Protective effect of Gymnema montanum against renal damage in experimental diabetic rats

Gymnema montanum Hook (Asclepiadaceae), is an endemic plant species of India, traditionally used for diabetes and its management. In this experiment, the ethanol extract of G. montanum (GLEt) at a dose of 200 mg/kg body weight was tested to evaluate its effect on renal damage in alloxan-induced diabetic rats and the efficacy was compared with standard hypoglycemic drug, glibenclamide (600 μg/kg body weight). The GLEt and glibenclamide were administered orally for 3 weeks and the effects on glucose, insulin, renal markers including urea, creatinine and uric acid, lipid peroxidation markers including thiobarbituric reactive substances (TBARS) and hydroperoxides and antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities in kidney were studied. In addition, the urinary protein profile was studied using SDS–PAGE. The results indicated that the GLEt significantly normalized the elevated blood glucose, renal markers and lipid peroxidation markers and increased antioxidant levels in diabetic kidney. The diabetic rats excreted large amount of proteins than untreated rats which was normalized during the treatment with GLEt. In conclusion, the GLEt was found to be more effective in reducing oxidative stress, thus confirming the ethnopharmacological use of G. montanum in protecting diabetes and its complications.     

Antidiabetic activity of alcoholic stem extract of Gymnema montanum in streptozotocin-induced diabetic rats

In the present study, the effect of alcoholic stem extract of Gymnema montanum (GMSt) on blood glucose, plasma insulin, and carbohydrate metabolic enzymes were studied in experimental diabetes. Diabetes mellitus was induced by a single intraperitoneal injection of STZ (60 mg/kg bw). Five days after STZ induction, diabetic rats received GMSt orally at the doses of 25, 50, 100 and 200 mg/kg daily for 3 weeks. Graded doses of stem extract showed a significant reduction in blood glucose levels and improvement in plasma insulin levels. The effect was more pronounced in 100 and 200 mg/kg than 50 mg/kg. GMSt showed significant increase in hexokinase, Glucose-6-phosphate dehydrogenase and glycogen content in liver of diabetic rats while there was significant reduction in the levels of glucose-6-phosphatase and fructose-1,6-bisphosphatase. The present study clearly indicated significant antidiabetic effect with the stem extract of G. montanum and lends support for its traditional usage.     

Antidiabetic effect of Gymnema montanum leaves: effect on lipid peroxidation induced oxidative stress in experimental diabetes

Gymnema montanum is widely used in ancient medicine for the ailment of various diseases. Oral administration of 200 mg kg(-1) (body weight) BW of the alcoholic extract of the leaf for 3 weeks resulted in a significant reduction in blood glucose and an increase in plasma insulin, whereas the effect of 50 and 100 mg kg(-1) BW was not significant. The alcoholic extract also resulted in decreased free radical formation in plasma of diabetic rats. Thus, this study shows that Gymnema montanum leaf extract (GLEt) possess antihyperglycemic and antiperoxidative effect. The decrease in lipid peroxides and increase in reduced glutathione (GSH), ascorbic acid (Vitamin C) and alpha-tocopherol (Vitamin E) clearly show the antioxidant properties of GLEt. The effect of GLEt was most prominently seen in the case of animals given 200 mg kg(-1) BW. In addition, the results suggest that GLEt was highly effective than the reference drug glibenclamide.     

Potential in vitro antioxidant and protective effects of Soymida febrifuga on ethanol induced oxidative damage in HepG2 cells

There is increasing evidence that oxidative stress is implicated in pathogenesis of various diseases, including alcoholic liver injury. In the present study, we investigated the comparative protective effects of leaf, bark, root and root bark extracts of Soymida febrifuga (Roxb.) A. Juss. (Meliaceae) against ethanol induced oxidative damage in HepG2 cells. Comparatively, methanolic and aqueous extracts of bark and leaf significantly attenuated the cytotoxicity of the ethanol, as determined by cytotoxicity, lipid peroxidation, lactate dehydrogenase, alanine aminotransferases and asparatate aminotransferases, than the root and root bark extracts. Ethanol induces liver toxicity through free radical generation so initially in vitro antioxidant activity of the extracts was evaluated. Methanolic and aqueous extracts of bark and leaf have shown higher total phenolic content, reducing power, metal chelating, superoxide, hydroxyl radical, hydrogen peroxide and nitric oxide (murine macrophage cells) scavenging activity than the root and root bark extracts.     

