Acetylcholinesterase from human erythrocytes membrane: a screen for evaluating the activity of some traditional plant extracts

The extraction of plant constituents is essential to isolate biologically active compounds and understanding their role in disease prevention, treatment and in knowing their toxic effects as well. However, meager information is available about the properties and biological activities of phytochemicals derived from certain plants found in Allahabad and adjoining areas. Keeping this information in view, we prepared aqueous extracts and determined their biochemical properties including their impact on the activity of human RBC's acetylcholinesterase (AChE). The UV—Visible spectrophotometric profiles of the aqueous extracts of different parts of the four plant species viz. Calotropis procera, Datura metal, Cannabis sativa, Argemone mexicana and Thevitia peruviana displayed two major peaks at 302 and 336 nm corresponding to the presence of different flavonoids in these preparations. These extracts indicated presence of protein in the range of 1.12 to 19.25mg/g wet weight of the plant tissues. The impact of different phytochemicals present in these extracts was studied on the activity of AChE isolated from human erythrocytes (RBCs). The extracts derived from Argemone mexicana and Datura metal exhibited strong AChE inhibitory potential, whereas others did not show significant inhibition even at higher concentrations. The results indicate that human RBC's can be used as a potential biomarker towards evaluation of the efficacy and toxic potential of varied plant extracts.

Neutraceutical approaches to control diabetes: A natural requisite approach

Objective:

The aim of this study is to screen the polyherbal preparation for antidiabetic activity in rats.

Materials and Methods:

The blood glucose lowering activity of the polyherbal preparation-I (1:1:1 of wheat germ oil, Coraidrum sativum, and Aloe vera) was studied in normal rats after oral administration at doses of 1.0 ml/kg and 2.0 ml/kg and polyherbal preparation-I, II (wheat germ oil, fresh juice of C. sativum, and A. vera in the ratio of 2:2:1), and III (wheat germ oil, fresh juice of C. sativum and A. vera in the ratio of 1:2:2) on alloxan-induced diabetic rats, after oral administration at doses of 1.0 ml/kg and 2.0 ml/kg. Blood samples were collected from the tail vein method at 0, 0.5, 1, 2, 4, 8, 12, and 24 h in normal rats and in diabetic rats at 0, 1, 3, 7, 15, and 30 days. Blood plasma glucose was estimated by the GOD/POD (glucose oxidase and peroxidase) method. The data were compared statistically by using the one-way ANOVA method followed by the Dunnett multiple component test. Statistical significance was set at P < 0.05.

Results:

The polyherbal preparation-I produced significant (P < 0.05) reduction in the blood glucose level of normal rats and polyherbal preparation-I, II, and III produced significant (P < 0.01) reduction in the blood glucose level of diabetic rats during 30-day study and compared with that of control and glibenclamide.

Conclusion:

The polyherbal preparation-I showed a significant glucose lowering effect in normal rats and polyherbal preparation-I, II, and III in diabetic rats. This preparation is going to be promising antidiabetic preparation for masses; however, it requires further extensive studies in human beings.

Radiative Boundary Layer Flow in Porous Medium due to Exponentially Shrinking Permeable Sheet

This communication pertains to the study of radiative heat transfer in boundary layer flow over an exponentially shrinking permeable sheet placed at the bottom of fluid saturated porous medium. The porous medium has permeability of specified form. The fluid considered here is Newtonian, without phase change, optically dense, absorbing-emitting radiation but a nonscattering medium. The setup is subjected to suction to contain the vorticity in the boundary layer. The radiative heat flux in the energy equation is accounted by Rosseland approximation. The thermal conductivity is presumed to vary with temperature in a linear fashion. The governing partial differential equations are reduced to ordinary differential equations by similarity transformations. The resulting system of nonlinear ordinary differential equations is solved numerically by fourth-order Runge-Kutta scheme together with shooting method. The pertinent findings displayed through figures and tables are discussed.

