PLGA- corosolic acid implants for potential application in ocular neovascularization diseases

Angiogenesis is the formation of new blood vessels from preexisting vasculature. Uncontrolled angiogenesis is associated with progression of several ocular pathologies, such as diabetic retinopathy and macular degeneration. Thus, the inhibition of this process consists in an interesting therapeutic target. Corosolic acid (CA) is a natural derivative of ursolic acid, found in many medicinal herbs and exhibits numerous biological properties, including the antiangiogenic activity. The present study reports the production of CA-loaded poly d,l-lactidecoglycolide acid (PLGA) devices by melt technique. HPLC-UV method was developed and validated to evaluate the uniformity and the release profile of the developed systems. The devices were also characterized by Fourier transform infrared spectroscopy, thermal analysis, and scanning electron morphology. It was studied the antiangiogenic activity of the CA-polymer system, using an in vivo model, the chorioallantoic membrane assay (CAM). CA was dispersed uniformly in the polymer matrix and no chemical interaction between the components of the formulation was verified. The implants presented a sustained release of the drug, which was confirmed by the morphological study and demonstrated an antiangiogenic activity. Therefore, the developed delivery system is a promising therapeutic tool for the treatment of ocular diseases associated with neovascularization or others related to the angiogenic process.

Content Determination of 6 Kinds of Triterpene Acid in Tibetan Medicine Rubus biflorus by Pre-column Derivatization HPLC/ FLD-APCI/MS / 中国药房

OBJECTIVE： To establish the method for content determination of 6 kinds of triterpene acids such as haw acid， corosolic acid， betula acid， betulonic acid， oleanolic acid and ursolic acid in Tibetan medicine Rubus biflorus. METHODS： Pre-column devrivatization HPLC-FLD-APCI/MS method was adopted. 2-（7H-dibenzo[a，g]carbazol-7-yl） ethyl-4-methylbenzene- sulfonate was used as the pre-column derivatization reagent．Hypersil C18 column was used with the mobile phase consisted of 5％ acetonitrile water solution-acetonitrile （gradient elution） at the flow rate of 1.0 mL/min. The excitation wavelength of fluorescence was 300 nm and the emission wavelength was 395 nm. The column temperature was 35 ℃， and sample size was 10 μL. Under atmospheric-pressure chemical ionization （APCI） source in positive-ion mode， pressure was 60 psi， the drying gas flow rate was 9 L/min， the dry gas temperature was 350 ℃， the gasification temperature was 450 ℃， and the capillary voltage was 3 500 V. RESULTS： The linear range of haw acid，corosolic acid，betula acid，betulonic acid，oleanolic acid and ursolic acid were 0.025-6.4 μg/mL（r≥0.999 6）. The quantitative limits were 5.11， 4.78， 4.42， 4.22， 4.29， 4.51 ng/mL； and detection limits were 1.42， 1.27， 1.30， 1.28， 1.16， 1.22 ng/mL， respectively. RSD of precision test was less than 5％， stability and repeatability tests were all less than 2％（no betulonic acid detected）. The recovery rates were 97.90％-100.55％（RSD＝1.00％，n＝6）， 97.95％-102.95％（RSD＝1.74％，n＝6）， 96.00％-101.20％（RSD＝2.00％，n＝6）， 93.25％-104.20％（RSD＝4.25％，n＝6）， 92.20％-103.30％（RSD＝3.58％，n＝6）， 97.80％-103.50％（RSD＝2.03％，n＝6）， respectively. CONCLUSIONS： The method is accurate， reliable and exclusive， and can be used for simultaneous determination of 6 kinds of triterpene acids in Tibetan medicine R. biflorus.

A new triterpenic acid from the roots of Rosa laevigata / 药学学报

This study was designed to investigate triterpenoids from the roots of Rosa laevigata Michx. The silica gel column chromatography was used to separate the chemical constituents from the roots of Rosa laevigata Michx. HPLC was used to analyze its purity and chemical constitution. Spectroscopy methods were used to determine their structures. Five constituents were isolated and identified as19α-OH-3β-E-feruloyl corosolic acid (1), 23-hydroxy-tormentic acid (2), 2α, 3β, 19α, 23-tetrahydroxy-12-en-28-oleanolic acid (3), 2α, 3α, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (4), 2α, 3β, 20β-trihydroxyurs-13 (18)-en-28-oic-acid (5). Compound 1 was assigned as a new compound, compounds 4, 5 were obtained from the genus Rosa for the first time.

Nrf2 activator corosolic acid meliorates alloxan induced diabetic nephropathy in mice

Objective:To determine whether corosolic acid (CA) targeting nuclear protein expression of Nrf2 activation can be used to attenuate renal damage and preserve renal function in alloxan diabetic mice.Methods:A mouse model with diabetic nephropathy was established to examine the Nrf2 expression.Mice were randomly divided into control,diabetic control,and CA groups treated at 0.4 mg/kg,2 mg/kg and 10 mg/kgp.o.for 8 weeks.Diabetes was induced in mice by single intraperitoneal injection of alloxan 200 mg/kg in all groups except the control.The mice with fasting blood glucose level over 200 mg/dL were considered as diabetic and were employed in the study.After 4th and 8th weeks,urine samples were collected (using metabolic cages) to measure protein and urea.Animals were euthanized,and serum samples were collected to estimate the glucose,creatinine,total protein,urea and blood urea nitrogen.Kidney was isolated at the end of experiment for histology to evaluate anti-oxidant parameters.Immunohistochemistry was performed to examine the Nrf2 expression.Results:CA treatment showed dose dependent reduction in level of biochemical parameters in serum and urine.CA group (10 mg/kg) showed significantly higher body weight and reduced kidney weight.Histopathological examination revealed reduced inflammation,collagen deposition and glomerulosclerosis in renal tissue.CA attenuated renal dysfunction,oxidative stress and inflammatory pro-cytokine levels.Conclusions:CA treatment exhibited ameliorative effect on kidney in mice with its enhanced Nrf2 expression.

