Dr. Ravi Gooneratne

Author: | published date:2014-10-08

Speaker: Dr. Ravi Gooneratne 
                 Associate professor in toxicology, Lincoln University, Christchurch, New Zealand
Time: Oct 9 , 2014 , 10:30--11:30

Location: Room 1 , overseas exchange center, PKU

Abstract: Humans and environmental organisms can be exposed to over 100,000 chemical substances, and many others of natural origin, as environmental pollutants and food contaminants. But analytical procedures for environmental health risk assessment are often lacking, even for some high-volume production chemicals, or, when available, can be expensive. To fill that gap, use of biomarkers has evolved in recent years. Biomarkers are indicators of effects in a living organism exerted by a chemical and can be bimolecular, biochemical or physiological responses. Some chemicals are selective in their action on biological systems but many are non-selective and act on several body systems. In the context of environmental toxicology and terrestrial and aquatic pollution, non-target organisms that are continually exposed to, and adversely affected by a wide variety of pesticides, heavy metals, industrial chemicals, farm chemicals and pharmaceuticals include bacteria, earthworms, fish, aquatic worms, zebrafish, and even beneficial wolf spiders (found in many agricultural farming systems).. Some of these organisms – because of their small size, high fecundity, experimental tractability and cost-effectiveness have also been used in mammalian mechanistic studies and preclinical models for predicting drug toxicity in humans. To monitor exposure to a variety of environmental chemicals, we have developed a range of biomarkers using these organisms: bacterial respiration (for many environmental pollutants), cholinesterase enzyme assay (for neurotoxic pesticides); nerve conduction velocity measurement (for a range of neurotoxins, heavy metals, and silver nanoparticles); cytochrome P4501A enzyme induction (for polyaromatic hydrocarbons); chromosomal aberrations and genetic damage markers (for cadmium, lead); a range of endogenous metabolites in fish plasma (on exposure to treated sewage water); and a P-glycoprotein transporter assay (for chemosensitisers, a new class of environmental toxins, which can cause multi-xenobiotic resistance). The relevance of these biomarkers for risk assessment and ideas for future studies using genomics, proteomics, and metabolomics will be discussed.

Short Bio: Dr. Ravi Gooneratne is an associate professor in the Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture & Life Sciences, Lincoln University, New Zealand. He got B.V.Sc. in University of Ceylon, Sri Lanka in 1972, and Ph.D. in 1979 in the filed of toxicopathology, Murdoch University, Western Australia. His research theme has centered around developing biomarkers / biosensors for environmental contaminants, food toxicology, food safety and heavy metal metabolism in ruminants. To date he has published 98 peer reviewed articles.