PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF SWIETENIA MAHAGONI – A HIGHLY MEDICINAL PLANT IN INDIA

The present study was designed to evaluate the phytochemical analysis and antibacterial activity of Swietenia mahagoni leaf extract. The leaf extract was subjected to a variety of phytochemical analysis. The qualitative phytochemical tests exhibited the presence of common phytocompounds like alkaloids, tannins, saponins, phlobatannins, flavanoids, terpenoids and volatile oils as major active constituents. The plant (Swietenia mahagoni) leaf has valuable medicinal uses, hence petroleum ether (18.2g) was found to be a good solvent for the phytochemical and antibacterial study. Similarly, the Methanolic leaf extract of Swietenia mahagoni has highest zone of inhibition on Bacillus subtilis

Efficacy of trans-cerebellar diameter/abdominal circumference ratio versus head circumference/abdominal circumference ratio in prediction of asymmetrical intrauterine growth retardation

Background: Determination of gestational age is an important step of pregnancy management and foetal development evaluation in obstetrics. Any error in this gestational age estimation results in prematurity or post maturity and in case if the expected date of delivery is not known, there is high chance of perinatal mortality in the near outcome. Hence it is important in achieving an uneventful gestation to have a sensitive, specific and age independent obstetric biometric parameter that stays constant throughout the gestation. Trans-cerebellar diameters (TCD)/ abdominal circumference (AC) ratio are reliable, constant predictors to assess the gestational age and to evaluate fetal growth. Aim was to compare the accuracy of TCD/ AC ratio with head circumference (HC)/ AC ratio in predicting asymmetrical IUGR.Methods: A prospective study was conducted over a period of one year on 100 clinically suspected IUGR pregnancies who were evaluated with BPD, HC, AC and FL along with TCD were measured for assessing the sonological gestational age. Two morphometric ratios-TCD/AC and HC/AC were calculated. Estimated fetal weight was calculated for all these pregnancies and its percentile was determined. Then those clinically suspected IUGR cases were followed up to delivery and post-delivery new Ballord score and CAN score (clinical assessment of nutritional status at birth) were calculated.Results: In the present study, the sensitivity, specificity, PPV, NPV and DA were 83.93%, 65.91%, 75.81%, 76.32% and 76% respectively for TCD/AC ratio versus respectively for HC/AC ratio in predicting IUGR.  Conclusions: Both ratios were gestational age independent and can be used in detecting IUGR with good diagnostic accuracy. However, TCD/AC ratio had a better diagnostic validity and accuracy compared to HC/AC ratio in predicting asymmetric IUGR

Development and validation of integrated pest management modules against spotted pod borer Maruca vitrata Fabricius on garden bean Lablab purpureus var. typicus (L.)

To reduce the detrimental effect of insecticides, an effective Integrated Pest Management (IPM) module is necessary for the eco-friendly management of Maruca vitrata in garden bean ecosystem. Two field trials were carried out to evaluate the efficacy of different insecticides and botanicals against M. vitrata on Lablab purpureus var. typicus. Two seasons field evaluation of insecticides revealed that chlorantraniliprole 18.5 SC  was the most effective treatment to control the pest recorded 0.11 and 0.36 larva/plant in two seasons, respectively after two rounds of spray followed by flubendiamide 20 WG (0.46 and 0.92 larva/ plant) and emamectin benzoate 5 SG (0.50 and 0.95 larva/plant). Among botanicals tested, commercial neem formulation and 5% Ageratina adenophora recorded the least larval count of 1.64 & 1.05 larva/plant and 2.24 & 1.45 larva/plant in two seasons, respectively. IPM modules were developed with three effective insecticides (chlorantraniliprole 18.5 SC, flubendiamide 20 WG and emamectin benzoate 5 SG), two effective botanicals (commercial neem formulation 1500 ppm and 5% A. adenophora) along with the pheromone trap for validation. All the IPM modules were equally effective in managing M. vitrata population on L. purpureus and recorded a significantly (at 5 %) lower larval population than the farmer’s practice. The residues of chlorantraniliprole, flubendiamide and emamectin benzoate reached below the detectable level at the time of harvest. The population reduction of predatory coccinellids and spiders was also lower in IPM modules than in farmer’s practice. An increased benefit cost (1.95 to 1.99) ratio was observed in IPM modules. 

