Low-dose phloretin alleviates diabetic atherosclerosis through endothelial KLF2 restoration.

We investigated whether low-dose phloretin served as daily dietary supplements could ameliorate diabetic atherosclerosis and the role of kruppel-like factor 2 (KLF2). HUVECs cultured in high glucose medium were treated with different concentrations of phloretin and KLF2 mRNA, and protein level was detected. Diabetes was induced using streptozotocin in Apoe-/- mice after which they were fed a high-cholesterol diet for 8 weeks. Diabetic mice injected with KLF2 shRNA-lentivirus or control virus were treated with 20 mg/kg phloretin. Glucose, lipid profile, aortic atheroma, and endothelial nitric oxide synthase (eNOS) expression were detected. Phloretin retained endothelial function by KLF2-eNOS activation under hyperglycemia. Low-dose phloretin helped with lipid metabolism, and blocked the acceleration of atherosclerosis in STZ-induced diabetic mice since the early stage, which was diminished by KLF2 knockdown. Low-dose phloretin exhibited athero-protective effect in diabetic Apoe-/- mice dependent on KLF2 activation. This finding makes phloretin for diabetic atherosclerosis.

[Effect of fertilization levels on soil microorganism amount and soil enzyme activities].

Field experiments were conducted in Shangluo pharmaceutical base in Shaanxi province to study the effect of nitrogen, phosphorus and potassium in different fertilization levels on Platycodon grandiflorum soil microorganism and activities of soil enzyme, using three-factor D-saturation optimal design with random block design. The results showed that N0P2K2, N2P2K0, N3P1K3 and N3P3K1 increased the amount of bacteria in 0-20 cm of soil compared with N0P0K0 by 144.34%, 39.25%, 37.17%, 53.58%, respectively. The amount of bacteria in 2040 cm of soil of N3P1K3 increased by 163.77%, N0P0K3 increased the amount of soil actinomycetes significantly by 192.11%, while other treatments had no significant effect. N2P0K2 and N3P1K3 increased the amounts of fungus significantly in 0-20 cm of soil compared with N0P0K0, increased by 35.27% and 92.21%, respectively. N3P0K0 increased the amounts of fungus significantly in 20-40 cm of soil by 165.35%, while other treatments had no significant effect. All treatments decrease soil catalase activity significantly in 0-20 cm of soil except for N2P0K2, and while N2P2K0 and NPK increased catalase activity significantly in 2040 cm of soil. Fertilization regime increased invertase activity significantly in 2040 cm of soil, and decreased phosphatase activity inordinately in 0-20 cm of soil, while increased phosphatase activity in 2040 cm of soil other than N1P3K3. N3P0K0, N0P0K3, N2P0K2, N2P2K0 and NPK increased soil urease activity significantly in 0-20 cm of soil compared with N0P0K0 by 18.22%, 14.87%,17.84%, 27.88%, 24.54%, respectively. Fertilization regime increased soil urease activity significantly in 2040 cm of soil other than N0P2K2.

[Responses of Scutellaria baicalensis Georgi yield and root baicalin content to the fertilization rates of nitrogen, phosphorus, and potassium].

A field experiment with three-factor (N, P, and K) and quadratic saturation D-optimal design was conducted to evaluate the effects of the fertilization rates of N, P, and K on the yield and root baicalin content of Scutellaria baicalensis Georgi at harvesting time. A ternary quadratic polynomial mathematical model was built, in which, the N, P, and K fertilization rates were independent variables, and the yield and root baicalin content were the target functions. Through the analysis of the model, the optimum fertilization pattern was obtained. The results showed that the fertilization rates of N and P had significant effects on the yield of S. baicalensis. Under low fertilization level, the yield increased with increasing N and P fertilization rates; after exceeding definite fertilization range, no obvious effects were observed. N, P, and K fertilization all had significant effects on the root baicalin content. With increasing fertilization rates of N and K, the root baicalin content rates decreased after an initial increase. Under low fertilization level, the root baicalin content increased with increasing P fertilization rate first, and kept stable then. There existed interactive effects between the fertilization rates of N and P, N and K, and P and K on the yield and root baicalin content of S. baicalensis. Under our experimental conditions, the optimum fertilization model for obtaining over 4000 kg x hm(-2) of S. baicalensis yield and > 14% of root baicalin content was 90.5-104.7 kg x hm(-2) of N, 163.9-199.9 kg x hm(-2) of P2O5, and 84.1-140.8 kg x hm(-2) of K2O, with an N:P2O5:K2O ratio of approximately 1:1.86:1.15.