Polymorphism (C677T) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene: A preliminary study on north Indian men

An elevated level of plasma homocysteine, sulfur containing amino acid generated through demethylation of methionine has been widely accepted as a risk factor for cardiovascular disease (CVD). The increase can result from genetic and/or nutrient related disturbances in the remethylation or transsulfuration pathways for homocysteine metabolism. A common mutation (C677T) in the gene encoding for the enzyme 5, 10-methylenetetrahydrofolate reductase (MTHFR) or deficiency of the B vitamins namely folic acid, B(12), B(6) can lead to hyperhomocysteinemia.In the present study, we have investigated the incidence of the (C677T) MTHFR polymorphism in the North Indian males. 141 angiographically proven coronary artery disease (CAD) patients and 55 age and sex matched healthy volunteers were examined for the association between MTHFR gene polymorphism and CAD. The MTHFR genotyping was performed using polymerase chain reaction (PCR) followed by restriction-isotyping with Hinf 1 endonuclease. A trend for higher 'T' allele frequency (0.19) was observed in patients than in controls (0.16). However no significant association was found between C677T mutation and CAD severity. The lack of statistical significance could be due to the small sample size studied. Hence a larger study including various ethnic groups is warranted.

Effect of vitamin D supplementation of low birth weight term Indian infants from birth on cytokine production at 6 months

BACKGROUND/OBJECTIVES

Vitamin D deficiency has been associated with impaired resistance to infection, which may be mediated by alterations in cytokine responses. We investigated the effect of vitamin D supplementation to infants on whole blood in-vitro cytokine production and on the inflammatory marker, plasma C-reactive protein (CRP).

SUBJECTS/METHODS

Blood samples were taken at 6 months of age from infants participating in the DIVIDS (Delhi Infant Vitamin D Supplementation) randomized controlled trial of weekly vitamin D supplements (1400 IU = recommended intake) from birth to 6 months with the aim of decreasing mortality and severe morbidity. We measured plasma CRP and whole blood in-vitro production of tumour necrosis factor-α (TNFα), interferon-γ (INFγ), interleukin (IL)-10 and IL-13 following no stimulation or stimulation with lipopolysaccharide or phytohemagglutinin.

RESULTS

Although the intervention improved vitamin D status in a severely deficient population, there were no differences between treatment groups in plasma CRP or in the production of any of the cytokines in either unstimulated or stimulated cultures. Recent illness had limited association with immunological markers. Plasma 25-hydroxyvitamin D levels were not associated with CRP or production of any cytokines.

CONCLUSIONS

Vitamin D supplementation did not affect plasma CRP or whole blood cytokine production of vitamin D-deficient low birth weight infants. This is consistent with the lack of effect of vitamin D on mortality and severe morbidity among infants in the DIVIDS trial.

Association of circulating resistin with metabolic risk factors in Indian females having metabolic syndrome

Role of resistin in insulin sensitivity and metabolic syndrome (MetS) is controversial till date. Increased serum resistin levels are associated with MetS and insulin resistance. The aim of this study was to investigate the relationship between serum resistin levels with markers of the MetS in females. In a cross-sectional study, a total of 170 healthy female subjects were selected for the study. Out of which 71 (age 31.59 ± 4.88 years) were with MetS and 99 (age 31.75 ± 6.34 years) were without MetS. Different parameters of MetS and serum resistin level were measured according to the standard protocols as given in NCEP ATP III 2001 guideline. Serum resistin levels were significantly higher in subjects with MetS when compared with subjects without MetS [13.54 ± 4.14 ng/ml (n = 71) vs. 7.42 ± 2.31 ng/ml (n = 99); P ≤ 0.001]. Resistin levels were positively associated with waist circumference, systolic and diastolic blood pressure, plasma glucose, waist/hip ratio, serum triglycerides, serum cholesterol, serum VLDL, plasma insulin, and insulin resistance, while it was negatively associated with high-density lipoprotein. This study demonstrates a positive correlation between resistin and factors of MetS except high-density lipoprotein which was found to be negatively correlated in Indian female subjects.

Plaque removal efficacy of powered and manual toothbrushes under supervised and unsupervised conditions: a comparative clinical study

The present study was undertaken to determine and compare the efficacy of manual and powered toothbrushes under supervised and unsupervised conditions in 200 school-going children between 6 and 13 years of age. Two hundred school-going children aged between 6 and 13 years were selected. Children were randomly divided into two groups of 100 in each. Group 1 children were given manual brushes, while group 2 children were given powered brushes. The groups were further divided into two subgroups, with supervised brushing in subgroup A and unsupervised brushing in subgroup B. At 3, 6, 9 and 12 weeks, plaque was recorded according to Turseky-Gilmore-Glickman modification of Quingley Hein index and oral hygiene performance index. Data were statistically analyzed. Both brushes significantly reduced the plaque accumulation, though to different degrees. Powered brushes showed significant plaque reduction as compared to the manual brushes. Supervised group of both brushes showed a greater plaque reduction.

