scholarly journals α-Glucosidase inhibitory activities, functional properties, and safety of green tea polysaccharides as a potential source of dietary supplement

2018 ◽  
Vol 3 ◽  
pp. 124-132
Author(s):  
Ayse Karadag ◽  
Kubra Dogan ◽  
Ebru Pelvan ◽  
Arzu Tas ◽  
Ozlem Atli Eklioglu ◽  
...  

Procuring valuable bioactive compounds from low quality green tea is of great interest. Green tea polysaccharides (GTPS), obtained from low quality tea leaves, were examined for their yield, monosaccharide composition, total phenolic content, antioxidant potential, and structures as well as molecular weight distribution and in vitro anti-diabetic activities. GTPS were also evaluated for their toxicity by performing cytotoxicity and genotoxicity. Additionally, 50% lethal dose (LD50) for GTPS was determined using an acute toxicity test to assess the safe use of it as a dietary supplement. Monosaccharides of GTPS were mainly composed of xylose, glucose, ribose, galactose, arabinose, and glucuronic acid. GTPS exhibited 91.86% α-glucosidase inhibition at 0.5 mg/mL concentration. The α-glucosidase inhibitory activity of GTPS was higher than that of pharmacological glucosidase inhibitor, acarbose, which exhibited only 47.86% inhibition at 2.5 mg/mL concentration. Neither cytotoxic nor no mutagenic effects were found for GTPS. The acute toxicity also showed that LD50 of GTPS was greater than 5,000 mg/kg. The present work suggests that GTPS can be considered as an anti-diabetic dietary supplement without posing any potential health risk.

2021 ◽  
Vol 13 ◽  
Author(s):  
Ebru Pelvan ◽  
Ayse Karadag ◽  
Kubra Dogan ◽  
Soner Aksu ◽  
Arzu Tas ◽  
...  

Type 2 diabetes (T2D) is one of the fast growing diet-related chronic diseases throughout the world. Tea contains several bioactive compounds, some of which render health benefits. Black tea polysaccharides (BTPS), extracted from low grade quality tea leaves, after processing, were examined for their in-vitro antidiabetic activities (α-glucosidase inhibitory and glucose uptake activities), chemical compositions (yield, monosaccharides, amino acids, and minerals), and antioxidant activities as well as toxicity (cytotoxicity and genotoxicity). In addition, 50% lethal dose (LD50) for BTPS was determined using an acute toxicity test to assess the safe use of it as a dietary ingredient. BTPS had strong α-glucosidase inhibitory activity with IC50 value of 3.4 µg/mL. This was much lower than that of the positive control, pharmaceutical glucosidase inhibitor acarbose with IC50 of 1.06 mM. BTPS also increased glucose uptake into the adipocyte differentiated 3T3-L1 MBX cells. Neither cytotoxic nor mutagenic effects were found for BTPS. The LD50 of BTPS for acute toxicity demonstrated that it was safe to use. The present work suggests that BTPS can be used as an antidiabetic dietary ingredient without posing any potential health risk.


Antioxidants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 560 ◽  
Author(s):  
Oracz ◽  
Zyzelewicz

Melanoidins from real foods and model systems have received considerable interest due to potential health benefits. However, due to the complexity of these compounds, to date, the exact structure of melanoidins and mechanism involved in their biological activity has not been fully elucidated. Thus, the aim of this study was to investigate the total phenolic content, antioxidant properties, and structural characteristics of high-molecular weight (HMW) melanoidin fractions isolated by dialysis (>12.4 kDa) from raw and roasted cocoa beans of Criollo, Forastero, and Trinitario beans cultivated in various area. In vitro antioxidant properties of all studied HMW cocoa fractions were evaluated by four different assays, namely free radical scavenging activity against DPPH● and ABTS●+ radicals, ferric reducing antioxidant power (FRAP), and metal-chelating ability. Additionally, the structure–activity relationship of isolated HMW melanoidin fractions were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The results show that roasting at a temperature of 150 °C and a relative air humidity of 0.3% effectively enhances the total phenolics content and the antioxidant potential of almost all HMW cocoa melanoidin fractions. The ATR-FTIR analysis revealed that the various mechanisms of action of HMW melanoidins isolates of different types of cocoa beans related to their structural diversity. Consequently, the results clearly demonstrated that HMW cocoa fractions isolated from cocoa beans (especially those of Criollo variety) roasted at higher temperatures with the lower relative humidity of air possess high antioxidant properties in vitro.


