C0818, a novel curcumin derivative, interacts with Hsp90 and inhibits Hsp90 ATPase activity

The aims of the present study were to estimate the affinity between 3,5-()-bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride (C0818) and heat shock protein 90 (Hsp90) and to investigate the inhibitory effects of this compound on Hsp90 ATPase activity. Fluorescence spectroscopy was used to examine the affinity between varying concentrations of C0818 and Hsp90, N-Hsp90, M-Hsp90 and C-Hsp90. Fluorescence intensities were recorded in the range of 290-510 nm at 293, 303 and 310 K, respectively. A colorimetric assay for inorganic phosphate (based on the formation of a phosphomolybdate complex and the subsequent reaction with malachite green) were used to examine the inhibitory effects of C0818 on Hsp90 ATPase activity. The equilibrium dissociation constantvalue of C0818 was found to be 23.412±0.943 μmol/L. The interaction between C0818 and Hsp90 was driven mainly by electrostatic interactions. C0818 showed the strongest affinity with C-Hsp90. These results conclusively demonstrate the inhibitory activity of C0818 on the activity of Hsp90 ATPase.

The effects of curcumin derivatives C66 on proliferation and activation of rat hepatic stellate cells induced by transforming growth factor-β / 中华传染病杂志

Objective To investigate the effects of curcumin derivatives (C66) on proliferation and expressions of α-smooth muscle (α SMA) and Collagen Ⅰ in rat hepatic stellate cells (HSC) induced by transforming growth factor-β (TGF-β) in vitro and the relationship with cannabinoid receptor type 1 (CB1).Methods To determine the optimum time and concentration of C66,HSC-T6 cell line was cultured in vitro and divided into control group and groups with different doses of C66 (1 μmol/L,2 μmol/L,5 μmol/L,10 μmol/L,20 μmol/L).Cell proliferation was detected by Cell Counting Kit-8 assay.Then,according to the time and concentration of C66 above,cells were divided into 5 groups including control group,TGF-β only group,TGF-β combined with CB1 antagonist group,TGF-β combined with C66 group and TGF β combined with CB1 antagonist plus C66 group.Quantitative realtime polymerase chain reaction and western blot were used to assess the expressions of α SMA,Collagen Ⅰ,CB1,JNK and phosphorylation of JNK (p-JNK).The variance homogeneity of multiple samples was compared by LSD method.The variance was compared with Dunnett T3 test.One-way analysis of variance was performed to compare the mean values among the groups.Results The inhibitory effect of C66 on HSC-T6 proliferation was dose and time dependent.The optimum time and concentration were 48h and 10 μmol/L,respectively,with the inhibition rate of 54％.Compared with control group,expressions of α-SMA,collagen Ⅰ and CB1 were significantly elevated in TGF-β group (t=6.188,3.48 and 20.64,respectively,all P＜0.05).TGF-β1 could increase the relative mRNA expressions of CB1,collagen Ⅰ and α-SMA with significant differences (t =4.705,9.492 and 38.27,respectively,all P＜ 0.05).Compared with control group,p-JNK expression was significantly elevated in TGF-β group (t=9.567,P＜0.05).Conclusions C66 could inhibit the proliferation and collagen synthesis in HSC-T6 induced by TGF-β and the effect is strengthened when combined with CB1 antagonist,which may involve JNK phosphorylation.Our study provides a better understanding on the mechanism and a new target for treatment of liver fibrosis.

Effect of curcumin derivative B06 Bob on synthesis of testosterone from type 2 diabetic rats / 中国病理生理杂志

