Objective:To investigate the antioxidative and antidiabetic effects of Harpephyllum caffrum bark infusion as well as its effects on glucogenic and nucleotide hydrolyzing enzyme activities in FeSO4-induced oxidative st...Objective:To investigate the antioxidative and antidiabetic effects of Harpephyllum caffrum bark infusion as well as its effects on glucogenic and nucleotide hydrolyzing enzyme activities in FeSO4-induced oxidative stress in rat hepatic tissue.Methods:Harpephyllum caffrum infusion was prepared from dried plant materials(40 g)infused in boiling water(400 mL)for 20 min at room temperature.The antioxidative and inhibitory activities against carbohydrate digestive enzymes of the infusion were determined using established protocols.The liver tissues of rats were used for glucose uptake assay and to evaluate the infusion’s effect on endogenous antioxidant,glucogenic,and nucleotide hydrolyzing enzyme activities in FeSO4-induced hepatic injury.Results:The Harpephyllum caffrum infusion significantly reduced ferric iron(FRAP)and free radicals(OH•and DPPH)in a dose-dependent manner.It inhibitedα-amylase andα-glucosidase activities and increased glucose uptake in hepatic tissues.FeSO4 significantly decreased glutathione concentration,catalase,and superoxide dismutase activities while increasing malondialdehyde level,glycogen phosphorylase,fructose-1,6-bisphosphatase,and adenosine triphosphatase activities.However,treatment with Harpephyllum caffrum infusion reversed FeSO4-induced changes.Characterization of the infusion revealed the presence of catechol,O-pyrocatechuic acid,mequinol,maltol,and glycoside derivatives.Conclusions:The Harpephyllum caffrum infusion demonstrates antidiabetic and antioxidative potentials in in vitro models of type 2 diabetes as depicted by its ability to inhibit carbohydrate digestive enzymes,mitigate oxidative imbalance,and regulate glucogenic and nucleotide hydrolyzing enzyme activities in oxidative hepatic injury.展开更多
Crude phenolic extracts of indigenous sub-Saharan fruit byproducts have potent antioxidant activity.Purification of these extracts and evaluation of their antioxidant activity and viability using appropriate biologica...Crude phenolic extracts of indigenous sub-Saharan fruit byproducts have potent antioxidant activity.Purification of these extracts and evaluation of their antioxidant activity and viability using appropriate biological models,has,however,not yet been completed.The current study quantitatively evaluated the phenolic composition and in vitro antioxidant activity of crude and purified extracts(PE)of Harpephyllum caffrum peel(HCP)and Syzygium guineense seed(SGS),and cellular antioxidant and viability efficacy of the PE.Phenols were extracted by 60%ethanol(v/v)solvent system and purified using XAD7HP macroporous adsorption resin.The UPLC/Q-TOF-MS was used for the characterization and identification of phenols.Cellular antioxidant activity(CAA)assay was applied to assess the antioxidant efficacy and cytotoxicity of the PE.Analysis of variance of data was done using a generalized linear mixed model with fruit type,extract purity and their interaction as fixed effects.Purification increased(P≤0.05)HCP total phenolic concentration(TPC)by over 200%,while SGS TPC decreased(P≤0.05)by 20%.Regardless of fruit type,PE had higher(P≤0.05)quantities of proanthocyanidins and anthocyanins than crude extracts.The HCP-PE had greater(P≤0.05)in vitro antioxidant activity than the other extracts(P≤0.05).Cellular antioxidant activity of HCP-PE was comparable to that of sodium metabisulphite(P>0.05).Also,HCP-PE had lower(P≤0.05)cytotoxic effects than SGS and sodium metabisulphite with increasing antioxidant concentration.It was concluded that HCP-PE is a potential source of safe natural antioxidants for nutraceutical applications.展开更多
Indigenous,underutilized fruits-byproducts are potential sources of novel antioxidants for the food industry.The current study evaluated the effects of different levels of purified ethanolic extracts of Harpephyllum c...Indigenous,underutilized fruits-byproducts are potential sources of novel antioxidants for the food industry.The current study evaluated the effects of different levels of purified ethanolic extracts of Harpephyllum caffrum Bernh peel(HCP,0,250,450 and 650 ppm)on shelf life and sensory attributes of fresh ground beef patties stored at 4℃during 9 days in comparison with sodium metabisulfite(SMB,450 ppm).Antioxidant type×day interactions influenced(P≤0.05)shelf life parameters,including loss of colour,myoglobin and protein oxidation.The HCP extracts improved colour and protein(i.e.,reduced thiol loss)stability during storage compared to the control.The HCP treatments had lower(P≤0.05)TBARS on day 9 compared to the control.Also,HCP reduced(P≤0.05)tenderness and juiciness,and increased undesirable flavours in beef patties compared to control and SMB.The study indicates that HCP is a potential alternative to SMB in improving oxidative shelf life of the beef patties,with additional studies recommended to reduce adverse effects on sensory quality.展开更多
基金funded by the Research Office,University of KwaZulu-Natal,Durban,and with support from the National Research Foundation-the World Academy of Science(NRF-TWAS),Pretoria,South Africa under(UID:116093).