Author(s):  
E.N. Kurmanova ◽  
E.V. Ferubko ◽  
L.B. Strelkova ◽  
R.K. Kurmanov ◽  
O.P. Sheichenko

Змееголовник молдавский (Dracocephalum moldavica L.) в народной медицине используется в качестве противовоспалительного, ранозаживляющего, отхаркивающего и седативного средства. В ФГБНУ ВИЛАР разработан змееголовника молдавского травы экстракт сухой под условным названием «Люкатил» (сумма фенольных соединений 64,12% в пересчёте на цинарозид). Цель работы - изучение острой токсичности и противовоспалительной активности экстракта змееголовника для разработки на его основе лекарственного препарата. Методика. Проведено определение параметров острой токсичности и противовоспалительной активности экстракта. При изучении острой токсичности экстракта по методу Кербера использованы белые нелинейные мыши-самцы в количестве 30 особей. «Люкатил» вводили животным внутрижелудочно в дозах 500, 1000, 1500 и 2000 мг/кг. Для выявления противовоспалительной активности экстракта змееголовника молдавского использована in vitro ферментная биотест-система на основе индуцибельной NO-синтазы. Для выявления противовоспалительной активности экстракта in vivo использованы нелинейные мыши-самцы. Оценку влияния экстракта в дозе 200 мг/кг на экссудативную стадию воспаления проводили на модели 1% формалинового отёка. В качества препарата сравнения использовали индометацин (5 мг/кг). Формалиновый отёк вызывали однократным субплантарным введением под апоневроз задней правой лапки мыши 0,05 мл 1% формалина в качестве флогогенного агента. Величину отёка определяли по разнице в массе лапок контрольных и опытных животных и рассчитывали процент снижения степени отёка. Результаты. При однократном введении экстракт «Люкатил» не приводил к гибели животных, изменения внешнего вида и поведенческих реакций мышей не наблюдалось. В соответствии с классификацией токсичности химических веществ по ГОСТ 12.1.007-76 «Люкатил» является малотоксичным веществом. In vitro установлена высокая противовоспалительная активность экстракта, при этом остаточная активность iNOS снижалась до 25%. Экстракт в дозе 200 мг/кг in vivo обладал статистически значимым противовоспалительным эффектом. Он подавлял развитие экссудативной фазы воспаления на 33,7%, по сравнению с контрольной группой животных, уступая противовоспалительному эффекту индометацина. Заключение. Змееголовника молдавского травы экстракт сухой под условным названием «Люкатил» является малотоксичным веществом, обладает выраженным противовоспалительным эффектом в опытах in vitro, in vivo и является перспективным объектом для дальнейшего фармакологического изучения в качестве противовоспалительного лекарственного средства.Moldavian dragonhead (Dracocephalum moldavica L.) is used in traditional medicine as an anti-inflammatory, wound-healing, expectorant, and sedative means. In our Institute, a Moldavian dragonhead herb dry extract (total phenolic content, 64.12% in cynaroside equivalent) was developed and conventionally named Lyukatil. Objective. To study acute toxicity and anti-inflammatory activity of the dragonhead extract for developing a drug based on this extract. Method. Parameters of acute toxicity and anti-inflammatory activity of the extract were assessed. The study of acute toxicity of the extract was performed using the Kerber method on male white mongrel mice (n=30). Lyukatil was administered to the animals intragastrically at doses of 500 mg/kg, 1000 mg/kg, 1500 mg/kg, and 2000 mg/kg. Anti-inflammatory activity of the Moldavian dragonhead extract was determined in vitro using an enzyme Biotest system based on inducible NO synthase. Mongrel male mice were used to study the anti-inflammatory activity of the extract in vivo. The effect of the extract at a dose of 200 mg/kg on the exudative phase of inflammation was evaluated on a model of 1% formalin-induced edema. Indomethacin 5 mg/kg was used as a reference drug. Formalin edema was induced by a single subplantar injection of 0.05 ml of 1% formalin as a phlogogenic agent under the aponeurosis of the right hind leg. The degree of edema was determined by the difference in leg weights in control and experimental animals; then the decrease in edema was calculated in per cent. Results. A single administration of the extract Lyukatil did not cause death of animals, changes in the appearance or in behavioral responses, shortness of breath, or drowsiness. In accordance with the toxicity classification for chemical substances as per GOST Standard 12.1.007-76, Lyukatil is a low-toxic substance. The extract at a dose of 200 mg/kg exerted a significant anti-inflammatory effect as shown by suppression of the exudative phase of formalin-induced inflammation by 33.7% compared to the control group. However, this effect was inferior to the anti-inflammatory effect of indomethacin. Conclusions. The Moldavian dragonhead herb dry extract under the conventional name of Lyukatil is a low-toxic substance that has a significant anti-inflammatory effect both in vitro and in vivo and is a promising target for further pharmacological studies as an anti-inflammatory drug.


