Advances in Pharmacological Research of Psidium Guajava L.Leaves in Resisting Diabetes and Its Complications

Modern pharmacological studies have shown that Psidium Guajava L.leaves have a variety of pharmacological effects,such as anti-inflammation,anti-oxidation,anti-tumor,reducing blood lipid,and reducing blood sugar.In recent years,the effect of Psidium Guajava L.leaves on diabetes and its complications has become the focus of research.This paper reviews the pharmacological research trends of effect of Psidium Guajava L.leaves on diabetes and its complications,in order to provide reference for the application and research and development of this plant.

Anti-insect Bioactivity of the Extracts from Cichorium intybus L. Leaves

In order to develop a new plant-source insecticide,some active components from Cichorium intybus L.were extracted with mineral ether,ethyl ether,ethyl acetate,respectively.It were testified the effects of the components on the development of Mythimna separate Walker and anti-feeding by feeding and weighting method.The results showed that the body weight of the larvae fed by the extracts with organic solvents was significantly lower than the control;the body weight of the larvae fed by the extracts with organic solvents was significantly different in different solvents in 3-5 days.The corrected mortality of the ethyl acetate treatment was the highest（52.05%）,and the development period of the larvae treated by ethyl acetate was about 4-10 days longer than the control and the corresponding pupating rate was the lowest（43.30%）.Therefore,the effect of ethyl acetate extract was most significant.Moreover,the pupa weight of the treatments was little more than the control.The extracts from Cichorium intybus L.leaves had highest bioactivity mainly in anti-feeding activity on Mythimna separate Walker.

Correlation between Different Morus alba L. Leaf Nodes and the Change in Leaf Size or Mass

This paper aimed to explore the correlation between Morus alba L. leaf node and its size or mass change and provide a theoretical basis for the development of scientific Morus alba L. cultivation technology. During 2016-2017,the correlation between Morus alba L. leaf node and its size or mass change was investigated and researched. Results showed that through the correlation coefficient analysis,there was a weakly positive correlation between the leaf node and some indicators such as( leaf length ÷ leaf width) and petiole length,there was a weakly negative correlation between the leaf node and some indicators such as leaf width,( leaf length + leaf width),( leaf length × leaf width) and leaf mass,and there was a weakly negative correlation between the leaf node and the other indicators; there was a highly positive correlation between the leaf mass and some indicators such as Morus alba L. leaf length,leaf width,( leaf length + leaf width) and( leaf length × leaf width),there was a significantly positive correlation between the leaf mass and some indicators such as petiole transverse diameter in width and petiole mass,and there was a weakly positive correlation between the leaf mass and some indicators such as petiole transverse diameter in thickness. In terms of significant level of difference,it was found that there was no significant difference in the correlation coefficients between the leaf nodes on the Morus alba L. shoots and some indicators such as leaf length,leaf width,( leaf length + leaf width),( leaf length × leaf width) and leaf mass; there was an extremely significant difference in the correlation coefficients between the leaf mass and some indicators such as Morus alba L. leaf length,leaf width,( leaf length + leaf width),( leaf length × leaf width),petiole transverse diameter in width and petiole mass; there was no significant difference in the correlation coefficients between the leaf mass and the other indicators. The regression analysis was performed on the leaf node and leaf length,leaf width,( leaf length + leaf width),( leaf length × leaf width),( leaf length ÷ leaf width),petiole length,petiole diameter in width,petiole diameter in thickness,petiole mass and leaf mass. Significance F values were0. 4864,0. 1995,0. 2888,0. 3004,0. 2350,0. 2407,0. 8925,0. 5227,0. 7022 and 0. 2000,respectively,that is,there was an extremely significant difference between Morus alba L. leaf node and petiole diameter in width,there was a significant difference between Morus alba L.leaf node and petiole mass,and there was no significant difference between Morus alba L. leaf node and the other indicators. The comparative analysis of quadratic curve regression equation and linear regression equation was performed on some indicators such as leaf length,and it was found that the R value between the leaf node and petiole diameter in width was in line with the logarithmic curve regression equation,and the other R values of quadratic curve regression equation was larger than the other R values of linear regression equation,indicating that different Morus alba L. leaf nodes,leaf length,leaf mass and other indicators were in line with the quadratic curve regression equation. It was concluded that by investigating the leaf node on the Morus alba L. shoots and regression equation,we could predict the leaf size,leaf mass and other indicators,and we could take the leaf node on the Morus alba L. shoots as a main factor affecting the Morus alba L. leaf size and mass.

