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Hui Teng - One of the best experts on this subject based on the ideXlab platform.
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anti inflammatory effect of self emulsifying delivery system containing Sonchus oleraceus linn extract on streptozotocin induced diabetic rats
Food and Chemical Toxicology, 2020Co-Authors: Lei Chen, Xiaowei Xu, Lihao Wang, Hui TengAbstract:Abstract Edible Sonchus oleraceus Linn is a medicinal plant with many bioactivities such as anti-diabetic activity and anti-inflammatory activity. However, the main bioactive components such as polyphenols in S. oleraceus Linn are poorly absorbed in gastrointestinal tract and rapidly metabolized. Thereby, a self-emulsifying delivery system containing S. oleraceus Linn extracts (SSEDDS) was introduced to evade these problems. Herein, the anti-inflammatory effect of SSEDDS on streptozotocin-induced diabetic rats was investigated. The plasma glucose level was increased and plasma insulin level was decreased in diabetic rats. The levels of NF-κB, TNF-α, and IL-6 in the liver were significantly improved in diabetic rats (p
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Sonchus oleraceus linn protects against lps induced sepsis and inhibits inflammatory responses in raw264 7 cells
Journal of Ethnopharmacology, 2019Co-Authors: Lei Chen, Jianbo Xiao, Yuting Tian, Baodong Zheng, Hui TengAbstract:Abstract Ethnopharmacological relevance Sonchus oleraceus Linn (SOL) belongs to family of Asteraceae, is a traditional medicinal plant, which has been used to treat tumor, inflammatory diseases, infection and so on in Chinese folk culture. Aim of the study This work investigated the influence of aqueous ethanol extract of whole plant of SOL and contribution of its main components on inflammation Methods and results Oral administration of SOL (10 mg/kg) to mice reduced the expression of inflammatory cytokines including IL-6, IL-1β, and TNF-α, in the LPS-induced sepsis mouse model. Major phenolics in SOL were isolated and determined by HPLC. Results indicate that SOL at the concentration range from 25 to 100 μg/mL and its main components, chlorogenic acid, caffeic acid (25–100 μM) significantly reduced the pro-inflammatory cytokine IL-1β, IL-6, TNF-α, attenuated iNOS and COX-2 expression in LPS-stimulated Macrophages. In addition, western blot analysis showed SOL suppressed inducible nitric oxide synthase (iNOS) protein expression and the phosphorylation of extracellular signal-regulated kinase (ERK), p38, c-Jun N-terminal kinase (JNK). Conclusion The underlying mechanism of anti-inflammation might be in according with the inhibition of MAPKs activation as well as down regulation of iNOS and cyclooxygenase-2 (COX-2).
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chlorogenic acid and caffeic acid from Sonchus oleraceus linn synergistically attenuate insulin resistance and modulate glucose uptake in hepg2 cells
Food and Chemical Toxicology, 2019Co-Authors: Lei Chen, Hui TengAbstract:Abstract The crude extract of Sonchus oleraceus Linn (CE) and its main phenolic acids (PA), chlorogenic acid and caffeic acid have anti-diabetic activity, but the mechanisms for their effects on glucose intake remain largely unknown. Aim of this study was to examine the synergistic effect of chlorogenic and caffeic acid from S. oleraceus Linn attenuate insulin resistance and modulate glucose uptake in HepG2 cells. Major phenolic acids in SOL were isolated and identified by HPLC. Insulin-resistance HepG2 cell model was used to elucidate the effect of CE on glucose metabolism. Pre-treatment of HepG2 cells with CE or PA enhanced levels of glucose production and avoided the decrease total levels of IRS-1 triggered by high insulin concentration. CE or PA pre-treatment also could prevent the inactivation of the PI3K/AKT pathway, as well as the diminution of GLUT4 levels induced by high glucose. These findings suggested that CE and its main phenolic acids improved insulin sensitivity of HepG2 cells treated with insulin, preventing or delaying a potential hepatic dysfunction through the attenuation of the insulin signaling blockade and the modulation of glucose consumption.
