The Insect That Keeps Giving

Materials derived from insects and plants were frequently used in healthcare. The honeybee is an insect that has been of great importance to human society since ancient times across various cultures. Anytime you take a bite of a fruit or vegetable, it is highly likely a honeybee was an important cog in the growth of that produce. Honeybees are excellent pollinators. The United State Department of Agriculture (USDA) estimates that bees pollinate 80% of our crops.  Bee-based products are widely used in food and medicine. Bee materials used in these products include honey, bee pollen, royal jelly or bee milk, bee venom, propolis, beeswax, and silk.

The table on the right lists the composition of these bee materials. One aspect you will immediately notice is the diversity of compounds across materials. It is also interesting how bees prepare these materials, and how the differences in compositions give rise to different physical and chemical properties for each bee material.

Honey is preparing from the flower nectar collected by bees. Inside the honeycomb, the nectar gets stripped down by enzymes into simple sugars and further evaporated to form honey as a thick syrup. Honey’s color and flavor depends on the nectar type. It’s antimicrobial and anti-inflammatory properties are well documented. It is orally ingested or topically applied to treat infections and wounds.

Storage sacs attached to back leg of honey bees. The bee on the left has stored with resin which is semi-clear and shiny. The bee on the left has pollen which looks more opaque and dry like a powder. Photo: M. Simone-Finstrom. http://www.coloss.org/beebook/III/propolis

Bee pollen is the primary ingredient of bee bread. Worker bees collect pollen and mix small amounts of salivary secretion or nectar to form small balls (see right figure) that are stored in sacs. The pollen falls are eventually stored in honeycomb cells. Here the balls undergo anaerobic fermentation to form bee bread. They are preserved due to the lactic acid formed during fermentation. Bee bread is the main protein source for the bee colony and source of nutritional and mineral substances for royal jelly.

Royal Jelly. The image shows developing queen larvae surrounded by royal jelly (milky substance). Photo source: Waugsberg. wikipedia.org/wiki/Royal_jelly#/media/File:Weiselzellen_68a.jpg

Royal jelly is secreted from the bee’s head glands. It is a product that is the digestive outcome of all the food (pollen, honey) bee eats. Royal jelly is a beehive royalty food served to queen bees. It is also known as “bee milk,” and is a white creamy emulsion. The bees don’t make royal jelly directly from pollen the way they do honey from nectar.

Bee pollen and Royal jelly are marketed as a dietary supplement and natural medication. However, their effectiveness for many healthcare applications remains inconclusive.

Honeybees also collect propolis,  a resinous material (see the left bee in the above figure) from buds of trees, for sealing cracks in the hive or for covering foreign objects in the hive that they cannot remove. Propolis is used as a natural antiseptic, antioxidant and anti-inflammatory ointment.

The image shows a drop of bee venom “milked” from bees. The process involves passing weak electric current pulses through bees sitting on a piece of glass. The annoyed bees sting the glass. The venom deposited during the stinging is dried and scraped off. Photo Source: keepingbee.org

A peptide called that melittin is the major component of bee venom and cause the burning sensation when a bee stings.  Bee venom is cytotoxic (ie. toxic to cells). It has opposite effects of the human organs. It the inhibits functioning of the nervous system and stimulates the heart and adrenal glands. Bee venom therapy is used in complementary medicine to treat a number of inflammatory diseases.

Beeswax. Photo Source: Center for Dental Implants

Beeswax is the major component of honeycomb. It is secreted in the tiny layer underneath the abdomens of worker bees, and molded into honeycomb. Beeswax texture is soft to brittle, and it melts over  60°C. You will find beeswax in skin care (lip balm, lip gloss, handcreams) and cosmetic (eye liners mustache wax) products. Surgical bone wax, used to control bleeding from bone surface, contains beeswax as a major constituent.

Bee Silk. The image shows hand-drawn fine threads of bee silk Photo Source: Living with insects blog.

Most people don’t know that bees generate silk too. The comb, covered with wax, hide the silk. Unlike silkworm and spider silk, honey bee silk strands are formed without being forced through a spinneret. One can hand-draw or pull the silk strands from bee’s silk (labial) gland. Bee silk is currently not used for any biomedical application. However, it needs to be manufactured in bulk to compete with spider silk for a range of biomedical applications.