Significance of interactions of low molecular weight crystallin fragments in lens aging and cataract formation

Analysis of aged and cataract lenses shows the presence of increased amounts of crystallin fragments in the high molecular weight aggregates of water-soluble and water-insoluble fractions. However, the significance of accumulation and interaction of low molecular weight crystallin fragments in aging and cataract development is not clearly understood. In this study, 23 low molecular mass (<3.5-kDa) peptides in the urea-soluble fractions of young, aged, and aged cataract human lenses were identified by mass spectroscopy. Two peptides, B-(1-18) (MDIAIHHPWIRRPFFPFH) and A3/A1-(59-74)(SD(N)AYHIERLMSFRPIC), present in aged and cataract lens but not young lens, and a third peptide, S-(167-178) (SPAVQSFRRIVE) present in all three lens groups were synthesized to study the effects of interaction of these peptides with intact -, -, and -crystallins and alcohol dehydrogenase, a protein used in aggregation studies. Interaction of B-(1-18) and A3/A1-(59-74) peptides increased the scattering of light by - and -crystallin and alcohol dehydrogenase. The ability of -crystallin subunits to function as molecular chaperones was significantly reduced by interaction with B-(1-18) and A3/A1-(59-74) peptides, whereas S peptide had no effect on chaperone-like activity of -crystallin. The A3/A1-(59-74 peptide caused a 5.64-fold increase in B-crystallin oligomeric mass and partial precipitation. Replacing hydrophobic residues in B-(1-18) and A3/A1-(59-74) peptides abolished their ability to induce crystallin aggregation and light scattering. Our study suggests that interaction of crystallin-derived peptides with intact crystallins could be a key event in age-related protein aggregation in lens and cataractogenesis

AN IN VITRO STUDY OF CINNAMOMUM ZEYLANICUM AS NATURAL INHIBITOR OF ANGIOTENSIN-CONVERTING ENZYME (ACE) ON SHEEP (OVIS ARIES) TISSUES

Objective: The present study was aimed to find the angiotensin-converting enzyme (ACE) inhibitory activity using the methanolic extract ofCinnamomum zeylanicum (as a natural inhibitor) on sheep tissues as the enzyme source.Methods: Hippuryl-histidyl-leucine (HHL) as a substrate, tissue ACE activity was measured spectrophotometrically at 228 nm. For an incubationperiod of 30 minutes at 37°C, the linearity of ACE activity of kidney, lung, and testis enzyme was established. A known medicinal plant C. zeylanicumwas used as natural inhibitor of ACE. In this enzyme assay, inhibitory effect of methanolic extract of C. zeylanicum on kidney, lung and testicular ACEwas determined. ACE activity was confirmed by captopril, a standard inhibitor of ACE.Results: In the presence of a methanolic extract of C. zeylanicum (10:1), ACE activity was determined and this has inhibited ACE activity verysignificantly. C. zeylanicum leaves extract has reduced sheep kidney, lung, and testis ACE activity by 70.06%, 12.63%, and 20.23%, respectively.Conclusion: Significant inhibition was observed in the kidney ACE than in lung and testis ACE activity. This can propose that there may be a possiblerole in controlling blood pressure or reduction in cardiovascular diseases. Some plants with the great medicinal property may be considered aspromising sources of natural inhibitors of ACE for medicine and commercial uses. This comprehensive study may show numerous beneficial effects asa potential therapeutic agent for lowering blood pressure.Keywords: Angiotensin-converting enzyme, Natural angiotensin-converting enzyme inhibitor, Kinetic assay, Hippuryl-histidyl-leucine, Cinnamomumzeylanicum, Cardiovascular diseases

Angiotensin converting enzyme from sheep mammary, lingual and other tissues

1003-1006Occurrence of angiotensin converting enzyme (ACE) in mammary gland and tongue taste epithelium was demonstrated for the first time. Six times higher ACE activity in lactating mammary gland, than non-lactating mammary gland, suggested pregnancy and lactation hormonal dependent expression of ACE in female mammals. ACE activity was highest in choroid plexus, less in spinal cord and moderate in cerebrum, medulla, cerebellum and pons. Distribution of ACE in different regions of skin, kidney and among other tissues was different. Presence of ACE in adrenal glands, pancreas, bone marrow and thyroid gland indicated functions other than blood pressure homeostasis for this enzyme

Evaluation of paraoxonase I and hemoglobin levels in farmers and agricultural workers in relation to pesticide levels in their blood and urine samples: A cross sectional study

Data of pesticides levels, time of exposure, haemoglobin levels and paraoxanase levels 1</p

ISSN 2347-954X (Print) Angiotensin Converting Enzyme (ACE): Inhibition of Sheep Kidney and Lung ACE In vitro by Rauwolfia serpentina and Allium sativum