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self nano emulsifying formulation of Sonchus oleraceus linn for improved stability implications for phenolics degradation under in vitro gastro intestinal digestion food grade drug delivery system for crude extract but not single compound
Journal of Functional Foods, 2019Co-Authors: Lei Chen, Xiaowei Xu, Yi Chen, Kang Li, Jie Pang, Hui TengAbstract:Abstract The objective of this study was to evaluate self-emulsifying drug delivery system (SNEDDS) for phenolic-extract of Sonchus oleraceus Linn (TSF-SNEDDS). The optimal prescription of the SNEDDS was as follows: isopropyl myristate (IPM) as the oil phase, Tween-20 as the emulsifier, polyethylent glycol-400 (PEG-400) as the co-emulsifier, and the weight ratio of the three was 1:3:1 (w/w/w). The phenolic-extract loading was 11% of the prescription and it remained stable after storing at room temperature at least for 30 days without delamination. TSF-SNEDDS was found to be uniform, spherical distribution and the particle size of the emulsion was 183 ± 0.7 nm. A dynamic gastro-intestinal model was used to evaluate the behavior of TSF-SNEDDS under digestion. SNEDDS had a significant impact on stability of major phenolic compounds presented in Sonchus oleraceus Linn within the simulated gastric-intestine tract. These results indicate that SNEDDS is a promising delivery system for functional extract by increasing its stability.
Xiangjing Wang - One of the best experts on this subject based on the ideXlab platform.
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verrucosispora sonchi sp nov a novel endophytic actinobacterium isolated from the leaves of common sowthistle Sonchus oleraceus l
International Journal of Systematic and Evolutionary Microbiology, 2016Co-Authors: Shanshan Zhao, Wensheng Xiang, Ying Huang, Xiangjing WangAbstract:A novel actinobacterium, designated strain NEAU-QY3T, was isolated from the leaves of Sonchus oleraceus L. and examined using a polyphasic taxonomic approach. The organism formed single spores with smooth surface on substrate mycelia. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the strain had a close association with the genus Verrucosispora and shared the highest sequence similarity with Verrucosispora qiuiae RtIII47T (99.17 %), an association that was supported by a bootstrap value of 94 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. The strain also showed high 16S rRNA gene sequence similarities to Xiangella phaseoli NEAU-J5T (98.78 %), Jishengella endophytica 202201T (98.51 %), Micromonospora eburnea LK2-10T (98.28 %), Verrucosispora lutea YIM 013T (98.23 %) and Salinispora pacifica CNR-114T (98.23 %). Furthermore, phylogenetic analysis based on the gyrB gene sequences supported the conclusion that strain NEAU-QY3T should be assigned to the genus Verrucosispora . However, the DNA–DNA hybridization relatedness values between strain NEAU-QY3T and V. qiuiae RtIII47T and V. lutea YIM 013T were below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA–DNA hybridization results, strain NEAU-QY3T was readily distinguished from its most closely related strains and classified as a new species, for which the name Verrucosispora sonchi sp. nov. is proposed. The type strain is NEAU-QY3T (=CGMCC 4.7312T=DSM 101530T).
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plantactinospora sonchi sp nov an actinobacterium isolated from the leaves of common sowthistle Sonchus oleraceus l
International Journal of Systematic and Evolutionary Microbiology, 2015Co-Authors: Hairong He, Chuang Li, Jiansong Li, Shanshan Zhao, Wensheng Xiang, Xiangjing WangAbstract:A novel actinobacterium, designated strain NEAU-QY2T, was isolated from the leaves of Sonchus oleraceus L. specimen, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic position of this strain. The organism formed single spores with rough surfaces on substrate mycelia. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-QY2T belonged to the genus Plantactinospora and formed a monophyletic clade with its closest related strains Plantactinospora endophytica YIM 68255T (99.2 % 16S rRNA gene sequence similarity), Plantactinospora veratri NEAU-FHS4T (98.8 %) and Plantactinospora mayteni YIM 61359T (98.7 %), an association that was supported by a bootstrap value of 90 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. However, DNA–DNA hybridization values between strain NEAU-QY2T and the three closely related strains were below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA–DNA hybridization results, strain NEAU-QY2T was distinguished from closely related strains and is classified as representing a novel species of the genus Plantactinospora, for which the name Plantactinospora sonchi sp. nov. is proposed. The type strain is NEAU-QY2T ( = CGMCC 4.7216T = JCM 30345T).
