Page 4 - Pharmacy History 23 July 2004

Cone shells
Pacific waters has been extensively documented. Queensland records of fatalities from what must be presumed in current light of the evidence to be box jellyfish stings, date back to 1884. Fatalities can be found in the literature throughout the Indo-Pacific region, including Papua New Guinea, Solomon Islands, the Philippines, Borneo and Malaysia.
Also as a consequence of my FPS researches, I became aware of other invertebrate dangers, in particular, cone shells, implicated in one death in Australia at Hayman Island in 1935 and in many injuries world wide especially in tropical waters. Keen local shell collectors offered many opportunities to accumulate knowledge on the natural history of some venomous cone species through personal contacts and field trips with people who, although not trained zoologists in the academic sense, were nonetheless keen observers of the natural world, possessed great practical knowledge and acumen and were keen to share their enthusiasm and to enlighten the novice.
Some 20 years ago, cone shell conotoxins were identified as having great potential for biopharmaceutical products by Professor Robert Endean and his co-workers at the University of Queensland.
In 2000, workers showed that peptides from cone shell venoms, by acting on neuronal calcium channels, provide a promising new treatment for chronic intractable pain. Cone
shells, which are more exotic relations of your common garden snail, have evolved specialised venom apparatus from the salivary gland and duct
and have a sophisticated delivery system using a dart or harpoon-like structure. This enables them rapidly to subdue their natural prey which may be worms, molluscs or fish.
Fish are of course vertebrates as are we humans, so it is little wonder that some bioactive peptides from cones have exciting possibilities in human medicine.
Many drugs used in human therapy had their origin in natural resources. Folklore and serendipitous discoveries had played a major role in the recognition of the properties of drugs of natural origin, whether you were Dr William Withering of digitalis fame, or indeed Lucretia Borgia!
Since the early 1960s there has been an increasing awareness of the sea
as a source of new natural products. As approximately 90% of living organisms are found in the oceans, in substantially different biosynthetic environments to those on land,
it is highly probably that many novel biologically-active substances exist there, especially in tropical waters where species biodiversity is extremely high.
A common attribute of sessile (stationary) marine organisms is the possession of defence mechanisms such as sharp spines, toxic components, or feeding deterrents within their tissues. They may also have the ability to release chemicals
into their immediate environment
to weaken or kill neighbouring organisms which would otherwise overgrow them or crowd them out. Such antibiosis (in the strict sense of the word) is an important survival strategy especially in tropical reefs, which possess great habitat diversity and a very complex web of biological interactions.
In 1987, I had the privilege of organising a conference on
Man, Drugs and the Sea in North Queensland. Invitations to speak were extended to a number of experts in the fields of marine biology, organic chemistry, the extraction and characterisation of drugs from marine organisms and in medical aspects of the marine environment
One of my most treasured memories is the enthusiasm of one guest,
a specialist chest physician (and therefore a potential end-user of the ultimate product), interacting with a primary researcher at the Australian Institute of Marine Science who
was extracting potential anti-cancer drugs from Trididemnum a genus of sea squirt, (or for the southern rock fishermen amongst our readers – a relation of the cunjevoi). Although the resulting Didemnin B stalled after the clinical trial stage in the USA, it is still to be found in Martindale. A most rewarding aspect of such events is the chance to create or renew contacts with colleagues in the field of marine research, both in Australia, for example the Australian Institute of Marine Science and overseas, such as the British Museum (Natural History).
To whet the reader’s appetite with some additional examples of marine research potential, sunscreens have been developed from species of soft corals. Corals after all, lie in the sun in the tropics all day, but have you ever seen a sunburnt coral?
Clown fish
4 ■ Pharmacy History Australia
volume 2 ■ no 24 ■ November 2004