Abstract: Regulation of blood pressure is one of the important functions of Angiotensin I converting enzyme (ACE, EC. 3.4.15.1). ACE is widely distributed and appears to have several important physiological functions including its major role in blood pressure regulation. In the treatment of congestive heart failure, coronary artery disease, diabetic nephropathy etc.ACE inhibitors are used. The current study was aimed to find the effect of aqueous extracts of Rauwolfia serpentina leaves and Allium sativum cloves on sheep kidney and lung ACE. The method is Hippuryl-Histidyl-Leucine (HHL) as substrate, sheep kidney and lung ACE activity was measured and the hippuric acid released was measured spectrophotometrically at 228 nm. Aqueous extracts of Rauwolfia serpentina leaves and Allium sativum cloves were used in the enzyme assay to determine their effect on kidney and lung ACE. The results of linearity of ACE activity in kidney and lung was established with HHL as substrate for the incubation period of 30 min at 37°C. ACE activity was confirmed with specific ACE inhibitors like Captopril, Lisinopril, and Enalapril.25 µl of R. serpentina leaf extract reduced ACE activity by 68% and 57% in kidney and lung respectively. 25 µl of A. sativum cloves extract reduced ACE activity by 50% and 60% in kidney and lung respectively. In conclusion, use of medicinal plants is gaining considerable significance as a drug to treat hypertension. The significant inhibition of kidney and lung ACE activity by these two plant products suggests their possible role in controlling blood pressure as a mode of treatment for cardiovascular diseases, when used as supplement medicine

A comparative study to evaluate the effect of limited access dressing on diabetic ulcers

Aim: Emerging evidence favors the important role of antioxidants, matrix metalloproteinases (MMPs) and nitric oxide (NO) in the healing of diabetic wounds. There is a lack of substantial evidence regarding the effects of negative pressure on antioxidants, MMPs and NO in chronic wounds associated with diabetes.Methods: A total of 55 type 2 diabetic patients with leg ulcers were divided into 2 groups: a limited access dressing (LAD) group (n = 27) and a conventional dressing group (n = 28). Levels of hydroxyproline, total protein, MMP-2 and MMP-9, NO and antioxidants including reduced glutathione (GSH), and the oxidative biomarker malondialdhyde (MDA) were measured in the granulation tissue at days 0 and 10. Changes in levels between the LAD and conventional groups were determined by the student's t-test.Results: After 10 days of treatment, the LAD vs. conventional dressing group showed increases in the levels of hydroxyproline (mean ± SD = 55.2 ± 25.1 vs. 29.2 ± 1; P &lt; 0.05), total protein (12.8 ± 6.5 vs. 8.34 ± 3.2; P &lt; 0.05), NO (1.13 ± 0.52 vs. 0.66 ± 0.43; P &lt; 0.05), GSH (7.0 ± 2.4 vs. 6.6 ± 2.2; P &lt; 0.05) and decreases in MMP-2 (0.47 ± 0.33 vs. 0.62 ± 0.30; P &lt; 0.05), MMP-9 (0.32 ± 0.20 vs.0.53 ± 0.39; P &lt; 0.05) and MDA (6.8 ± 2.3 vs. 10.4 ± 3.4; P &lt; 0.05).Conclusion: When compared to conventional dressings, LAD induces biochemical changes by significantly increasing the levels of hydroxyproline, total protein, NO and antioxidants levels, and significantly reducing MMPs (MMP-2 and MMP-9) and an oxidative biomarker in diabetic wounds. These biochemical changes are thought to favor diabetic wound healing

Effects of limited access dressing in chronic wounds: A biochemical and histological study

Background: Negative pressure wound therapy has emerged as an attractive treatment modality for the management and healing of chronic ulcers. Though numerous clinical studies are available, there is a lack of biochemical and histological studies evaluating the healing of chronic wounds. Materials and Methods: In the present study, a total 60 patients were divided into two groups: Limited access dressing (LAD) group (n = 30) and conventional dressing group (n = 30). Various biochemical parameters such as hydroxyproline, total protein and antioxidants such as reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT) and oxidative biomarker malondialdhyde (MDA) are measured in the granulation tissue. Histologically amount of inflammatory infiltrate, angiogenesis, and collagen deposition are studied to assess wound healing. Results: Patients treated with LAD have shown significant increase in the mean (±standard deviation) hydroxyproline (77.3 ± 30.1 vs. 32.3 ± 16.18; P = 0.026), total protein (13.89 ± 9.0 vs. 8.9 ± 4.59; P = 0.004), GSH (7.4 ± 1.91 vs. 5.1 ± 1.28; P = 0.039), GPx (122.3 ± 59.3 vs. 88.7 ± 34.11; P = 0.030), CAT (1.80 ± 1.14 vs. 0.9 ± 0.71; P = 0.002) and decrease in MDA (13.4 ± 5.5 vs. 8.6 ± 3.8; P = 0.004). Histological study showed comparatively fewer inflammatory cells, increased and well organised collagen bundles, and more angiogenesis in the LAD group when compared with that with conventional dressing after 10 days of treatment. Conclusion: In the present study, we have found beneficial effect of newer intermittent negative pressure therapy in combination with moist environment (LAD) on chronic wound healing by increasing collagen deposition and angiogenesis; and reducing oxidative stress and inflammatory infiltrate