Protective effect of Panax ginseng against serum biochemical changes and apoptosis in kidney of rats treated with gentamicin sulphate

The protective effects of Panax ginseng (PG) on gentamicin sulphate (GS) induced acute nephrotoxicity were investigated in rats. A total of 32 adult Sprague-Dawley rats were randomly divided into 4 equal groups and treated by intraperitoneous route for 10?days with: 0.5?mL of isotonic saline (group C), GS 100?mg/kg/day (group GS), co treatment PG (100 and 200?mg/kg/day) plus GS (100?mg/kg/day). After the last injection, kidney markers (urea, creatinine and blood urea nitrogen-BUN) and hepatic markers (aspartate aminotransferase-AST, alanine aminotransferase-ALT, gama glutamil transferase-GGT), and biochemical parameters were analyzed using diagnostic kits. Also, kidney changes were evaluated by immunohistochemical and stereological methods. GS treatment induced significant elevation (P?相似文献   

Detection and characterization of <Emphasis Type="Italic">Wolbachia</Emphasis> infections in laboratory and natural populations of different species of tsetse flies (genus <Emphasis Type="Italic">Glossina</Emphasis>)

BACKGROUND: Wolbachia is a genus of endosymbiotic α-Proteobacteria infecting a wide range of arthropods and filarial nematodes. Wolbachia is able to induce reproductive abnormalities such as cytoplasmic incompatibility (CI), thelytokous parthenogenesis, feminization and male killing, thus affecting biology, ecology and evolution of its hosts. The bacterial group has prompted research regarding its potential for the control of agricultural and medical disease vectors, including Glossina spp., which transmits African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. RESULTS: In the present study, we employed a Wolbachia specific 16S rRNA PCR assay to investigate the presence of Wolbachia in six different laboratory stocks as well as in natural populations of nine different Glossina species originating from 10 African countries. Wolbachia was prevalent in Glossina morsitans morsitans, G. morsitans centralis and G. austeni populations. It was also detected in G. brevipalpis, and, for the first time, in G. pallidipes and G. palpalis gambiensis. On the other hand, Wolbachia was not found in G. p. palpalis, G. fuscipes fuscipes and G. tachinoides. Wolbachia infections of different laboratory and natural populations of Glossina species were characterized using 16S rRNA, the wsp (Wolbachia Surface Protein) gene and MLST (Multi Locus Sequence Typing) gene markers. This analysis led to the detection of horizontal gene transfer events, in which Wobachia genes were inserted into the tsetse flies fly nuclear genome. CONCLUSIONS: Wolbachia infections were detected in both laboratory and natural populations of several different Glossina species. The characterization of these Wolbachia strains promises to lead to a deeper insight in tsetse flies-Wolbachia interactions, which is essential for the development and use of Wolbachia-based biological control methods.     

Long-term instability of alkaloid production by stably transformed cell lines of Catharanthus roseus

The productivity of several transgenic cell lines of Catharanthus roseus was monitored over a period of 30 months. The transgenic cultures were obtained by Agrobacterium-mediated transformation of leaf explants with constructs containing recombinant versions of the endogenous Str and Tdc genes, which, respectively, encode strictosidine synthase (STR) and tryptophan decarboxylase (TDC). The expression of these transgenes and the -glucuronidase marker gene were also measured periodically, at the enzymatic level, during this time. Cultures were maintained in selective medium containing either hygromycin or kanamycin and showed GUS activity in the presence of X-gluc, indicating that they carried functional transgenes. The activities of STR and TDC varied greatly over time, occasionally falling to levels not significantly different from those of non-transgenic cultures, and showed susceptibility to the composition of the culture medium. Despite maintaining their transgenic character, the cell lines gradually lost the ability to accumulate terpenoid indole alkaloids (TIAs). The diversity of alkaloids produced was also negatively affected by long-term subculture. We conclude that a strategy of indirect selection, such as the use of antibiotic-resistance genes, is insufficient to maintain the concerted expression of TIA-pathway elements necessary for high productivity.     

Effect of precursor feeding on alkaloid accumulation by a tryptophan decarboxylase over-expressing transgenic cell line T22 of Catharanthus roseus

To obtain more insight into the regulation of terpenoid indole alkaloid (TIA) biosynthesis in Catharanthus roseus (L.) G. Don cell cultures and particularly to identify possible rate limiting steps, a transgenic cell line over-expressing tryptophan decarboxylase (Tdc), and thus having a high level of tryptamine, was fed with various amounts of precursors (tryptophan, tryptamine, loganin and secologanin) in different time schedules and analyzed for TIA production. When these precursors were added to this culture it was found that the optimal time for supplying the precursors was at inoculation of the cells into the production medium. Alkaloid accumulation by line T22 was enhanced by addition of loganin or secologanin; however, the secologanin feeding was less effective. Tryptamine or tryptophan alone had no effect on TIA accumulation. The over-expression of Tdc causes this cell line to produce quite large quantities of alkaloids after feeding loganin or secologanin. However, in combination with tryptophan or tryptamine, feeding of these precursors resulted in an even further increase of alkaloid accumulation and under optimal conditions line T22 accumulated around 1200 micromol l(-1) of TIAs whereas the control cultures accumulated less than 10 micromol l(-1) TIAs.     

What can we hope to gain for trypanosomiasis control from molecular studies on tsetse biology ?

At times of crisis when epidemics rage and begin to take their toll on affected populations, as we have been witnessing with African trypanosomiasis in subSahara, the dichotomy of basic versus applied research deepens. While undoubtedly the treatment of thousands of infected people is the top priority, without continued research and development on the biology of disease agents and on ecological and evolutionary forces impacting these epidemics, little progress can be gained in the long run for the eventual control of these diseases. Here, we argue the need for additional research in one under-investigated area, that is the biology of the tsetse vector. Lacking are studies aimed to understand the genetic and cellular basis of tsetse interactions with trypanosomes as well as the genetic and biochemical basis of its ability to transmit these parasites. We discuss how this knowledge has the potential to contribute to the development of new vector control strategies as well as to improve the efficacy and affordability of the existing control approaches.     

Gastric protection by alpha-melanocyte-stimulating hormone against ethanol in rats: involvement of somatostatin

The proopiomelanocortin-derived tridecapeptide alpha-melanocyte-stimulating hormone (alpha-MSH) is a neuropeptide that exerts broad anti-inflammatory actions in mammals. This study aimed to investigate the effect of alpha-MSH on ethanol-induced gastric ulcer in rats and to evaluate the involvement of endogenous somatostatin in the actions of the peptide. The rats received 1 mL 75% ethanol or saline orally. alpha-MSH was given (25 micro g/rat; i.p.) alone or following the somatostatin antagonist cyclo-(7-aminoheptanoyl-PH-E-d-Trp-Lys-THR) (10 microM/kg; i.p.) administration. Gastric lesions were scored macroscopically and microscopically following decapitation at 30 min after ethanol challenge. Gastric malondialdehyde (MDA) level, myeloperoxidase (MPO) activity and mast cell counts were assessed. Ethanol-induced gastric hemorrhagic lesions were characterized by increased gastric MDA level, MPO activity and mast cell counts. alpha-MSH treatment decreased the extent of tissue injury and reversed tissue MDA level, MPO activity and mast cell counts. The effect of the peptide on the severity of gastric lesions, MDA level and MPO activity was reversed by the somatostatin antagonist. In conclusion, alpha-MSH is beneficial in a rat model of gastric ulcer via mechanisms which partly involve the endogenous somatostatin.