Thumbnail Image

Kerala Veterinary and Animal Sciences University, Wayanad

Browse

20151
Reset filters
Subject: Veterinary Pharmacology and Toxicology × Author: SREELEKHA K. P. × End date: 2019 × Start date: 2010 × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    IDENTIFICATION, ISOLATION AND CHARACTERIZATION OF POTENTIAL ACARICIDAL MOLECULE(S) FROM PLANT EXTRACT AND STUDIES ON THEIR MODE OF ACTION
    (COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR, 2015-09-30) SREELEKHA K. P.; Sanis Juliet
    The present study was conducted to isolate active biomolecule(s) from Blumea mollis plant extract having potent acaricidal activity against R. (B.) annulatus and to study their mode of action. Blumea mollis (D. Don) Merr., Asteraceae family is an annual aromatic herb indigenous to tropical South India. The plant materials were collected from identified phytogeographical zones. The ethanolic extract of different accessions of the plant was assayed for acaricidal activity using adult immersion test and larval packet test. Further, isolation and characterization of bioactive fractions / sub-fractions were performed using standard chromatographic and spectral techniques. The accession CAS 01 of B. mollis was selected as the best accessions with more than 80-100% efficacy against R.(B.) annulatus.The freeze dried crude extract of elite accession of CAS-01 was tested for safety using OECD guidelines. Phytochemical analysis revealed the presence of high content of terpenoids in the accession CAS 01. The hexane fraction was found to be active and HPTLC profiling showed marker concentration comparable to that of ethanolic extract of CAS 01. Phytochemical analysis of hexane fraction revealed the presence of high content terpenoids further confirmed by GC-MS. The GC-MS analysis of active sub-fractions revealed the presence of several components ranging from monoterpenes, diterpenes to sesquiterpenoids. Among the four molecules selected based on their chemical nature and area percent, ethyl palmitate, VP5 and marker compound VP1 elicited the acaricidal activity varying from 95 - 100 %. The histology and transmission electron microscopic analysis of active biomolecules exhibited marked changes comparable to that of synthetic acaricides deltamethrin and amitraz. The β octopamine receptor gene expression studies using whole tick and ovary showed significant down regulation comparable to amitraz in case of VP1 whereas ethyl palmitate and VP5 showed no significant change. Structural analogy results revealed similarity with compounds mediating action through GPCR receptors. The isolated molecules can be used as template for the development of promising acaricides.