The ensemble learning model is not better than the Asian modified CKD-EPI equation for glomerular filtration rate estimation in Chinese CKD patients in the external validation study.

OBJECTIVE: To assess the clinical practicability of the ensemble learning model established by Liu et al. in estimating glomerular filtration rate (GFR) and validate whether it is a better model than the Asian modified Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in a cohort of Chinese chronic kidney disease (CKD) patients in an external validation study. METHODS: According to the ensemble learning model and the Asian modified CKD-EPI equation, we calculated estimated GFRensemble and GFRCKD-EPI, separately. Diagnostic performance of the two models was assessed and compared by correlation coefficient, regression equation, Bland-Altman analysis, bias, precision and P30 under the premise of 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) dual plasma sample clearance method as reference method for GFR measurement (mGFR). RESULTS: A total of 158 Chinese CKD patients were included in our external validation study. The GFRensemble was highly related with mGFR, with the correlation coefficient of 0.94. However, regression equation of GFRensemble = 0.66*mGFR + 23.05, the regression coefficient was far away from one, and the intercept was wide. Compared with the Asian modified CKD-EPI equation, the diagnostic performance of the ensemble learning model also demonstrated a wider 95% limit of agreement in Bland-Altman analysis (52.6 vs 42.4 ml/min/1.73 m2), a poorer bias (8.0 vs 1.0 ml/min/1.73 m2, P = 0.02), an inferior precision (18.4 vs 12.7 ml/min/1.73 m2, P < 0.001) and a lower P30 (58.9% vs 74.1%, P < 0.001). CONCLUSIONS: Our study showed that the ensemble learning model cannot replace the Asian modified CKD-EPI equation for the first choice for GFR estimation in overall Chinese CKD patients.

Study on Adsorption and Sustained Release of Eucommia ulmoides Oliv. Leaf Extracts on Activated Carbon.

BACKGROUND: Due to its excellent adsorption capability, activated carbon(AC) has also been employed as a drug carrier. However, applications of the AC carrier in traditional Chinese medicine (TCM) have been rare. We selected the Eucommia ulmoides leaf extract as the drug of choice and AC as its carrier, to investigate the adsorption and sustained release behavior of the Eucommia ulmoides leaf extract on the AC. METHODS: AC was employed in this study as the sustained release carrier and its capability for adsorption and sustained release of Eucommia ulmoides leaf extracts was systematically investigated. Acid or alkali modified AC was assessed for its ability to absorb and sustain release of Eucommia ulmoides leaf extracts according to a variety of adsorption/release rate and composition. RESULTS: Results demonstrated that the adsorption rate for the differently modified AC reached above 80 %, whereas the adsorption of Eucommia ulmoides leaf extracts on the AC was selective. The composition of the sustained release liquid, which was treated by the acid modified AC, was almost similar to the original extract. The acid modified AC was therefore taken as an optimal carrier that can be used for Eucommia ulmoides leaf extracts sustained release. CONCLUSION: The synchronous release and absorption of different ingredients in the active ingredient release process ensures the global and cooperative effect with sustained and less toxic advantages. The ideal synchronous release is that the absorbed component proportion is consistent with its release. The acid modified AC was therefore taken as the optimal carrier that can be used for Eucommia ulmoides leaf extracts sustained release.

Preparation methods and release kinetics of Litsea cubeba essential oil microcapsules.

In this paper, using ß-cyclodextrin (ß-CD) as the shell material, LCEO (Litsea cubeba essential oil) microcapsules were prepared by various preparation methods, such as grinding, saturated solution, freeze-drying and spray-drying. The encapsulation yield, encapsulation efficiency, retention rate of the microcapsules and the citral content of the microcapsules were investigated. The surface morphologies of the microcapsules were observed using SEM (Scanning Electronic Microscopy); the entrapment efficiencies of the microcapsules were detected using IR (Infrared Spectrum) analysis; the citral contents of microcapsules were detected by GC (Gas Chromatography) analysis. The highest encapsulation efficiency for the microcapsules was obtained using spray-drying, followed by freeze-drying, saturated aqueous solution and grinding, while the encapsulation yield followed the opposite sequence to the encapsulation efficiency. At a specific storage temperature (15 °C) and humidity (60%), spray-drying had the most satisfactory protective effect on citral in LCEO, followed by freeze-drying and saturated aqueous solution, while the grinding method appeared to provide the worst protective effect. Avrami's model was used to simulate the release rates of the four kinds of microcapsules. The release mechanism parameters of microcapsules prepared by grinding, saturated aqueous solution, freeze-drying and spray-drying were 0.961, 1.096, 1.156 and 0.945, respectively. The release rate constants of microcapsules prepared by grinding, saturated aqueous solution, freeze-drying and spray-drying were 2.53 × 10-2, 2.22 × 10-2, 1.84 × 10-2, and 7.27 × 10-3 d-1, respectively. It was concluded that the release reactions of the microcapsules prepared by grinding or spray-drying lay between the diffusion limiting kinetics and the first-order release kinetics, and the release reactions of the microcapsules prepared by saturated aqueous solution or freeze-drying were larger than the first-order release kinetics.