[L-cysteine influx in diabetic erythrocytes]

Erythrocyte oxidative stress has been implicated in the pathogenesis of diabetes mellitus, and the deficiency of antioxidant defense by the glutathione (GSH) pathway is thought to be one of the factors responsible for development of complications in diabetes. Erythrocytes require L-cysteine for thesynthesis of GSH and the rate of synthesis is determined only by L-cysteine availability. In the present study we have found that the L-cysteine influx in erythrocytes from type 2 diabetic patients was significantly lower compared to age-matched controls. The decreased influx may be one of the factors leading to low GSH concentration observed in type 2 diabetes. Since L-cysteine is the limiting amino acid in GSH synthesis, any strategy aimed to increase L-cysteine influx in erythrocytes may be beneficial for type 2 diabetic patients.

Comparative evaluation of shear bond strength of various esthetic restorative materials to dentin: an in vitro study

AIM

To comparatively evaluate the shear bond strength of recent tooth-colored restorative materials to dentin.

MATERIALS AND METHODS

Flat dentinal surface were prepared from 60 caries free, extracted human permanent molars and were mounted in acrylic rings. These were randomly divided into four groups - Group A to Group D, according to the restorative material used i.e. Glass ionomer cement (Fuji IX), Giomer (Beautifil), an Ormocer-based composite (Admira) and Nano Ceramic restorative material (Ceram X). These restorative materials were applied on dentinal surface of all the specimens using nylon cylinders. The mounted samples were stored in distilled water for 24 hours and thermocycled. They were then subjected to shear bond strength test using universal testing machine. Data was analyzed using a one-way analysis of variance (ANOVA) and student's 't'-test.

RESULTS

Ceram X (16.63 ± 0.94 MPa) and Admira (17.31 ± 0.95 MPa) were comparable in their bond strength values, but depicted significantly higher bond strength when compared to Beautifil (12.39 ± 1.05 MPa) and Fuji IX (7.76 ± 1.07 MPa).

CONCLUSION

Nano-ceramic and ormocer-based restorative materials showed better bonding potential to dentin as compared to GIC and Giomer.

A novel hydrogen sulfide donor causes stomatal opening and reduces nitric oxide accumulation

Effects of hydrogen sulfide (H(2)S) on plant physiology have been previously studied, but such studies have relied on the use of NaSH as a method for supplying H(2)S to tissues. Now new compounds which give a less severe H(2)S shock and a more prolonged exposure to H(2)S have been developed. Here the effects of one such compound, GYY4137, has been investigated to determine its effects on stomatal closure in Arabidopsis thaliana. It was found that both NaSH and GYY4137 caused stomatal opening in the light and prevented stomatal closure in the dark. Nitric oxide (NO) has been well established as a mediator of stomatal movements and here it was found that both NaSH and GYY4137 reduced the accumulation of NO in guard cells, perhaps suggesting a mode of action for H(2)S in this system. GYY4137, and future related compounds, will be important tools to unravel the effects of plant exposure to H(2)S and to determine how H(2)S may fit into plant cell signalling pathways.

Technique-sensitivity of dentin-bonding agent application: the effect on shear bond strength using one-step self-etch adhesive in primary molars: an in vitro study

AIM

The present study was undertaken to compare and evaluate the effect of technique-sensitivity on shear bond strength (SBS) of one-step self-etch adhesive, using multiple coats and different applicator designs, to dentin in deciduous molars.

MATERIALS AND METHODS

Flat buccal dentinal surfaces were obtained on 60 extracted human primary molars. The specimens were divided into 3 equal groups (n = 20). Self-etch adhesive was applied on the dentinal surface of group I with cotton pellet, group II with microapplicator tip, and group III using 3M brush. The groups were further divided into 2 subgroups-single coat of dentin-bonding agent (DBA) in subgroups A and triple coat (with no curing in between coats) in subgroups B. The composite was placed on the dentinal surface using split nylon cylinder and cured. SBS was tested for all specimens with Instron Universal testing machine. Data were statistically analyzed using one-way analysis of variance and Student's t test.