[Effects of nitrogen, phosphorus and potassium application on growth and active ingredient of Astragalus membranaceus].

OBJECTIVE: To study the effects of fertilizers with the different proportional of nitrogen, phosphorus and potassium on growth and active ingredient of Astragalus membranaceus. METHOD: Field experiment was conducted based on the D-saturation optimal design with three factors of nitrogen, phosphorus and potassium. The effects on growth and active ingredient of A. membranaceus were analyzed. RESULT: Fertilization promoted the seedling growth and provided abundant supply of nutrition for growth of root, yield and accumulation of active ingredient at the later growth stage, and increased the accumulation of dry matter of stem-leaf and root system. The effect of nitrogen, phosphorus and potassium application on the total dry matter accumulation of A. membranaceus was as following: nitrogen > potassium > phosphorus; the effect on the stem-leaf dry matter accumulation was as following: nitrogen > phosphorus > potassium; the effect on the root dry matter accumulation was as following: nitrogen > potassium > phosphorus. Nitrogen, phosphorus and potassium fertilizer increased the root yield of A. membranaceus. Obviously, the effect on the root yield was as following: nitrogen > potassium > phosphorus. The application of different proportional with nitrogen, phosphorus and potassium increased the content of polysaccharide and astragaloside, but had no distinct effect on the content of total flavonoids. The effect on the content of polysaccharide was as following: potassium > phosphorus > nitrogen, but the effect on the conten,t of astragaloside was as following: nitrogen > potassium > phosphorus. CONCLUSION: Nitrogen and potassium fertilizer application had more important effect on growth, yield and the contents of polysaccharide and astragaloside in A. membranaceus. During medicinal plants cultivation process, it should pay attention to the application of nitrogen fertilizer and potassium fertilizer and make balance application of nitrogen, phosphorus and potassium fertilizer.

Effects of grape seed proanthocyanidin extracts on peripheral nerves in streptozocin-induced diabetic rats.

Diabetic peripheral neuropathy (DPN) is one of the most common diabetic chronic complications. The aim of this study was to clarify whether grape seed proanthocyanidins extracts (GSPE) are therapeutic agents against DPN. In this study, we used streptozocin (STZ) to induce diabetic rats. GSPEs (250 mg/kg body weight/d) were administrated to diabetic rats for 24 wk. Motor nerve conductive velocity (MNCV) and mechanical hyperalgesia were determined in the rats. Serum glucose, glycated hemoglobin, advanced glycation end products (AGEs), and tissue malondialdehyde (MDA) and superoxide dismutase (SOD) were determined. Light and electron microscopy were used to observe the changes of nerval ultrastructure.GSPE significantly increased the MNCV, mechanical hyperalgesia and SOD of diabetic rats (p<0.05) and reduced the AGEs and MDA of diabetic rats (p<0.05). After being treated by GSPE, the severe segmental demyelination was decreased and Schwann cells were improved. In conclusion, GSPE plays an important role against DPN. With the decreasing of AGEs and MDA, it can ameliorate oxidation-associated nerval damage. This study may provide a new recognition of natural medicine for the treatment of DPN.

[Study on difference of biological characteristics and resistance to powdery mildew of different Astragalus populations].

OBJECTIVE: To study difference among populations which belong to Astragalus membranaceus and A. membranaceus var. mongholicus on morphology, habit, characteristics of physiology and resistance to powdery mildew, and classify them in order to provide theoretical basis for breeding and improving varieties. METHOD: Morphology, habits, isozyme and soluble protein electrophoretograms were compared among the populations. They were categorized by cluster analysis based on those electrophoretograms. Different ability of resistance to powdery mildew was also studied through comparing disease indices among six populations. RESULT: The results showed A. membranaceus var. mongholicus was distinctly different from A. membranaceus. There was a special type in colonies of A. membranaceus, which showed hairy upper epidermis of leaflets and later florescence. CONCLUSION: Astragalus for medicine could be categorized in three types A. membranaceus var. mongholicus, A. membranaceus early florescence type and A. membranaceus late florescence type. Among them A. membranaceus var. mongholicus is most resistant to powdery mildew, while A. membranaceus is easily infected, and the early florescence type is even more easily infected.

