Mastitis is a common disease that affects women during lactation,posing a threat to the health of both mothers and infants.Recent studies have shown that insufficient nutrient intake increase the risk of mastitis.Phlo...Mastitis is a common disease that affects women during lactation,posing a threat to the health of both mothers and infants.Recent studies have shown that insufficient nutrient intake increase the risk of mastitis.Phlorizin(PHZ)is one of the nutrients present in apples.This study uses lipopolysaccharide(LPS)-induced mastitis mice and LPS+ATP-stimulated mouse mammary epithelial cells(mMECs)as research objects to explore the effect and mechanism of PHZ on mastitis.Different from in vitro beliefs,our findings demonstrated that PHZ significantly reduced inflammation and protected the blood-milk barrier(BMB)in vivo.Additionally,we observed that oral administration of PHZ regulated the intestinal flora and exhibited prebiotic functions.However,the anti-inflammatory effect of PHZ was not solely dependent on the intestinal flora,as antibiotic disruption of the intestinal flora does not completely abolish the improvement of mastitis by PHZ.Further mechanistic research revealed that the anti-inflammatory properties of PHZ were attributed to its metabolism into phloretin(PHT).Moreover,our results demonstrated that PHT reduced inflammation and protected the BMB by promoting autophagy to prevent the pyroptosis of mMECs.This study provides a theoretical basis for reducing inflammation in lactating women by consuming fruits,such as apples,that contain PHZ.展开更多
This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer p...This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.展开更多
Acinetobacter baumannii(A.baumannii)is well known for its virulence and persistence,particularly in intensive care units.Therefore,new strategies and candidates to treat A.baumannii infection are urgently needed consi...Acinetobacter baumannii(A.baumannii)is well known for its virulence and persistence,particularly in intensive care units.Therefore,new strategies and candidates to treat A.baumannii infection are urgently needed considering the emergence of drug-resistant bacteria.Polyphosphate kinase 1(PPK1)is required for bacterial survival as it is involved in maintaining antibiotic resistance or tolerance,pathogenesis,and adversity resistance.Multiple phenotypic assays related to virulence and persistence were performed in this study,and phloretin was shown to attenuate A.baumannii virulence and persistence by inhibiting PPK1 activity.Phloretin hampered mobility,interfered with biofilm formation and decreased resistance to ampicillin,heat,and hydrogen peroxide stress in A.baumannii.The therapeutic effect was also examined in a mouse pneumonia infection model.Molecular simulation and site-directed mutagenesis revealed that ARG-22,MET-622,ASN-57,and ARG-65 were the sites of phloretin action against PPK1.Phloretin treatment led to changes in metabolic pathways associated with A.baumannii virulence and persistence,including glycerophospholipid metabolism and fatty acid biosynthesis.Furthermore,phloretin alleviated pneumonic injury in a mouse pneumonia infection model in vivo,indicating that phloretin is a promising compound for preventing A.baumannii infection resistance by targeting PPK1.展开更多
Objective:To compare the cardioprotective efficacy of equimolar doses(50 mM/kg,p.o.)of phloretin and genistein against doxorubicin-induced cardiotoxicity in rats.Methods:Cardiotoxicity was induced in rats by intraperi...Objective:To compare the cardioprotective efficacy of equimolar doses(50 mM/kg,p.o.)of phloretin and genistein against doxorubicin-induced cardiotoxicity in rats.Methods:Cardiotoxicity was induced in rats by intraperitoneal injection of 6 mg/kg doxorubicin on alternative days till the cumulative dose reached 30 mg/kg.This study included four treatment groups of rats(n=6):the control group(0.5%carboxymethyl cellulose solution-treated),the doxorubicin-treated group(0.5%carboxymethyl cellulose solution along with doxorubicin),the genistein-treated group(50 mM/kg/day;p.o.along with doxorubicin)and phloretin-treated group(50 mM/kg/day;p.o.along with doxorubicin).On the 10th day of dosing,rats were anesthetized for recording ECG,mean arterial pressure,and left ventricular function.Oxidative stress,nitric oxide levels,and inflammatory cytokines were estimated in the cardiac tissue.Cardiac function parameters(creatine kinase MB,lactate dehydrogenase,aspartate aminotransferase,and alanine transaminase)were estimated in the serum samples.Results:Phloretin treatment inhibited doxorubicin-induced oxidative stress and also reduced nitric oxide levels in cardiac tissues of rats.Phloretin administration attenuated doxorubicin-induced alterations in hemodynamic parameters(heart rate,mean arterial blood pressure,and left ventricular function)and suppressed the expression of pro-inflammatory cytokines.The cardiac injury markers like creatine kinase MB,lactate dehydrogenase,aspartate aminotransferase,and alanine transaminase were reduced by both genistein and phloretin.All these effects of phloretin were more prominent than genistein.Conclusions:Phloretin offers cardioprotection that is comparable to genistein,a clinically validated cardioprotectant against doxorubicin-induced cardiotoxicity.Further studies are needed to confirm and establish the therapeutic utility of phloretin as a chemopreventive adjuvant to doxorubicin chemotherapy.展开更多
Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the...Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 μg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 μg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC<sub>50</sub> value. The lowest IC<sub>50 </sub>value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.展开更多
Phloretin is an important skin-lightening and depigmenting agent from the peel of apples. Although de novo production of phloretin has been realized in microbes using the natural pathway from plants, the efficiency of...Phloretin is an important skin-lightening and depigmenting agent from the peel of apples. Although de novo production of phloretin has been realized in microbes using the natural pathway from plants, the efficiency of phloretin production is still not enough for industrial application. Here, we established an artificial pathway in the yeast to produce phloretin via assembling two genes of p-coumaroyl-CoA ligase(4CL) and chalcone synthase(CHS). CHS is a key enzyme which conventionally condenses a CoA-tethered starter with three molecules of malonyl-CoA to form the backbone of flavonoids. However, there was 33% of byproduct generated via CHS by condensing two molecules of malonyl-CoA during the fermentation process. Hence, we introduced a more efficient CHS and improved the supply of malonyl-CoA through two pathways;the by-product ratio was decreased from 33% to 17% and the production of phloretin was improved from 48 to 83.2 mg L^(-1). Finally, a fed-batch fermentation process was optimized and the production of phloretin reached 619.5 mg L^(-1), which was 14-fold higher than that of the previous studies. Our work established a platform for the biosynthesis of phloretin from the low-cost raw material 3-(4-hydroxyphenyl) propanoic acid and also illustrated the potential for industrial scale bio-manufacturing of phloretin.展开更多
Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Fla...Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Flavonifractor plautii(F.plautii)was synthesized and heterologously expressed in Escherichia coli BL21(E.coli BL 21).Phloretin hydrolase(PHY)was purified from cell extracts of recombinant E.coli BL21,and PHY's molecular weight was about 32 kDa.The purified PHY effectively cleaved phloretin into 3-(4-hydroxyphenyl)propionic acid(HPPA)and phloroglucinol(PG).PHY's kinetic parameters were determined:Km was 2.8×10^(−3)±0.4 mM and Vmax was 411.2±7.1 U/mg.Besides,PHY's optimal temperature and pH were 50℃ and 7.5,respectively,and PHY exhibited 75%activity after 5 h at 50℃.Furthermore,PHY's activity was inhibited in the presence of Ba^(2+),Cu^(2+),and Fe^(2+),while Mg^(2+) slightly elevated PHY's activity.Finally,the catalytic model between phloretin and PHY was built using molecular docking,and PHY's conformational changes were further demonstrated through the multispectral techniques.This study is conducive to understanding phloretin metabolism in the colon and adding a valuable source of PHY for food industry application.展开更多
基金National Natural Science Foundation of China(32272955,32172807)。
文摘Mastitis is a common disease that affects women during lactation,posing a threat to the health of both mothers and infants.Recent studies have shown that insufficient nutrient intake increase the risk of mastitis.Phlorizin(PHZ)is one of the nutrients present in apples.This study uses lipopolysaccharide(LPS)-induced mastitis mice and LPS+ATP-stimulated mouse mammary epithelial cells(mMECs)as research objects to explore the effect and mechanism of PHZ on mastitis.Different from in vitro beliefs,our findings demonstrated that PHZ significantly reduced inflammation and protected the blood-milk barrier(BMB)in vivo.Additionally,we observed that oral administration of PHZ regulated the intestinal flora and exhibited prebiotic functions.However,the anti-inflammatory effect of PHZ was not solely dependent on the intestinal flora,as antibiotic disruption of the intestinal flora does not completely abolish the improvement of mastitis by PHZ.Further mechanistic research revealed that the anti-inflammatory properties of PHZ were attributed to its metabolism into phloretin(PHT).Moreover,our results demonstrated that PHT reduced inflammation and protected the BMB by promoting autophagy to prevent the pyroptosis of mMECs.This study provides a theoretical basis for reducing inflammation in lactating women by consuming fruits,such as apples,that contain PHZ.
