The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional pe...The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional permeability tests were carried out, and the apparent permeability coefficients （Papp） were calculated. The two protopanaxatriol epimers showed good permeability with Papp values of-10^-5 cm/s, whereas dammar-20（22）E,24-diene-3β,6α, 12β-triol showed poor permeability with Papp of 〈1 × 10^-7 cm/s. The three compounds showed differences in intracellular accumulations due to their different structures. Inhibition of P-gp with verapamil showed that the transport mechanisms in MDCK-pHaMDR cell monolayer for compounds 1 and 2 epimers were not only simple passive diffusion but also involving an effiux way mediated by P-gp. These findings provided new basis for the further study of compounds 1 and 2 acting on the brain.展开更多
Cationic lipids have been applied to siRNA delivery for tumor therapeutics. However, the excess positive charges of these nanoplexes may lead to high cytotoxicity and nonnegligible immunogenicity both in vitro and in ...Cationic lipids have been applied to siRNA delivery for tumor therapeutics. However, the excess positive charges of these nanoplexes may lead to high cytotoxicity and nonnegligible immunogenicity both in vitro and in vivo, which limited the applications of gene drugs. We constructed multi-component lipoplex to delivery 3＇,3＂-bis-peptide-siRNA conjugate （pp-siRNA） by the treatment of melanoma. Based on the previous studies that the gemini lipid （CLD） encapsulated pp-siRNA, a novel neutral cytosin-l-yl- lipid （DNCA） was considered to replace a certain ration of CLD by hydrogen bonds and ~t-n stacking for reducing the cytotoxicity. It similarly retained in both the loading efficiency and targeted mRNA inhibition when DNCA was accounted for 40% in the lipoplex, with lower toxicity. Moreover, CLD/DNCA/pp-siRNA nanoplex could be uptake in A375 cells and internalized mainly by macropinocytosis and caveolin-mediated endocytosis. Besides, 90% CLD/DNCA/pp-siRNA nanoplexes presented the highest efficient knockdown for the mutant B-RAF mRNA （-80%）. All the results demonstrated that the mixed cationic and neutral lipids could efficiently realize the delivery of pp-siRNA and had potential application for cancer therapy.展开更多
Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal ...Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal drug. Recently, we have prepared a bis（（5-hydroxy-4-oxo-4H-pyran-2-yl） methyl 2-hydroxy-benzoatato） oxovanadium（BSOV）, which exhibited excellent hypoglycemic effect with low acute toxicity. In order to facilitate the development of anti-diabetic vanadium complexes, especially BSOV, we studied the long-term toxicity and hypoglycemic effect of BSOV in comparison with bis（maltolato） oxovanadium（BMOV） on both non-diabetic and type II diabetic mice. The experiments confirmed a stable hypoglycemic effect for both the vanadium complexes over the testing period（6–7 months）. However, the chronic administration of vanadium compounds slightly increased oxidative stress in ICR mice and the induced renal interstitial edema（RIE） in a part of the diabetic animals associated with low levels of serum albumin. The use of an antioxidant dietary supplement（a combination of vitamin C and Zinc gluconate） could prevent vanadium-induced oxidative stress but have marginal effect on RIE. However, BSOV caused much lower incidence of RIE than BMOV did, suggesting that BSOV is an important step towards the successful development of anti-diabetic vanadium drugs.展开更多
Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying t...Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying the mechanisms of its various pharmacological properties and developing novel drugs from the mangiferin derivatives. Among the metabolites of mangiferin, mangiferin-7-O-β-D-glucuronide has been reported as the phase Ⅱ metabolite of mangiferin. Herein we described the first semi-synthesis of mangiferin-7-O-β-D-glucuronide with the natural product mangiferin as the starting material. In this work, we adopted several regioselective protection procedures to distinguish the different hydroxyl groups in the structure of mangiferin, and we accomplished the glycosylation under the phase-transfer catalysis conditions. In this method, we efficiently synthesized the glucuronide derivative of mangiferin in 10 steps with highly regioselective protection.展开更多