Leaves of Cassia tora as a novel cancer therapeutic – An in vitro study

Cassia tora Linn (Leguminacea) is a medicinal plant traditionally used as laxative, for the treatment of leprosy and various skin disorders. Preliminary phytochemical analysis of leaf showed the presence of polyphenols (3.7 mg gallic acid equivalent per gram dried leaves). The presence of phenolic compound prompted us to evaluate its antioxidant and antiproliferative potential. In the present study C. tora methanolic leaf extract (CTME) was evaluated for its nitric oxide scavenging activity and reducing power assays using Rutin and BHT as standards. The extract was studied for its lipid peroxidation inhibition assay using rat liver and brain. In all assays, a correlation existed between concentration of extract and percentage inhibition of free radical, reducing power and inhibition of lipid peroxidation. The antiproliferative activity of CTME with Cisplatin, anticancer drug was studied using human cervical cancer cells (HeLa). Proliferation of HeLa was measured by MTT assay, cell DNA content by modified diphenylamine method and apoptosis by Caspase 3 activity. The plant extract induced a marked concentration dependent inhibition on proliferation, reduced DNA content and apoptosis in HeLa. These results clearly indicate that C. tora is effective against free radical mediated diseases.     

Postsynaptic α-adrenoceptors in the perfused canine saphenous vein in vitro

To study the relative localization of α₁- and α₂-adrenoceptors in relation to the intima and the adventitia of canine saphenous vein, a comparison was made of the potency of α₁- and α₂-adrenoceptors agonists applied by intraluminal and extraluminal route of perfused segments of that vessel. Noradrenaline was the most potent of the agonists used and was approximately as potent by intraluminal as by extraluminal route. Cocaine (12 μmol/1) caused supersensitivity to noradrenaline which was of about the same magnitude (threefold) irrespective of the route of administration of noradrenaline. The selective α₁-agonist phenylephrine was about 10 times less potent than noradrenaline and was also equieffective by both routes. The selective α₂-agonist UK-14,304, at concentrations lower than 0.3 μmol/l, caused very small responses and only in 3 out of 14 experiments. In all cases it caused responses at concentrations higher than 0.3 μmol/l. Cocaine did not change the sensitivity to either phenylephrine or UK-14,304. Thus, it is concluded that the results obtained with cocaine agreed with expectations for a homogeneously innervated tissue. Furthermore, α₁-adrenoceptors seem to predominate and to be evenly distributed throughout the media. The lack of responses to the low concentrations of UK-14,304—those selectively acting on α₂-adrenoceptors—was ascribed to the very low efficacy of this agonist on the distal part of the canine saphenous vein and to the tone created by the perfusion pressure which might be high enough to mask this small response.     

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.     

Screening for in vitro antioxidant properties and fatty acid profiles of five Centaurea L. species from Turkey flora

Centaurea species are used for the treatment of various ailments in the popular medicine in some countries. This study was designed to examine antioxidant potentials and fatty acid profiles of five Centaurea species from Turkey flora. Antioxidant properties of methanolic extracts from these species were evaluated by six different methods: phosphomolybdenum assay, free radical scavenging assay, β-carotene/linoleic acid test system, metal chelating activity, ferric and cupric reducing power. Total phenolic and flavonoid concentrations of each extract were also determined using the Folin–Ciocalteu reagent and aluminum chloride. The results of these assay showed a significant antioxidant capacity in all researched extracts. Centaurea cheirolopha extract, with the highest amount of total phenolic and flavonoids, showed the highest antioxidant activities in all assay, except for metal chelating. Fatty acid profiles of these species were examined by GC–FID and 30 fatty acids were identified. Palmitic, linoleic, oleic, and linolenic acid were detected as the main components. The results of the study indicated that the Centaurea species can be considered as a source of new natural antioxidants and unsaturated fatty acids for food, cosmetic and pharmaceutical industries.     