基金supported by the Science and Technology Council,Taiwan,China(NSTC 112-2320-B-039-057 and MOST 111-2320-B-039-067-MY3)the China Medical University,Taiwan,China(CMU112-S-18),awarded to Yuan-Soon Ho+1 种基金the China Medical University,Taiwan,China(CMU112-N-02),awarded to Li-Ching Chenthe Science and Technology Council,Taiwan,China(MOST 110-2320B-039-079)。
文摘This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.
基金supported by the National Natural Science Foundation of China(U23A20242 and U22A20523)the Fundamental Research Funds for the Central Universities under Grant 2023JCXK-01。
文摘Acinetobacter baumannii(A.baumannii)is well known for its virulence and persistence,particularly in intensive care units.Therefore,new strategies and candidates to treat A.baumannii infection are urgently needed considering the emergence of drug-resistant bacteria.Polyphosphate kinase 1(PPK1)is required for bacterial survival as it is involved in maintaining antibiotic resistance or tolerance,pathogenesis,and adversity resistance.Multiple phenotypic assays related to virulence and persistence were performed in this study,and phloretin was shown to attenuate A.baumannii virulence and persistence by inhibiting PPK1 activity.Phloretin hampered mobility,interfered with biofilm formation and decreased resistance to ampicillin,heat,and hydrogen peroxide stress in A.baumannii.The therapeutic effect was also examined in a mouse pneumonia infection model.Molecular simulation and site-directed mutagenesis revealed that ARG-22,MET-622,ASN-57,and ARG-65 were the sites of phloretin action against PPK1.Phloretin treatment led to changes in metabolic pathways associated with A.baumannii virulence and persistence,including glycerophospholipid metabolism and fatty acid biosynthesis.Furthermore,phloretin alleviated pneumonic injury in a mouse pneumonia infection model in vivo,indicating that phloretin is a promising compound for preventing A.baumannii infection resistance by targeting PPK1.
文摘Objective:To compare the cardioprotective efficacy of equimolar doses(50 mM/kg,p.o.)of phloretin and genistein against doxorubicin-induced cardiotoxicity in rats.Methods:Cardiotoxicity was induced in rats by intraperitoneal injection of 6 mg/kg doxorubicin on alternative days till the cumulative dose reached 30 mg/kg.This study included four treatment groups of rats(n=6):the control group(0.5%carboxymethyl cellulose solution-treated),the doxorubicin-treated group(0.5%carboxymethyl cellulose solution along with doxorubicin),the genistein-treated group(50 mM/kg/day;p.o.along with doxorubicin)and phloretin-treated group(50 mM/kg/day;p.o.along with doxorubicin).On the 10th day of dosing,rats were anesthetized for recording ECG,mean arterial pressure,and left ventricular function.Oxidative stress,nitric oxide levels,and inflammatory cytokines were estimated in the cardiac tissue.Cardiac function parameters(creatine kinase MB,lactate dehydrogenase,aspartate aminotransferase,and alanine transaminase)were estimated in the serum samples.Results:Phloretin treatment inhibited doxorubicin-induced oxidative stress and also reduced nitric oxide levels in cardiac tissues of rats.Phloretin administration attenuated doxorubicin-induced alterations in hemodynamic parameters(heart rate,mean arterial blood pressure,and left ventricular function)and suppressed the expression of pro-inflammatory cytokines.The cardiac injury markers like creatine kinase MB,lactate dehydrogenase,aspartate aminotransferase,and alanine transaminase were reduced by both genistein and phloretin.All these effects of phloretin were more prominent than genistein.Conclusions:Phloretin offers cardioprotection that is comparable to genistein,a clinically validated cardioprotectant against doxorubicin-induced cardiotoxicity.Further studies are needed to confirm and establish the therapeutic utility of phloretin as a chemopreventive adjuvant to doxorubicin chemotherapy.