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streptosporangium sonchi sp nov and streptosporangium kronopolitis sp nov two novel actinobacteria isolated from a root of common sowthistle Sonchus oleraceus l and a millipede kronopolites svenhedind verhoeff
Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2015Co-Authors: Hairong He, Jiansong Li, Xiangjing Wang, Junwei Zhao, Xin Wang, Wensheng XiangAbstract:Two novel actinobacteria, designated strains NEAU-QS7T and NEAU-ML10T, were isolated from a root of Sonchus oleraceus L. and a Kronopolites svenhedind Verhoeff specimen, respectively, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic positions of these strains. The two strains were observed to form abundant aerial hyphae that differentiated into spherical spore vesicles. The phylogenetic analysis based on the 16S rRNA gene sequences of strains NEAU-QS7T and NEAU-ML10T showed that the two novel isolates exhibited 99.7 % 16S rRNA gene sequence similarity with each other and that they are most closely related to Streptosporangium shengliense NEAU-GH7T (99.1, 99.0 %) and Streptosporangium longisporum DSM 43180T (99.1, 99.0 %). However, the DNA–DNA hybridization value between strains NEAU-QS7T and NEAU-ML10T was 46.5 %, and the values between the two strains and their closest phylogenetic relatives were also below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA–DNA hybridization results, the two strains can be distinguished from each other and their closest phylogenetic relatives. Thus, strains NEAU-QS7T and NEAU-ML10T represent two novel species of the genus Streptosporangium, for which the names Streptosporangium sonchi sp. nov. and Streptosporangium kronopolitis sp. nov. are proposed. The type strains are NEAU-QS7T (=CGMCC 4.7142T =DSM 46717T) and NEAU-ML10T (=CGMCC 4.7153T =DSM 46720T), respectively.
Arlene Mcdowell - One of the best experts on this subject based on the ideXlab platform.
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effects of boiling and in vitro gastrointestinal digestion on the antioxidant activity of Sonchus oleraceus leaves
Food & Function, 2016Co-Authors: S M M R Mawalagedera, Zong Quan Ou, Arlene Mcdowell, Kevin S GouldAbstract:Leaves of Sonchus oleraceus L. are especially rich in phenolic compounds and have potent extractable antioxidants. However, it is not known how their antioxidant activity changes after cooking and gastrointestinal digestion. We recorded the profile of phenolics and their associated antioxidant activity in both raw and boiled S. oleraceus leaf extracts after in vitro gastric and intestinal digestion, and quantified their antioxidant potentials using Caco-2 and HepG2 cells. Boiling significantly diminished the oxygen radical absorbance capacity (ORAC) and concentrations of ascorbate and chicoric acid in the soluble fractions. In contrast, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and concentrations of caftaric and chlorogenic acids were unaffected. Phenolics in the soluble fraction were absorbed into cultured human cells and exerted antioxidant activity. Only chlorogenic acid content remained stable during gastrointestinal digestion. S. oleraceus appears to be an excellent dietary source of phenolic antioxidants.
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anti ageing effects of Sonchus oleraceus l pūhā leaf extracts on h2o2 induced cell senescence
Molecules, 2015Co-Authors: Zong Quan Ou, Thomas Rades, Arlene McdowellAbstract:Antioxidants protect against damage from free radicals and are believed to slow the ageing process. Previously, we have reported the high antioxidant activity of 70% methanolic Sonchus oleraceus L. (Asteraceae) leaf extracts. We hypothesize that S. oleraceus extracts protect cells against H2O2-induced senescence by mediating oxidative stress. Premature senescence of young WI-38 cells was induced by application of H2O2. Cells were treated with S. oleraceus extracts before or after H2O2 stress. The senescence- associated β-galactosidase (SA-β-gal) activity was used to indicate cell senescence. S. oleraceus extracts showed higher cellular antioxidant activity than chlorogenic acid in WI-38 cells. S. oleraceus extracts suppressed H2O2 stress-induced premature senescence in a concentration-dependent manner. At 5 and 20 mg/mL, S. oleraceus extracts showed better or equivalent effects of reducing stress-induced premature senescence than the corresponding ascorbic acid treatments. These findings indicate the potential of S. oleraceus extracts to be formulated as an anti-ageing agent.
