Christina Gertrude Yap

Dr. Christina Gertrude Yap

Monash University Malaysia, Subang Jaya, Malaysia
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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1 December 2021 in Diabetes Research and Clinical Practice
Verified
Journal Article
Closed access
KQKok Ying Quan
Kok Ying Quan
CYChristina Gertrude Yap
Christina Gertrude Yap
NJNowrozy Kamar Jahan
Nowrozy Kamar Jahan
NPNaganathan Pillai
Naganathan Pillai

21 March 2023 in Biology
Verified
Journal Article
Open access
PDF file
TRTEH RASYIDAH
TEH RASYIDAH
CYChristina Gertrude Yap
Christina Gertrude Yap
RNRakesh Naidu
Rakesh Naidu
NPNarendra Pamidi
Narendra Pamidi
Background: The Western-style diet-induced type 2 diabetes mellitus (T2D) may eventually trigger neurodegeneration and memory impairment. Thus, it is essential to identify effective therapeutic strategies to overcome T2D complications. This study aimed to investigate the effects of environmental enrichment (EE) and metformin interventions on metabolic dysfunctions, hippocampal neuronal death, and hippocampal-dependent memory impairments in high-fat/high-sucrose (HFS) diet-induced T2D rats. Methods: Thirty-two male rats (200–250 g) were divided into four groups: C group (standard diet + conventional cage); D group (HFS diet + conventional cage); DE group (HFS diet + EE cage/6hr daily); and DM group (HFS diet + metformin + conventional cage). Body weight was measured every week. T-maze tasks, anthropometric, biochemical, histological, and morphometric parameters were measured. The expression changes of hippocampal genes were also analyzed. Results: The anthropometric and biochemical parameters were improved in DE and DM groups compared with the D group. DE and DM groups had significantly higher T-maze percentages than the D group. These groups also had better histological and morphometric parameters than the D group. The interventions of EE and metformin enhanced the expression of hippocampal genes related to neurogenesis and synaptic plasticity (BDNF/TrkB binding, PI3K-Akt, Ras–MAPK, PLCγ–Ca2+, and LTP). Conclusion: Environmental enrichment (EE) and metformin improved metabolic functions, hippocampal neuron survival, and hippocampal-dependent memory in HFS diet-induced T2D rats. The underlying mechanisms of these interventions involved the expression of genes that regulate neurogenesis and synaptic plasticity.

17 January 2026 in Toxicology Reports
Verified
Journal Article
Open access
NLNatasha Sura Anak Lubau
Natasha Sura Anak Lubau
Vinod BalasubramaniamVinod Balasubramaniam
Vinod Balasubramaniam
CYChristina Gertrude Yap
Christina Gertrude Yap
AAAlina Arulsamy
Alina Arulsamy
Vetriselvan SubramaniyanVetriselvan Subramaniyan
Vetriselvan Subramaniyan
Karanjin (KRN) is a benzofuran flavonoid derived from Pongamia pinnata seeds, known for its antihyperglycemic and anti-inflammatory properties. Despite its traditional use, comprehensive toxicological data are limited. This study evaluated the acute and subacute oral toxicity of KRN in Sprague Dawley rats. In the acute study, single doses of 5, 500, or 2000 mg/kg were administered, and animals were observed for 14 days. In the subacute study, daily doses of 5, 50, or 250 mg/kg were given for 28 days. Clinical signs, body weight, food and water intake were monitored throughout. At termination, organs (liver, kidney, heart, etc.) were weighed, blood was analysed for biochemical parameters (ALT, AST, ALP, total protein, albumin, lipids), and tissues were examined histopathologically. No mortality or treatment-related clinical signs occurred at any dose. Body weight, food/water intake, and organ weights did not differ significantly between treated and control groups. Serum biochemical values remained within normal limits, showing only minor, non-dose-dependent variations. Histopathology revealed normal architecture of major organs without evidence of necrosis, inflammation, or degeneration. These findings demonstrate a wide margin of safety for oral KRN and support its potential for further pharmacological development.