The root of Hedysarum multijugum（RHM） is recorded as a folk herbal medicine in China and is sometimes used as a substitute for Hedysari Radix, which is a famous traditional Chinese medicine derived from the roots of...The root of Hedysarum multijugum（RHM） is recorded as a folk herbal medicine in China and is sometimes used as a substitute for Hedysari Radix, which is a famous traditional Chinese medicine derived from the roots of Hedysarum polybotrys. In the present study, a sensible, reliable, and reproducible HPLC-DAD fingerprint analysis method for RHM was developed and then subsequently applied to analyze RHM samples from different origins. The chemical constituents of the RHM samples were generally consistent, although it was slightly affected by the local environment of the plant. In addition, the chemical constituency of RHM was shown to be significantly different from that of Hedysari Radix, suggesting that RHM is not suitable as a substitute for Hedysari Radix, at least from the chemical point of view.展开更多
A series of E and Z-isomers of 3-（4＇-substituted benzylidene）-indolin-2-one derivatives were synthesized and separated. Based on their 1H NMR characterization, an unusual counterintuitive deshielding phenomenon for...A series of E and Z-isomers of 3-（4＇-substituted benzylidene）-indolin-2-one derivatives were synthesized and separated. Based on their 1H NMR characterization, an unusual counterintuitive deshielding phenomenon for the protons presenting in the shielding zone of phenyl ring was observed and analyzed for the first time.展开更多
Common chemotherapy is unable to eliminate the heterogeneous side population of cancer cells （such as cancer stem-like cells）, resulting in poor prognosis. The heterogeneity of cancer cells causes an extensive multi...Common chemotherapy is unable to eliminate the heterogeneous side population of cancer cells （such as cancer stem-like cells）, resulting in poor prognosis. The heterogeneity of cancer cells causes an extensive multidrug resistance through the aberrantly active Hedgehog （Hh） signaling pathway. Cyclopamine is a chemical compound that can block Hh signaling pathway, and a combination use of cyclopamine with anticancer drug would be beneficial for killing heterogeneous cancer cells. In the present study, we aimed to develop a kind type of fimctional drug liposomes for eliminating heterogeneous cancer, The study was performed on human breast cancer cells. A distearoylphosphoethanolamine polyethylene glycol （DSPE-PEG2000）-cyclopamine conjugate was newly synthesized by a nucleophilic substitution reaction, and confirmed by MALDI-TOF mass. An HPLC method was established and validated for qualification of epirubicin. Functional epimbicin liposomes were successful constructed by modifying with DSPE-PEG2o00-cyclopamine, displaying a particle size in nano-scale （approximately 98 nm） and a high epirubicin encapsulation （〉97%）. The CD44＋/CD24-side population was characterized in defining heterogeneous breast cancer cells. As compared with regular epirubicin liposomes, fimctional epirubicin liposomes exhibited an evidently enhanced cellular drug uptake and a significant killing effect in overall breast cancer cells. In conclusion, the functional epirubicin liposomes could be a useful drug delivery carrier for eliminating heterogeneous breast cancer cells.展开更多
The Alzheimer＇s disease （AD） is one of the common cognitive disorders in the elderly. AD shares some similar pathological characters with diabetes mellitus （DM）, suggesting potential application of anti-diabetic ...The Alzheimer＇s disease （AD） is one of the common cognitive disorders in the elderly. AD shares some similar pathological characters with diabetes mellitus （DM）, suggesting potential application of anti-diabetic agents, such as vanadyl complexes, in therapeutic treatment of AD. In the present work, we studied the effects of vanadyl acetylacetonate （VO（acac）2） and cinnamaldehyde （CA） on an AD model based on SH-SY5Y neural cells. The experimental results showed that VO（acac）2 at sub-micromolar concentrations could improve the viability of neural cells with or without increased β-amyloid （Aβ） burden; and the combination of VO（acac）2 and CA showed an additive cell protection effects. Further investigation revealed that for SH-SY5Y neural cells, VO（acac）2 could activate PPART-AMPK signal transduction and inhibit GSK 3β, one of the major kinases for Tau hyperphosphorylation. Meanwhile, CA could correct the abnormal mitochondrial morphology due to Aβ-induced excessive mitochondrial fission, thus restoring/enhancing the mitochondrial function. In addition, both VO（acac）2 and CA decreased intracellular reactive oxygen species （ROS） level and inhibited formation of toxic Aβ oligomers. Overall, VO（acac）2 might work with CA in improving the neural cell viability under the Aβ burden, suggesting application of vanadium metallodrugs in AD treatment.展开更多
