ABSTRACT
OBJECTIVES: The effect of a herbal medicine, Sho-seiryu-to (TJ-19), on oleic acid-induced lung injury, an animal model of acute respiratory distress syndrome or acute lung injury (ARDS/ALI), was examined. METHODS: Acute lung injury was induced by an intravenous injection of 15 microl/kg oleic acid to guinea-pigs. TJ-19 was administered by a single oral dose (3 g/kg) or by multiple oral doses (0.75 g/kg). KEY FINDINGS: The decrease in partial oxygen pressure of arterial blood (Pao(2)) and the increase in airway vascular permeability induced by the oleic acid injection were attenuated by a single dose of TJ-19. When TJ-19 was administered orally twice a day for two weeks and then oleic acid was injected, a potent prophylactic effect of the drug was observed. TJ-19 also prevented airway vascular hyperpermeability, lung cell injury, oxidative stress and thromboxane A(2) generation, associated with the oleic acid injection. CONCLUSIONS: TJ-19 significantly attenuated the oleic acid-induced lung injury probably through the antioxidative effect and inhibitory effect of thromboxane A(2) generation, although the precise inhibitory mechanisms were not fully elucidated due to the diversity in constituents of the herbal medicine. We suggest that TJ-19 is a promising drug candidate and a medicinal resource for preventing ARDS/ALI.
Subject(s)
Acute Lung Injury/prevention & control , Drugs, Chinese Herbal/therapeutic use , Phytotherapy , Acute Lung Injury/chemically induced , Animals , Capillary Permeability/drug effects , Disease Models, Animal , Drugs, Chinese Herbal/pharmacology , Guinea Pigs , Herbal Medicine , Male , Oleic Acid , Oxidative Stress/drug effects , Plants, Medicinal , Thromboxane A2/antagonists & inhibitors , Thromboxane A2/biosynthesisABSTRACT
Hepatitis E, an acute infectious disease transmitted via the fecal-oral route, is caused by hepatitis E virus. However, no effective treatment currently exists for hepatitis E, and the only epidemic control approach is vaccination. But so for there are no commercial vaccine for hepatitis E available in the world. To find a new expression system to develop recombinant hepatitis E vaccine, in this study the expression system of methylotrophic yeast Hansenula polymorpha was used to express the gene encoding amino acid 112 - 607 of the open reading frame 2 (ORF2) of hepatitis E virus (HEV) genotype IV. In order to achieve high expression level, the coding sequence was optimized according to codon usage bias of Hansenula polymorpha and synthesized through overlapping PCR. Subsequently the gene was subcloned into the multi-copy expression vectors of Hansenula polymorpha, which include pDGXHP1.0 (MOX promotor), pDGXHP2.0 (MOX promotor) and pDGXHP2.1 ( FMD promotor). The series of one-copy and multi-copy recombinant plasmids were transformed into ATCC26012(Ura3-) by electroporation. The transformants were cultured in selection media MDL and screened for the existence of foreign gene by PCR. Then the strains were induced in MM media and the expression products were detected by SDS-PAGE, ELISA and Western blot assays to select the high-level expression strains. The result of SDS-PAGE showed that the HEV ORF2 expression product was accumulated up to 12% of total cellular protein and its molecular weight is 56kD. The expression product showed high immunoreactivity detected by ELISA and the highest titer is 1:2048. The result of Western blot demonstrated that the expression product could be specifically recognized by the polyclonal antibody against HEV. The successful expression of HEV ORF2 protein in Hansenula polymorpha provides foundation for the further development of recombinant subunit vaccine against hepatitis E.