Siroshini K Thiagarajan

Ms. Siroshini K Thiagarajan

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 May 2019 in Evidence-Based Complementary and Alternative Medicine
Verified
Journal Article
Open access
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STSiroshini K Thiagarajan
Siroshini K Thiagarajan
KKKhamini Rama Krishnan
Khamini Rama Krishnan
TEThandar Ei
Thandar Ei
NSNurul Husna Shafie
Nurul Husna Shafie
DADaryl J. Arapoc
Daryl J. Arapoc
HBHasnah Bahari
Hasnah Bahari
Momordica charantiaLinn., commonly known as bitter gourd, has many protective roles due to its medicinal value as it contains bioactive components. However, this extract showed possible toxicity effect on zebrafish embryo. Thus this study was designed to differentiate the toxicity activities in two types ofM. charantiasample which are Indian and ChineseM. charantia, as well as to compare between two different aqueous extraction methods, hot and cold aqueous method, using zebrafish embryo assay assessment. It was observed that the survival rate of zebrafish embryo decreased as the concentration of test extract increased for all samples ofM. charantia. The LC50values of hot aqueous ChineseM. charantia, hot aqueous IndianM. charantia, and cold aqueous ChineseM. charantiawere 144.54μg/ml, 199.53μg/ml, and 251.19μg/ml, respectively. However, cold aqueous IndianM. charantiahas a higher LC50which was not in the range of the tested concentration. Hatchability ofDanio rerioembryo reduced as the concentration ofM. charantiaextract increased while no hatching was observed in the highest concentration (1000μg/ml). Scoliosis of zebrafish larvae was only seen in higher concentrations (125-1000μg/ml) of extract. The heartbeat of zebrafish larvae treated withM. charantiaextract was within the normal range, 120-180 bpm, but at higher concentrations (125-1000μg/ml) the heartbeat differed for all samples of test extract. Hence, although this plant extract was safe to be consumed due to its pharmaceutical effect, it still exhibited mild toxicity effect at higher concentration when it was evaluated on zebrafish embryo.

6 March 2019 in Evidence-Based Complementary and Alternative Medicine
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Journal Article
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STSiroshini K Thiagarajan
Siroshini K Thiagarajan
DADaryl J. Arapoc
Daryl J. Arapoc
NSNurul Husna Shafie
Nurul Husna Shafie
Yoke Keong YongYoke Keong Yong
Yoke Keong Yong
HBHasnah Bahari
Hasnah Bahari
TEThandar Ei
Thandar Ei
Lung cancer is the leading cause of cancer related deaths worldwide with about 40% occurring in developing countries. The two varieties of Momordica charantia, which are Chinese and Indian bitter melon, have been subjected to antiproliferative activity in human non-small cell lung cells A549. The A549 cells were treated with hot and cold aqueous extraction for both the bitter melon varieties, and the antiproliferative activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptotic mechanism of action on A549 human lung cancer cells was evaluated first morphologically using Hoechst 33358, and cytoskeleton staining using Filamentous-actin (F-actin) cytoskeleton FICT and DAPI followed by caspase-3/7, reactive oxygen species (ROS), and p53 activity. Chinese hot aqueous extraction (CHA) exhibited potent antiproliferative activity against A549 human lung cancer cells. The morphological analysis of mitochondria destruction and the derangement of cytoskeleton showed apoptosis-inducing activity. CHA increased the caspase-3/7 activity by 1.6-fold and the ROS activity by 5-fold. Flow cytometric analysis revealed 34.5% of apoptotic cells significantly (p<0.05) compared to cisplatin-treated A549 human cancer cells. CHA is suggested to induce apoptosis due to their rich bioactive chemical constituents. These findings suggest that the antiproliferative effect of CHA was due to apoptosis via ROS-mediated mitochondria injury.

