Sangram Singh

A Nonhost Peptidase Inhibitor of ~14 kDa from Butea monosperma (Lam.) Taub. Seeds Affects Negatively the Growth and Developmental Physiology of Helicoverpa armigera

Helicoverpa armigera is one of the major devastating pests of crop plants. In this context a serine peptidase inhibitor purified from the seeds of Butea monosperma was evaluated for its effect on developmental physiology of H. armigera larvae. B. monosperma peptidase inhibitor on 12% denaturing polyacrylamide gel electrophoresis exhibited a single protein band of ~14 kDa with or without reduction. In vitro studies towards total gut proteolytic enzymes of H. armigera and bovine trypsin indicated measurable inhibitory activity. B. monosperma peptidase inhibitor dose for 50% mortality and weight reduction by 50% were 0.5% w/w and 0.10% w/w, respectively. The IC50 of B. monosperma peptidase inhibitor against total H. armigera gut proteinases activity was 2.0 µg/mL. The larval feeding assays suggested B. monosperma peptidase inhibitor to be toxic as reflected by its retarded growth and development, consequently affecting fertility and fecundity of pest and prolonging the larval-pupal duration of the insect life cycle of H. armigera. Supplementing B. monosperma peptidase inhibitor in artificial diet at 0.1% w/w, both the efficiencies of conversion of ingested as well as digested food were downregulated, whereas approximate digestibility and metabolic cost were enhanced. The efficacy of Butea monosperma peptidase inhibitor against progressive growth and development of H. armigera suggest its usefulness in insect pest management of food crops.

Application of Immobilized Pointed Gourd (Trichosanthes dioica) Peroxidase-Concanavalin A Complex on Calcium Alginate Pectin Gel in Decolorization of Synthetic Dyes Using Batch Processes and Continuous Two Reactor System

Ammonium sulphate fractionated pointed gourd (Trichosanthes dioica) peroxidase- concanavalin A (PGP-Con A) complex was entrapped into calcium alginate-pectin gel. Catalytic performance of immobilized PGP-Con A complex in dye decolorization was examined on repeated use and reusing after a prolonged period of storage. Immobilized and entrapped peroxidase preparation retained 59.6% of the original activity after a period of 50 d. Entrapped PGPCon A complex decolorized 91.2% and 82.1% of the initial color from DR19 and dye mixture [DR19+DB9] after 20 d, respectively. Considerable color removal was found even after 120 d and 80 d respectively, of operation of two reactor system and total organic carbon analysis was quite comparable to color loss. This study shows the efficacy, durability and sustainability of using immobilized T. dioica peroxidase in batch and continuous two reactor catalytic system for the removal of synthetic dyes from industrial effluents.

The influence of organophosphate and carbamate on sperm chromatin and reproductive hormones among pesticide sprayers

This study is aimed at evaluating the association between occupational exposure to organophosphate (OP) and carbamate (CB) pesticides and semen quality as well as levels of reproductive and thyroid hormones of pesticide sprayers in Malihabad, Lucknow, Uttar Pradesh, India. Thirty-five healthy men (unexposed group) and 64 male pesticide sprayers (exposed group) were recruited for clinical evaluation of fertility status. Fresh semen samples were evaluated for sperm quality and analyzed for DNA fragmentation index (DFI) by flow cytometry. Pesticide exposure was assessed by measuring erythrocyte acetylcholinesterase and plasma butyrylcholinesterase (BuChE) with a Test-mate ChE field kit. Serum levels of total testosterone (Tt), prolactin (PRL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and free thyroxine (FT4) were analyzed using enzyme immunoassay kits. Evidence of pesticide exposure was found in 88.5% of sprayers and significant increments were observed in sperm DFI with significant decrease in some semen parameters. DFI was negatively correlated with BuChE, sperm concentration, morphology, and vitality in these pesticide sprayers. The levels of Tt, PRL, FT4, and TSH appeared to be normal; however, there was a tendency for increased LH and FSH levels in exposed workers. The results confirm the potential impact of chronic occupational exposure to OP and CB pesticides on male reproductive function, which may cause damage to sperm chromatin, decrease semen quality, and produce alterations in reproductive hormones, leading to adverse reproductive health outcomes.

