Earthworm extracts help relieve asthma symptoms
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January 28, 2007
Filed under Uncategorized
CM NEWS – A group of scientists have been able to show in a study that extracts from earthmworm, or Pheretima (di long, ??, picture left, usually dried), have led to some encouraging results in combating asthmatic symptoms.The study was conducted by traditional Chinese medicine researchers in Shanghai and has been published in the Journal of Ethnopharmacology.
The researchers write that Pheretima (family Megascolecidae, i.e. earthworm) has been documented as a potent agent for the treatment of cough and breathing difficulty in traditional Chinese medicine for nearly 2000 years.
In the study, the water extract of Pheretima was separated into three fractions of the ethanolic precipitate, the alkaline fraction and the acidic fraction.
Guinea pig’s tracheal rings were stimulated by histamine to contract, while isolated rat tracheal epitheliums was triggered by carbachol to increase short circuit current.
Results show that among the three fractions of Pheretima, the acidic fraction shows the most potent spasmolytic effects on histamine-induced contractions and the most inhibitory activities on carbachol triggered increase in short circuit current.
Further in vivo studies also display that the acidic fraction could protect experimental asthma model induced by the combination of histamine and acetylcholine chloride in guinea pigs to prolong the latent periods of asthma (P<0.05) and significantly decrease the cough frequency caused by ammonia water in mice (P<0.001).
According to TCM (traditional Chinese medicine) texts, Pheretima is known for its anti-asthmatic effects and diuretic effects. It’s used commonly in TCM treatments (here).
Earthworms used as TCM would have their internal organs removed before they are dried under the sun. One dried earthworm (Pheretima) is about 15-20 cm in length and 1-1.5 cm in width.
Pheretimas are brownish in colour and smell a little fishy. Earthworms suitable to be processed into Pheretima are mainly found in Guangdong and Guangxi.
Ingredients extracted from Pheretimas include, but not limited to, xanthine (which helps relax the airway muscles) and succinic acid (which helps calm down the respiratory system); as well as lumbritin which serves like blood thinner.
[Journal of Ethnopharmacol. 2006 Dec 17]