Content Determination of Quercetin in Ferment of Ginkgo biloba L. Leaves by HPLC

[Objectives] This study aimed to determine the content of quercetin in ferment of Ginkgo biloba L.leaves.[Methods]Bacillus licheniformis was selected for solid-state fermentation of G.biloba leaf powder,and the content of quercetin in ferment of G.biloba leaves was determined by reversed-phase high-performance liquid chromatography.First,the flavonoid glycosides were extracted with methanol.Then,the flavonoid glycosides were hydrolyzed with hydrochloric acid to prepare the test solution.The chromatographic conditions were as follows:Platisil ODS C_(18) column(150 mm × 4.6 mm,5 μm);V_(methonal)∶V_(water)(0.4% phosphoric acid solution) =55∶45;flow rate of 1 m L/min;Shimadzu UV detector;detection wavelength of 360 nm.[Results] Quercetin was used as a reference substance.In the range of 0.002 6-0.036 0 g/L,there was a good linear relationship,with correlation coefficient of 0.999 8 and RSD of 1.26%.[Conclusions] This method is simple,easy to operate,accurate,and reproducible.It is suitable for the determination of quercetin content in G.biloba leaves.

The Influence of Portulaca Oleracea L. Leaves Extracts on the Histoarchitecture of Culex Quinquefasciatus and Anopheles Stephensi Larvae

Background:Mosquito is a big threat to the human health.Mosquito-borne diseases cause millions of death to the human beings.Hence,a permanent solution is eagerly to be established to control its excessive growth in stagnant water.Portulaca oleracea Linn is a natural larvicidal agent,which contains active ingredients such as linolenic acid,linoleic acid(omega-3 fatty acids).These bioactive compounds may be responsible for its larvicidal properties on mosquito.Objective:The present study is focussed on identifying the bioactive compounds,such as linolenic acid,through GC-MS,and analyzing the larvicidal efficacy of Portulaca oleracea L.against Culex quinquefasciatus and Anopheles stephensi larvae.Methods:Preliminary phytochemical analysis,total protein content,total carbohydrate content,total phenol content,total flavonoid content and GC-MS analysis exhibited the presence of rich phytoconstituents in Portulaca oleracea.DPPH analysis was carried out to analyze the antioxidant potential of plant extract.Larvicidal activity and histological change were detected to evaluate the efficacy of Portulaca oleracea L.on the Culex quinquefasciatus and Anopheles stephensi larvae.Results:Aqueous and ethanol leaf extracts of Portulaca oleracea L.against both Culex quinquefasciatus and Anophe-les stephensi larvae,showed a very good larvicidal activity at 500μg/mL among the various concentrations.His-tological damages of mosquito larvae were observed when treated with the Portulaca oleracea L.extract,and provided further evidence for its larvicidal activity.Conclusion:This study concluded that the plant Portulaca oleracea L.contained many useful bioactive compounds,can be a strong larvicidal agent against both Culex quinquefasciatus and Anopheles stephensi larvae.The molecular mechanism for the larvicidal activity will be identified in future studies.

Study on chemical constituents of Apocynum venetum L. leaves by LC/MS and determination of the best harvest season

The dried leaves of Apocynum venetum L. （AVL） is a traditional Chinese medicine widely used as antihypertensive medicine in China. Accurate determination of its best harvest season is important for its effective and safe use. In the present study, we developed a reliable method based on high-performance liquid chromatography-diode array detector-electro spray ionization-ion trap-time of flight （HPLC-DAD-ESI-IT-TOF） mass spectrometry and HPLC-DAD for the identification and quantification of major components in AVL leaves. Quantitative analysis of 24 samples collected weekly helped monitor the changes of compounds dynamically in AVL leaves to determine the best harvest season. A total of 30 compounds were identified, including quinic acid, five phenolic acids and 24 flavonoids. For the first time, 16 compounds were selected as marker compounds and simultaneously monitored weekly instead of monthly during the growth of the plant. The results showed that in May the leaves had the highest amount of phenolic acids, flavonoids and total compounds. Therefore, May should be the best harvest season for AVL leaves, which was distinct from previous studies. The established method was validated to be simple, accurate and precise, and thus it was of great importance for determination of the best harvest season.