1 April 2022
Verified
Journal Article
Closed access
NPN. Pamidi
N. Pamidi
CYChristina Gertrude Yap
Christina Gertrude Yap
SNS. Nayak
S. Nayak

21 July 2025 in Animal Models and Experimental Medicine
Verified
Journal Article
Open access
LZLee Yeong Zher
Lee Yeong Zher
EZEason Kong Qi Zheng
Eason Kong Qi Zheng
RRRayneshia Elaura Raymond
Rayneshia Elaura Raymond
YJYe Zhen Jie
Ye Zhen Jie
CYChristina Gertrude Yap
Christina Gertrude Yap
This review focuses on rat models for studying the short‐term and long‐term effects of mild and severe hypoglycemia. We explored the physiological mechanisms to understand the consequences of hypoglycemia in rat experimental models. This study aims to investigate the therapeutic potential of phytotherapeutic agents and their efficacy in mitigating the adverse effects of hypoglycemia. Insights from our planned research will be beneficial in improving quality of life for individuals at risk of episodes of low blood sugar. Optimizing hypoglycemic rat models for research requires selecting a suitable experimental model that will be susceptible to hypoglycemia induction, effective monitoring of blood glucose levels, and maintaining a high survival rate throughout the required experimental duration.

30 June 2016 in Journal of Biological Research-Thessaloniki
Verified
Journal Article
Open access
PDF file
CYChristina Gertrude Yap
Christina Gertrude Yap
AZAnuar Zaini
Anuar Zaini
IOIekhsan Othman
Iekhsan Othman
The Cytochrome P450 enzymes are commonly known for their major role in metabolism. Besides its metabolic role, CYP2E1 gene expression has been associated with the onset of diabetic nephropathy. CYP2E1 protein elevation has also been reported to be responsible for the production of reactive oxygen species. The aims of this study were (i) to optimize and validate a targeted proteomic approach for quantitating CYP2E1 and validating it as a suitable clinical test, (ii) to investigate the concurrency between ESI-LCMS-MS quantitated circulating CYP2E1 and gold standard indices in the context of outpatient point-of-care clinical settings involving various groups of diabetic patients and (iii) to investigate the concurrency profile of circulating CYP2E1 protein, CYP2E1 gene expression and reactive oxygen species (ROS). This is a cross sectional study involving three groups of subjects (n = 166): control, pre-diabetes, and diabetes. We optimized a targeted proteomic approach for absolute quantification of CYP2E1. “YPEIEEK” and “GTVVVPTLYDNQEFPDPEK” were the representative peptides of CYP2E1 for our analytical method. Deuterated forms of “YPEIEEK” and “GTVVVPTLYDNQEFPDPEK” were used as internal standards. Lymphocytes were isolated from whole blood, microsomes were prepared, followed by in-solution digestion for production of tryptic peptides. Amounts of “YPEIEEK” and “GTVVVPTLYDNQEFPDPEK” from patients’ samples were calculated from a calibration curve. “YPEIEEK” is a unique and reliable representative peptide for CYP2E1 quantification. “GTVVVPTLYDNQEFPDPEK” showed poor reproducibility and sensitivity. Incremental amounts of CYP2E1 protein in the peripheral circulation clearly showed concurrency with CYP2E1 gene expression and ROS levels in our study population. Elevations of CYP2E1 were observed even when gold standard clinical indicator for glycemic control (HbA1c) was within normal reference limits. Quantitated amounts of CYP2E1 protein in the pre-diabetes and diabetes groups showed significant difference relative to control group (p < 0.001). No significant differences were observed between the medians of pre-diabetes and diabetes groups (p = 0.870). CYP2E1 protein in peripheral blood can be reliably quantitated by the validated targeted proteomic approach method. Quantifiable amounts of CYP2E1 preceded abnormal HbA1C levels which indicates quantitation of CYP2E1 could be useful as an additional tool for early indication of diabetic risks and it complications.