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Anti-ageing effects of Sonchus oleraceus L. (pu¯ha¯) leaf extracts on H2O2-induced cell senescence
Molecules, 2015Co-Authors: Zong Quan Ou, Thomas Rades, Arlene McdowellAbstract:Antioxidants protect against damage from free radicals and are believed to slow the ageing process. Previously, we have reported the high antioxidant activity of 70% methanolic Sonchus oleraceus L. (Asteraceae) leaf extracts. We hypothesize that S. oleraceus extracts protect cells against H2O2-induced senescence by mediating oxidative stress. Premature senescence of young WI-38 cells was induced by application of H2O2. Cells were treated with S. oleraceus extracts before or after H2O2 stress. The senescence- associated beta-galactosidase (SA-beta-gal) activity was used to indicate cell senescence. S. oleraceus extracts showed higher cellular antioxidant activity than chlorogenic acid in WI-38 cells. S. oleraceus extracts suppressed H2O2 stress-induced premature senescence in a concentration-dependent manner. At 5 and 20 mg/mL, S. oleraceus extracts showed better or equivalent effects of reducing stress-induced premature senescence than the corresponding ascorbic acid treatments. These findings indicate the potential of S. oleraceus extracts to be formulated as an anti-ageing agent.
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influence of postharvest processing and storage conditions on key antioxidants in pūhā Sonchus oleraceus l
Journal of Pharmacy and Pharmacology, 2014Co-Authors: Zong Quan Ou, Thomas Rades, David M Schmierer, Clare J Strachan, Arlene McdowellAbstract:Objectives To investigate effects of different postharvest drying processes and storage conditions on key antioxidants in Sonchus oleraceus L. leaves. Methods Fresh leaves were oven-dried (60°C), freeze-dried or air-dried (∼25°C) for 6 h, 24 h and 3 days, respectively. Design of experiments (DOE) was applied to study the stability of antioxidants (caftaric, chlorogenic and chicoric acids) in S. oleraceus leaves and leaf extracts stored at different temperatures (4, 25 and 50°C) and relative humidities (15%, 43% and 75%) for 180 days. The concentration of antioxidants was quantified by a HPLC–2,2′-diphenylpicrylhydrazyl post-column derivatisation method. Antioxidant activity was assessed by a cellular antioxidant activity assay. Key findings The three antioxidants degraded to unquantifiable levels after oven-drying. More than 90% of the antioxidants were retained by freeze-drying and air-drying. Both leaf and extract samples retained > 90% of antioxidants, except those stored at 75% relative humidity. Leaf material had higher antioxidant concentrations and greater cellular antioxidant activity than corresponding extract samples. Conclusion Freeze-drying and air-drying preserved more antioxidants in S. oleraceus than oven-drying. From DOE analysis, humidity plays an important role in degradation of antioxidants during storage. To preserve antioxidant activity, it is preferable to store S. oleraceus as dried leaf material.
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application of an online post column derivatization hplc dpph assay to detect compounds responsible for antioxidant activity in Sonchus oleraceus l leaf extracts
Journal of Pharmacy and Pharmacology, 2013Co-Authors: Zong Quan Ou, Thomas Rades, David M Schmierer, Lesley Larsen, Arlene McdowellAbstract:Objectives To use an online assay to identify key antioxidants in Sonchus oleraceus leaf extracts and to investigate the effect of leaf position and extraction conditions on antioxidant concentration and activity. Methods Separation of phytochemicals and simultaneous assessment of antioxidant activity were performed online using HPLC and post-column reaction with a free-radical reagent (2, 2-diphenylpicrylhydrazyl, DPPH). Active compounds were identified using nuclear magnetic resonance spectroscopy and mass spectrometry. We applied the online HPLC-DPPH radical assay to evaluate antioxidants in leaves from different positions on the plant and to assess the effect of pre-treatment of leaves with liquid N2 before grinding, extraction time, extraction temperature and method of concentrating extracts. Key findings Key antioxidants identified in S. oleraceus leaf extracts were caftaric acid, chlorogenic acid and chicoric acid. Middle leaves contained the highest total amount of the three key antioxidant compounds, consisting mainly of chicoric acid. Pre-treatment with liquid N2, increasing the extraction temperature and time and freeze-drying the extract did not enhance the yield of the key antioxidants. Conclusion The online HPLC-DPPH radical assay was validated as a useful screening tool for investigating individual antioxidants in leaf extracts. Optimized extraction conditions were middle leaves pre-treated with liquid N2, extraction at 25°C for 0.5 h and solvent removal by rotary evaporation.
