◽  
...  

Although defensins have been isolated from a variety of metazoan, their role in cellular immunity has not been answered. In the study, we found that the hemocytes of the Manila clams Ruditapes philippinarum release defensin (designated as Rpdef3) in response to Vibrio parahaemolyticus challenge. The antimicrobial Rpdef3 was proved to be involved in the extracellular traps (ETs) that hemocytes released in response to Vibrio challenge. Scanning electron microscopy observation proved the patterns how ETs eliminate invading bacteria. Furthermore, Rpdef3 involved in ETs had broad-spectrum antimicrobial effect on both Gram-negative bacteria and Gram-positive bacteria. ELISA assay revealed that Rpdef3 could bind lipopolysaccharides and peptidoglycan in a dose-dependent manner. As concerned to the antibacterial mechanisms, Rpdef3 can cause bacterial membrane permeabilization, leading to cell death. As a result, Rpdef3 might contribute to the trap and the elimination of invading Vibrio in clam ETs. Taken together, our study suggest that the formation of ETs is a defense mechanism triggered by bacterial stimulation, coupled with antibacterial defensin.


2019 ◽  
pp. 7-14
Author(s):  
Hai Trieu Ly ◽  
Tuan Anh Vo ◽  
Viet Hong Phong Nguyen ◽  
Thi My Sa Pham ◽  
Bich Thao Lam ◽  
...  

Background: The natural antioxidants have an important role in the prevention of many diseases. The aim of study is to investigate phytochemical components, antioxidant activity and acute oral toxicity of Pomegranate (Punica granatum L.) fruit peel (PFP) extract. Materials and methods: Phytochemicals of PFP were determined by qualitative chemical tests, thin layer chromatography, total polyphenol and flavonoid contents. The PFP extract was evaluated for antioxidant activity by DPPH assay and MDA assay. In vivo acute oral toxicity test was conducted using Karber-Behrens method to determine LD50. Results: Results illustrated that PFP mainly contains flavonoids, alkaloids, tannins, triterpenes, saponins, and coumarins. PFP extract exhibited the total polyphenol and flavonoid contents with 189.97 mg gallic acid equivalent/g dry weight and 9.42 mg quercetin equivalent/g dry weight, respectively. The DPPH free radical scavenging and anti-lipid peroxidation activities of PFP extract were expressed with IC50 value of 4.80 μg/mL and 0.38 μg/ mL, sequentially. Simultaneously, the Dmax (the maximum dose administered to mice that no toxicity was observed) of PFP extract was determined to be 21.28 g/kg, equivalent to 35.64 g dried herb. Conclusion: The PFP extract is relatively safe and revealed high antioxidant activity. Key words: Punica granatum L.; polyphenols; flavonoids; gallic acid; quercetin; antioxidant activity; acute oral toxicity


Author(s):  
Hadi Shariati ◽  
Mohammad Hassanpour ◽  
Gholamreza Sharifzadeh ◽  
Asghar Zarban ◽  
Saeed Samarghandian ◽  
...  

Objective: The present study has been carried out to evaluate the diuretic and antioxidant properties of pine herb in an animal model. Materials and Methods: 45 adult male rats were randomly divided into nine groups including: groups I (the negative control), groups II (positive control, furosemide 10 mg/kg), groups III to VIII (treatment groups received 100, 200, 400 mg/kg of the aqueous extracts of bark and fruit) and group IX received the combination of aqueous extract of bark (100 mg/kg) and the fruit (100 mg/kg). The urine output, glomerular filtration rate (GFR), electrolytes, urea, and creatinine levels were evaluated . Furthermore, the phenolic content and antioxidant activity of both extracts were also assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and Folin–Ciocalteu methods. Results: The aqueous extracts of the pine bark and fruit increased the urinary output in a dose-dependent manner. The combination of the two extracts compared to the other extracts alone significantly increased the serum potassium level. This study also showed each extract increase creatinine clearance in a dose-dependent manner (p<0.01 and p<0.05). The increase of GFR in the combination group was not significant. The current data showed a significant increase in the total phenolic content in pine bark extract in compared with the fruit extract. Conclusion: The pine bark and fruit can be useful in the prevention and treatment of kidney stones due to the high antioxidant activity.


2019 ◽  
Vol 15 (2) ◽  
pp. 156-164 ◽  
Author(s):  
Reza Farahmandfar ◽  
Maryam Asnaashari ◽  
Yegane Asadi ◽  
Batool Beyranvand

Background: It is important to study about the use of natural antioxidants as alternatives to synthetic ones due to the possibility of carcinogenic effects of synthetic antioxidants. This study is comparing the effect of the ultrasound-assisted and maceration extraction methods on antioxidant activity of Matricaria recutita. Methods: Bioactive compounds including phenolic, tocopherol, flavonoid and tannins and antioxidant activity of the extracts were evaluated. Moreover, extracts obtained from ultrasound and maceration methods were added to sunflower oil without any antioxidants at level of 200, 500 and 800 ppm, after that samples were heated at 180°C. Oxidation of the samples were evaluated after 0, 4, 8, 12, 16, 20 and 24 hours by measuring Peroxide Value (PV), Conjugated Diene (CD), Iodine Value (IV), Carbonyl Value (CV), Total Polar Compounds (TPC), Oil Stability Index (OSI), Color Index (CI) and acid value (AV). Results: The result showed total phenol (42.90 mg gallic acid/g extract), tocopherol (120.46 &#181;g &#945; - tocopherol/ml extract), flavonoid (2.64 mg/100 g extract) and tannins (3.89 mg gallic acid/g extract) of ultrasound extracts were higher than maceration extracts. Antioxidant activity of the extract was evaluated by DPPH assay which indicated 800 ppm of the Matricaria recutita extracted by ultrasound was the highest radical scavenging ability. Conclusion: Result indicated both ultrasound and maceration extracts could increase the oil oxidative stability but could not increase compared to BHA. In most cases, the extract samples by ultrasound had a better effect on stabilizing of sunflower oil during frying.