Rho GTPases play an important role on the regulation of cytoskeleton, which can affect the cell morphogenesis, cell migration, endocytosis and vesicle transport by controlling the growth and maintenance of microfilame...Rho GTPases play an important role on the regulation of cytoskeleton, which can affect the cell morphogenesis, cell migration, endocytosis and vesicle transport by controlling the growth and maintenance of microfilaments and microtubules. It has been known that regulation of cell cytoskeleton is inseparable from the cell uptake of nano-medicine or nano-drug delivery systems. However, only few studies have focused on the impacts of Rho GTPases on cell uptake of nano-medicine or nano-drug delivery systems. This study selected single-walled carbon nanohoms （SWCNHs）, which have emerged as promising drug delivery systems, to explore the impacts of Rho GTPases on cell uptake of nano-drug delivery systems. SWCNHs were oxidized with concentrated nitric acid and prepared into nano dispersion by ultrasonic dispersion. Confocal laser scanning microscope （CLSM） and transmission electron microscopy （TEM） were used to observe the cell uptake and intracellular distribution of nanoparticles after incubated A549 cells with the dispersion mentioned above. Mechanism of cell uptake was assessed using various inhibitors. The results showed that the cell uptake of oxSWCNHs was significantly reduced when RhoA was inhibited. The oxSWCNHs were internalized through clathrin-mediated endocytosis and mainly positioned in lysosomes ofA549 cells.展开更多
基金The National New Drug R&D Program(Grant No.2011BAI07B082009ZX09301-010)of China
文摘The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional permeability tests were carried out, and the apparent permeability coefficients （Papp） were calculated. The two protopanaxatriol epimers showed good permeability with Papp values of-10^-5 cm/s, whereas dammar-20（22）E,24-diene-3β,6α, 12β-triol showed poor permeability with Papp of 〈1 × 10^-7 cm/s. The three compounds showed differences in intracellular accumulations due to their different structures. Inhibition of P-gp with verapamil showed that the transport mechanisms in MDCK-pHaMDR cell monolayer for compounds 1 and 2 epimers were not only simple passive diffusion but also involving an effiux way mediated by P-gp. These findings provided new basis for the further study of compounds 1 and 2 acting on the brain.
基金The National Natural Science Foundation of China(Grant No.21778006 and 20932001)the Ministry of Science and Technology of China(Grant No.2012AA022501)
文摘Cationic lipids have been applied to siRNA delivery for tumor therapeutics. However, the excess positive charges of these nanoplexes may lead to high cytotoxicity and nonnegligible immunogenicity both in vitro and in vivo, which limited the applications of gene drugs. We constructed multi-component lipoplex to delivery 3＇,3＂-bis-peptide-siRNA conjugate （pp-siRNA） by the treatment of melanoma. Based on the previous studies that the gemini lipid （CLD） encapsulated pp-siRNA, a novel neutral cytosin-l-yl- lipid （DNCA） was considered to replace a certain ration of CLD by hydrogen bonds and ~t-n stacking for reducing the cytotoxicity. It similarly retained in both the loading efficiency and targeted mRNA inhibition when DNCA was accounted for 40% in the lipoplex, with lower toxicity. Moreover, CLD/DNCA/pp-siRNA nanoplex could be uptake in A375 cells and internalized mainly by macropinocytosis and caveolin-mediated endocytosis. Besides, 90% CLD/DNCA/pp-siRNA nanoplexes presented the highest efficient knockdown for the mutant B-RAF mRNA （-80%）. All the results demonstrated that the mixed cationic and neutral lipids could efficiently realize the delivery of pp-siRNA and had potential application for cancer therapy.
