PRELIMINARY PHYTOCHEMICAL ANALYSIS AND GAS CHROMATOGRAPHY MASS SPECTROMETRY SPECTRA OF CHLOROFORM EXTRACT FROM SPERMACOSE HISPIDA L. SEED

  Objectives: Globally, scientific evaluation of traditional uses of herbal medicine, isolation, and characterization of bioactive constituents from herbs are some of the leading research areas. Spermacoce hispida (SH) is well known for its hypolipidemic and anti-obesity activity. The aim of this study is to qualitatively analyze the presence of primary and secondary metabolites in various extracts of SH seeds and to examine the presence of bioactive principles of chloroform extract from SH seeds.Methods: Physicochemical analysis such as ash content, acid-soluble ash, water-soluble ash, moisture content, fiber content, ethanol soluble extractive value, and water-soluble extractive value for seeds of SH was determined as per WHO guidelines. Cold percolative extracts of seeds of SH with different solvents were carried out. Preliminary phytochemical analysis for the presence of various primary and secondary metabolites in extracts was determined. Gas chromatography mass spectrometry (GC-MS) analysis of chloroform extract was carried out.Results: Physicochemical analysis values were found to be present in permissible level (<5%). Yield of ethyl acetate (4.9/100 g), ethanolic (4.2/100 g), and hydroalcoholic extract (4.0/100 g) of seeds of SH was found to be higher than that of extract obtained by soaking with different low polar solvents. Secondary metabolites such as phenol, flavonoid, and tannin are present in ethyl acetate, ethanolic, hydroalcoholic extract. Fat and alkaloid are present in chloroform extract. GC-MS spectra show the presence of 30 different bioactive constituents. Among them, n-hexadecanoic acid was found to constitute (5.83%) highest peak area than the remaining compounds.Conclusion: Seeds of SH is a rich source of primary and secondary metabolites and various bioactive phytoconstituents

COMPARATIVE STUDY ON HIGH-PERFORMANCE THIN LAYER CHROMATOGRAPHY PROFILE AND ANTIMICROBIAL ACTIVITY OF ETHANOLIC AND HYDROALCOHOLIC EXTRACT OF VETIVERIA ZIZANIOIDES L. ROOT

Objective: Scientific evaluation of traditionally using medicinal herbs for their pharmacological activity is a leading and valuable area of research. The aim of this study is to compare the antimicrobial activity of ethanolic and hydroalcoholic extract of Vetiveria zizanioides root and analyze the major bioactive compounds present in those extracts. Methods: Antimicrobial activity of both ethanolic and hydroalcoholic extracts was carried out against various pathogens such as Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. A number of active compounds present in both extracts were compared by developing different compounds of the sample in high-performance thin layer chromatography (HPTLC) stationary phase using mobile phase petroleum ether:ethyl acetate:toluene:formic acid (5:5:1:1). Results: Ethanolic extract acts against pathogens such as S. aureus and MRSA, significantly (p<0.05) potent than that of hydroalcoholic extract. Significant difference has not been observed between ethanolic and hydroalcoholic extract when acts against P. aeruginosa and C. albicans. HPTLC profile of hydroalcoholic and ethanolic extract shows the presence of 10 and 14 different compounds, respectively, when developed with the same mobile phase. Gallic acid, a phenolic compound, was found to be present with higher % peak area in hydroalcoholic extract (3.25%) against ethanolic extract (2.98%). Conclusion: The results of this study reveal that zone of inhibition exhibited by both ethanolic and hydroalcoholic extracts was found to be different with dissimilar pathogens. A more number of compounds were eluted from hydroalcoholic extract than ethanolic extract.Â

Functional role of tropomyosin on thin filament activation and cross bridge kinetics in transgenic cardiac muscle: a model study

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 63-67).Issued also on microfiche from Lange Micrographics.Regulation of contractile activity in cardiac muscle is a cooperative interaction between thick and thin filament sarcomeric proteins. Tropomyosin (Tm), an essential thin filament protein, interacts with troponin (Tn) and regulates muscle contraction in a Ca²⁺-dependent manner. Striated muscle-specific α-Tm isoform is the predominant isoform in the adult vertebrate heart, while both α- and β-Tm striated isoform are present in skeletal muscles. Studies have shown that exchange of myofibrillar proteins can be achieved via a single kakogenic manipulation with no change in the stoichiometry of myofibrillar proteins. One of the mouse models with exchange of β-Tm for α-Tm demonstrates that altering the ratio of α- and β-Tm leads to physiological change in myocardial relaxation and increases Ca²⁺ sensitivity myofilaments. In addition, reduction in maximum force and ATPase activity in this transgenic mouse model suggests no change in the rate-limiting step of cross-bridge detachment. To further understand the mechanisms of how Tm isoform population modulates cardiac muscle dynamics, this study uses a modeling approach. Although existing models address thin filament activation and cross-bridge kinetics, cooperative interactions among myofibrillar proteins have not been explicitly demonstrated. In this study, Tn, Tm and actin are introduced as three different variables to analyze thin filament activation and cross-bridge cycling. The model is initially tested for normal output using data from literature obtained from in vitro and in vivo experiments. Using this model and data obtained from β-Tm transgenic mouse experiments, key parameters that determine functional alteration in the kakogenic mouse hearts are identified. Results show that increased calcium sensitivity and decreased maximum force in β-Tm transgenic mouse hearts is due to increased capability of strong cross-bridges in activating the thin filament and decreased rate of attachment of myosin heads to actin