Effervescent Granules Prepared Using Eucommia ulmoides Oliv. and Moso Bamboo Leaves: Hypoglycemic Activity in HepG2 Cells.

Eucommia ulmoides Oliv. (E. ulmoides Oliv.) and moso bamboo (Phyllostachys pubescens) leaves are used as folk medicines in central-western China to treat diabetes. To investigate the hypoglycemic activity of the effervescent granules prepared using E. ulmoides Oliv. and moso bamboo leaves (EBEG) in HepG2 cells, EBEG were prepared with 5% of each of polysaccharides and chlorogenic acids from moso bamboo and E. ulmoides Oliv. leaves, respectively. HepG2 cells cultured in a high-glucose medium were classified into different groups. The results displayed EBEG-treated cells showed better glucose utilization than the negative controls; thus, the hypoglycemic effect of EBEG was much greater than that of granules prepared using either component alone, thereby indicating that this effect was due to a synergistic action of the components. Further, glucose consumption levels in the cells treated with EBEG (156.35% at 200 µg/mL) and the positive controls (metformin, 162.29%; insulin, 161.52%) were similar. Thus, EBEG exhibited good potential for use as a natural antidiabetic agent. The hypoglycemic effect of EBEG could be due to the synergistic action of polysaccharides from the moso bamboo leaves and chlorogenic acids from E. ulmoides Oliv. leaves via the inhibition of alpha-glucosidase and glucose-6-phosphate displacement enzyme.

Formulation of intumescent flame retardant coatings containing natural-based tea saponin.

Natural product tea saponin (TS), extracted from the nutshell of camellia (Camellia oleifera Abel, Theaceae), was introduced into intumescent flame retardant formulations as blowing agent and carbon source. The formulations of the flame retardant system were optimized to get the optimum proportion of TS, and intumescent flame retardant coatings containing tea saponin (TS-IFRCs) were then prepared. It was found that TS can significantly affect the combustion behavior and the thermal stability of TS-IFRCs evaluated by cone calorimetry and simultaneous thermal analyzer, respectively. It was shown that TS, degraded to water vapor and carbon at high temperatures, can combine with other components to form a well-developed char layer. The char layer was supposed to inhibit erosion upon exposure to heat and oxygen and enhance the flame retardancy of TS-IFRCs. In addition, the smoke release of TS-IFRCs was also studied, which provided a low amount of smoke production.

Inhibition of α-glucosidase by polysaccharides from the fruit hull of Camellia oleifera Abel.

We isolated and purified polysaccharides from the Camellia oleifera Abel. fruit hull and studied its hypoglycemic potential. Our results revealed six polysaccharides (CFPA-1-5 & CFPB) from the aqueous extract from the defatted C. oleifera fruit hull. Purified polysaccharides (purity >90%) were investigated for the inhibition of α-glucosidase activity in vitro. Two polysaccharides, CFPB and CFPA-3 were present in high concentration in the fruit hull and showed a dose-dependent inhibition of α-glucosidase activity, with IC50 concentrations of 11.80 and 10.95 µg/mL, respectively. This result suggests that polysaccharides (CFP) extracted from the fruit hull of C. oleifera may have potential as functional foods with featuring a hypoglycemic effect.

[Study on enzyme-solvent extraction process of flavonoids from leaves of Ginkgo biloba].

OBJECTIVE: To study the optimum enzyme-solvent extraction conditions of flavonoids from leaves of Ginkgo biloba. METHODS: To optimize the process by single factor experiments and orthogonal test according to the yield of flavonoids. RESULTS: The optimum extraction conditions were established as follows: pH 5.7, the concentration of enzyme 0.4 mg/mL, enzymatic hydrolysis temperature 45 degrees C, enzymatic hydrolysis time 2 h, the rate of liquid to material 20:1, extraction temperature 70 degrees C, extraction time 2 h, the concentration of ethanol 70%, the average yield of flavonoids from leaves of Ginkgo biloba was 3.62%. CONCLUSION: The method is simple and can increase material utility effectively.