Syringes make it easier to inject venom, but before there were needles there were, well, stingers. Modern practitioners often still use the live honey bee herself as the delivery vehicle for venom. Tweezers are used to place and hold the bee directly on the part of the body being treated; in doing so, the bee, instinctively, stings (although some may require a little nudge — most honey bees aren't aggressive until you provoke them).
When bee venom is delivered via syringe, it's first collected not by crushing honey bees but, usually, with an electroshock treatment that's mild enough not to injure the bees yet strong enough to annoy them into stinging. Their venom is collected from pre-positioned collection plates. While in the wild it's unusual for the full contents of the venom sac to be used in one sting, it is not unusual for therapy bees to do so, producing between 0.15 and 0.3 grams of venom per sting [source: Krell]. Depending on the individual and the condition being treated, the BVT schedule may vary; it could be as many as hundreds of stings per week. While that may sound like a lot of stings, on average, an adult can safely withstand the effects of 10 bee stings per every 1 pound (0.5 kilogram) of his or her body weight [source: USDA].
Only 22 percent of honey-bee venom is pharmacologically active — the remainder is just water. Scientists have identified amines, enzymes and peptides that are responsible for the pain of — or allergic reaction to — a sting. The largest percentage, 52 percent, of active components in bee venom is a peptide called melittin [source: Downey]. Melittin is toxic to humans and destructive because it pokes holes in cell walls. Melittin poisoning is associated with a powerful, burning pain because it tricks the body into thinking it's on fire. More than one toxin is released during a honey-bee sting, though. Apamin, for instance, is a neurotoxin that blocks the body's ability to regulate neural activity, including impacting how fast neurons fire and the plasticity of our synaptic connections.
Additionally, two enzymes, hyaluronidase and phospholipase A2 (bvPLA2), together make up between 11 and 15 percent of bee venom. Hyaluronidase dilates blood vessels, triggering inflammation throughout the body. Phospholipase A2 breaks down cell walls, decreases blood pressure and suppresses the blood's ability to clot. It also triggers the body's production of prostaglandins, used to regulate the immune system's inflammatory response. Together these enzymes activate the body's immune cells and produce an antibody called immunoglobulin E (IgE); this plays a part in the body's allergic response to the sting [source: Bowling].
Peptide 401, a mast-cell degranulating peptide (MCDP) also found in bee venom, plays a role in the body's allergic response. Mast cells are found in the connective tissues throughout the body, mostly near the surface, and are vital in the body's defense against pathogens. They signal the immune system to intruder alerts and play a role in triggering the release of histamine. At high levels, MCDP is known to be epileptogenic, a neurotoxin that causes epileptic seizures.
The swelling and itching associated with bee stings is caused by the small percentages, just 1 to 2 percent, of dopamine and noradrenaline, which increase the body's pulse rate and the levels of histamine produced [source: Ali].