Effect of unsaponifiable fraction of seeds of Hygrophila spinosa T. Ander on testosterone production of rat Leydig cells in vitro

Objective of the study: Seeds of Hygrophila spinosa (HS) T. Ander (Acanthaceae) are traditionally used as aphrodisiac and spermatogenic in Indian System of medicine. Preliminary phytochemical screening of plant revealed the presence of triterpenoids and sterols in seeds. The study was planned to assess the effect of unsaponifiable fraction prepared from seeds of HS on isolated rat Leydig cells for testosterone (T) production using in vitro method.Materials and methods: Leydig cells were isolated from wistar rats, aseptically, in vitro by collagenase cell dispersion method. Cells (2 X 106 cells/ml) were then incubated with unsaponifiable fraction of HS (10, 100 and 1000 µg/ml dose levels in triplicate) in incubator at 37°C under atmosphere of 95% CO2 condition for 3 hours in aseptic condition. Dehydroepiandrosterone (DHEA) was used as positive control in the study. The amount of T secreted in culture media was estimated using HPTLC. Benzene: Ethyl acetate (5:5% v/v) was employed as mobile phase and silica gel G F254 aluminum coated TLC plate as stationary phase.Results: The results indicated dose dependent increase in testosterone concentration in test groups. Isolated rat Leydig cells treated with the test fraction showed increased amount of testosterone present in culture media as compared to that of control.Conclusion: Unsaponifiable fraction prepared from seeds of HS showed ability to enhance biosynthesis of T in Isolated rat leydig cells. In vitro studies showed that the fraction might act locally in testis on Leydig cells and stimulated testosterone synthesis

ISOLATION OF CYTOTOXIC CONSTITUENT FROM BIOACTIVITY GUIDED FRACTION OF ALYSICARPUS MONILIFER L. (DC.)

Objective: Alysicarpus monilifer (Family Papilionaceae) has been used in the Indigenous system of medicine in tumor removal. The present study was designed to isolate and identify the constituent responsible for cytotoxic (anti-tumor) effects of the plant Alysicarpus monilifer. Methods: The plant was powdered and extracted to give a methanolic extract. Initially, Hexane, chloroform, ethyl acetate and methanolic fractions of the methanolic extract of the plant were subjected to cytotoxic screening using cell line based assay (MTT assay and NRU assay). The chloroform fraction showed significant cytotoxicity, so it was further subjected to column chromatography, to separate the cytotoxic phytoconstituent. The cell lines selected were breast cancer cells (MCF-7 and MDA-MB-468) and Liver cancer cells (HepG2 and HLE cell). Results were calculated as percentage growth inhibition with respect to untreated (control) cells versus treated cells. Result: A triterpene, Betulinic acid, was isolated from the aerial parts of Alysicarpus monilifer. The cytotoxic activity of the identified compound against MCF-7, MDA-MB-231, HLE and HepG2 cells was also found to be highly significant with 90% growth inhibition. Conclusion: The triterpene was identified to be betulinic acid, to which the cytotoxic activity can be attributed. It is a first report of isolation of betulinic acid from the Alysicarpus species

CYTOTOXIC EFFECT OF CORCHORUS DEPRESSUS AGAINST HEPG2 AND HLE HUMAN LIVER CANCER CELLS

Objective: The present study was designed to examine the cytotoxic effects of methanolic extract of aerial parts of Corchorus depressus and hexane, chloroform, ethyl acetate, and aqueous fractions of the same extract in the human hepatocellular carcinoma (HCC) (HepG2) and invasive hepatocellular carcinoma cell lines (HLE).Methods: Anti-proliferative effects were evaluated using 3-(4,5-dimethythiazol2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and neutral red uptake (NRU) assay. Human HCC (HepG2) and invasive hepatocellular carcinoma cell lines (HLE) were treated with different concentrations of methanolic extract (10, 25, 50, 100, 200, 300, 400, and 500 μg/mL) of aerial parts of C. depressus as well as hexane, chloroform, ethyl acetate, and aqueous fractions (200 μg/mL) for 24 and 48 h. The cell viability and the half maximal inhibitory concentration (IC50) were determined.Results: The maximum cytotoxic effect was noticed with a maximum dose of methanolic extract (500 μg/mL) and alkaloidal fraction (200 μg) in this study with an IC50 value of about 200 μg.Conclusion: The set of studies showed that methanolic extract of aerial parts of C. depressus and alkaloidal, chloroform and ethyl acetate fractions fractions was capable of inhibiting cell growth and cell proliferation by inducing cytotoxicity of HepG2 and HLE cells