基金National Natural Science Foundation of China(Grant No.21271012)
文摘Vanadium compounds are promising anti-diabetic agents. However, the concern in the toxicity, especially the long-term renal side effect along with diabetic status, is restricting the further development of this metal drug. Recently, we have prepared a bis（（5-hydroxy-4-oxo-4H-pyran-2-yl） methyl 2-hydroxy-benzoatato） oxovanadium（BSOV）, which exhibited excellent hypoglycemic effect with low acute toxicity. In order to facilitate the development of anti-diabetic vanadium complexes, especially BSOV, we studied the long-term toxicity and hypoglycemic effect of BSOV in comparison with bis（maltolato） oxovanadium（BMOV） on both non-diabetic and type II diabetic mice. The experiments confirmed a stable hypoglycemic effect for both the vanadium complexes over the testing period（6–7 months）. However, the chronic administration of vanadium compounds slightly increased oxidative stress in ICR mice and the induced renal interstitial edema（RIE） in a part of the diabetic animals associated with low levels of serum albumin. The use of an antioxidant dietary supplement（a combination of vitamin C and Zinc gluconate） could prevent vanadium-induced oxidative stress but have marginal effect on RIE. However, BSOV caused much lower incidence of RIE than BMOV did, suggesting that BSOV is an important step towards the successful development of anti-diabetic vanadium drugs.
基金The National Research Foundation for the Doctoral Program of Higher Education of China(Grant No.20130001110058)
文摘Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying the mechanisms of its various pharmacological properties and developing novel drugs from the mangiferin derivatives. Among the metabolites of mangiferin, mangiferin-7-O-β-D-glucuronide has been reported as the phase Ⅱ metabolite of mangiferin. Herein we described the first semi-synthesis of mangiferin-7-O-β-D-glucuronide with the natural product mangiferin as the starting material. In this work, we adopted several regioselective protection procedures to distinguish the different hydroxyl groups in the structure of mangiferin, and we accomplished the glycosylation under the phase-transfer catalysis conditions. In this method, we efficiently synthesized the glucuronide derivative of mangiferin in 10 steps with highly regioselective protection.
基金Quality Standards for Chinese Medicines of Chinese Pharmacopeia 2010 edition(Grant No.YZ-029)National Natural Science Foundation of China(Grant No.21372015)
文摘The root of Hedysarum multijugum（RHM） is recorded as a folk herbal medicine in China and is sometimes used as a substitute for Hedysari Radix, which is a famous traditional Chinese medicine derived from the roots of Hedysarum polybotrys. In the present study, a sensible, reliable, and reproducible HPLC-DAD fingerprint analysis method for RHM was developed and then subsequently applied to analyze RHM samples from different origins. The chemical constituents of the RHM samples were generally consistent, although it was slightly affected by the local environment of the plant. In addition, the chemical constituency of RHM was shown to be significantly different from that of Hedysari Radix, suggesting that RHM is not suitable as a substitute for Hedysari Radix, at least from the chemical point of view.
基金National Natural Science Foundation of China(Grant No.21172008 and 21372015)
文摘A series of E and Z-isomers of 3-（4＇-substituted benzylidene）-indolin-2-one derivatives were synthesized and separated. Based on their 1H NMR characterization, an unusual counterintuitive deshielding phenomenon for the protons presenting in the shielding zone of phenyl ring was observed and analyzed for the first time.