2020 ◽  
Vol 13 (1) ◽  
pp. 1-5
Author(s):  
Ratnaker Singh ◽  
Y. Trilochana

For over a century, peptic ulcer has been one of the most common gastrointestinal tract (GIT) disorder. There are number of drugs are now available for treatment. Drugs of herbal origin reduce the offensive factors and have proved to be safe, clinically effective, relatively less expensive, globally competitive, and with better patient tolerance.This study was performed to assess the anti-ulcer activity on different parts of B.aristata. Apart from that, acute toxicity, qualitative chemical analysis, total phenolic content (TPC), total flavonoid content(TFC) and in vitro antioxidant activities were evaluated. The potentially active plant part was selected for screening as gastro protective, in vivo antioxidant and antisecretory activities in ulcerated rats.The 50% ethanolic extract of B. aristata were subjected to preliminary phytochemical screening, estimation of TFC and TPC. The crude extract from the leaves of B. aristata gave best antiulcer activity among flower and stem. In acute toxicity studies, the administration of the crude extract of B. aristata leaves did not reveal any adverse effects or toxicity in rats at fourteen days observations.The results of these studies have shown that ethylexract of B.aristata leaf (EEBAL) produced a significant dose dependent ulcerprotective, antioxidant and antisecretory activity by blocking the activity of proton pump, protecting from antioxidants produced during stress induced ulcer and by enhancing glycoprotein levels.


Author(s):  
Swarup Kumar Kundu ◽  
Shonkor Kumar Das ◽  
M. Sohidullah

Green tea obtained from the leaves of Camellia sinensis (L.) Kuntze having potential health benefits. It contains significant amounts of antioxidant and is considered as world healthiest drink. Polyphenols in tea are thought to exhibits anti-carcinogenic and anti-inflammatory effects. Green tea catechins acts as immune modulators in immune dysfunction and also play a role in protection from degenerative diseases. Intake of green tea catechins suppress high fat diet induced obesity, prevent lipid and glucose metabolism disorders and reduce risk of coronary heart disease. Green tea constituent epigallocatechin-3-gallate (EGCG) is a potential antioxidant that shows protective effects against photo toxicity and photo carcinogenesis. In vitro animal experiments have suggested that polyphenols in green tea protect from lung cancer by their antioxidant and antimutagenic properties. This study chiefly highlights the convenience of green tea on health and propagates its further prospects.


Author(s):  
Manal Mortady Hamed ◽  
Aboelfetoh Mohamed Abdalla ◽  
Mosad Ahmed Ghareeb ◽  
Said Abdelhalim Saleh

Objective: The objective of this study was undertaken to estimate the total phenolic contents (TPCs), in vitro antioxidant of different solvent extracts of M. oleifera leaves, oral acute toxicity and LD50 determination of the 85% methanolic extract as well as the chromatographic isolation and identification of the extract constituents.Methods: The antioxidant activity of different solvent extracts of Moringa oleifera leaves were estimated using three antioxidant assays and the total phenolic contents (TPCs) were also evaluated using Folin-Ciocalteu’s assay. The n-BuOH extract undergoes further chromatographic isolation owing to the high antioxidant activity using 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) method, which resulted in the isolation of seven compounds.Results: The results showed that the TPCs values of the tested extracts were varied from 309.52 to 43.28 mg gallic acid equivalent/g dry extract. The reducing power antioxidant activities (RPAA) were 0.434, 0.402, 0.395, 0.149, 0.143 and 0.124, while the total antioxidant capacity (TAC) values were 316.43, 203.35, 181.56, 86.70, 76.62 and 50.83 mg ascorbic acid equivalent/g dry extract; for n-BuOH, EtOAc, 85% MeOH, H2O, CH2Cl2, and pet. ether extracts, respectively. The oral acute toxicity study of the 85% methanol extracts of M. oleifera and M. peregrina revealed that; their LD50 values were 3458.3 and 4125 mg/kg respectively, thus the two plants could be classified as slightly toxic in the scale of Hodge and Sterner which reflected their nutrient values as edible plants. The isolated compounds were identified on the basis of their 1H and 13C-NMR spectra as; cis-p-coumaric acid 4-O-(2'-O-β-D-apiofuranosyl)-β-D-glucopyranoside (1), chlorogenic acid (2), niazirin (3), 3,4-dihydroxy-β-phenylethoxy-O-α-L-rhamnopyranosyl-(l→2)-α-L-rhamnopyranosyl-(1→3)-4-O-caffeoyl-β-D-glucopyranoside (4), gallic acid (5), taxifolin (6), and benzyl-carbamo-thioethionate (7).Conclusion: The M. oleifera leaves showed promising antioxidant activities and slightly toxic behavior.