Interrelation of Glycemic Status and Neuropsychiatric Disturbances in Farmers with Organophosphorus Pesticide Toxicity

Background: Diverse group of agro-chemicals are indiscriminately sprayed by the farmers for pest control to enhance crop yield. About 25 million agricultural workers in the developing world suffer from at least one episode of poisoning each year, mainly by anticholinesterase- like organophosphates (OPs). Objective: The present study was aimed to establish the OP toxicity in 187 occupationally exposed pesticide sprayers of mango plantation in rural Malihabad, Lucknow, in terms of neuro-cognitive impairment, mental health status, clinical symptoms, diabetes, and hematological factors. Method: The exposed group was compared to 187 pesticides-unexposed normal healthy persons engaged in normal usual agricultural work (age, sex and education corresponding to age group of selected subject group) from Rural Malihabad, Lucknow (India). Neuro-cognitive impairment was measured using the Subjective Neurocognition Inventory and mental health status using the General Health questionnaire-28. The subjects were also tested for biochemical and enzymatic parameters. Results: The exposed farmers showed alterations in enzymatic and clinical parameters. While the rates of anxiety / insomnia and severe depression were also significantly higher in the pesticide sprayers, disorders affecting psychomotor speed, selective attention, divided attention, verbal memory, nonverbal memory, prospective memory, spatial functioning, and initiative/energy were all lower in the sprayers. Pesticide sprayers showed a number of clinical symptoms like eczema, saliva secretion, fatigue, headache, sweating, abdominal pain, nausea, superior distal muscle weakness, inferior distal muscle weakness, hand tingling and etc. which all significantly correlated with the number of working years. Conclusion: These findings suggested that farmers who work with OPs are prone to neuro-psychological disorders and diabetes.

Exploring putative molecular mechanisms of human pyruvate kinase enzyme deficiency and its role in resistance against Plasmodium falciparum malaria.

Malaria is the third most prevalent cause of global mortality and is an interesting case of evolutionary selection. In response to high frequency of malaria infection, several host genetic factors have been selected, such as Hemoglobin variants, Glucose-6-phosphate dehydrogenase (G6PD) deficiency and pyruvate kinase deficiency. Among these popular host genetic factors, deficiency of pyruvate kinase enzyme is one of the most important factor that provide resistance against malaria. Regulation of this enzyme at the level of transcription is important and several factors may play crucial role in regulation of this enzyme. DNA sequence variation and epigenetic factors modifying transcriptional regulation of gene have been explored in context of several diseases. In the present study, we explored the factors modifying transcription regulation of pyruvate kinase gene with the help of Bioinformatics tools. On the basis of our predictions we hypothesize that any factor that reduces the availability (level) or activity of pyruvate kinase enzyme must play a strong role in resistance to malaria. Thus, factors reducing the activity (loss of function) or level of pyruvate kinase have been selected to provide resistance against malaria primarily in endemic regions.

The Influence of Pesticides on Hepatic and Renal Functions in Occupational Sprayers of Rural Malihabad, Lucknow (India)