基金National Basic Research Program of China(973 Program,Grant No.2013CB932501)the National Science Foundation of China(Grant No.81373343,81673367)
文摘Common chemotherapy is unable to eliminate the heterogeneous side population of cancer cells （such as cancer stem-like cells）, resulting in poor prognosis. The heterogeneity of cancer cells causes an extensive multidrug resistance through the aberrantly active Hedgehog （Hh） signaling pathway. Cyclopamine is a chemical compound that can block Hh signaling pathway, and a combination use of cyclopamine with anticancer drug would be beneficial for killing heterogeneous cancer cells. In the present study, we aimed to develop a kind type of fimctional drug liposomes for eliminating heterogeneous cancer, The study was performed on human breast cancer cells. A distearoylphosphoethanolamine polyethylene glycol （DSPE-PEG2000）-cyclopamine conjugate was newly synthesized by a nucleophilic substitution reaction, and confirmed by MALDI-TOF mass. An HPLC method was established and validated for qualification of epirubicin. Functional epimbicin liposomes were successful constructed by modifying with DSPE-PEG2o00-cyclopamine, displaying a particle size in nano-scale （approximately 98 nm） and a high epirubicin encapsulation （〉97%）. The CD44＋/CD24-side population was characterized in defining heterogeneous breast cancer cells. As compared with regular epirubicin liposomes, fimctional epirubicin liposomes exhibited an evidently enhanced cellular drug uptake and a significant killing effect in overall breast cancer cells. In conclusion, the functional epirubicin liposomes could be a useful drug delivery carrier for eliminating heterogeneous breast cancer cells.
基金National Natural Science Foundation of China(Grant No.21571006 and 21271012)
文摘The Alzheimer＇s disease （AD） is one of the common cognitive disorders in the elderly. AD shares some similar pathological characters with diabetes mellitus （DM）, suggesting potential application of anti-diabetic agents, such as vanadyl complexes, in therapeutic treatment of AD. In the present work, we studied the effects of vanadyl acetylacetonate （VO（acac）2） and cinnamaldehyde （CA） on an AD model based on SH-SY5Y neural cells. The experimental results showed that VO（acac）2 at sub-micromolar concentrations could improve the viability of neural cells with or without increased β-amyloid （Aβ） burden; and the combination of VO（acac）2 and CA showed an additive cell protection effects. Further investigation revealed that for SH-SY5Y neural cells, VO（acac）2 could activate PPART-AMPK signal transduction and inhibit GSK 3β, one of the major kinases for Tau hyperphosphorylation. Meanwhile, CA could correct the abnormal mitochondrial morphology due to Aβ-induced excessive mitochondrial fission, thus restoring/enhancing the mitochondrial function. In addition, both VO（acac）2 and CA decreased intracellular reactive oxygen species （ROS） level and inhibited formation of toxic Aβ oligomers. Overall, VO（acac）2 might work with CA in improving the neural cell viability under the Aβ burden, suggesting application of vanadium metallodrugs in AD treatment.
基金National Basic Research Program of China(973Pro gram,Grant No.2015CB932100)National Natural Science Foundation of China(Grant No.81130059)
文摘Rho GTPases play an important role on the regulation of cytoskeleton, which can affect the cell morphogenesis, cell migration, endocytosis and vesicle transport by controlling the growth and maintenance of microfilaments and microtubules. It has been known that regulation of cell cytoskeleton is inseparable from the cell uptake of nano-medicine or nano-drug delivery systems. However, only few studies have focused on the impacts of Rho GTPases on cell uptake of nano-medicine or nano-drug delivery systems. This study selected single-walled carbon nanohoms （SWCNHs）, which have emerged as promising drug delivery systems, to explore the impacts of Rho GTPases on cell uptake of nano-drug delivery systems. SWCNHs were oxidized with concentrated nitric acid and prepared into nano dispersion by ultrasonic dispersion. Confocal laser scanning microscope （CLSM） and transmission electron microscopy （TEM） were used to observe the cell uptake and intracellular distribution of nanoparticles after incubated A549 cells with the dispersion mentioned above. Mechanism of cell uptake was assessed using various inhibitors. The results showed that the cell uptake of oxSWCNHs was significantly reduced when RhoA was inhibited. The oxSWCNHs were internalized through clathrin-mediated endocytosis and mainly positioned in lysosomes ofA549 cells.