AIM:To investigate the effect of curcumin derivatives B06(B06) on the synthesis of testosterone from type 2 diabetic rats.METHODS: Male Sprague-Dawley rats were evenly divided into 5 groups randomly: normal control group (C group), high fat group (H group), high fat treatment group (HT group), diabetes mellitus group (D group) and diabetes treatment group ( DT group) .The rats in the later 4 groups were fed with high fat diet, after 4 weeks of high fat diet feeding, the rats from D group and DT group were injected with low dose of streptozotocin intraperitoneally to induce diabetes mellitus, while the rats in HT group and DT group were gavaged with B06 at the dose of 0.2 mg· kg-1 · d-1 for 8 weeks.The blood glucose was detected by glucometer, blood insulin was assayed by ELISA and the insulin resist-ance index was calculated.The morphology of testes were observed by light and transmission electron microscopy.Serum testosterone and estradiol were measured by radioimmunoassay.The protein expression of steroidogenic acute regulatory pro-tein ( StAR) was detected by immunohistochemistry.The mRNA expression of StAR, cholesterol side-chain cleavage en-zyme (P450scc), cytochrome P450 17A1 (P450c17), cytochrome P450 aromatizing enzyme (P450arom), 3β-hydroxyste-roid dehydrogenase ( HSD) and 17β-HSD was detected by RT-PCR.RESULTS:The levels of blood glucose and insulin resistance index were increased in H group and D group, and serum testosterone was decreased, all of which were reversed after the treatment of B06.Testicular seminiferous tubule was distorted, spermatogenic cells were dropped in H group and D group.In addition, leydig cells were found to have swelling mitochondria in H group and D group, endoplasmic reticu-lum was reduced, and there was karyopyknosis accompany with sparse chromatin, all of which were ameliorated by B06. The protein expression of StAR was decreased in D group.The mRNA expression of StAR and P450scc was decreased in H group and D group, all of which were increased in B06 treatment group.There was no significant difference in the mRNA expression of P450c17, P450arom, 3β-HSD and 17β-HSD.CONCLUSION: B06 may increase serum testosterone and relieve the damage of testes from type 2 diabetic rats.B06 improves metabolic disorder by up-regulating mRNA expression of StAR and P450scc.

Curcumin derivative C085 inhibits proliferation of K562/G01 cells and activity of Bcr-Abl kinase in vitro / 中国药理学通报

Aim To find new kinase inhibitors that o-vercome the imatinib resistance in the treatment of chronic myeloid leukemia ( CML ) by synthesizing C085, a novel derivative of curcumin , and testing its activities against wild-type( WT) and imatinib-resistant mutant Abl kinases , as well as in imatinib-resistant CML cells in vitro.Methods Cell proliferation and apoptosis were examined using MTT assay and flow cy-tometry, respectively;Kinase activity was measured u-sing Kinase-Glo Luminescent Kinase Assay Platform in recombinant WT and mutant ( Q252H, Y253F, and T315I) Abl kinases.The phosphorylation levels of Bcr-Abl initiated signaling proteins were analyzed using Western blotting .Colony forming units ( CFU ) growth was used to test the effects of C 085 on human leukemia progenitor/stem cells.Results C085 suppressed the growth of imatinib-resistant K562/G01 cells and po-tently inhibited both WT and mutant ( Q252H, Y253F, and T315I) Abl kinase activities in a non-ATP com-petitive manner with the values of IC 50 at low nanomole levels.C085 dose-dependently down-regulated Bcr-Abl kinase activity in K562/G01 cells as judged by auto-phosphorylation and Stat 5 , Crkl phosphorylation , and inhibited the phosphorylation of downstream targets Raf,Mek and Erk with protein content reducing .C085 could directly impact mitochondrial PT hole and make it open, which prevents the activation of caspase cas-cade reaction and induces the apoptosis .Furthermore, C085 significantly suppressed CFU growth , implicating that C085 could inhibit human leukemia progenitor/stem cells.Conclusion C085 may inhibit K562/G01 cells through inhibiting Bcr-Abl kinase activity and down-regulating the downstream signal proteins .Di-rectly acting on mitochondrial PT hole and then activa-ting apoptosis-associated proteins are also involved in the pro-apoptotic effect of C085.C085 is a promising compound for the treatment of CML patients with Bcr-Abl kinase domain mutations that confer imatinib re-sistance .

The effect of curcumin derivatives on the nuclear factor-κB expression in mice with hepatic fibrosis / 中华传染病杂志