泻白散及其主药体外抗氧化活性研究

目的 建立泻白散和方中3味主药甘草、地骨皮、桑白皮的体外抗氧化活性测定方法,并对31批药材和10批泻白散煎液的抗氧化活性进行测定。方法 采用紫外可见分光光度法检测一定浓度的药材提取液引起DPPH溶液吸光度（A）值降低,考察波长为517 nm,分别探索3味药材抗氧化活性成分的提取条件;并进行不同溶剂的吸收考察、专属性考察、DPPH线性考察、药材提取液线性考察、精密度试验、重复性试验、耐用性考察等方法学验证;以清除DPPH自由基的半抑制浓度（IC₅₀）作为评价指标,对泻白散和方中3味药材的体外抗氧化活性进行考察。结果 地骨皮、甘草、桑白皮和泻白散提取液的IC₅₀均值为0.31、1.24、1.49和0.91 g/L,泻白散提取工艺对方中药物抗氧化活性的保留均值为56%。结论 建立的抗氧化活性测定方法可用于泻白散及方中主药的抗氧化活性测定,为多维度评价中药和中药材质量提供新思路。     

Water extracts of Brassica oleracea var. costata potentiate paraquat toxicity to rat hepatocytes in vitro

Tronchuda cabbage extracts have been proven to have antioxidant potential against various oxidative species in cell free systems, though its antioxidant potential in cellular models remained to be demonstrated. In the present study, we used primary cultures of rat hepatocytes for the cellular assay system and paraquat PQ exposure as a pro-oxidant model agent, to test whether tronchuda cabbage hydrolysed water extracts provide protective or aggravating effects towards PQ-induced oxidative stress and cell death. For this purpose cellular parameters related to oxidative stress were measured, namely the generation of superoxide anion, glutathione oxidation, lipid peroxidation, intracellular ATP levels, activation of nuclear factor-κB (NF-κB), activity of antioxidant enzymes, and cell death.The obtained results demonstrated that the studied hydrolysed water extracts of tronchuda cabbage, especially rich in kaempferol (84%) and other polyphenols, namely hydroxycinnamic acids and traces of quercetin, can potentiate the toxicity of PQ in primary cultures of rat hepatocytes. These results highlight that prospective antioxidant effects of plant extracts, observed in vitro, using non-cellular systems, are not always confirmed in cellular models, in which the concentrations required to scavenge pro-oxidant species may be highly detrimental to the cells.     

In ovo exposure of a Fusarium mycotoxin butenolide induces hepatic and renal oxidative damage in chick embryos, and antioxidants provide protections

Butenolide is a mycotoxin produced by several toxigenic Fusarium species. It frequently invades many important grains, and evokes a broad spectrum of toxic effects. For these reasons, butenolide poses a health risk to both humans and animals. However, many toxicology issues of butenolide including targets and mechanisms of toxicity remain to be elucidated so far. The present study therefore attempts to reveal the toxic profile of butenolide from a viewpoint of oxidative damage, using chick embryos as an in vitro model. A single in ovo injection of butenolide resulted in significant oxidative injuries in embryonic livers and kidneys, as manifested by a dose-dependent depletion of sulfhydryl groups, reduction of glutathione peroxidase activity, and increase of thiobarbituric acid reactive substances production, an indicator of lipid peroxidation. In contrast, co-injections of butenolide with antioxidants sodium selenite, vitamin C and a representative antioxidative enzyme superoxide dismutase markedly abated these oxidative toxicities. In conclusion, the present study suggests that oxidative damage may serve as a mediator in the toxicity of butenolide, and amelioration of antioxidant defense capacity by exogenous supplementation may play a role in the prevention and treatment of butenolide intoxication.     

金樱子提取液对H2O2诱导HaCaT细胞氧化损伤保护作用研究

目的探讨金樱子提取液对H2O2诱导后人角质形成细胞(HaCaT cell)氧化损伤的保护作用。方法体外培养人角质形成细胞,用不同浓度的H2O2诱导细胞构建氧化应激损伤模型。CCK-8法检测不同浓度金樱子提取液对细胞增殖作用的影响;Hochest染色法检测不同浓度金樱子提取液对细胞凋亡作用的影响。结果100μmol·L-1 H2O2为构建氧化应激损伤模型的最适浓度。CCK-8法检测结果表明金樱子提取液能显著提高细胞的增殖,且随浓度的升高而增大。Hochest染色结果表明金樱子提取液能有效抑制由H2O2氧化损伤引起的细胞凋亡。结论金樱子提取液对H2O2诱导后的人角质形成细胞具有一定的氧化损伤保护作用。     

In vitro antioxidant activity and total phenolic content of ethanolic leaf extract of Stevia rebaudiana Bert.