[Study on accumulation of dry matter and aborption of N, P and K of Astragalus membranaceus].

OBJECTIVE: To study Astragalus membranaceus absorption characteristic of nitrogen, phosphorus and potassium at different growth stages. METHOD: Through the field experiment and the sampling analysis, the absorbing capacity of nitrogen, phosphorus and potassium as well as the growth of plant at different growth stages in A. membranaceus were analyzed. RESULT: The dry matter accumulation reached 88.22% of the total accumulation in 100-163 days after seedling emergence, The content of N, P, K in the stem was higher than that in the root system. Nitrogen, phosphorus and potassium absorbing capacity in the stem, the leaf and the root systems was N > K > P. In the whole growth period, nitrogen accumulation reached the highest, and followed with the accumulation of potassium, and the accumulation of phosphorus was the lowest. In the last phase of the exuberant growth period, the accumulation intensity of nitrogen, phosphorus and potassium reduced. During the harvesting time, the accumulation intensity of nitrogen and potassium increased, and the accumulation intensity of phosphorus remained stable. CONCLUSION: The dry matter accumulation reached the maximum in 100-163 days after seedling emergence. The absorption strength of nitrogen, phosphorus and potassium in aerial part reached the maximum in 100-132 days after seeding emergence, the maximum absorption comes earlier than that of phosphorus and potassium, at that time the needs of nutrients reach the highest. For producing of 100 kg A. membranaceus 2.32 kg N, 0.323 kg P2O5, 1.62 kg K2O are needed to be absorbed from soil and fertilizer.

[Preliminary study on the characteristics of Bupleurum chinense in nutrition uptake].

It was studied that the characteristics of Bupleurum chinense DC. in nutrition uptake based on potted and field experiment to provide a properly fertilizer application measure. The result showed that the absorption amounts of N, P and K were in the order of K > N > P under field condition. For one-year-old B. chinesnse DC., the average N, P2O5 and K2O absorption per 100 kg dry matter of root were 11.77 kg, 2.43 kg, 14.07 kg respectively; for two-year-old, the average N, P2O5 and K2O absorption amount per 100 kg dry matter of root were 12.11 kg, 2.74 kg, 18.39 kg respectively. The total absorption amount of N, P2O5 and K2O were lower in the first year, while the percentage of content was higher, that was to say, the demand for N, P and K was urgent in the first year. The accumulation peak of N, P2O5 and K2O occurred regreening to later elongation stage in the second year. The ratio of N, P and K were differential in different growth stages.

[Preliminary study on N, P, K fertilizer to control of root rot of Bupleurum chinense].

The application of N and K fertillizer could improve the sensibility of Bupleurvum chinense DC. to Root Rot, while large application of P fertilizer could decrase the sensibility. The fertilizer measure which could obtain highest yield but could not increase its disease resistense. To protect Bupleurum chinense against root rot, more phosphorous fertilizer, certain nitrogen and potassium ferilizer should be applied in early elongation stage in the second growing year.

[The growth of Salvia miltiorrhiza seedling and root system following transplantation].

OBJECTIVE: To study the relationship between plant growth and accumulation of active ingredients in Salvia miltiorrhiza. METHOD: Transplants of S. miltiorrhiza were sampled at 20 day intervals. At each stage, the growth of seedling and root system was recorded and the contents of tanshinone II (A) and salvia acid were measured. RESULT AND CONCLUSION: This study showed that the rapid growth stage of the root system lags behind that of the seedling system, but the growing period of root system lasts longer. The quantitative change of roots reveals a double "S" curve; two rapid growth stages emerge during 30 - 70 days and 140 - 200 days after the seedlings were transplanted. The content of salvia acid reaches the highest level during 140 - 180 days, whereas the content of tanshinone peaks during 100 - 120 days.