Finding new sources of medicines/drugs

• WHO estimates 30 new viral diseases emerged in the last 50 years; Covid-19, HIV/AIDS, SARS, and Lyme disease, but many known diseases lacking effective treatments; also antibiotics are less effective as bacteria develops resistance
• New drugs discovered: by accident (e.g. penicillin), 80% of world’s population relies on traditional medicine, animal self-medications observed, modern research and 40% of prescriptions originated from plants and animals
• Tropical rainforests contain 70% of plant-derived drugs, 25% of natural medicines, but fewer than 10% have been examined; has huge biodiversity so hoped many new drugs will be discovered; one reason for conservation
• WHO ensures shared resources and financial benefits from genetic research by pharmaceutical companies; in the UK, new chemical fingerprinting allows scientists to screen natural chemicals for their activity as medicines
• Most antibiotics come from the bacterium Streptomyces, scientists are studying its genes to determine their control mechanisms for antibiotic production; aim is to improve current large scale production methods
• Pharmaceutical companies research how microorganisms cause disease; many use receptors on host cell plasma membranes in order to enter; so if the receptor site can be blocked by a drug, the pathogen cannot enter the cell
• HIV virus attaches to CD4 receptors on T helper cell plasma membranes, allowing molecular modeling and so a drug can be developed to block CD4 without side effects through comparison with plant and human DNA sequences
• New drugs come from organisms in the natural environment but since habitats are being destroyed as a result of man’s activities (global warming, logging, industrialisation and urbanisation, pollution), biodiversity is reducing