ESTIMATION OF GUGGULSTERONE-Z IN GOKSHURADI GUGGULU USING REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Objective: A study was aimed to estimate guggulsterone-Z (GZ) in Gokshuradi Guggulu (GG).Methods: An analytical method was developed and validated using Waters Alliance high-performance liquid chromatography system (Empower software), equipped with photodiode array detector. Separation was achieved using Phenomenex, C-18 (250 mm×4.6 mm, 5 μ) column. Mobile phase consisted of acetonitrile:water (70:30,v/v). Flow rate was set to 1 ml/min and detection was performed at 251 nm.Results and Discussion: Validation parameters such as linearity, precision, accuracy, limit of detection, limit of quantification, and robustness were performed. Amount of GZ was estimated using linearity equation.Conclusion: GG was found to contain 0.815±0.03 g% w/w GZ. Validated method may be used as one of the parameters to standardize the formulation

Design and Fabrication of GaAs/AlGaAs Slot Waveguards

We present the theoretical simulation and experimental results of a slot waveguide structure and a strip-to-slot waveguide coupler implemented in the GaAs/AlGaAs system. Although there have been many demonstrations of slot waveguides in silicon and silicon nitride, there has been limited work devoted to demonstrating this device in a III-V semiconductor material system. Implementing slot waveguides in a III-V material system such as GaAs/AlGaAs would provide the advantage of monolithic integration with active photonic components such as lasers and photodetectors. Slot waveguides have been widely studied for biosensing applications because of their ability to confine a significant portion of the electric field in an air slot, thereby increasing the spatial overlap of the optical mode with surrounding analytes. Monolithic integration in the III-V system would therefore enable the development of photonic lab-on-a-chip biosensing platforms. Due to the low refractive index contrast in the GaAs/AlGaAs relative to that of the silicon-on-insulator (SOI) material system, AlGaAs material composition, epitaxial waveguide layer thicknesses, and slot etch depth must be optimized to realize low-loss propagation in the slot waveguide. Specifically, we demonstrate elevated and suspended slot waveguide structures. The first is formed by etching into the underlying AlGaAs cladding layer and the second is formed by etching away the underlying AlGaAs cladding. These structures are fabricated and tested at a wavelength of 1550 nm.Ope

Nanophotonic visible light phased arrays

Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.Cataloged from PDF version of thesis.Includes bibliographical references (pages 81-85).Previously demonstrated integrated optical phased arrays have primarily been implemented in silicon-based platforms and have therefore been limited to operation at infrared wavelengths, where silicon provides low-loss transmission. Developing integrated optical phased arrays for visible wavelengths would enable the exploration of new applications for this technology, such as autostereoscopic displays and neuronal targeting for optogenetics. The work presented in this thesis involves the development of visible light integrated optical phased array components and systems with a focus on autostereoscopic image projection applications. Practical 3D microdisplay applications will require (1) large-aperture phased array systems for diffraction minimization, (2) integrated phase modulation for implementing dynamically reconfigurable phased array antenna elements, and (3) a phased array system architecture for accurately encoding the light field of virtual objects. Integrated photonic architectures for all three aforementioned goals are investigated in this thesis. With respect to the first goal, a 1x1 mm2 aperture visible light phased array with a near diffraction limited far-field spot size is demonstrated. With respect to the second goal, the design of an integrated phase modulator based on the electro-optic tuning of a nematic liquid crystal waveguide cladding layer is developed and a near-x phase shift is demonstrated in a fabricated device. Finally, an autostereoscopic image projection system comprised of multiple tiled phased arrays configured to project a virtual image with parallax in one dimension within an 8.58° field of view is demonstrated.by Manan Raval.S.M