2019 ◽  
Vol 20 (10) ◽  
pp. 874-880 ◽  
Author(s):  
Georgakopoulou Vasiliki ◽  
Dimou Charalampia ◽  
Karantonis Christos Haralabos

Background: The present work evaluated the in vitro antioxidant, antithrombotic, antiatherogenic and antidiabetic activities of Urtica dioica, Sideritis euboea and Cistus creticus and investigated pasta fortification with the most bioactive one. The methods employed were total phenolic content (TPC) in mg of gallic acid equivalents per g of dried-herb, 2,2'-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) free radical scavenging in mg of dried-herb, cupric reducing antioxidant capacity (CUPRAC) in micromol trolox equivalent per g of dried-herb, platelet aggregation inhibition (PAF-PAI); plasma oxidation inhibition (POxI); and alpha glucosidase inhibition (a-GaseI) all in mg of dried-herb. Pasta fortified with the most bioactive herb was also studied for the above activities. Methods: Cistus creticus extract was more bioactive (p < 0.05) compared to Sideritis euboea and Urtica dioica in all but antithrombotic assay, where Sideritis euboea was superior to the others (TPC: 37.9 ± 0.56 versus 9.6 ± 0.83 and 5.4 ± 0.70; SA50-ABTS: 0.040 ± 0.001 versus 0.400 ± 0.010 and 0.520 ± 0.008; ACUPRAC: 860 ± 6.23 versus 170 ± 4.25 and 80 ± 3.63; IA50-PAF: 1.8 ± 0.14 versus 1.2 ± 0.10 and 5.2 ± 0.21; POxI: 0.095 ± 0.016 versus 0.216 ± 0.021 and 0.534 ± 0.029; IA50-aGase: 0.2 ± 0.01 versus 2.1 ± 0.16 and 1.7 ± 0.12). Results: Fortified pasta with cistus creticus extract exhibited significantly higher levels (p < 0.05) in all assays compared to plain pasta (TPC: 0.392 ± 0.064 versus 0.137 ± 0.020; SA50-ABTS: 9.4 ± 0.2 versus 126.9 ± 2.7; ACUPRAC: 5.4 ± 0.5 versus 0.9 ± 0.1; IA50-PAF: 1.87 ± 0.04 versus 2.28 ± 0.06; POxI: 3.21 ± 0.18 versus 12.2 ± 0.73; IA50-aGase: 8.9 ± 1.1 versus 18.2 ± 0.9). Conclusion: The current findings add to the mounting evidence on the potential health benefits to be derived from consuming pasta fortified with herbal extracts and indicate that Cistus creticus could form an ideal raw material towards the production of fortified pasta with increased nutritional value.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mariscal Brice Tchatat Tali ◽  
Cedric Derick Jiatsa Mbouna ◽  
Lauve Rachel Yamthe Tchokouaha ◽  
Patrick Valere Tsouh Fokou ◽  
Jaures Marius Tsakem Nangap ◽  
...  

Background. Terminalia mantaly is used in Cameroon traditional medicine to treat malaria and related symptoms. However, its antiplasmodial efficacy is still to be established. Objectives. The present study is aimed at evaluating the in vitro and in vivo antiplasmodial activity and the oral acute toxicity of the Terminalia mantaly extracts. Materials and Methods. Extracts were prepared from leaves and stem bark of T. mantaly, by maceration in distilled water, methanol, ethanol, dichloromethane (DCM), and hexane. All extracts were initially screened in vitro against the chloroquine-resistant strain W2 of P. falciparum to confirm its in vitro activity, and the most potent one was assessed in malaria mouse model at three concentrations (100, 200, and 400 mg/kg/bw). Biochemical, hematological, and histological parameters were also determined. Results. Overall, 7 extracts showed in vitro antiplasmodial activity with IC50 ranging from 0.809 μg/mL to 5.886 μg/mL. The aqueous extract from the stem bark of T. mantaly (Tmsbw) was the most potent (IC50=0.809 μg/mL) and was further assessed for acute toxicity and efficacy in Plasmodium berghei-infected mice. Tmsbw was safe in mice with a median lethal dose (LD50) higher than 2000 mg/kg of body weight. It also exerted a good antimalarial efficacy in vivo with ED50 of 69.50 mg/kg and had no significant effect on biochemical, hematological, and histological parameters. Conclusion. The results suggest that the stem bark extract of T. mantaly possesses antimalarial activity.