Pesticides affect several human organs, resulting in a wide variety of physiological changes. In context with the occupational pesticide sprayers it is important to understand the influence of toxic exposure on human health. The present study is a comparative analysis of hematologic parameters, hepatic and renal function in the occupationally exposed pesticide sprayers of mango plantation of rural Malihabad, Lucknow. This area is predominantly a mango cultivation belt in North India. The select group of study comprises of sixty (60) pesticide sprayers [study group] and the control group included thirty (30) pesticides-unexposed normal healthy persons engaged in normal usual agricultural work [age group 20 to 45 years corresponding to age group of select subject group] from rural Malihabad, Lucknow [India]. Blood samples were collected from both groups. Questionnaire, interview and observation were employed to obtain demographic, occupational, dietary and clinical data. The sprayers as compared with control participants showed significantly increased serum C reactive protein, liver function marker enzymes, serum bilirubin, creatinine, blood glucose, and blood urea; whereas the acetyl cholinesterase activity and the level of serum cholesterol declined. No significant alteration was observed in the serum total protein, globulin, and the albumin/globulin ratio; however, a slight downfall in the level of serum albumin was recorded. Compared with the control group, hematologic parameters significantly decreased in pesticide sprayers. It is suggested that a high degree of pesticide absorption in occupationally exposed pesticides sprayers is responsible for decrease in the level of serum acetyl cholinesterase and consequently there is impairment of liver and kidney functions and slightly altered hematologic parameters. The present study suggests the toxic effect of pesticides on the occupational sprayer and precautionary measures must be taken to ameliorate their health status. It also suggests that restrain must be imposed on the indiscriminate use of lethal pesticides as it affects the ecosystem.

Immobilized Enzymes – Characteristics and Potential Applications in Synthetic Dye Color Removal

In recent times, enzymatic approaches have been used in treatment of colored wastewa‐ ter/industrial effluents. Peroxidases are very useful in removal of recalcitrant toxic com‐ pounds or transforming them into innocuous products. Although much attention has been paid in the utilization of biocatalysts in several fields, their involvement in solving the environmental problems has gained support. Enzymes in soluble states have limita‐ tions of catalytic ability and stability. As the complexity of the effluents increases, the ability of the enzymes to execute its catalytic potential decreases. Therefore, one of the ap‐ proaches to improve stability, catalytic ability, reusability and shelf life of enzymes is by immobilization. Work in the area of enzyme technology has provided significant clues that facilitate using enzymes optimally at large scale by cross-linking, entrapping and im‐ mobilizing. The current article presents an insight into the use of peroxidases immobi‐ lized on several different supports for the dye color removal of synthetic dyes as well as several different contaminants.

Application of Diethylaminoethyl Cellulose Immobilized Pointed Gourd (Trichosanthes dioica) Peroxidase in Treatment of Phenol and α-Naphthol

Recently, enzymatic treatment using peroxidases in removal of aromatic compounds has gained importance. In this study pointed gourd peroxidase was salt fractionated and direct immobilization of these proteins on diethylaminoethyl cellulose for oxidation of phenol and α-naphthol has been investigated. The activated diethylaminoethyl cellulose was quite effective in high yield immobilization of peroxidases from pointed gourd and it could bind ~576 units per g of the matrix. Immobilized pointed gourd peroxidase on this anion exchanger showed very high effectiveness factor ‘Ɛ’ as 0.91 with an activity yield of 91%. Immobilized PGP (I-PGP) as compared to soluble counterparts (s-PGP) were more effective and removed 79%, 88% and 54% oxidation of phenol and α-naphthol by 75%, 81% and 61% at 30, 40 and 50°C respectively, with a treatment time of 140 min. In the absence CdCl2 s-PGP as well as I-PGP exhibited upto 93% of oxidation of these compounds; whereas the presence of CdCl2 of negatively affected the removal of phenol and α-naphthol. The reactor worked well continuously for over one month for effectively oxidizing/ removing phenol and α-naphthol by 54% and 61% respectively. Thus, such immobilized enzyme systems in reactor have a great future and could be exploited for treating organic pollutants present in industrial effluents.

Biomedical Importance of Host Genetic Factors in Infectious Diseases

Tuberculosis, human immunodeficiency virus/acquired immunodeficiency syndrome and malaria are the three most profound cause of death worldwide. In developing country tuberculosis is a serious problem. It is estimated that one third of the world’s population is infected with M. tuberculosis; however, only a minority (10%) of those infected ever develop clinical disease (Corbett et al., 2003). Such clinical diversity suggests that factors other than bacterial infection alone determine disease development. Tuberculosis (TB) is a significant disease affecting both humans and animals. Susceptibility to Mycobacterium tuberculosis is relatively higher in humans than other primates and guinea pigs. Cattle, rabbits and cats are susceptible to M. bovis and are quite resistant to M. tuberculosis.