ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Cyclocarya paliurus (CP) is a traditional Chinese herb and possesses a variety of biological activities including anti-hyperglycemia, anti-hyperlipidemia, antioxidant and anti-inflammation. Arjunolic acid (AA) is an abundant and bioactive ingredient in CP that shows significant protection against many metabolic diseases such as diabetic complication. Diabetic retinopathy (DR) is a serious complication of diabetes and may lead to vision loss. However, the protective effects and underlying mechanisms of AA against DR is not still understood. AIM OF THE STUDY: We aimed to investigate whether AA activates AMPK/mTOR/HO-1 regulated autophagy pathway to alleviate DR. MATERIALS AND METHODS: In the study, the STZ-induced diabetic model of rats was established, and AA with 10 and 30 mg/kg dosages was given orally for ten weeks to investigate their effect on retinal injury of DR. H2O2-induced ARPE-19 cells were applied to evaluate anti-apoptosis and anti-oxidant effect of AA. RESULTS: The results revealed that AA could prevent STZ-induced weight loss and increase the retinal thickness and nuclei counts. The level of HO-1 protein was upregulated both in vivo and in vitro. In addition, AA prevented retinal damage and cell apoptosis through the AMPK-mTOR-regulated autophagy pathway. Furthermore, anti-apoptosis capacity, as well as the expression of HO-1 and LC3 protein, were effectively locked by AMPK inhibitor dorsomorphin dihydrochloride (compound C). CONCLUSIONS: This finding implies that AA may be a promising candidate drug by protecting retinal cells from STZ-induced oxidative stress and inflammation through the AMPK/mTOR/HO-1 regulated autophagy pathway.
Subject(s)
Adenylate Kinase/metabolism , Diabetic Retinopathy/drug therapy , Heme Oxygenase (Decyclizing)/metabolism , Juglandaceae/chemistry , TOR Serine-Threonine Kinases/metabolism , Triterpenes/therapeutic use , Adenylate Kinase/genetics , Animals , Autophagy/drug effects , Diabetes Mellitus, Experimental , Diabetic Retinopathy/metabolism , Gene Expression Regulation/drug effects , Heme Oxygenase (Decyclizing)/genetics , Male , Molecular Structure , Phytotherapy , Plant Extracts , Random Allocation , Rats , Rats, Sprague-Dawley , Triterpenes/chemistryABSTRACT
OBJECTIVE: To investigate if the Ribbond polyethylene fiber has the effect of reinforcing polymethyl methacylate. METHODS: 28 specimens were fabricated and divided into 3 groups: group of chemical-cured PMMA, group of chemical-cured PMMA reinforced by stainless steel wire and group of chemical-cured PMMA reinforced by Ribbond polyethylene fiber. A three-point bending test was used to measure the flexural strength and flexural modulus of specimens. Then the data were analyzed with a one-way analysis of variance. RESULTS: The flexural strength of chemical-cured PMMA group was (51.383 +/- 2.761) MPa, the flexural modulus was (1791.2 +/- 113.760) MPa; The flexural strength of stainless steel wire reinforced group was (58.725 +/- 1.218) MPa, the flexural modulus was (2092.76 +/- 120.28) MPa; The flexural strength of Ribbond polyethylene fiber reinforced group was (80.975 +/- 2.58) MPa, the flexural modulus was (2866.53 +/- 107.51) MPa. The one-way analysis of variance showed that the results were significant (P < 0.001). Newman-Keuls method showed that the differences among all groups were significant (P < 0.05). CONCLUSION: The Ribbond polyethylene fiber can raise the flexural strength and flexural modulu of polymethyl methacylate.
