Cutoff Point of HbA1c for Diagnosis of Diabetes Mellitus in Chinese Individuals.

BACKGROUND: The purpose of the present study was to find the optimal threshold of glycated hemoglobin (HbA1c) for diagnosis of diabetes mellitus in Chinese individuals. METHODS: A total of 8 391 subjects (including 2 133 men and 6 258 women) aged 40-90 years with gradable retinal photographs were recruited. The relationship between HbA1c and diabetic retinopathy (DR) was examined. Receiver operating characteristic (ROC) curves were used to find the optimal threshold of HbA1c in screening DR and diagnosing diabetes. RESULTS: HbA1c values in patients with DR were significantly higher than in those with no DR. The ROC curve for HbA1c had an area under the curve of 0.881 (95%CI 0.857-0.905; P = 0.000). HbA1c at a cutoff of 6.5% had a high sensitivity (80.6%) and specificity (86.9%) for detecting DR. CONCLUSIONS: HbA1c can be used to diagnose diabetes in a Chinese population, and the optimal HbA1c cutoff point for diagnosis is 6.5%.

A simple and convenient method for the preparation of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates.

BACKGROUND: Walnut (Juglans regia L.), that belongs to the Juglandaceae family, is one of the nuts commonly found in Chinese diets. Researchers had obtained peptides from walnut protein hydrolysates, and these peptides exhibited the high antioxidant activities. The objective of this study was to develop a simple and convenient method for a facile and reproducible preparation of antioxidant peptides from walnut protein hydrolysates. RESULTS: Walnut proteins were extracted from walnut kernels using continuous countercurrent extraction process, and were separately hydrolyzed with six types of proteases (neutrase, papain, bromelain, alcalase, pepsin, and pancreatin). Then, hydrolysates were purified by ultrafiltration. The yields and purity of the peptides prepared using neutrase and papain were 16 and 81 % at least, respectively, higher than others, and had low molecular weight, 99 % of which were less than 1500 Da. Furthermore, the bioassay indicated that the two peptides exhibited the high antioxidant activities in the DPPH (IC50 values: 59.40 and 31.02 µg/mL, respectively), ABTS (IC50 values: 80.36 and 62.22 µg/mL, respectively), and superoxide radical scavenging assay (IC50 values: 107.47 and 80.00 µg/mL, respectively). CONCLUSIONS: The method combines the advantages of generality, rapidity, simplicity, and is useful for the mass production of walnut peptides.Graphical AbstractPreparation of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates.

Synthesis and in vitro antitumor evaluation of betulin acid ester derivatives as novel apoptosis inducers.

Nineteen betulin derivatives modified at the C-3 and C-28 positions were synthesized and assessed for antitumor activities against the MGC-803, PC3, Bcap-37, A375, and MCF-7 human cancer cell lines in vitro by MTT assay. Some derivatives (compounds 3a-3d and 5) displayed strong antitumor properties, with IC50 values between 4 and 18 µM. Compound 3c, containing piperidine group at C-28 position, had IC50 values of 4.3, 4.5, 5.2, 7.5, and 5.2 µM on the five cancer cell lines, respectively. Subsequent fluorescence staining and flow cytometric analysis indicated that compound 3c induced apoptosis in MGC-803 cell line, with an apoptosis ratio of 31.11% after 36 h of treatment at 10 µM 3c.

Synthesis and biological evaluation of betulonic acid derivatives as antitumor agents.

Structural modification was performed at the C-28 position of betulonic acid (BetA). Twenty-five BetA derivatives were synthesized, and evaluated for their antitumor activities against MGC-803, PC3, Bcap-37, A375, and MCF-7 human cancer cell lines by MTT assay. Among the derivatives, most of the derivatives had significant antiproliferative ability (IC50 < 19 µM). Compound 3k, the most active compound, showed IC50 values of 3.6, 5.6, 4.2, 7.8, and 5.2 µM on the five cancer cell lines respectively, and was selected to investigate cell apoptosis by subsequent florescence staining and flow cytometry analysis. The results revealed that compound 3k could induce apoptosis in MGC-803 cell lines, and the apoptosis ratios reached 28.33% after 36 h of treatment at 10 µM. In addition, the study of cancer cell apoptotic signaling pathway indicated that the apoptosis of MGC-803 cells induced by compound 3k could be through the mitochondrial intrinsic pathway.

