Buffalo (Bubalus bubalis) epiphyseal proteins give protection from arsenic and fluoride-induced adverse changes in acetylcholinesterase activity in rats

The objective of this study was to determine the effect of fluoride (F) and arsenic (As) on the activity of acetylcholinesterase (AChE), a critically important nervous system enzyme, and to test the protective role of buffalo epiphyseal (pineal) proteins (BEP) in rats. Arsenic (20 mg/kg BW, intraperitoneally) and F (150 ppm, perorally) were exposed, and BEP was administered intraperitoneally (100 μ g/kg BW) along with F and As to rats for 7 days. As and F exposure significantly (p < 0.05) increased their levels in plasma and decreased the activity of AChE in plasma, RBCs, heart, and brain of rats. Interestingly, As- and F-induced inhibition of AChE activities increased As and F levels in plasma, and organs were significantly (p < 0.05) counteracted by BEP administration. These findings indicate the protective role of buffalo (Bubalus bubalis) epiphyseal proteins on F- and As-induced adverse changes in AChE activity as a candidate biomarker for neurotoxicity in female rats.     

Methicillin-Resistant Staphylococcus aureus Phage Plaque Size Enhancement Using Sublethal Concentrations of Antibiotics

Phage therapy presents an alternative approach against the emerging methicillin-resistant Staphylococcus aureus (MRSA) threat. Some of the problems encountered during isolation of MRSA phages include the high prevalence of enteric phages in natural sources, nonspecific absorption of viable phage, and the formation of pinpoint or tiny plaques. The phage isolated in this study, MR-5, also formed tiny plaques against its host S. aureus ATCC 43300 (MRSA), making its detection and enumeration difficult. An improved method of increasing the plaque size of MRSA phage by incorporating sublethal concentrations of three different classes of antibiotics (inhibitors of protein synthesis) in the classical double-layer agar (DLA) method was investigated. The β-lactam and quinolone antibiotics commonly employed in earlier studies for increasing the plaque size did not show any significant effect on the plaque size of isolated MR-5 phage. Linezolid (oxazolidinone class), tetracycline, and ketolide antibiotics brought significant enhancements (3 times the original size) in the plaque size of MR-5 phage. Prior treatment with these antibiotics resulted in significant reductions in the time of adsorption and the latent period of MR-5 phage. To rule out whether the action of linezolid (which brought the maximum increase in plaque size) was specific for a single phage only, its effect on the plaque size of seven other S. aureus-specific phages was also assessed. Significant enhancements in the plaque size of these phages were observed. These results indicate that this modification can therefore safely be incorporated in the traditional DLA overlay method to search for new MRSA-virulent phages.     

Impaired methylation as a novel mechanism for proteasome suppression in liver cells

The proteasome is a multi-catalytic protein degradation enzyme that is regulated by ethanol-induced oxidative stress; such suppression is attributed to CYP2E1-generated metabolites. However, under certain conditions, it appears that in addition to oxidative stress, other mechanisms are also involved in proteasome regulation. This study investigated whether impaired protein methylation that occurs during exposure of liver cells to ethanol, may contribute to suppression of proteasome activity. We measured the chymotrypsin-like proteasome activity in Huh7CYP cells, hepatocytes, liver cytosols and nuclear extracts or purified 20S proteasome under conditions that maintain or prevent protein methylation. Reduction of proteasome activity of hepatoma cell and hepatocytes by ethanol or tubercidin was prevented by simultaneous treatment with S-adenosylmethionine (SAM). Moreover, the tubercidin-induced decline in proteasome activity occurred in both nuclear and cytosolic fractions. In vitro exposure of cell cytosolic fractions or highly purified 20S proteasome to low SAM:S-adenosylhomocysteine (SAH) ratios in the buffer also suppressed proteasome function, indicating that one or more methyltransferase(s) may be associated with proteasomal subunits. Immunoblotting a purified 20S rabbit red cell proteasome preparation using methyl lysine-specific antibodies revealed a 25 kDa proteasome subunit that showed positive reactivity with anti-methyl lysine. This reactivity was modified when 20S proteasome was exposed to differential SAM:SAH ratios. We conclude that impaired methylation of proteasome subunits suppressed proteasome activity in liver cells indicating an additional, yet novel mechanism of proteasome activity regulation by ethanol.     

Role of estrogen receptors in pro-oxidative and anti-oxidative actions of estrogens: A perspective

Background

Estrogens are steroid hormones responsible for the primary and secondary sexual characteristics in females. While pre-menopausal women use estrogens as the main constituents of contraceptive pills, post-menopausal women use the same for Hormone Replacement Therapy. Estrogens produce reactive oxygen species by increasing mitochondrial activity and redox cycling of estrogen metabolites. The phenolic hydroxyl group present at the C3 position of the A ring of estrogens can get oxidized either by accepting an electron or by losing a proton. Thus, estrogens might act as pro-oxidant in some settings, resulting in complicated non-communicable diseases, namely, cancer and cardiovascular disorders. However, in some other settings the phenolic hydroxyl group of estrogens may be responsible for the anti-oxidative beneficial functions and thus protect against cardiovascular and neurodegenerative diseases.

