Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.
1. This study was conducted to determine the effect of early-age food restriction on heat shock protein (hsp) 70 synthesis in the brains of female broiler chickens exposed to high ambient temperatures. 2. Chicks were brooded for 3 weeks and then maintained at 24+/-1 degrees C. 3. On d 0, chicks were assigned to one of 4 feeding regimens; each regimen was applied to 4 cages of chicks. The regimens were: (1) ad libitum feeding (AL); (2) 80% food restriction at 4, 5 and 6 d of age (F80); (3) 60% food restriction at 4, 5, and 6 d of age (F60); and (4) 40% food restriction at 4, 5 and 6 d of age (F40). From d 35 to d 41, all chicks were subjected to 38+/-1 degrees C for 2 h/d. 4. One day following food restriction (d 7), hsp 70 expression in the brain samples of F60 and F40 chicks was augmented but not those fed AL and F80. 5. Prior to the heat challenge (d 35), all chicks had similar hsp 70 response. Irrespective of feeding regimen, there was a marked increase in hsp 70 expression after 4 d of heat treatment (d 38). Following 7 d of heat exposure (d 41), except for the F60 chicks, the augmented hsp 70 expression in the brains of AL, F80 and F40 birds was not maintained. 6. Enhancement of hsp 70 expression was noted in birds subjected to F60, but not AL, F80 or F40, throughout the period of heat exposure.
Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.
This study aimed to determine the effect of neonatal feed restriction on plasma corticosterone concentration (CORT), hippocampal glucocorticoid receptor (GR) expression, and heat shock protein (Hsp) 70 expression in aged male Japanese quail subjected to acute heat stress. Equal numbers of chicks were subjected to either ad libitum feeding (AL) or 60% feed restriction on d 4, 5, and 6 (FR). At 21 (young) and 270 (aged) d of age, birds were exposed to 43 ± 1°C for 1 h. Blood and hippocampus samples were collected to determine CORT and Hsp 70 and GR expressions before heat stress and following 1 h of heat stress, 1 h of post-heat stress recovery, and 2 h of post-heat stress recovery. With the use of real-time PCR and enzyme immunoassay, we examined the hippocampal expression of GR and Hsp 70 and CORT. The GR expression of the young birds increased following heat stress and remained consistent throughout the period of recovery. Conversely, no significant changes were noted on GR expression of aged birds. Although both young and aged birds had similar CORT before and during heat stress, the latter exhibited greater values following 1 and 2 h of recovery. Within the young group, feeding regimens had no significant effect on Hsp 70 expression. However, neonatal feed restriction improved Hsp 70 expression in aged birds. Neonatal feed restriction, compared with the AL group, resulted in higher CORT on d 21 but the converse was noted on d 270. Neonatal feed restriction appears to set a robust reactive hypothalamo-pituitary-adrenal response allowing the development of adaptive, healthy, and resilient phenotypes in aged quail as measured by a higher hippocampal Hsp 70 expression along with lower CORT.
Annona muricata, a member of the Annonaceae family, is commonly known as soursop and graviola. The leaves of this tropical fruit tree are widely used in folk medicine against skin diseases and abscesses, however there is no scientific evidence justifying the use of A. muricata leaves. The aim of the present study is to evaluate the wound healing potential of ethyl acetate extract of A. muricata leaves (EEAM) towards excisional wound models in rats.
Xanthones are phytochemical compounds found in a number of fruits and vegetables. Characteristically, they are noted to be made of diverse properties based on their biological, biochemical, and pharmacological actions. Accordingly, the apoptosis mechanisms induced by beta-mangostin, a xanthone compound isolated from Cratoxylum arborescens in the human promyelocytic leukemia cell line (HL60) in vitro, were examined in this study. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was done to estimate the cytotoxicity effect of β-mangostin on the HL60 cell line. Acridine orange/propidium iodide and Hoechst 33342 dyes and Annexin V tests were conducted to detect the apoptosis features. Caspase-3 and caspase-9 activities; reactive oxygen species; real-time polymerase chain reaction for Bcl-2, Bax, caspase-3, and caspase-9 Hsp70 genes; and western blot for p53, cytochrome c, and pro- and cleavage-caspase-3 and caspase-9 were assessed to examine the apoptosis mechanism. Cell-cycle analysis conducted revealed that β-mangostin inhibited the growth of HL60 at 58 µM in 24 h. The administration of β-mangostin with HL60 caused cell morphological changes related to apoptosis which increased the number of early and late apoptotic cells. The β-mangostin-catalyzed apoptosis action through caspase-3, caspase-7, and caspase-9 activation overproduced reactive oxygen species which downregulated the expression of antiapoptotic genes Bcl-2 and HSP70. Conversely, the expression of the apoptotic genes Bax, caspase-3, and caspase-9 were upregulated. Meanwhile, at the protein level, β-mangostin activated the formation of cleaved caspase-3 and caspase-9 and also upregulated the p53. β-mangostin arrested the cell cycle at the G0/G1 phase. Overall, the results for β-mangostin showed an antiproliferative effect in HL60 via stopping the cell cycle at the G0/G1 phase and prompted the intrinsic apoptosis pathway.
Feeding of bacterially encapsulated heat shock proteins (Hsps) to invertebrates is a novel way to limit Vibrio infection. As an example, ingestion of Escherichia coli overproducing prokaryotic Hsps significantly improves survival of gnotobiotically cultured Artemia larvae upon challenge with pathogenic Vibrio campbellii. The relationship between Hsp accumulation and enhanced resistance to infection may involve DnaK, the prokaryotic equivalent to Hsp70, a major molecular chaperone in eukaryotic cells. In support of this proposal, heat-stressed bacterial strains LVS 2 (Bacillus sp.), LVS 3 (Aeromonas hydrophila), LVS 8 (Vibrio sp.), GR 8 (Cytophaga sp.), and GR 10 (Roseobacter sp.) were shown in this work to be more effective than nonheated bacteria in protecting gnotobiotic Artemia larvae against V. campbellii challenge. Immunoprobing of Western blots and quantification by enzyme-linked immunosorbent assay revealed that the amount of DnaK in bacteria and their ability to enhance larval resistance to infection by V. campbellii are correlated. Although the function of DnaK is uncertain, it may improve tolerance to V. campbellii via immune stimulation, a possibility of significance from a fundamental perspective and also because it could be applied in aquaculture, a major method of food production.
A series of new 2-(ethylthio)benzohydrazone derivatives (1-6) were prepared and characterised by IR, 1H NMR, and 13C NMR spectroscopy and mass spectrometry. The newly prepared compounds were screened for their in vitro antioxidant activities using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Among them, most powerful antioxidant, compound 1 has been selected in order to illustrate anti-ulcer effect on ethanol-induced gastric mucosal lesions in rats. Four groups of Sprague Dawley rats were respectively treated with 10% Tween 20 as ulcer control group, 20 mg/kg omeprazole as reference group, 50 mg/kg and 100 mg/kg compound 1 as experimental animals. Macroscopically, ulcer control group showed extensive hemorrhagic lesions of gastric mucosa compared with omeprazole or compound 1. Rats pre-treated with compound 1 showed increased in gastric pH and gastric mucus. Histologically, ulcer control group showed severe damage to gastric mucosa with edema and leucocytes infiltration of submucosal layer. In immunohistochemical analysis, rats which were pre-treated with compound 1 showed up-regulation of HSP70 and down-regulation of Bax proteins. In conclusion, the gastroprotective effect of compound 1 may be due to its antioxidant activity, and/or due to up-regulation of HSP70 and down-regulation of Bax protein in stained tissue section.