文摘Objective:To investigate the antioxidative and antidiabetic effects of Harpephyllum caffrum bark infusion as well as its effects on glucogenic and nucleotide hydrolyzing enzyme activities in FeSO4-induced oxidative stress in rat hepatic tissue.Methods:Harpephyllum caffrum infusion was prepared from dried plant materials(40 g)infused in boiling water(400 mL)for 20 min at room temperature.The antioxidative and inhibitory activities against carbohydrate digestive enzymes of the infusion were determined using established protocols.The liver tissues of rats were used for glucose uptake assay and to evaluate the infusion’s effect on endogenous antioxidant,glucogenic,and nucleotide hydrolyzing enzyme activities in FeSO4-induced hepatic injury.Results:The Harpephyllum caffrum infusion significantly reduced ferric iron(FRAP)and free radicals(OH•and DPPH)in a dose-dependent manner.It inhibitedα-amylase andα-glucosidase activities and increased glucose uptake in hepatic tissues.FeSO4 significantly decreased glutathione concentration,catalase,and superoxide dismutase activities while increasing malondialdehyde level,glycogen phosphorylase,fructose-1,6-bisphosphatase,and adenosine triphosphatase activities.However,treatment with Harpephyllum caffrum infusion reversed FeSO4-induced changes.Characterization of the infusion revealed the presence of catechol,O-pyrocatechuic acid,mequinol,maltol,and glycoside derivatives.Conclusions:The Harpephyllum caffrum infusion demonstrates antidiabetic and antioxidative potentials in in vitro models of type 2 diabetes as depicted by its ability to inhibit carbohydrate digestive enzymes,mitigate oxidative imbalance,and regulate glucogenic and nucleotide hydrolyzing enzyme activities in oxidative hepatic injury.
基金Stellenbosch Gardens and Kirstenbosch Gardens for their support.Financial support for the research was provided by the South African Research Chairs Initiative(SARChI)in Meat Science:Genomics to Nutrinomics as well as the South African Department of Science and Technology(UID:84633),as directed by the NRF of South Africa.TMP would also like to thank SARChI for bursary support.
文摘Crude phenolic extracts of indigenous sub-Saharan fruit byproducts have potent antioxidant activity.Purification of these extracts and evaluation of their antioxidant activity and viability using appropriate biological models,has,however,not yet been completed.The current study quantitatively evaluated the phenolic composition and in vitro antioxidant activity of crude and purified extracts(PE)of Harpephyllum caffrum peel(HCP)and Syzygium guineense seed(SGS),and cellular antioxidant and viability efficacy of the PE.Phenols were extracted by 60%ethanol(v/v)solvent system and purified using XAD7HP macroporous adsorption resin.The UPLC/Q-TOF-MS was used for the characterization and identification of phenols.Cellular antioxidant activity(CAA)assay was applied to assess the antioxidant efficacy and cytotoxicity of the PE.Analysis of variance of data was done using a generalized linear mixed model with fruit type,extract purity and their interaction as fixed effects.Purification increased(P≤0.05)HCP total phenolic concentration(TPC)by over 200%,while SGS TPC decreased(P≤0.05)by 20%.Regardless of fruit type,PE had higher(P≤0.05)quantities of proanthocyanidins and anthocyanins than crude extracts.The HCP-PE had greater(P≤0.05)in vitro antioxidant activity than the other extracts(P≤0.05).Cellular antioxidant activity of HCP-PE was comparable to that of sodium metabisulphite(P>0.05).Also,HCP-PE had lower(P≤0.05)cytotoxic effects than SGS and sodium metabisulphite with increasing antioxidant concentration.It was concluded that HCP-PE is a potential source of safe natural antioxidants for nutraceutical applications.
基金supported by the South African Research Chairs Initiative(SARChI)in Meat Science:Genomics to Nutrinomicspartly funded by the South African Department of Science and Technology(UID:84633)+1 种基金by the NRF of South Africathe SARChI for bursary support.
文摘Indigenous,underutilized fruits-byproducts are potential sources of novel antioxidants for the food industry.The current study evaluated the effects of different levels of purified ethanolic extracts of Harpephyllum caffrum Bernh peel(HCP,0,250,450 and 650 ppm)on shelf life and sensory attributes of fresh ground beef patties stored at 4℃during 9 days in comparison with sodium metabisulfite(SMB,450 ppm).Antioxidant type×day interactions influenced(P≤0.05)shelf life parameters,including loss of colour,myoglobin and protein oxidation.The HCP extracts improved colour and protein(i.e.,reduced thiol loss)stability during storage compared to the control.The HCP treatments had lower(P≤0.05)TBARS on day 9 compared to the control.Also,HCP reduced(P≤0.05)tenderness and juiciness,and increased undesirable flavours in beef patties compared to control and SMB.The study indicates that HCP is a potential alternative to SMB in improving oxidative shelf life of the beef patties,with additional studies recommended to reduce adverse effects on sensory quality.