Integrated optical phased arrays for three-dimensional display applications

This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2020Cataloged from student-submitted PDF of thesis.Includes bibliographical references (pages 154-164).The compatibility of silicon photonic platforms with complementary metal-oxide-semiconductor (CMOS) fabrication processes has facilitated a surge in the development of silicon-based integrated optical phased arrays (OPAs) for light detection and ranging (LiDAR) and free-space communications. However, silicon is limited to operating at infrared wavelengths since its bandgap prevents visible light transmission. The development of integrated OPAs for arbitrary complex wavefront synthesis in the visible spectrum would enable the expansion of this technology into a multitude of new applications spaces such as optical trapping, imaging through scattering media, underwater LiDAR, optogenetic stimulation, and three-dimensional (3D) displays. Silicon nitride, a CMOS-compatible material that is transparent in the visible spectrum, may be used as the waveguiding material in phased array systems designed for the above applications.In this work, we develop large-scale visible light integrated OPA systems fabricated in a silicon-nitride-based platform for 3D display applications. We begin by presenting the first demonstrations of visible light integrated OPAs. Building on this, we demonstrate a chip-scale architecture for autostereoscopic image projection using a system of multiple integrated OPAs to reconstruct virtual light fields. Specically, we generate a static virtual 3D image with horizontal parallax and a viewing angle of 5. Next, we present an architecture for realizing a transparent near-eye direct-view augmented/mixed reality (AR/MR) display using a system of integrated OPAs to directly project holographic images onto the user's retina. This display architecture was developed to address the deficiencies in current AR/MR headsets with respect to brightness, field of view (FOV), and the vergence-accommodation conflict, which causes eye fatigue.Here, we present a passive demonstration of the display as well as a number of key photonic components required to realize a system for 3D video.by Manan Raval.Ph. D.Ph.D. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Scienc

ISOLATION AND CHEMICAL CHARACTERIZATION OF BIOACTIVE ALKALOID FROM ARGYREIA SPECIOSA LINN. HAVING ACTION ON ISOLATED RAT LEYDIG CELLS

Objective: Present study was aimed to isolate and chemically characterize bioactive constituent from alkaloid enriched fraction, prepared from roots of Argyreia speciosa Linn. Materials and methods: Literature review revealed presence of ergoline type of alkaloids in roots. Alkaloidal fraction was prepared and screened for its action on testosterone biosynthesis, in- vitro, using isolated rat leydig cells. Dehydroepiandosterone was used as positive control. This bioactive fraction was subjected to open column chromatography followed by flash chromatography, to isolate constituent. One compound (A1) was isolated from the fraction and its purity was ascertained using TLC and HPLC studies. A1 was chemically characterized by IR, Mass and 1H-NMR studies, to elucidate probable chemical structure. A1 was screened for action on testosterone synthesis too, using isolated rat Leydig cells model. The fraction was standardized with respect to amount of A1 present.   Results: Alkaloidal fraction (1000 µg/ml) incubated Leydig cells showed nearly, 22 fold increase in testosterone content as compared to untreated cells. The studies also yielded increase in testosterone content, in cells treated with test fractions and as observed in case of positive control. TLC studies indicated that A1 might possess ergoline moiety in the structure. IR, Mass and 1H NMR spectral studies suggested that A1 might be N-methyl ergometrine. This was the first report included isolation and chemical characterization of N-methyl ergometrine from Argyreia speciosa. A1 (1000 µg/ml) was found to stimulate testosterone content, by 14.62 fold, in culture media of Leydig cells after incubation. Conclusion: The results of in vitro studies, confirmed that the standardized alkaloid fraction as well as A1 had ability to stimulate Leydig cells to secrete testosterone. A1 might be N-methyl ergometrine and being ergometrine derivative it might act through oxytocine receptors expressed on the Leydig cells and stimulates testosterone synthesis

Standardization, evaluation and quantification of herbal drugs by various analytical methods

This review article encompasses the various evaluation parameters of standardization of different medicinal plants and its constituents. In today’s life, more and more people of the world are turning towards the use of natural or herbal products as these have very less or negligible side effects. As the use of herbal medicinal products is increasing day by day, the questions regarding their quality are also arising. This is due to lack of parameters for the standardization of these products. There is a need to set different parameters or methods that can help to standardize the herbal medicinal plant materials. Various methods like physical, chemical, biological is used for standardization and quality evaluation of herbal medicinal plants. These methods can act as a basic tool for the quality evaluation of herbal plant materials. Different parameters of standardization are the fundamental tool for evaluating and assuring the quality of the herbal plant material and its products. This review article includes the quantitative evaluation of more than 20 herbal drugs. The evaluation parameters such as TLC, HPLC, HPTLC, GC, LC-MS, UPLC, UHPLC, UPLC-MS, UHPLC-MS will help to maintain quality of different herbal medicinal drugs as well as its formulations. The set parameters can ultimately lead to the quality and efficacy of the herbal medicinal formulations. Analytical methods and standardization can ensure the quality and consistency of active ingredients in herbal medicinal formulations