Nrf2 activator Corosolic acid meliorates alloxan induced diabetic nephropathy in mice

Objective To determine whether Corosolic acid (CA) targeting nuclear protein expression of Nrf2 activation can be used to attenuate renal damage and preserve renal function in alloxan diabetic mice. Methods A mouse model with diabetic nephropathy was established to examine the Nrf2 expression. Mice were randomly divided into control, diabetic control, and CA groups treated at 0.4 mg/kg, 2 mg/kg and 10 mg/kg p.o. for 8 weeks. Diabetes was induced in mice by single intraperitoneal injection of alloxan 200 mg/kg in all groups except the control. The mice with fasting blood glucose level over 200 mg/dL were considered as diabetic and were employed in the study. After 4th and 8th weeks, urine samples were collected (using metabolic cages) to measure protein and urea. Animals were euthanized, and serum samples were collected to estimate the glucose, creatinine, total protein, urea and blood urea nitrogen. Kidney was isolated at the end of experiment for histology to evaluate anti-oxidant parameters. Immunohistochemistry was performed to examine the Nrf2 expression. Results CA treatment showed dose dependent reduction in level of biochemical parameters in serum and urine. CA group (10 mg/kg) showed significantly higher body weight and reduced kidney weight. Histopathological examination revealed reduced inflammation, collagen deposition and glomerulosclerosis in renal tissue. CA attenuated renal dysfunction, oxidative stress and inflammatory pro-cytokine levels. Conclusions CA treatment exhibited ameliorative effect on kidney in mice with its enhanced Nrf2 expression.

Synthesis and biological evaluation of novel amide derivatives of pentacyclic triterterpenes as inhibitors of glycogen phosphorylase / 中国药科大学学报

@#Eight novel amide derivatives of corosolic acid were synthesized by acylation, amidation and hydrolysis reactions, etc. Six novel amide derivatives of oleanolic acid were synthesized by acylation, alkylation and reduction reactions, etc. Biological evaluation of the target compounds as inhibitors of glycogen phosphorylase(GP)has been described. Results indicated that eleven derivatives exhibited moderate-to-good inhibitory activities against glycogen phosphorylase. Among them, four target compounds possess better inhibition effects than lead compounds and compound 6 show the best inhibition effect with the IC50 of 11. 2 μmol/L.

Chemical constituents from leaves of Acanthopanax evodiaefolius / 中草药

Objective: To study the chemical constituents from the leaves of Acanthopanax evodiaefolius. Methods: The compounds were isolated and purified by silica gel and Sephadex LH-20 column chromatography. Their structures were identified on the basis of their physicochemical properties and spectroscopic data. Results: Thirteen compounds were isolated from the methanol extract of A. evodiaefolius and their structures were identified as heptadecanoic acid (1), heptacosanol (2), trans-cinnamic acid (3), ursolic acid (4), oleanolic acid (5), betulinic acid (6), corosolic acid (7), apigenin (8), naringenin (9), maltol (10), syringic acid (11), stigmasterol (12), and daucosterol (13), respectively. Conclusion: Compounds 1-3 and 7-10 are obtained from the plans in genus Acanthopanax Miq. for the first time and all the compounds are obtained from A. evodiaefolius for the first time.

Antitumor effect of corosolic acid and it’s impact on CAM and YSM angiogenesis / 中国生化药物杂志

Objective To evaluate the antitumor effect of corosolic acid and its impact on CAM and YSM angiogenesis.Methods The effects of CRA on A549 proliferation was studied by MTT method in vitro.Tumor-bruden nude mice model were established by injecting A549 lung cancer cell marked with bioluminescent to nude mice,and the growth of tumor in mice were detected by IVIS small animal in vivo imaging system.Experiment of chicken embryos eggs are used to observe the role of drugs on CAMand YSMblood vessels. Results The value of IC50 of CRA for A549 in vitro was 26.8μg/mL.A tumor-burdened animal experiment results showed that the CRA to A549 solid tumor has a certain therapeutic effect.CAM and YSM blood vessels of chicken embryos eggs treated with CRA were decreased significantly than negative control group.Conclusion CRA has certain therapeutic effect for A549,which may be related to the inhibition of angiogenesis in tumor tissues.

Determination of six triterpene acid contents in effective fraction of Eriobotryae Folium by quantitative analysis of multi-components by single-marker / 中草药

Objective: To develop a quantitative analysis of multi-components by single-marker (QAMS) method for the simultaneous determination of six triterpene acid (euscaphic acid, tormentic acid, maslinic acid, corosolic acid, oleanolic acid, and ursolic acid) contents in the effective fraction of Eriobotryae Folium. Methods: Ursolic acid was used as the internal reference substance, and the relative correlation factors (RCF) of euscaphic acid, tormentic acid, maslinic acid, corosolic acid, and oleanolic acid were determined by HPLC-ELSD with good reproducibility. The contents of the five components were calculated according to the RCF, respectively. The contents of these six triterpene acids in 15 batches of effective fraction were determined by the external standard method. The rationality, feasibility, and repeatability of the QAMS method were verified by comparing the results obtained from the two different methods. Results: For the six triterpene acids, there was no significant difference between the quantitative results with the two different methods in the 15 batches. Conclusion: The method established in this research is accurate and feasible that it just needs to assay single-marker (ursolic acid) for the determination of six triterpene acids in the effective fraction of Eriobotryae Folium simultaneously. Therefore, this method could provide a new reference for the quality assess of multi components in Chinese materia medica.