2019 ◽  
Vol 4 (3) ◽  
pp. 102-109
Author(s):  
K. M. Korytov ◽  
V. I. Dubrovina ◽  
A. B. Pyatidesyatnikova ◽  
S. A. Vityazeva ◽  
V. V. Voitkova ◽  
...  

Introduction. The current direction in medicine is the creation of immunobiological preparations to increase the effectiveness of specific immunotherapy and immunoprophylaxis, containing immunomodulators in their composition. These natural or synthetic substances can have a regulating effect on the immune system. At present, water-soluble organic-inorganic polymeric materials with nanoparticles of various chemical substances with bactericidal and immunomodulating properties can serve as such promising compounds.The aimof the work is to study the acute toxicity of polymer nanocomposites based on 1-vinil-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles and their effect on the functional state of immune system cells in vitro.Materials and methods.The study of acute toxicity was performed on outbred white mice. The activity of superoxide dismutase and glucose-6-phosphate dehydrogenase were studied in guinea pig peritoneal macrophages. The study of spontaneous and nanocomposite-induced production of pro- (interferon gamma and tumor necrosis factor alpha) and anti-inflammatory (interleukin-4) cytokines by blood cells was carried out using clinical material obtained from volunteers using the ELISA method. Results. It has been established that nanocomposites with silver and gold nanoparticles do not cause the death of white mice, their temperature increase and body weight decrease. The average lethal dose for a nanocomposite with selenium nanoparticles was determined as 1 gram per 1 kilogram of animal mass. It was shown that the tested nanocomposites have a stimulating effect on the production of cytokines by human blood cells in vitro. It was established that a nanocomposite with selenium nanoparticles increases the activity of superoxide dismutase and glucose-6-phosphate dehydrogenase. A comparative analysis of their actions with the actions of commercial preparations of biological origin, with immunomodulatory properties.Conclusion. The data obtained allow us to substantiate the need for further research on the effects of nanocomposites based on 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles on the macroorganism in both in vitro and in vivo conditions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nathalia de Assis Aguilar Duarte ◽  
Lindiane Eloisa de Lima ◽  
Flora Troina Maraslis ◽  
Michael Kundi ◽  
Emilene Arusievicz Nunes ◽  
...  

Triclosan (TCS) is an antimicrobial agent widely used in personal care products (PCP) and the di-(2-ethyl hydroxy-phthalate) (DEHP) is a chemical compound derived from phthalic acid, used in medical devices and plastic products with polyvinyl chloride (PVCs). As result of their extensive use, TCS and DEHP have been found in the environment and previous studies demonstrated the association between their exposure and toxic effects, mostly in aquatic organisms, but there is a shortage in the literature concerning the exposure of TCS and DEHP in human cells. The aim of the present study was to assess the impact of exposure to TCS and DEHP, as well as their combinations, on biomarkers related to acute toxicity and DNA instability, in HepG2 cells, by use of cytokinesis-block micronucleus cytome (CBMNCyt) assay. For that, the cultures were exposed to TCS, DEHP and combinations at doses of 0.10, 1.0, and 10 μM for the period of 4 h and the parameters related to DNA damage (i.e., frequencies of micronuclei (MN) and nuclear buds (NBUDs), to cell division (i.e., nuclear division index (NDI) and nuclear division cytotoxic index (NDCI) and to cell death (apoptotic and necrotic cells) were scored. Clear mutagenic effects were seen in cells treated with TCS, DEHP at doses of 1.0 and 10 μM, but no combined effects were observed when the cells were exposed to the combinations of TCS + DEHP. On the other hand, the combination of the toxicants significantly increased the frequencies of apoptotic and necrotic cells, as well as induced alterations of biomarkers related to cell viability (NDI and NDCI), when compared to the groups treated only with TCS or DEHP. Taken together, the results showed that TCS and DEHP are also able to induce acute toxicity and DNA damage in human cells.


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