Biodiversity: A continuing source of novel drug leads

Abstract

Nature has been a source of medicinal agents for thousands of years and continues to be an abundant source of novel chemotypes and pharmacophores. With only 5 to 15 % of the approximately 250 000 species of higher plants systematically investigated, and the potential of the marine environment barely tapped, these areas will remain a rich source of novel bioactive compounds. Less than 1 % of bacterial and 5 % of fungal species are currently known, and the potential of novel microbial sources, particularly those found in extreme environments, seems unbounded. To these natural sources can be added the potential to investigate the rational design of novel structure types within certain classes of microbial metabolites through genetic engineering. It is apparent that Nature can provide the novel chemical scaffolds for elaboration by combinatorial approaches (chemical and biochemical), thus leading to agents that have been optimized on the basis of their pharmacological activities. The proven natural product drug discovery track record, coupled with the continuing threat to biodiversity through the destruction of terrestrial and marine ecosystems and the current low number of new chemical entities in pharmaceutical industry pipelines, provides a compelling argument in favor of expanded multidisciplinary and international collaboration in the exploration of Nature as a source of novel leads for the development of drugs and other valuable bioactive agents. BIODIVERSITY: MEDICINALS FOR THE MILLENNIA Recorded historyThroughout the ages, humans have relied on Nature for their basic needs for the production of foodstuffs, shelters, clothing, means of transportation, fertilizers, flavors and fragrances, and, not least, medicines. Plants have formed the basis of sophisticated traditional medicine systems that have been in existence for thousands of years. The first records, written on clay tablets in cuneiform, are from Mesopotamia and date from about 2600 B.C.; among the substances they used were oils of Cedrus species (cedar) and Cupressus sempervirens (cypress), Glycyrrhiza glabra (licorice), Commiphora species (myrrh), and Papaver somniferum (poppy juice), all of which are still in use today for the treatment of ailments ranging from coughs and colds to parasitic infections and inflammation. Egyptian medicine dates from about 2900 B.C., but the best known Egyptian pharmaceutical record is the Ebers Papyrus dating from 1500 B.C.; this documents some 700 drugs (mostly plants), and includes formulas, such as gargles, snuffs, poultices, infusions, pills, and ointments, with beer, milk, wine, and honey being commonly used as vehicles. The Chinese Materia Medica has been extensively documented over

Effect of Tulbaghia violacea on the blood pressure and heart rate in male spontaneously hypertensive Wistar rats

“…Drug discovery from medicinal plants led to the isolation of early drugs such as cocaine, codeine, digitoxin, quinine, diosgenin, reserpine, pilocarpine and morphine, of which some are still in use (Farnsworth et al, 1985;Newman et al, 2000;Butler, 2004;Samuelsson, 2004;Gurib-Fakim, 2006). There has also been a rekindling of interest in 'rediscovering natural products' (Cragg & Newman, 2005) and it seems only 6% of potential medicinal plants has been investigated for biological activity and 15% of these for their chemical constituents (Gurib-Fakim, 2006).…”

Marine Ecosystem: A Majorly Unexplored Domain for Drug Discovery

“…The reports on the first bioactive marine compounds viz. spongothymidine and spongouridine dates back more than 65 years from the Caribbean sponge Cryptotheca crypta in the early 1950s [2]. Thereof, there has been eventual investigation of novel bioactive constituents from marine sources and till date several therapeutic agents of marine origin are available that are used for the treatment of various diseases and ailments.…”

Bioprospecção De Antibióticos Produzidos Por Fungos Da Caatinga

“…1 Vários medicamentos foram e são desenvolvidos a partir de substâncias encontradas na natureza nos mais diversos ambientes, como a Antracimicina, potente antibiótico contra o bacilo Anthrax, isolada de um Actinomiceto marinho. 2 Ao passar dos anos, a biotecnologia aliou-se à indústria farmacêutica para impulsionar e otimizar a descoberta e o aprimoramento de novos fármacos.…”