Scope of review

To date, no single review article has mentioned the implication of estrogen receptors in both the pro-oxidative and anti-oxidative actions of estrogens.

Major conclusion

The controversial role of estrogens as pro-oxidant or anti-oxidant is largely dependent on cell types, ratio of different types of estrogen receptors present in a particular cell and context specificity of the estrogen hormone responses. Both pro-oxidant and anti-oxidant effects of estrogens might involve different estrogen receptors that can have either genomic or non-genomic action to manifest further hormonal response.

General significance

This review highlights the role of estrogen receptors in the pro-oxidative and anti-oxidative actions of estrogens with special emphasis on neuronal cells.     

Effect of a juvenoid on embryonic development of Earias fabia (Stoll) (Lepidoptera: Noctuidae)

Eggs of Earias fabia were treated with three different quantities of a juvenoid, 6–7 epoxy-3-ethyl-1-(p-ethyl phenoxy)-7 methylnonane at 5 distinct stages. These were: (a) before blastoderm formation; (b) before gastrulation; (c) before segmentation; (d) before blastokinesis; and (e) just after blastokinesis. The effect on embryonic development was studied. If sufficient hormone is administered early enough, development may be arrested at stages as early as blastoderm formation. With moderate and smaller doses, developmental arrest mostly occurred at certain well-defined stages, such as germ-band formation; before blastokinesis; post blastokinesis; when the embryo assumes its larval form; at the time of chitin formation and during embryonic moulting. Observations also bring in focus the importance of the quantity of hormone and its relationship to the speed of its action. Toxic action is apparent when eggs are treated with relatively larger quantities of the compound: application of juvenoid to younger stages causes fewer deaths.     

Vestolide,a guaianolide from vicoa vestita

A new sesquiterpene lactone, vestolide, of the guaiane series was isolated from the aerial parts of Vicoa vestita. Its structure was established on the basis of chemical and spectral evidence.     

Cytomorphology of lipomatous tumors of soft tissue

OBJECTIVE: To evaluate the cytomorphologic features of benign and malignant lipomatous tumors of soft tissue on fine needle aspirates (FNA) and determine if the variants of liposarcoma could be identified. STUDY DESIGN: FNA of histologically documented benign (51 cases) and malignant (39 cases) lipomatous tumors were reviewed. Twenty-six of the 51 FNA from lipomas and 34 of the 39 FNA from malignant lipomatous tumors were satisfactory for evaluation. RESULTS: FNA from 26 cases of lipomas were cellular, with lobulated, fibroadipose tissue. Thin and thick capillaries were seen in 92% and 65% of cases, though a chicken wire vascular pattern was seen in only 4 cases (15%). A cytodiagnosis of liposarcoma could be made in 23 cases (88%), and these could be further subtyped into well-differentiated (4 cases), myxoid (8), pleomorphic (4), round cell (3) and liposarcoma, ?type (4). Only 50% of the well-differentiated liposarcomas, 3 of the 10 pleomorphic liposarcomas and 8 of the 17 myxoid liposarcomas were diagnosed as such on FNA. Cytologic diagnosis of the remaining 9 cases of myxoid liposarcoma were pleomorphic liposarcoma (1); liposarcoma, ?type (3); malignant mesenchymal tumor (1); suspicious for malignancy (2); and benign (2). There were no false positives, but there were 3 false negative cases (1 well-differentiated and 2 myxoid liposarcoma). CONCLUSION: Lipomas can be diagnosed readily. Arborizing vessels can be seen in lipomas and should be interpreted with caution. Subclassification of liposarcomas on FNA is possible but not very reliable. Myxoid liposarcomas pose a problem, and aspirates from them can mimic a wide range of morphologic subtypes. The role of FNA in identification of variants of liposarcoma is limited.     

Protective effect of resveratrol against oxidative stress in middle cerebral artery occlusion model of stroke in rats

Free radicals have been implicated in neuronal injury during ischemia reperfusion in stroke. Trans resveratrol, a potent antioxidant, polyphenolic compound found in grapes and wines has recently been shown to have neuroprotective activity against oxidative stress in in vitro studies. In the present study the effect of chronic treatment of trans resveratrol was evaluated in focal ischemia induced by middle cerebral artery [MCA] occlusion in rats. Male Wistar rats were pretreated with trans resveratrol 20 mg/kg i.p. for 21 days and were subjected to focal ischemia by occlusion of MCA using intraluminal thread. After two hours of MCA occlusion reperfusion was allowed by retracting the thread. Animals were assessed for motor performance after 24 hours and subsequently rats were sacrificed for estimation of markers of oxidative stress [malondialdehyde [MDA] and reduced glutathione] and for evaluation of volume of infarction. Control group received vehicle and similar protocol was followed. Significant motor impairment, with elevated levels of MDA and reduced glutathione was observed in the vehicle treated MCA occluded rats. Treatment with trans resveratrol prevented motor impairment, rise in levels of MDA and reduced glutathione and also significantly decreased the volume of infarct as compared to control. The study provides first evidence of effectiveness of trans resveratrol in focal ischemia most probably by virtue of its antioxidant property.