The aim of this study was to assess the in vitro potential of ethanolic leaf extract of Stevia rebaudiana 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 36.93–68.76% 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 93.46 and 26.75 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 S. rebaudiana was achieved using Folin–Ciocalteau reagent containing 61.50 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 93.46, 132.05 and 81.08 μg/ml, respectively. However, the IC₅₀ values for the standard ascorbic acid were noted to be 26.75, 66.01 and 71.41 μg/ml respectively. The results obtained in this study clearly indicate that S. rebaudiana has a significant potential to use as a natural antioxidant agent.     

HPLC-ELSD同时测定铁破锣中3种三萜皂苷含量及体外抗氧化性研究

目的 建立同时测定铁破锣中3种三萜皂苷BeesiosideⅠ、Ⅱ、Ⅲ含量的方法,并研究铁破锣中三萜皂苷的体外抗氧化性。方法 运用反相高效液相色谱-蒸发光散射检测法（HPLC-ELSD）对铁破锣中三萜皂苷进行含量测定,并对所用含量测定方法进行方法学考察;同时,对铁破锣中三萜皂苷清除自由基的能力和总的抗氧化能力进行体外试验。结果 HPLC-ELSD方法可同时测定BeesiosideⅠ、Ⅱ、Ⅲ的含量,且该方法线性关系良好、精密度、重复性、稳定性均好,回收率高;铁破锣中三萜皂苷能够有效清除ABTS⁺、DPPH·和羟基自由基,并且具有很好的抗氧化能力。结论 HPLC-ELSD方法简便、快速、准确、重现性好,可作为铁破锣中三萜皂苷（BeesiosideⅠ、Ⅱ、Ⅲ）的含量测定及质量控制标准方法,体外试验表明铁破锣中三萜皂苷具有良好的自由基清除和抗氧化能力。     

Potential of coculture in vitro models to study inflammatory and sensitizing effects of particles on the lung

Exposure to particulate matter (PM) like nanoparticles (NPs) has increased in the last century due to increased combustion processes, road traffic, etc. In addition, the progress in chemical and cosmetic industry led to many new compounds, e.g. fragrances, which humans are exposed to every day. Many chemicals are known to act as contact and some as respiratory sensitizers, causing allergic reactions. Exposure to small particles of less than 100 nm in diameter is linked with an increased risk of respiratory diseases, such as asthma or rhinitis. To date already more than 1000 customer products contain eNPs without knowing much about the health effects. In comparison to chemicals, the mechanisms by which PM and eNPs can cause sensitization are still not fully understood. Validated and regulatory accepted in vitro models to assess this hazard in its full range are still missing. While a huge number of animal studies contributed to our knowledge about sensitization processes, knowledge on involved cellular mechanisms is still limited. In this review relevant in vitro models to study and elucidate these mechanisms in more detail are presented and their potential to serve as part of a tiered testing strategy is discussed.     

In vitro digestibility of β-casein and β-lactoglobulin under simulated human gastric and duodenal conditions: A multi-laboratory evaluation

Initially the resistance to digestion of two cow’s milk allergens, β-casein, and β-lactoglobulin (β-Lg), was compared using a “high-protease assay” and a “low-protease assay” in a single laboratory. The low-protease assay represents an alternative standardised protocol mimicking conditions found in the gastrointestinal tract. For the high-protease assay, both proteins were incubated with either pepsin or pancreatin and digestion monitored by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and reverse phase-high performance liquid chromatography. The low-protease assay involved gastroduodenal digestion in the presence or absence of phosphatidylcholine (PC). Both β-casein and β-Lg were susceptible to hydrolysis by pepsin and pancreatin in the high-protease assay. In contrast, the kinetics of β-casein digestion in the low-protease assay were slower, β-Lg being pepsin resistant. During duodenal digestion, β-Lg was gradually degraded and addition of PC slowed digestion. Subsequently, the reproducibility of the low-protease assay was assessed in 12 independent laboratories by visual assessment of the gels and densitometric analysis: the inter- and intra-laboratory variability was affected by sampling and electrophoresis method employed. The low-protease assay was shown to be reproducible. Future studies will extend these findings using a broader panel of proteins.     