The NH2 Terminus of RCK1 Domain Regulates Ca2+-dependent BKCa Channel Gating

Large conductance, voltage- and Ca2+-activated K+ (BKCa) channels regulate blood vessel tone, synaptic transmission, and hearing owing to dual activation by membrane depolarization and intracellular Ca2+. Similar to an archeon Ca2+-activated K+ channel, MthK, each of four α subunits of BKCa may contain two cytosolic RCK domains and eight of which may form a gating ring. The structure of the MthK channel suggests that the RCK domains reorient with one another upon Ca2+ binding to change the gating ring conformation and open the activation gate. Here we report that the conformational changes of the NH2 terminus of RCK1 (AC region) modulate BKCa gating. Such modulation depends on Ca2+ occupancy and activation states, but is not directly related to the Ca2+ binding sites. These results demonstrate that AC region is important in the allosteric coupling between Ca2+ binding and channel opening. Thus, the conformational changes of the AC region within each RCK domain is likely to be an important step in addition to the reorientation of RCK domains leading to the opening of the BKCa activation gate. Our observations are consistent with a mechanism for Ca2+-dependent activation of BKCa channels such that the AC region inhibits channel activation when the channel is at the closed state in the absence of Ca2+; Ca2+ binding and depolarization relieve this inhibition

Calcium sparks in the intact gerbil spiral modiolar artery

<p>Abstract</p> <p>Background</p> <p>Calcium sparks are ryanodine receptor mediated transient calcium signals that have been shown to hyperpolarize the membrane potential by activating large conductance calcium activated potassium (BK) channels in vascular smooth muscle cells. Along with voltage-dependent calcium channels, they form a signaling unit that has a vasodilatory influence on vascular diameter and regulation of myogenic tone. The existence and role of calcium sparks has hitherto been unexplored in the spiral modiolar artery, the end artery that controls blood flow to the cochlea. The goal of the present study was to determine the presence and properties of calcium sparks in the intact gerbil spiral modiolar artery.</p> <p>Results</p> <p>Calcium sparks were recorded from smooth muscle cells of intact arteries loaded with fluo-4 AM. Calcium sparks occurred with a frequency of 2.6 Hz, a rise time of 17 ms and a time to half-decay of 20 ms. Ryanodine reduced spark frequency within 3 min from 2.6 to 0.6 Hz. Caffeine (1 mM) increased spark frequency from 2.3 to 3.3 Hz and prolonged rise and half-decay times from 17 to 19 ms and from 20 to 23 ms, respectively. Elevation of potassium (3.6 to 37.5 mM), presumably via depolarization, increased spark frequency from 2.4 to 3.2 Hz. Neither ryanodine nor depolarization changed rise or decay times.</p> <p>Conclusions</p> <p>This is the first characterization of calcium sparks in smooth muscle cells of the spiral modiolar artery. The results suggest that calcium sparks may regulate the diameter of the spiral modiolar artery and cochlear blood flow.</p

Characterization of Little millet (Panicum sumatrense) varieties using Morphological descriptors and SSR based DNA fingerprinting

Little millet varieties are generally distinguished by morphological descriptors which are being used for seed certification and DUS characterization [1]. But in practical terms, these key differentiation descriptors between varieties of little millet are very fewer and hence difficult to differentiate germplasm accessions. Germplasm registration in NBPGR needs DNA fingerprint to show the uniqueness of germplasm in comparison to existing varieties. DNA fingerprinting is a better option to identify unique markers to differentiate the varieties. Available genomic resources are scarce since little millet is still considered to be an orphan crop. Therefore markers from other cereal genomes such as maize, pearl millet and barnyard millet that are been utilized for DNA fingerprinting purpose with a clue of cereal synteny relationship. Twenty-one morphological descriptors studies revealed that the variety ATL 1 is different from the other varieties for more than 16 morphological characters studied. DNA fingerprinting is attempted in five genotypes of little millets such as BL6, ATL 1, TNPsu 176, Co (Samai) 4, Paiyur 2 using cereal SSR markers. Among the 25 maize SSR markers used two markers viz., phi213984 and phi295450 scored polymorphism by the amplicon size of 310bp and 600bp respectively. From the 25 Pearl millet SSR markers used only one SSR marker found polymorphic at 305bp allele size for ATL 1 and Hence, SSR based DNA fingerprinting helped to differentiate ATL1, the newly released high yielding variety from other genotypes of little millets which can be used for varietal identification purpose