1.Antimicrobial Activity of Emilia sonchifolia DC., Tridax procumbens L. and Vernonia cinerea L. of Asteracea Family: Potential as Food Preservatives
Yoga Latha L ; Darah I ; Sasidharan S ; Jain K
Malaysian Journal of Nutrition 2009;15(2):223-231
Chemical preservatives have been used in the food industry for many years.
However, with increased health concerns, consumers prefer additive-free products
or food preservatives based on natural products. This study evaluated
antimicrobial activities of extracts from Emilia sonchifolia L. (Common name: lilac
tassel flower), Tridax procumbens L. (Common name: tridax daisy) and Vernonia
cinerea L. (Common name: Sahadevi), belonging to the Asteracea family, to explore
their potential for use against general food spoilage and human pathogens so
that new food preservatives may be developed. Three methanol extracts of
these plants were tested in vitro against 20 bacterial species, 3 yeast species, and
12 filamentous fungi by the agar diffusion and broth dilution methods. The V.
cinerea extract was found to be most effective against all of the tested organisms
and the methanol fraction showed the most significant (p < 0.05) antimicrobial
activity among all the soluble fractions tested. The minimum inhibitory
concentrations (MICs) of extracts determined by the broth dilution method ranged
from 1.56 to 100.00mg/mL. The MIC of methanol fraction was the lowest in
comparison to the other four extracts. The study findings indicate that bioactive
natural products from these plants may be isolated for further testing as leads in
the development of new pharmaceuticals in food preservation as well as natural
plant-based medicine.
2.Optimal protein extraction methods from diverse sample types for protein profiling by using Two-Dimensional Electrophoresis (2DE)
Tan, A.A. ; Azman, S.N. ; Abdul Rani, N.R. ; Kua, B.C. ; Sasidharan, S. ; Kiew, L.V. ; Othman, N. ; Noordin, R. ; Chen, Y.*
Tropical Biomedicine 2011;28(3):620-629
There is a great diversity of protein samples types and origins, therefore the
optimal procedure for each sample type must be determined empirically. In order to obtain a
reproducible and complete sample presentation which view as many proteins as possible on
the desired 2DE gel, it is critical to perform additional sample preparation steps to improve
the quality of the final results, yet without selectively losing the proteins. To address this, we
developed a general method that is suitable for diverse sample types based on phenolchloroform
extraction method (represented by TRI reagent). This method was found to yield
good results when used to analyze human breast cancer cell line (MCF-7), Vibrio cholerae,
Cryptocaryon irritans cyst and liver abscess fat tissue. These types represent cell line,
bacteria, parasite cyst and pus respectively. For each type of samples, several attempts were
made to methodically compare protein isolation methods using TRI-reagent Kit, EasyBlue Kit,
PRO-PREPTM Protein Extraction Solution and lysis buffer. The most useful protocol allows the
extraction and separation of a wide diversity of protein samples that is reproducible among
repeated experiments. Our results demonstrated that the modified TRI-reagent Kit had the
highest protein yield as well as the greatest number of total proteins spots count for all type
of samples. Distinctive differences in spot patterns were also observed in the 2DE gel of
different extraction methods used for each type of sample.