Objective To investigate the therapeutic effects and mechanisms of curcumin derivatives C66 treatment on hepatic fibrosis .Methods Thirty three C57BL/6J mice were randomly divided into 3 groups:normal control group ,model control group and curcumin derivatives C66 treatment group .Nine mice in normal control group were fed with water and food .Hepatic fibrosis model was induced in 24 mice by intraperitoneal injection of 40% carbon tetrachloride at a dose of 4 mL/kg for the first time ,followed by 2 mL/kg twice a week for 6 weeks . At week 6 ,6 mice were randomly selected to perform pathological examination to evaluate whether the hepatic fibrosis were successfully induced .Mice with hepatic fibrosis were randomized into model control group and curcumin derivatives C66 treatment group with 9 mice in each group .From week 6 on ,mice in the treatment group were lavaged with curcumin derivatives C66 at a dosage of 10 mg ·/(kg · d) .The rest mice were administered with equivalent dosage of 0 .5% carboxymethylcellulose sodium .Serum alanine aminotransferase (ALT) ,aspartate aminotransferase (AST ) and liver hydroxyproline ( Hyp ) contents were detected , and the semi‐quantitative analysis of liver fibrosis was performed by pathological examination in hepatic tissue by hematoxylin and eosin (HE) and Masson staining .The expressions of collagen Ⅰ ,α‐smooth muscle actin (α‐SMA) mRNA and collagen Ⅰ ,α‐SMA ,nuclear factor‐kappa B p65 (NF‐κB p65) ,inhibitor kappa B alpha (IκBα) protein in each group were detected by quantitative real‐time polymerase chain reaction (RT‐PCR) and Western blot .Data were analyzed with one‐way ANOVA analysis .Results The serum levels of ALT and AST in model control group ,C66 treatment group and normal control group were (202 .71 ± 19 .66 ) U/L , (233 .42 ± 23 .97 ) U/L ;(102 .00 ± 11 .04 ) U/L , (120 .87 ± 13 .83 ) U/L ;(36 .66 ± 6 .37) U/L and (43 .33 ± 8 .08)U/L ,respectively .The differences between model and normal control group were both significant (t=23 .96 and 22 .39 ,respectively ;both P<0 .05) .The C66 treatment group showed significantly lower levels of serum ALT and AST in contrast with model control group (t =11 .56 and 10 .52 ,respectively ;both P<0 .05) .Compared to the model control group ,hepatic Hyp contents in normal control group and C66 treatment group were significantly different (t= 17 .50 , P< 0 .05;t=11 .45 ,P<0 .05) .Collagen Ⅰand α‐SMA mRNA expressions in C66 treatment group were remarkably lower in contrast with that in model control group (t= 7 .23 and 7 .95 ,respectively ;both P< 0 .05) . Protein levels of Collagen Ⅰ ,α‐SMA and NF‐κB p65 decreased in C66 treatment group ,while IκBαincreased significantly (all P<0 .05) .Conclusion The application of C66 can contribute to the regression of liver fibrosis and the mechanism may rely on the regulation of NF‐κB expression .

Effects of curcumin derivatives C085 on K562 cells and its mechanism / 中国药理学通报

Aim To explore the anti-proliferation and apoptotic effects of C085, a curcumin derivative, on K562 cells and its mechanism. Methods MTT assay and flow cytometry were used to examine cell prolifera-tion and apoptosis, respectively. The phosphorylation levels of Bcr-Abl initiated signaling proteins were ana-lyzed using Western blot. Results The results showed that C085 suppressed the growth of K562 cells and the IC50 value was about 5-fold lower than that of Cur. C085 also induced significant apoptosis on K562 cells in 24 hours when compared with imatinib. Western blot results demonstrated that C085 down-regulated the phosphorylation of Bcr-Abl in K562 cells in a dose-de-pendent manner. The phosphorylation of Stat 5 and Crkl, which were downstream signaling proteins of Bcr-Abl kinase, was also inhibited by C085. C085 caused the opening of mitochondrial PT holes as detected by JC-1 fluorescent, which inhibited Bcl-2 and enhanced Bax , then induced apoptosis. Conclusion C085 in-hibited BCR-ABL+ K562 cells through inhibiting BCR-ABL kinase activity and down-regulating its down-stream signal proteins. Directly acting on mitochondrial PT hole and then activating apoptosis- associated pro-teins are also involved in the pro-apoptotic effect of C085 .

Potent anti-angiogenic activity of B19--a mono-carbonyl analogue of curcumin / 中国天然药物

AIM@#The compound B19 (C21H22O5) is a newly synthesized, mono-carbonyl analog of curcumin that has exhibited potential antitumor effects. This present study was performed to identify the anti-angiogenic activity of this compound.@*METHODS AND RESULTS@#B19 inhibited migration and tube formation of human umbilical vein endothelial cells, and arrested microvessel outgrowth from rat aortic rings. In addition, B19 suppressed the neovascularization of chicken chorioallantoic membrane. Mechanistic studies revealed that B19 suppressed the downstream protein kinase activation of vascular endothelial growth factor (VEGF) by decreasing phosphorylated forms of serine/threonine kinase Akt, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase, with or without stimulating vascular endothelial growth factor (VEGF).@*CONCLUSIONS@#B19 exerted anti-angiogenic activity in vitro and ex vivo, which suggests that it merits further investigation as a promising anticancer angiogenesis compound.