Lei Chen - One of the best experts on this subject based on the ideXlab platform.
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anti inflammatory effect of self emulsifying delivery system containing Sonchus oleraceus linn extract on streptozotocin induced diabetic rats
Food and Chemical Toxicology, 2020Co-Authors: Lei Chen, Xiaowei Xu, Lihao Wang, Hui TengAbstract:Abstract Edible Sonchus oleraceus Linn is a medicinal plant with many bioactivities such as anti-diabetic activity and anti-inflammatory activity. However, the main bioactive components such as polyphenols in S. oleraceus Linn are poorly absorbed in gastrointestinal tract and rapidly metabolized. Thereby, a self-emulsifying delivery system containing S. oleraceus Linn extracts (SSEDDS) was introduced to evade these problems. Herein, the anti-inflammatory effect of SSEDDS on streptozotocin-induced diabetic rats was investigated. The plasma glucose level was increased and plasma insulin level was decreased in diabetic rats. The levels of NF-κB, TNF-α, and IL-6 in the liver were significantly improved in diabetic rats (p
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Sonchus oleraceus linn protects against lps induced sepsis and inhibits inflammatory responses in raw264 7 cells
Journal of Ethnopharmacology, 2019Co-Authors: Lei Chen, Jianbo Xiao, Yuting Tian, Baodong Zheng, Hui TengAbstract:Abstract Ethnopharmacological relevance Sonchus oleraceus Linn (SOL) belongs to family of Asteraceae, is a traditional medicinal plant, which has been used to treat tumor, inflammatory diseases, infection and so on in Chinese folk culture. Aim of the study This work investigated the influence of aqueous ethanol extract of whole plant of SOL and contribution of its main components on inflammation Methods and results Oral administration of SOL (10 mg/kg) to mice reduced the expression of inflammatory cytokines including IL-6, IL-1β, and TNF-α, in the LPS-induced sepsis mouse model. Major phenolics in SOL were isolated and determined by HPLC. Results indicate that SOL at the concentration range from 25 to 100 μg/mL and its main components, chlorogenic acid, caffeic acid (25–100 μM) significantly reduced the pro-inflammatory cytokine IL-1β, IL-6, TNF-α, attenuated iNOS and COX-2 expression in LPS-stimulated Macrophages. In addition, western blot analysis showed SOL suppressed inducible nitric oxide synthase (iNOS) protein expression and the phosphorylation of extracellular signal-regulated kinase (ERK), p38, c-Jun N-terminal kinase (JNK). Conclusion The underlying mechanism of anti-inflammation might be in according with the inhibition of MAPKs activation as well as down regulation of iNOS and cyclooxygenase-2 (COX-2).
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chlorogenic acid and caffeic acid from Sonchus oleraceus linn synergistically attenuate insulin resistance and modulate glucose uptake in hepg2 cells
Food and Chemical Toxicology, 2019Co-Authors: Lei Chen, Hui TengAbstract:Abstract The crude extract of Sonchus oleraceus Linn (CE) and its main phenolic acids (PA), chlorogenic acid and caffeic acid have anti-diabetic activity, but the mechanisms for their effects on glucose intake remain largely unknown. Aim of this study was to examine the synergistic effect of chlorogenic and caffeic acid from S. oleraceus Linn attenuate insulin resistance and modulate glucose uptake in HepG2 cells. Major phenolic acids in SOL were isolated and identified by HPLC. Insulin-resistance HepG2 cell model was used to elucidate the effect of CE on glucose metabolism. Pre-treatment of HepG2 cells with CE or PA enhanced levels of glucose production and avoided the decrease total levels of IRS-1 triggered by high insulin concentration. CE or PA pre-treatment also could prevent the inactivation of the PI3K/AKT pathway, as well as the diminution of GLUT4 levels induced by high glucose. These findings suggested that CE and its main phenolic acids improved insulin sensitivity of HepG2 cells treated with insulin, preventing or delaying a potential hepatic dysfunction through the attenuation of the insulin signaling blockade and the modulation of glucose consumption.
