In snakes, venom composition varies both between species and within a particular species. Land snakes feed on a range of animals and birds, so scientists think that these snakes need a diverse array of toxins in their venom. Sea snakes, on the other hand, tend to have a more restricted diet, feeding only on fish. The toxins in these snakes have now been shown to be less diverse than those in terrestrial snakes.
Professor R Manjunatha Kini and colleagues from the National University of Singapore examined two kinds of sea snakes. They constructed complementary DNA libraries from the venom glands of the reptiles, representing only the stretches of DNA that code for venom gland proteins, and studied two types of protein toxins. The three-finger toxins (3FTx) and the phospholipase A2 (PLA2) enzymes are the main components of sea snake venom.
Although the sea snakes studied lived in very different aquatic environments, the toxins examined were similar in both and the genes encoding the toxins were highly conserved. By contrast, the same toxins in land snakes and sea kraits (which fall between land and sea snakes) showed much greater diversity. The researchers suggest that the toxin genes in sea snakes have remained relatively unchanged because of sea snakes share the same kind of feeding behaviour and diet.
"We examine toxin genes of snakes to identify new toxins, some of which will be useful in developing new therapeutic strategies to treat human diseases," says Prof Kini from the Department of Biological Sciences, National University of Singapore. "A new anticoagulant or a hypotensive toxin may help us develop new cardiovascular drugs to block unwanted clot formation or to lower the blood pressure."
biomedcentral/
Dr. Barak explains why this is good news, All the drugs in the diet pill market today have serious side effects. They may help a woman lose weight, but with that weight loss comes all sorts of bad things like depression and even suicide. Safety issues are a real concern for the FDA. But because this new drug has already been proven safe for other indications, we think Histalean has real blockbuster potential.
The recent results were based on a double-blind, placebo-controlled study on people with a Body Mass Index ranging from 30 to 40. (A BMI of 30 and above indicate obesity.) The study was conducted at 19 investigation sites across the U.S. over a 12 week treatment period. The subgroup of high-dose Histalean-treated women lost an average of 2.91% of their weight versus placebo group which lost only 0.4 %.
Dr. Barak's drug is also expected to compete for the $28 billion market of cholesterol-reducing drugs such as Lipitor. It could also be used in parallel with anti-psychotic drugs, which have unwanted side effects of extreme weight gain among mental health patients.
aftau/