Bee Stings

Worker bees possess a venomous sting, which they use to defend themselves and the hive against predators. The venom causes intense pain at the site of the sting, with swelling and reddening following later. In the act of stinging, the venom sac and attached muscles are torn from the bee, causing its death. The muscles then continue to work the sting deeper into the wound and inject further venom. To prevent this, the sting should be scraped out with a fingernail (not grasped and pulled out, as this forces all remaining venom into the wound).

Some people develop acute allergic reactions to bee stings. An allergic reaction becomes evident in less than an hour and consists of extreme difficulty in breathing, heart irregularity, shock, splotched skin, and speech difficulty. A person showing signs of an allergic reaction should see a medical doctor immediately.
Unlike many other insect venoms, bee venom is water soluble, not fat soluble, and so must be injected into moist tissue to be effective. It is haemorrhagic, unlike snake venom, which is a coagulant. Bee venom is a clear liquid, which forms greyish white crystals when exposed to air.

Caught in the act!

Bee venom is a mixture of histamine, pheromones (discussed on the pheromone page), enzymes, peptides, amino acids and other acids, with 63 components in total. The main enzymes present are phospholipase A, hyaluronidase, and lecithinase; while the main peptides are mellitin, apamin and peptide 401. Bee venom is cytotoxic (ie. cell-destroying), and has the contradictory effects of inhibiting the nervous system, while stimulating the heart and adrenal glands.

Phospholipase A makes up 12% of the venom, and destroys cells by breaking up phospholipids, the main component of cell membranes. Lecithinase converts lecithine to lysolecithine (or phospholipase B), which breaks down the membranes of blood cells. Hyaluronidase (3%) acts as a spreading factor, by breaking down hyaluronic acid, a polysaccharide interstitial fluid in connective tissue.

Mellitin, a 26 amino acid peptide, makes up 50% of the dry weight of bee venom, and acts to destroy blood cells by breaking up their membranes. It also lowers blood pressure, causes histamine release, and is the main pain-causing component. Both mellitin and apamin cause the body to release cortisol, a natural steroid, while peptide 401 is a powerful anti-inflammatory agent. The main amino acids in bee venom are cysteine and methionine, both of which contain sulphur. Sulphur is important in inducing cortisol release from the adrenal glands.
Histamine makes up 0.9% of venom, and causes itching and pain at the site of the sting. The acids present, which include formic, hydrochloric and orthophosphoric acids, are now believed to be much less important in causing pain than was previously thought.

Bee venom has recently found a use in a form of complementary therapy. In bee venom therapy, bees may be induced to sting the affected area, or the venom may be applied by intramuscular injection. The venom stimulates the release of cortisol, and so is effective in the treatment of rheumatic disorders such as Multiple Sclerosis, rheumatoid arthritis and gout. Mellitin is believed to be the main active agent. Bee venom therapy is one aspect of apitherapy - use of bee products for curing disease.
Mellitin is also being investigated as an anti-cancer agent. By modifying the mellitin molecule to prevent allergic reaction, and attaching a cancer-specific antibody (this combination of toxin and antibody is called an immunotoxin), researchers hope to produce a ‘magic bullet’ treatment - so called because it would only destroy cancer cells (unlike conventional chemotherapy agents, which destroy all types of cell, causing unpleasant side effects such as vomiting and hair loss).