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self nano emulsifying formulation of Sonchus oleraceus linn for improved stability implications for phenolics degradation under in vitro gastro intestinal digestion food grade drug delivery system for crude extract but not single compound
Journal of Functional Foods, 2019Co-Authors: Lei Chen, Xiaowei Xu, Yi Chen, Kang Li, Jie Pang, Hui TengAbstract:Abstract The objective of this study was to evaluate self-emulsifying drug delivery system (SNEDDS) for phenolic-extract of Sonchus oleraceus Linn (TSF-SNEDDS). The optimal prescription of the SNEDDS was as follows: isopropyl myristate (IPM) as the oil phase, Tween-20 as the emulsifier, polyethylent glycol-400 (PEG-400) as the co-emulsifier, and the weight ratio of the three was 1:3:1 (w/w/w). The phenolic-extract loading was 11% of the prescription and it remained stable after storing at room temperature at least for 30 days without delamination. TSF-SNEDDS was found to be uniform, spherical distribution and the particle size of the emulsion was 183 ± 0.7 nm. A dynamic gastro-intestinal model was used to evaluate the behavior of TSF-SNEDDS under digestion. SNEDDS had a significant impact on stability of major phenolic compounds presented in Sonchus oleraceus Linn within the simulated gastric-intestine tract. These results indicate that SNEDDS is a promising delivery system for functional extract by increasing its stability.
Zong Quan Ou - One of the best experts on this subject based on the ideXlab platform.
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effects of boiling and in vitro gastrointestinal digestion on the antioxidant activity of Sonchus oleraceus leaves
Food & Function, 2016Co-Authors: S M M R Mawalagedera, Zong Quan Ou, Arlene Mcdowell, Kevin S GouldAbstract:Leaves of Sonchus oleraceus L. are especially rich in phenolic compounds and have potent extractable antioxidants. However, it is not known how their antioxidant activity changes after cooking and gastrointestinal digestion. We recorded the profile of phenolics and their associated antioxidant activity in both raw and boiled S. oleraceus leaf extracts after in vitro gastric and intestinal digestion, and quantified their antioxidant potentials using Caco-2 and HepG2 cells. Boiling significantly diminished the oxygen radical absorbance capacity (ORAC) and concentrations of ascorbate and chicoric acid in the soluble fractions. In contrast, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and concentrations of caftaric and chlorogenic acids were unaffected. Phenolics in the soluble fraction were absorbed into cultured human cells and exerted antioxidant activity. Only chlorogenic acid content remained stable during gastrointestinal digestion. S. oleraceus appears to be an excellent dietary source of phenolic antioxidants.
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anti ageing effects of Sonchus oleraceus l pūhā leaf extracts on h2o2 induced cell senescence
Molecules, 2015Co-Authors: Zong Quan Ou, Thomas Rades, Arlene McdowellAbstract:Antioxidants protect against damage from free radicals and are believed to slow the ageing process. Previously, we have reported the high antioxidant activity of 70% methanolic Sonchus oleraceus L. (Asteraceae) leaf extracts. We hypothesize that S. oleraceus extracts protect cells against H2O2-induced senescence by mediating oxidative stress. Premature senescence of young WI-38 cells was induced by application of H2O2. Cells were treated with S. oleraceus extracts before or after H2O2 stress. The senescence- associated β-galactosidase (SA-β-gal) activity was used to indicate cell senescence. S. oleraceus extracts showed higher cellular antioxidant activity than chlorogenic acid in WI-38 cells. S. oleraceus extracts suppressed H2O2 stress-induced premature senescence in a concentration-dependent manner. At 5 and 20 mg/mL, S. oleraceus extracts showed better or equivalent effects of reducing stress-induced premature senescence than the corresponding ascorbic acid treatments. These findings indicate the potential of S. oleraceus extracts to be formulated as an anti-ageing agent.