2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.


2020 ◽  
Vol 10 (4) ◽  
pp. 488-494 ◽  
Author(s):  
Venugopal Singamaneni ◽  
Sudheer Kumar Dokuparthi ◽  
Nilanjana Banerjee ◽  
Ashish Kumar ◽  
Tulika Chakrabarti

Background: Emblica officinalis Gaertn. which belongs to the family Euphorbiaceae, Terminalia chebula Retz. and Terminalia bellerica Roxb. belong to the family Combretaceae. These are well known medicinal plants with phytochemical reservoir of great medicinal values and possess a vast ethnomedical history. Objective: The aim of the present study is to isolation of major compounds and to evaluate antimutagenic potential of the ethanol extracts of these plants. Methods: The dried fruits of E. officinalis, T. bellirica and T. chebula were powdered and extracted with 95% ethanol. The ethyl acetate portions were chromatographed over silica gel to isolate major compounds. Antimutagenic activity was determined by Ames test using TA98 and TA100 strains of Salmonella typhimurium. Results: Two major known compounds, gallic acid and ellagic acid were isolated from the dried fruits of Emblica officinalis, Terminalia chebula and T. bellirica. All the three extracts counteracted the mutagenicity induced by different genotoxic compounds in a dose dependent manner. Conclusion: This study showed that ethyl acetate portion of three extracts contain two major compounds, gallic acid and ellagic acid which might be responsible for potent antimutagenic activity of these extracts.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ali Mahmoud Muddathir ◽  
Ebtihal Abdalla M. Mohieldin ◽  
Tohru Mitsunaga

Abstract Background Dental caries and periodontal disease are the most common chronic infectious oral diseases in the world. Acacia nilotica was commonly known in Sudan as Garad or Sunt has a wide range of medicinal uses. In the present study, antibacterial activity of oral bacteria (Streptococcus sobrinus and Porphyromonas gingivalis), inhibitory activity against glucosyltransferase (GTF) enzyme and antioxidant activity were assayed for methanolic crude extract of A. nilotica bark and its fractions. Methods Methanoilc crude extract of A. nilotica bark was applied to a Sephadex LH-20 column and eluted with methanol, aqueous methanol, and finally aqueous acetone to obtain four fractions (Fr1- Fr4). Furthermore, the crude extract and fractions were subjected to analytical high performance liquid chromatography (HPLC). The crude extract and its fractions were assayed for antibacterial activity against S. sobrinus and P. gingivalis using a microplate dilution assay method to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), as well as GTF inhibition and antioxidant activity using ABTS radical scavenging method. Results Fractions (Fr1 and Fr2) exhibited MIC values of 0.3 mg/ml against the P. gingivalis. Additionally, Fr2 displayed MBC value of 1 mg/ml against two types of bacteria. Fr4 showed an especially potent GTF inhibitory activity with IC50 value of 3.9 μg/ml. Fr1 displayed the best antioxidant activity with IC50 value of 1.8 μg/ml. The main compound in Fr1 was identified as gallic acid, and Fr2 was mostly a mixture of gallic acid and methyl gallate. Conclusions The results obtained in this study provide some scientific rationale and justify the use of this plant for the treatment of dental diseases in traditional medicine. A. nilotica bark, besides their antibacterial potentiality and GTF inhibitory activity, it may be used as adjuvant antioxidants in mouthwashes. Further studies in the future are required to identify the rest of the active compounds.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Poovarasan Neelakandan ◽  
Chiu-Chung Young ◽  
Asif Hameed ◽  
Yu-Ning Wang ◽  
Kui-Nuo Chen ◽  
...  

AbstractTea leaves possess numerous volatile organic compounds (VOC) that contribute to tea’s characteristic aroma. Some components of tea VOC were known to exhibit antimicrobial activity; however, their impact on bacteria remains elusive. Here, we showed that the VOC of fresh aqueous tea leaf extract, recovered through hydrodistillation, promoted cell division and tryptophan-dependent indole-3-acetic acid (IAA) production in Pseudomonas sp. NEEL19, a solvent-tolerant isolate of the tea phylloplane. 1-octanol was identified as one of the responsible volatiles stimulating cell division, metabolic change, swimming motility, putative pili/nanowire formation and IAA production, through gas chromatography-mass spectrometry, microscopy and partition petri dish culture analyses. The bacterial metabolic responses including IAA production increased under 1-octanol vapor in a dose-dependent manner, whereas direct-contact in liquid culture failed to elicit such response. Thus, volatile 1-octanol emitting from tea leaves is a potential modulator of cell division, colonization and phytohormone production in NEEL19, possibly influencing the tea aroma.


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