Effect of Emblica officinalis fruits against metallic-lead induced biochemical and hematological alterations in Wistar rats

Lead toxicity and related health issues have become global concern due to increased use of lead-based products in the modern world. Though attempts are being made to tackle this malady through many ways, the use of naturally occurring materials that are available locally is a subtle approach. In this investigation, the fruits of E. officinalis (EO) were studied for their potential in overcoming biochemical and hematological alterations caused by metallic lead in rat model. Four groups of rats, each containing six animals, were considered for the study. Group I served as normal control while to other groups (II– IV), metallic lead powder (100 ppm/rat) was orally administrated for 30 consecutive days. From day 31, the animals in groups III and IV were treated with EO in doses of 50 and 100 mg/kg body weight (p. o.), respectively, for the following seven days. Group II served as lead-treated control. On day 38, the animals in all groups were sacrificed and the blood was collected and serum separated. The changes in biochemical (aspartate aminotrasferase, alanine aminotrasferase, alkaline phosphatase, gamma glutamyltrasferase, total cholesterol, triglycerides, urea, creatinine and calcium) and hematological (red blood cell count, white blood cell count, hemoglobin, packed cell volume and platelet count) parameters were estimated. Lead treated animals in Group - II showed appreciable changes in hematological and biochemical parameters. Treatment with EO (50 and 100 mg/kg) significantly restored the changes in the above parameters to near normal values implying that the fruit of E. officinalis is an effective natural material to overcome widespread lead toxicity. This observation is further supported by histopathological studies of liver and kidney tissues wherein the distorted architecture, degeneration and other changes found in lead-treated animals were brought back to near normal stages by the treatment of EO

Comparison of optimal performance at 300keV of three direct electron detectors for use in low dose electron microscopy

Low dose electron imaging applications such as electron cryo-microscopy are now benefitting from the improved performance and flexibility of recently introduced electron imaging detectors in which electrons are directly incident on backthinned CMOS sensors. There are currently three commercially available detectors of this type: the Direct Electron DE-20, the FEI Falcon II and the Gatan K2 Summit. These have different characteristics and so it is important to compare their imaging properties carefully with a view to optimise how each is used. Results at 300 keV for both the modulation transfer function (MTF) and the detective quantum efficiency (DQE) are presented. Of these, the DQE is the most important in the study of radiation sensitive samples where detector performance is crucial. We find that all three detectors have a better DQE than film. The K2 Summit has the best DQE at low spatial frequencies but with increasing spatial frequency its DQE falls below that of the Falcon II

Moringa oleifera seeds attenuate benzene-induced alterations in lipid peroxidation and antioxidant enzymes in liver and kidney tissues of Wistar rats

Benzene is a notorious toxicant that is responsible for a host of diseases including leukemia. Its concentration in the environment is increasing day-by-day due to excessive automobile use, accelerated industrial activities and cigarette smoke. The awareness on the harmful effects of benzene on health is limited and no antidote has been reported yet. In this study, an attempt has been made to find out a suitable remedy to overcome benzene toxicity in a living organism from a natural source with the seeds of the plant Moringa oleifera (MO). Thirty six Wistar rats were considered for the study and divided into six groups (n=6). While group I remained as control with normal animals, those in groups II – VI received benzene by oral route (800 mg/kg body weight) for 28 consecutive days. On day 29, the benzene-treated animals in groups III – VI received respectively the standard drug ascorbic acid (AA, 25 mg/kg body weight) and MO (50, 100 and 200 mg/kg body weight) for the following 7 days. Group II rats that received only benzene served as negative control without any treatment. On day 36, all the animals were sacrificed and vital organs liver and kidney were removed for studying lipid peroxidation (LPO) and antioxidant markers [Superoxide dismutase (SOD), Total reduced glutathione (TRG), Glutathione peroxidase (GPx) and Catalase (CAT)] in addition to histopathological changes in the tissues. The results of the study revealed that significant changes occurred in the above parameters due to benzene dosing to animals were reverted to near normal values on MO administration in the liver and kidney tissues as compared to untreated animals, suggesting MO’s pro-active role in attenuating benzene toxicity

A two-domain elevator mechanism for sodium/proton antiport

Sodium/proton (Na+/H+) antiporters, located at the plasma membrane in every cell, are vital for cell homeostasis1. In humans, their dysfunction has been linked to diseases, such as hypertension, heart failure and epilepsy, and they are well-established drug targets2. The best understood model system for Na+/H+ antiport is NhaA from Escherichia coli1, 3, for which both electron microscopy and crystal structures are available4, 5, 6. NhaA is made up of two distinct domains: a core domain and a dimerization domain. In the NhaA crystal structure a cavity is located between the two domains, providing access to the ion-binding site from the inward-facing surface of the protein1, 4. Like many Na+/H+ antiporters, the activity of NhaA is regulated by pH, only becoming active above pH 6.5, at which point a conformational change is thought to occur7. The only reported NhaA crystal structure so far is of the low pH inactivated form4. Here we describe the active-state structure of a Na+/H+ antiporter, NapA from Thermus thermophilus, at 3 Å resolution, solved from crystals grown at pH 7.8. In the NapA structure, the core and dimerization domains are in different positions to those seen in NhaA, and a negatively charged cavity has now opened to the outside. The extracellular cavity allows access to a strictly conserved aspartate residue thought to coordinate ion binding1, 8, 9 directly, a role supported here by molecular dynamics simulations. To alternate access to this ion-binding site, however, requires a surprisingly large rotation of the core domain, some 20° against the dimerization interface. We conclude that despite their fast transport rates of up to 1,500 ions per second3, Na+/H+ antiporters operate by a two-domain rocking bundle model, revealing themes relevant to secondary-active transporters in general

Structure of mammalian respiratory complex I.