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Anti-ageing effects of Sonchus oleraceus L. (pu¯ha¯) leaf extracts on H2O2-induced cell senescence
Molecules, 2015Co-Authors: Zong Quan Ou, Thomas Rades, Arlene McdowellAbstract:Antioxidants protect against damage from free radicals and are believed to slow the ageing process. Previously, we have reported the high antioxidant activity of 70% methanolic Sonchus oleraceus L. (Asteraceae) leaf extracts. We hypothesize that S. oleraceus extracts protect cells against H2O2-induced senescence by mediating oxidative stress. Premature senescence of young WI-38 cells was induced by application of H2O2. Cells were treated with S. oleraceus extracts before or after H2O2 stress. The senescence- associated beta-galactosidase (SA-beta-gal) activity was used to indicate cell senescence. S. oleraceus extracts showed higher cellular antioxidant activity than chlorogenic acid in WI-38 cells. S. oleraceus extracts suppressed H2O2 stress-induced premature senescence in a concentration-dependent manner. At 5 and 20 mg/mL, S. oleraceus extracts showed better or equivalent effects of reducing stress-induced premature senescence than the corresponding ascorbic acid treatments. These findings indicate the potential of S. oleraceus extracts to be formulated as an anti-ageing agent.
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influence of postharvest processing and storage conditions on key antioxidants in pūhā Sonchus oleraceus l
Journal of Pharmacy and Pharmacology, 2014Co-Authors: Zong Quan Ou, Thomas Rades, David M Schmierer, Clare J Strachan, Arlene McdowellAbstract:Objectives To investigate effects of different postharvest drying processes and storage conditions on key antioxidants in Sonchus oleraceus L. leaves. Methods Fresh leaves were oven-dried (60°C), freeze-dried or air-dried (∼25°C) for 6 h, 24 h and 3 days, respectively. Design of experiments (DOE) was applied to study the stability of antioxidants (caftaric, chlorogenic and chicoric acids) in S. oleraceus leaves and leaf extracts stored at different temperatures (4, 25 and 50°C) and relative humidities (15%, 43% and 75%) for 180 days. The concentration of antioxidants was quantified by a HPLC–2,2′-diphenylpicrylhydrazyl post-column derivatisation method. Antioxidant activity was assessed by a cellular antioxidant activity assay. Key findings The three antioxidants degraded to unquantifiable levels after oven-drying. More than 90% of the antioxidants were retained by freeze-drying and air-drying. Both leaf and extract samples retained > 90% of antioxidants, except those stored at 75% relative humidity. Leaf material had higher antioxidant concentrations and greater cellular antioxidant activity than corresponding extract samples. Conclusion Freeze-drying and air-drying preserved more antioxidants in S. oleraceus than oven-drying. From DOE analysis, humidity plays an important role in degradation of antioxidants during storage. To preserve antioxidant activity, it is preferable to store S. oleraceus as dried leaf material.
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application of an online post column derivatization hplc dpph assay to detect compounds responsible for antioxidant activity in Sonchus oleraceus l leaf extracts
Journal of Pharmacy and Pharmacology, 2013Co-Authors: Zong Quan Ou, Thomas Rades, David M Schmierer, Lesley Larsen, Arlene McdowellAbstract:Objectives To use an online assay to identify key antioxidants in Sonchus oleraceus leaf extracts and to investigate the effect of leaf position and extraction conditions on antioxidant concentration and activity. Methods Separation of phytochemicals and simultaneous assessment of antioxidant activity were performed online using HPLC and post-column reaction with a free-radical reagent (2, 2-diphenylpicrylhydrazyl, DPPH). Active compounds were identified using nuclear magnetic resonance spectroscopy and mass spectrometry. We applied the online HPLC-DPPH radical assay to evaluate antioxidants in leaves from different positions on the plant and to assess the effect of pre-treatment of leaves with liquid N2 before grinding, extraction time, extraction temperature and method of concentrating extracts. Key findings Key antioxidants identified in S. oleraceus leaf extracts were caftaric acid, chlorogenic acid and chicoric acid. Middle leaves contained the highest total amount of the three key antioxidant compounds, consisting mainly of chicoric acid. Pre-treatment with liquid N2, increasing the extraction temperature and time and freeze-drying the extract did not enhance the yield of the key antioxidants. Conclusion The online HPLC-DPPH radical assay was validated as a useful screening tool for investigating individual antioxidants in leaf extracts. Optimized extraction conditions were middle leaves pre-treated with liquid N2, extraction at 25°C for 0.5 h and solvent removal by rotary evaporation.