文摘Reactive oxygen species [ROS] cause oxidative damage to the tissues and protection from such damages is provided by endogenous and exogenous antioxidants. Much research work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. So, this study was aimed to evaluate the in vitro antioxidant capacity of one of the phenolic compounds phloretin. Phloretin was used at four different concentrations like 20, 40, 60 and 80 μg/ml to determine the antioxidant activity by different methods such as total antioxidant capacity, reducing power, DPPH radical scavenging, superoxide anion radical scavenging and metal chelating assays. In addition to that the ascorbic acid was used as reference compound. The results showed that the phloretin displayed potent in vitro antioxidant capacity. It was able to scavenge different in vitro free radicals in all tested concentrations. Among the different concentrations, 80 μg of phloretin has maximum activity when compared to other concentrations in all in vitro antioxidant assays. High antioxidant property and maximum protective effect of phloretin were observed in a concentration dependent manner. The results were expressed as IC<sub>50</sub> value. The lowest IC<sub>50 </sub>value indicates the highest scavenging activity. The reducing power of the phloretin was also found in concentration dependent. According to the results of this study, we concluded that the phloretin possesses antioxidant property. Therefore, phloretin is a powerful antioxidant phytocompound which can protect biological systems against the oxidative stress. From this study, we suggest that the phloretin may be used as a dietary natural antioxidant supplement for preventing free radical related diseases.
基金financially supported by Talents Team Construction Fund of Northwestern Polytechnical University (NWPU)the National Natural Science Foundation of China (31701722)+1 种基金the China Postdoctoral Science Foundation (2017M620471)the National Natural Science Foundation of China (31901026)。
文摘Phloretin is an important skin-lightening and depigmenting agent from the peel of apples. Although de novo production of phloretin has been realized in microbes using the natural pathway from plants, the efficiency of phloretin production is still not enough for industrial application. Here, we established an artificial pathway in the yeast to produce phloretin via assembling two genes of p-coumaroyl-CoA ligase(4CL) and chalcone synthase(CHS). CHS is a key enzyme which conventionally condenses a CoA-tethered starter with three molecules of malonyl-CoA to form the backbone of flavonoids. However, there was 33% of byproduct generated via CHS by condensing two molecules of malonyl-CoA during the fermentation process. Hence, we introduced a more efficient CHS and improved the supply of malonyl-CoA through two pathways;the by-product ratio was decreased from 33% to 17% and the production of phloretin was improved from 48 to 83.2 mg L^(-1). Finally, a fed-batch fermentation process was optimized and the production of phloretin reached 619.5 mg L^(-1), which was 14-fold higher than that of the previous studies. Our work established a platform for the biosynthesis of phloretin from the low-cost raw material 3-(4-hydroxyphenyl) propanoic acid and also illustrated the potential for industrial scale bio-manufacturing of phloretin.
基金supported by the National Natural Science Foundation(31972089)the 2020 Team Innovation Project from the Fundamental Scientific Research Special Capital Fund of the National Universities,China(GK202001008).
文摘Although the catabolic pathway of some flavonoids in the human colon has been elucidated,knowledge of related gut microbes and responsible enzymes is still limited.In this study,a phloretin hydrolase gene(phy)from Flavonifractor plautii(F.plautii)was synthesized and heterologously expressed in Escherichia coli BL21(E.coli BL 21).Phloretin hydrolase(PHY)was purified from cell extracts of recombinant E.coli BL21,and PHY's molecular weight was about 32 kDa.The purified PHY effectively cleaved phloretin into 3-(4-hydroxyphenyl)propionic acid(HPPA)and phloroglucinol(PG).PHY's kinetic parameters were determined:Km was 2.8×10^(−3)±0.4 mM and Vmax was 411.2±7.1 U/mg.Besides,PHY's optimal temperature and pH were 50℃ and 7.5,respectively,and PHY exhibited 75%activity after 5 h at 50℃.Furthermore,PHY's activity was inhibited in the presence of Ba^(2+),Cu^(2+),and Fe^(2+),while Mg^(2+) slightly elevated PHY's activity.Finally,the catalytic model between phloretin and PHY was built using molecular docking,and PHY's conformational changes were further demonstrated through the multispectral techniques.This study is conducive to understanding phloretin metabolism in the colon and adding a valuable source of PHY for food industry application.