Complex I (NADH:ubiquinone oxidoreductase), one of the largest membrane-bound enzymes in the cell, powers ATP synthesis in mammalian mitochondria by using the reducing potential of NADH to drive protons across the inner mitochondrial membrane. Mammalian complex I (ref. 1) contains 45 subunits, comprising 14 core subunits that house the catalytic machinery (and are conserved from bacteria to humans) and a mammalian-specific cohort of 31 supernumerary subunits. Knowledge of the structures and functions of the supernumerary subunits is fragmentary. Here we describe a 4.2-Å resolution single-particle electron cryomicroscopy structure of complex I from Bos taurus. We have located and modelled all 45 subunits, including the 31 supernumerary subunits, to provide the entire structure of the mammalian complex. Computational sorting of the particles identified different structural classes, related by subtle domain movements, which reveal conformationally dynamic regions and match biochemical descriptions of the 'active-to-de-active' enzyme transition that occurs during hypoxia. Our structures therefore provide a foundation for understanding complex I assembly and the effects of mutations that cause clinically relevant complex I dysfunctions, give insights into the structural and functional roles of the supernumerary subunits and reveal new information on the mechanism and regulation of catalysis

Diet composition and feeding behavior of largehead hairtail Trichiurus lepturus Linnaeus 1758 along the Eastern Arabian Sea and Western Bay of Bengal

Information on diet composition and feeding habits of species is very much essential for the scientific planning to develop sustainable management plans. The feeding biology of Trichiurus lepturus was studied during 2014 to 2018 from 6167 and 3346 specimens collected on a weekly basis along Eastern Arabian Sea (EAS) and Western Bay of Bengal (WBB), respectively. Crustaceans mainly represented Acetes spp. (98.6 %) and were categorized as dominant and preferred (%QI = 51.35; %IRI = 53.31) food item; teleosts were categorized as dominant and secondary (%QI = 47.46; %IRI = 45.71) food items and molluscs as accidental and accessory food items of T. lepturrus based on the values of dietary coefficient and Index of Relative Importance along the Eastern Arabian Sea (EAS) while, teleosts were completely dominant (%QI = 99.61; %IRI = 99.27) with both molluscs (%QI = 0.34; %IRI = 0.56) and crustaceans (%QI = 0.01; %IRI = 0.17) forming accessory and accidental food items along the Western Bay of Bengal (WBB). The teleostean prey items belonging to 23 genera were encountered in the guts of T. lepturus from EAS with Stolephorus spp. (17.09 %), Sardinella longiceps (6.65 %), Decapterus spp. (5.75 %), Rastrelliger kanagurta (1.36 %), and Megalaspis cordyla (0.89 %) as major component; whereas, in WBB, 16 genera of teleosts representing Sardinella longiceps (50 %), Stolephorus spp. (31.52 %), Decapterus spp. (4.57 %), and Rastrelliger kanagurta (2.26 %) formed the major portion of diet by %IRI. Crustaceans were dominated by Acetes spp. (52.61% IRI) in EAS, while other crustaceans’ contribution as prey item was negligible. However, along WBB, the crustaceans’ contribution as food components was very minimal. Molluscs did not contribute much as dietary constituents of T. lepturus in both EAS and WBB. About 50.15 % and 56.83 % of the stomachs had food content in various proportions in EAS and WBB, respectively and rest of the stomachs were empty

Cryo-EM structures of complex I from mouse heart mitochondria in two biochemically defined states.

Complex I (NADH:ubiquinone oxidoreductase) uses the reducing potential of NADH to drive protons across the energy-transducing inner membrane and power oxidative phosphorylation in mammalian mitochondria. Recent cryo-EM analyses have produced near-complete models of all 45 subunits in the bovine, ovine and porcine complexes and have identified two states relevant to complex I in ischemia-reperfusion injury. Here, we describe the 3.3-Å structure of complex I from mouse heart mitochondria, a biomedically relevant model system, in the 'active' state. We reveal a nucleotide bound in subunit NDUFA10, a nucleoside kinase homolog, and define mechanistically critical elements in the mammalian enzyme. By comparisons with a 3.9-Å structure of the 'deactive' state and with known bacterial structures, we identify differences in helical geometry in the membrane domain that occur upon activation or that alter the positions of catalytically important charged residues. Our results demonstrate the capability of cryo-EM analyses to challenge and develop mechanistic models for mammalian complex I