Verified
Journal Article
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STSiroshini K Thiagarajan
Siroshini K Thiagarajan
SMSiew Ying Mok
Siew Ying Mok
SATOSHI OGAWASATOSHI OGAWA
SATOSHI OGAWA
IPIshwar Parhar
Ishwar Parhar
PTPek Yee Tang
Pek Yee Tang
The link between substance abuse and the development of schizophrenia remains elusive. In this study, we assessed the molecular and behavioural alterations associated with schizophrenia, opioid addiction, and opioid withdrawal using zebrafish as a biological model. Larvae of 2 days post fertilization (dpf) were exposed to domperidone (DMP), a dopamine-D2 dopamine D2 receptor antagonist, and morphine for 3 days and 10 days, respectively. MK801, an N-methyl-D-aspartate (NMDA) receptor antagonist, served as a positive control to mimic schizophrenia-like behaviour. The withdrawal syndrome was assessed 5 days after the termination of morphine treatment. The expressions of schizophrenia susceptibility genes, i.e., pi3k, akt1, slc6a4, creb1 and adamts2, in brains were quantified, and the levels of whole-body cyclic adenosine monophosphate (cAMP), serotonin and cortisol were measured. The aggressiveness of larvae was observed using the mirror biting test. After the short-term treatment with DMP and morphine, all studied genes were not differentially expressed. As for the long-term exposure, akt1 was downregulated by DMP and morphine. Downregulation of pi3k and slc6a4 was observed in the morphine-treated larvae, whereas creb1 and adamts2 were upregulated by DMP. The levels of cAMP and cortisol were elevated after 3 days, whereas significant increases were observed in all of the biochemical tests after 10 days. Compared to controls, increased aggression was observed in the DMP-, but not morphine-, treated group. These two groups showed reduction in aggressiveness when drug exposure was prolonged. Both the short- and long-term morphine withdrawal groups showed downregulation in all genes examined except creb1, suggesting dysregulated reward circuitry function. These results suggest that biochemical and behavioural alterations in schizophrenia-like symptoms and opioid dependence could be controlled by common mechanisms.

4 April 2017 in Tropical Journal of Pharmaceutical Research
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Journal Article
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STSiroshini K Thiagarajan
Siroshini K Thiagarajan
FYFui-Lu Yong
Fui-Lu Yong
HSHemaroopini Subramaniam
Hemaroopini Subramaniam
VJVivien Yi- Mian Jong Jong
Vivien Yi- Mian Jong Jong
CLChan-Kiang Lim
Chan-Kiang Lim
YSYee-How Say
Yee-How Say
Anti-obesity effect of phenylcoumarins from two Calophyllum spp in 3T3-L1 adipocytes

Verified
Journal Article
Open access
PDF file
STSiroshini K Thiagarajan
Siroshini K Thiagarajan
SMSiew Ying Mok
Siew Ying Mok
SATOSHI OGAWASATOSHI OGAWA
SATOSHI OGAWA
IPIshwar Parhar
Ishwar Parhar
PTPek Yee Tang
Pek Yee Tang
Several theories have been proposed to explain the mechanisms of substance use in schizophrenia. Brain neurons pose a potential to provide novel insights into the association between opioid addiction, withdrawal, and schizophrenia. Thus, we exposed zebrafish larvae at 2 days post-fertilization (dpf) to domperidone (DPM) and morphine, followed by morphine withdrawal. Drug-induced locomotion and social preference were assessed, while the level of dopamine and the number of dopaminergic neurons were quantified. In the brain tissue, the expression levels of genes associated with schizophrenia were measured. The effects of DMP and morphine were compared to vehicle control and MK-801, a positive control to mimic schizophrenia. Gene expression analysis revealed that α1C, α1Sa, α1Aa, drd2a, and th1 were up-regulated after 10 days of exposure to DMP and morphine, while th2 was down-regulated. These two drugs also increased the number of positive dopaminergic neurons and the total dopamine level but reduced the locomotion and social preference. The termination of morphine exposure led to the up-regulation of th2, drd2a, and c-fos during the withdrawal phase. Our integrated data implicate that the dopamine system plays a key role in the deficits in social behavior and locomotion that are common in the schizophrenia-like symptoms and opioid dependence.

30 October 2020 in Proceedings
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Conference Paper
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STSiroshini K Thiagarajan
Siroshini K Thiagarajan
KPKokila Vani Perumal
Kokila Vani Perumal
NSNurul Husna Shafie
Nurul Husna Shafie
KKKhairul Kamilah Abdul Kadir
Khairul Kamilah Abdul Kadir
HBHasnah Bahari
Hasnah Bahari
Natural products derived from plants are used to treat cancer due to fewer side effects compared to standard treatments available for cancer. The second highest cancer that causes death worldwide is lung cancer. Therefore, this study aimed to determine the cytotoxic activity of hot and cold aqueous extract of E. tapos seed and shell on human cancer cell line A549 as well as the apoptosis mechanism. The apoptosis mechanisms were evaluated by cell viability (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction assay; MTT assay), Hoechst 33358 staining and detection of reactive oxygen species (ROS) activity. The apoptosis inducing activity was analyzed in set of morphological and biochemical features. Hot aqueous shell extract (SHH) showed an anti-proliferative effect at the IC50 of 49.8 ± 0.06 µg/mL correlated with apoptosis induction by increasing the ROS activity by significant (p < 0.05) increase of 3.25 folds compared to control. Results suggest that SHH poses an anti-proliferative effect on account of apoptosis through ROS mediated mitochondria mutilation.