Biochemistry
Welcome to Stellenbosch University

Abdul Group

​GROUP LEADER:  Dr N Sheik AbdulNaeemAbdulSheik.jpeg

Position: Lecturer

Office:       A101, JC Smuts building

Phone:     +27-(0)21-808-5865

Fax:           +27-(0)21-808-5863

Email:       sheikn@sun.ac.za

Educational Background

PhD, University of KwaZulu Natal, Medical Biochemistry (2019)

Research Emphasis

Dietary Bioactive Compounds, Cellular Bioenergetics, Mitochondrial Function, Molecular Mechanisms of Action, Oxidative Stress

Research Summary

Mitochondria play important roles in energy metabolism and are responsible for many cellular processes. The Abdul group is focused on understanding the impact that dietary bioactive compounds have on mitochondrial function and the molecular mechanisms involved within the context of toxicology and pharmacology.

Research Description

Foodborne toxins and their molecular mechanisms of toxicity

Food can contain a plethora of natural toxins or anthropogenic compounds that may be of concern to health, such as mycotoxins and microplastics respectively. There is a growing need for commitment to active rather than reactive research to better understand the toxicological profile of these foodborne toxins and help identify the consequences and implications of toxin exposure.

Mitochondria regulate and maintain several aspects of cell homeostasis and studies have revealed the importance of mitochondria in coping with toxic insults. The mitochondrial stress responses, including the mitochondrial unfolded protein response, antioxidant defences, and mitophagy are induced to maintain cellular integrity and organism homeostasis, while the sirtuin family of enzymes have emerged as fine tuners of mitochondrial function through post translational modifications of various mitochondrial proteins. Disruption of mitochondrial functions can lead to oxidative stress, inflammation, and metabolic aberrations which are recognised as contributing pathomechanisms to diseases such as cancer and diabetes.

Foodborne toxins disrupt mitochondrial stress responses; however, there remains a dearth of knowledge regarding the molecular events that contribute to mitochondrial dysfunction and its links to pathomechanisms of diseases. Our research focuses on identifying the mechanisms leading to mitochondrial dysfunction and downstream implications on cell physiology to provide relevant insight into the toxicity of foodborne toxins and disease states that these toxins may be implicated in.

The role of dietary bioactive compounds in mitochondrial function – Therapeutic applications

Mitochondrial dysfunction is associated with several human pathologies, such as cancer, metabolic, and cardiovascular diseases. Mitochondrial involvement in pathogenesis is strongly linked to the excessive production of reactive oxygen (ROS) or impaired bioenergetic processes which contribute to abnormal cell signalling, inflammation, damage to cellular macromolecules and apoptosis.

Therapeutic approaches that focus on improving mitochondrial function could represent innovative advances for the treatment or prevention of diseases. There has been a growing trend to discover and explore drugs of natural origin. Natural compounds are becoming increasingly appreciated as promising agents to reduce the risks and pathomechanisms involved in disease progression and initiation. South Africa has a diverse health care system, with ethnopharmacology and medicinal plant use featuring prominently. This highlights the need for detailed scientific evaluations of indigenous South African plants to support anecdotal health claims.

The phytoconstituents of indigenous medicinal plants have enormous potential to restore or maintain normal mitochondrial physiology and attenuate oxidative stress. Despite the benefits of medicinal plants, few studies have been conducted to determine the therapeutic potential of South African medicinal plants with a focus on mitochondrial health and function and the molecular mechanisms involved. Our group aims to fill this gap in knowledge and further the appeal of indigenous plants as an intervention strategy for diseases such as diabetes and cancer.

Techniques

Mammalian cell culture and new approach methodologies

Cytotoxicity assays

Mitochondrial activity and function

Oxidative stress biomarkers

Western Blotting (protein expression)

qPCR (gene expression, non-coding RNA)

Collaborations

We collaborate extensively with the group of Prof. Jeanine Marnewick at the Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology. We also collaborate with the group of Prof. Anil Chuturgoon, University of KwaZulu Natal.

Selected Publications

SHEIK ABDUL, N., NAGIAH, S., ANAND, K. & CHUTURGOON, A. A. 2020. Molecular docking and mechanisms of fusaric acid induced mitochondrial sirtuin aberrations in glycolytically and oxidatively poised human hepatocellular carcinoma (HepG2) cells. Toxicon, 173, 48-56.

SHEIK ABDUL, N., NAGIAH, S. & CHUTURGOON, A. A. 2020. The neglected foodborne mycotoxin Fusaric acid induces bioenergetic adaptations by switching energy metabolism from mitochondrial processes to glycolysis in a human liver (HepG2) cell line. Toxicology letters, 318, 74-85.

SHEIK ABDUL, N. & CHUTURGOON, A. A. 2021. Fumonisin B1 regulates LDL receptor and ABCA1 expression in an LXR dependent mechanism in liver (HepG2) cells. Toxicon, 190, 58-64.

AKINFENWA, A. O., SHEIK ABDUL, N., MARNEWICK, J. L. & HUSSEIN, A. A. 2021. Protective Effects of Linearthin and Other Chalcone Derivatives from Aspalathus linearis (Rooibos) against UVB Induced Oxidative Stress and Toxicity in Human Skin Cells. Plants, 10, 1936.

MOHAN, J., SHEIK ABDUL, N., NAGIAH, S., GHAZI, T. & CHUTURGOON, A. A. 2022. Fumonisin B2 Induces Mitochondrial Stress and Mitophagy in Human Embryonic Kidney (Hek293) Cells—A Preliminary Study. Toxins, 14, 171.

Full list of publications – Google Scholar:

https://scholar.google.com/citations?view_op=search_authors&mauthors=naeem+sheik+abdul&hl=en&oi=ao