Development of enzyme-linked immunosorbent assay for 8-iso-prostaglandin F2α, a biomarker of oxidative stress in vivo, and its application to the quantification in aged rats

8-iso-Prostaglandin F_2α (8-iso-PGF_2α) is one of the isoprostanes that are mainly generated nonenzymatically in vivo from arachidonic acid through free radical-induced lipid peroxidation. To assess oxidative stress in vivo, we developed a quantitative enzyme-linked immunosorbent assay (ELISA) for 8-iso-PGF_2α. A sensitive calibration curve allowed the quantification of the amounts from 0.23 pg to 98.4 pg with 4.7 pg of 50% displacement in one assay. The ELISA method was applied to the measurement of the plasma levels of 8-iso-PGF_2α in young rats (4–8 weeks of age) and aged rats (106–123 weeks). The average level of esterified form in the plasma from aged rats was 30.6-fold higher than that in the plasma from young rats, reflecting the enhanced status of oxidative stress in aged animals. In addition, the aged rats exhibited higher levels of this F₂-isoprostane esterified to lipids from liver and kidney, suggesting local oxidative injury in specific organs. These results indicate the utility and accuracy of our ELISA for 8-iso-PGF_2α as a biomarker in vivo to assess systemic oxidative stress in animals or humans as well as oxidative injury at local sites.     

啤酒花总查尔酮的提取工艺及对氧化损伤心肌细胞的保护作用研究

目的 探讨啤酒花总查尔酮的最佳提取工艺及其对过氧化氢(H₂O₂)氧化损伤H₉C₂心肌细胞的保护作用。方法 采用正交试验法研究了提取时间、料液比与提取次数对啤酒花总查尔酮得率的影响,并研究了总查尔酮对过氧化氢氧化损伤H₉C₂心肌细胞保护作用。结果 总查尔酮最佳提取工艺条件为,提取时间5 min、料液比1:20、提取次数2次,此条件下黄腐酚得率可达19.9 µg·mL^-1,明显提高过氧化氢损伤H9C2细胞细胞存活率,并降低乳酸脱氢酶（LDH）含量、提高超过氧化歧化酶（SOD）和过氧化氢酶（CAT）活性。结论 在最佳条件下黄腐酚具有较高的提取得率,对过氧化氢损伤H9C2心肌细胞具有较好的保护作用,为啤酒花进一步研究与开发提供依据。     

Mitigating effects of antioxidant properties of Artemisia campestris leaf extract on hyperlipidemia,advanced glycation end products and oxidative stress in alloxan-induced diabetic rats

Artemisia campestris is used as antivenom and anti-inflammatory Tunisian folk medicine. Recently, increased oxidative stress was shown to play an important role in the etiology and pathogenesis of diabetes mellitus and its complications. This study was designed to examine the effects of A. campestris leaf aqueous extract (Ac) on alloxan-induced diabetic rats by measuring glycemia, lipid profile, lipid peroxidation (MDA), protein carbonyl content (PCO), advanced oxidation protein products (AOPP), activities of both non-enzymatic and enzymatic antioxidants. Results of our study showed an increase in blood glucose levels, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), a decrease in high-density lipoprotein cholesterol (HDL-c) level and disturbed antioxidant enzyme activities (CAT, SOD, GPx) in the pancreatic tissue of diabetic rats. Furthermore, MDA, PCO and AOPP were elevated in the pancreas of the diabetic rats. The administration of Ac to diabetic rats at a dose of 200 mg kg⁻¹ bw resulted in a significant reduction in glycemia, TC, TG, LDL-c, pancreas LPO, PCO and AOPP levels, CAT and GPx activities associated with an elevation of GSH content and SOD activity in comparison with diabetic group. We conclude that A. campestris aqueous extract may be effective for correcting hyperglycemia and preventing diabetic complications.