RESULTS

There was no statistically significant difference in the main study groups, that is, no significant difference in the SBS with the use of different applicator tips. However, the use of triple coat of self-etch DBA exhibited highly significant difference in the SBS as compared with single coat.

CONCLUSION

This study revealed that one-step self-etch adhesive could prove attractive in pediatric dentistry because of its lesser technique-sensitivity; however, increasing the number of coats of DBA (with no curing in between the layers) enhanced the bond strength to dentin owing to the improved resin infiltration.

Molecular characterization of a distinct begomovirus species from Vernonia cinerea and its associated DNA-beta using the bacteriophage Phi 29 DNA polymerase

Vernonia cinerea plants with yellow vein symptoms were collected around crop fields in Madurai. A portion (550 bp) of the AV1 gene amplified using degenerate primers from the total DNA purified from diseased leaf sample was cloned and sequenced. Specific primers derived from the above sequence were used to amplify 2,745 nucleotides with the typical genome organization of begomoviral DNA A (EMBL Accession No. AM182232). Sequence comparison with other begomoviruses revealed the greatest identity (82.4%) with Emilia yellow vein virus (EmYVV-[Fz1]) from China and less than 80% with all other known begomoviruses. The International Committee on Taxonomy of Viruses (ICTV) has therefore recognized Vernonia yellow vein virus (VeYVV) as a distinct begomovirus species. Conventional PCR could not amplify the DNA B or DNA beta from the diseased tissue. However, the beta DNA (1364 bp) associated with the disease was obtained (Accession No. FN435836) by the rolling circle amplification-restriction fragment length polymorphism method (RCA-RFLP) using Phi 29 DNA polymerase. Sequence analysis shows that DNA beta of VeYVV has the highest identity (56.8%) with DNA beta of Sigesbeckia yellow vein Guangxi betasatellite (SibYVGxB-[CN: Gx111:05]) and 56-53% with DNA beta associated with other begomoviruses. This is the first report of the molecular characterization of VeYVV from V. cinerea in India. The complete molecular characterization, phylogenetic analysis, and putative recombination events in VeYVV are reported.

Comparative evaluation of 2% sodium fluoride iontophoresis and other cavity liners beneath silver amalgam restorations

BACKGROUND

This study was designed to compare 2% sodium fluoride (NaF) iontophoresis with other cavity liners.

MATERIALS AND METHODS

This study was carried out in 30 patients in the age group 10-14 years with bilateral carious permanent first molars. The study evaluated the use of 2% NaF iontophoresis as a cavity liner and also compared its desensitizing effect with varnish and an adhesive bonded liner. Sensitivity gradings were done on a subjective verbal rating scale.

RESULTS

All the liner treatments decreased the sensitivity following liner application. However, decrease of sensitivity in the case of 2% NaF iontophoresis was more compared with that of varnish and adhesive bonded liner. The results were statistically significant.

CONCLUSIONS

It was found that 2% NaF iontophoresis was more effective in reducing the postoperative sensitivity compared with that of varnish and scotchbond multipurpose.

Why the carioprotective potential of luting cements crucial?

Space maintainers make good oral hygiene difficult, modify the oral environment, and increase the chances of enamel demineralization. Demineralization can be prevented or reduced by improving patient oral hygiene or by using topical fluorides. However these methods depend on patient compliance and, therefore, are not very reliable. Thus, caries prevention in banding might be enhanced by using fluoride-releasing cements. The aim of the study was to comparatively evaluate the carioprotective potential of various luting media used for band cementation in permanent as well as deciduous molars. In this study, 100 molars were taken, which were banded and stored in artificial saliva for 1 month after which the teeth were debanded. An area of 2 x 2 mm was spared and the teeth were coated with nail varnish. The coated teeth were dipped in artificial caries solution in one month followed by 1-day immersion in methylene blue dye, after which the samples were sectioned through the window. The depth of dye penetration was measured and the results were statistically analyzed. Minimum dye penetration was observed with glass ionomer, which could be due to the fluoride release from the cement, whereas the control group showed the maximum, probably due to direct contact with the artificial caries solution.

