Date of Award
Master of Science (MS)
Dr. Aftab Ahmed
Dr. Sherif Elshahawi
Dr. Rakesh Tiwari
Marshmallow (Althaea officinalis) belongs to family Malvaceae, a medicinal plant used in traditional and alternative medicine in various parts of the world. Marshmallow is one of the seven medicinal plants that are collectively known as Joshanda. It is a herbal preparation which has been used traditionally as a home remedy for the treatment of common cold, coughs, nasal congestion, and fever. Previous studies showed that crude extract and/or purified compounds from flowers, root, and leaves from Marshmallow have anti-microbial, anti-inflammatory, and other pharmacological effects. However, there is no data reported on the biological activity and the structure of proteins isolated from the seeds. Therefore, this study is carried out to purify and characterize proteins and peptides from Marshmallow seeds as well as to evaluate their antimicrobial activity against Salmonella enterica, Staphylococcus aureus, Saccharomyces cerevisiae and cytotoxic activities in MCF-7 breast cancer cell line. Extraction of proteins was performed in 20 mM Tris/HCl pH 8.0, then purified by the combination of gel filtration and reverse-phase HPLC. Purified proteins were analyzed by SDS-PAGE gel electrophoresis. The partial amino acid sequence of 22 kDa protein was established up to 25 residues by N-terminal amino acid sequencing. The data suggest that Marshmallow RP-HPLC purified protein is a monomeric protein of 22 kDa. The amino acid sequence alignment using BLASTp revealed similarity in 22/25 amino acid residues with Thaumatin from Corchorus capsularis. The MTT assay of Marshmallow crude protein led to a dose-dependent cytotoxic effect in MCF-7 cells with an IC50 value of 163.29 μg/ml. The gel filtration pooled fractions 5-8, 9-11, and 12-13 showed 58%, 46% and 32% inhibition respectively. The antimicrobial activity of crude protein extract showed 69% inhibitory activity against Staphylococcus aureus. Proteomic evaluation of crude Marshmallow protein tryptic peptides achieved by LC-MS/MS and bioinformatic analysis using SwissProt Viridiplanta database and Mascot search engine. The De novo protein/peptide sequence search by Peaks Studio-X identified 76 proteins belonging to 9 protein groups.
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Amini M. Proteomics and Biological Evaluation of Marshmallow (Althea officinalis) Seeds. [master's thesis]. Irvine, CA: Chapman University; 2019. https://doi.org/10.36837/chapman.000091