1.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.
2.Evaluation of selected plant extracts for in vitro anti-marine leech (Zeylanicobdella arugamensis) activity
Wan Norhana, M.N. ; Kua, B.C. ; Liyana, R.
Tropical Biomedicine 2021;38(No.1):122-129
The aqueous extracts of thirty-four (34) tropical plants were tested in vitro for potential antimarine leech (Zeylanicobdella arugamensis) activity. The anti-leech activity was determined by
exposing 8 adult leeches (Z. arugamensis) (9.3 ± 1.5 mm, aged 15 days) to 20 μl of plant extract
(0.5 g/ml) for 5 min in a 24-well plate. After 5 min of exposure, the leeches were rinsed and
transferred into seawater, to enable them to revive from the effect of the extract. Leech
movements were observed from time to time and the numbers of paralyzed or dead leeches
were recorded at 5, 20, 30 and 240 min. The efficacy of the plant extract in killing the adult Z.
arugamensis during the 5 min exposure is reflected on the anti-leech property of the extract.
The anti-leech property of positive plant extracts was also determined at different exposure
time (1, 3, 5 min) and dilutions (1/2 (0.25 g/ml), 1/5 (0.1 g/ml) and 1/10 (0.05 g/ml). The extracts
of 4 plants (Melastoma malabathricum, Piper betle, Tetracera indica and Etlingera coccinea)
demonstrated anti-leech activity. The effects of M. malabathricum, P. betle and E. coccinea
extracts on the leeches were very rapid causing death as early as a few seconds upon
exposure. However, all four positive plant extracts were found not effective in killing the
leeches at 1/10 dilution (0.05 g/ml). A Scanning Electron Microscopy examination on leeches
exposed to the positive plant extracts exhibited effects such as protruding proboscis and
shrunken or swollen bodies.
3.Renocila richardsonae Williams & Bunkley-Williams, 1992 (Isopoda: Cymothoidae), a parasite of Japanese goatfish, Upeneus japonicus off Sarawak, South China Sea
Kua, B.C. ; Jamil, M. ; Bruce, N.L.
Tropical Biomedicine 2022;39(No.2):247-251
Renocila richardsonae Williams & Bunkley-Williams, 1992 is recorded for the first time from Sarawak
coastal waters. During a survey of marine fishes at depth of 200 metres in South China Sea, off the coast
of Sarawak from 3° to 5°N and 110° to 111°E, five specimens of Renocila richardsonae were collected
from Japanese goatfish, Upeneus japonicus (Houttuyn, 1782) (Mullidae) with average prevalence of
17% and mean intensity of one isopod per fish from examination of 64 fish. The isopod was observed
to cause tissue damage on the site of attachment to the host.