Plasmodium falciparum circumsporozoite protein: epidemiological variations among field isolates prevalent in India

OBJECTIVE

To investigate the extent of genetic variations in T-helper-cell epitopic regions of circumsporozoite (CS) protein in Plasmodium falciparum field isolates collected from different regions of India at different phases of malaria transmission.

METHODS

Genomic DNA was isolated from 507 P. falciparum wild-parasite isolates obtained from six geographical locations of India at three time points coinciding with malaria transmissions. The T-helper-cell epitopic regions were polymerase chain reaction (PCR)-amplified and the products were purified and then sequenced.

RESULTS

Based on sequences, nine variants were found among isolates and they were categorized into nine groups (V-1 to V-9), where V-1 and V-2 were observed in all three time points (TP). The variants V-1 to V-4 in TP-1; V-1, V-2, V-5 to V-8 in TP-2; and V-1, V-2, V-5 and V-9 in TP-3 were present and they showed restricted heterogeneity. During peak transmission (TP-2), parasite populations were more diverse and heterogeneous and the variants regionally unbiased and restricted. However, the alleles of V-6 and V-9 in both Th2R and Th3R showed identical sequence variation with those observed in other geographical regions of the world. The remaining seven groups did not show such similarity.

CONCLUSION

The Th2R and Th3R epitopes are implicated in host immune response to P. falciparum. The polymorphism in these epitopic regions indicates antigenic diversity, which may cause adverse outcome of a subunit vaccine including the CS prototype variant. Therefore, the formulation of a vaccine considering the restricted local repertoire parasite populations may be helpful.

Cytosolic alkalinization is a common and early messenger preceding the production of ROS and NO during stomatal closure by variable signals, including abscisic acid, methyl jasmonate and chitosan

Stomata are unique that they sense and respond to several internal and external stimuli, by modulating signaling components in guard cells. The levels of reactive oxygen species (ROS), nitric oxide (NO) and cytosolic calcium (Ca²⁺) increase significantly during stomatal closure by not only plant hormones [such as abscisic acid (ABA) or methyl jasmonate (MJ)] but also elicitors (such as chitosan). We observed that cytosolic alkalinization preceded the production of ROS as well as NO during ABA induced stomatal closure. We therefore propose that besides ROS and NO, the cytosolic pH is an important secondary messenger during stomatal closure by ABA or MJ. We also noticed that there is either a cross talk or feedback regulation by cytosolic Ca²⁺ and ROS (mostly H₂O₂). Further experiments on the interactions between cytosolic pH, ROS, NO and Ca²⁺ would yield interesting results.

Nitric oxide production occurs downstream of reactive oxygen species in guard cells during stomatal closure induced by chitosan in abaxial epidermis of Pisum sativum

The effects of chitosan (beta-1,4 linked glucosamine, a fungal elicitor), on the patterns of stomatal movement and signaling components were studied. cPTIO (NO scavenger), sodium tungstate (nitrate reductase inhibitor) or L: -NAME (NO synthase inhibitor) restricted the chitosan induced stomatal closure, demonstrating that NO is an essential factor. Similarly, catalase (H(2)O(2) scavenger) or DPI [NAD(P)H oxidase inhibitor] and BAPTA-AM or BAPTA (calcium chelators) prevented chitosan induced stomatal closure, suggesting that reactive oxygen species (ROS) and calcium were involved during such response. Monitoring the NO and ROS production in guard cells by fluorescent probes (DAF-2DA and H(2)DCFDA) indicated that on exposure to chitosan, the levels of NO rose after only 10 min, while those of ROS increased already by 5 min. cPTIO or sodium tungstate or L: -NAME prevented the rise in NO levels but did not restrict the ROS production. In contrast, catalase or DPI restricted the chitosan-induced production of both ROS and NO in guard cells. The calcium chelators, BAPTA-AM or BAPTA, did not have a significant effect on the chitosan induced rise in NO or ROS. We propose that the production of NO is an important signaling component and participates downstream of ROS production. The effects of chitosan strike a marked similarity with those of ABA or MJ on guard cells and indicate the convergence of their signal transduction pathways leading to stomatal closure.