Chemical constituents of Cyrtomium fortumei (J.) Smith.

Five known compounds, 6'-methylglucuronide-5-hydroxy-chromone (1), ethyl α-d-glactopyranoside (2), neoechinulin A (3), 9,12,13-trihydroxyoctadeca-10(E),15(Z)-dienoic acid (4) and phellopterin (5), were isolated from water extract of Cyrtomium fortumei (J.) Smith. Compounds 1-5 were isolated from this genus for the first time, and all the compounds were evaluated in vitro against a panel of human cancer cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Among them, compounds 3 and 4 exhibited significant cytotoxic activities, with IC50 values of 15.2 and 18.3 µg/mL on MGC-803 cells, respectively.

Synthesis and cytotoxicity of novel ursolic acid derivatives containing an acyl piperazine moiety.

This study designed and synthesized a series of novel ursolic acid derivatives in an attempt to develop potent antitumor agents. Their structures were confirmed using MS, IR, (1)H NMR and (13)C NMR. The inhibitory activities of the title compounds against the MGC-803 (gastric cancer cell) and Bcap-37 (breast cancer cell) human cancer cell lines were evaluated using standard MTT assay in vitro. The pharmacological results showed that some of the compounds displayed moderate to high levels of antitumor activities against the tested cancer cell lines and that most exhibited more potent inhibitory activities compared with ursolic acid. The mechanism of compound 4b was preliminarily investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, TUNEL assay and flow cytometry, which revealed that the compound can induce cell apoptosis in MGC-803 cells.

[Establishment of the Chang liver cell line stably overexpressing human UCP2 gene and its effect on mitochondrial membrane potential and reactive oxygen species].

To establish the Chang liver cell line stably overexpressing human uncoupling protein 2 (UCP2) and observe the effect of UCP2 on mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The Chang liver cell line was transfected with recombinant plasmid containing full-length human UCP2 cDNA (pcDNA3.1-hUCP2) or pcDNA3.1 empty vector. The stable cell line was established by antibiotic screening with Zeocin. UCP2 expression was detected by Western blotting and immunocytochemistry. The UCP2 overexpressing cells were pretreated with genipin at various doses (25, 50 and 100 munol/L). MMP and intracellular ROS were detected by fluorescence spectrophotometry. The total normalized protein content in UCP2 overexpressing cells was 1.6-fold higher than that in unmanipulated normal cells. The fluorescence intensities of Rhodamine123 and DCFH-DA in UCP2 overexpressing Chang liver cells (11.11+/-2.76 and 4.97+/-0.62, respectively) were significantly lower than those in unmanipulated normal cells (15.56+/-2.55, P less than 0.01 and 6.14+/-1.25, P less than 0.05, respectively) and in cells transfected with empty vector (16.11+/-2.93, P less than 0.01 and 6.23+/-1.13, P less than 0.05, respectively). Treatment of UCP2 overexpressing cells with 25, 50 and 100 munol/L genipin caused a dose-dependent increase in fluorescence intensities of Rhodamine123 (14.89+/-2.89, 17.89+/-2.93 and 24.00+/-2.55, respectively, all P less than 0.01) and DCFH-DA (9.16+/-0.78, 10.84+/-1.09 and 11.83+/-1.25, respectively, all P less than 0.01). The Chang liver cell line stably overexpressing UCP2 was established successfully. Using this cell system, UCP2 was found to play a role in mitochondrial function by regulating MMP and ROS.