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Bee Propolis |
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Bee Propolis may limit production of DHT...
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Darrell Miller | 05/17/05 |
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Bee Propolis
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Darrell Miller | 05/12/05 |
Date:
May 17, 2005 05:00 PM
Author: Darrell Miller
(dm@vitanetonline.com)
Subject: Bee Propolis may limit production of DHT...
Chrysin controls aromatase activity, and thus the production of estradiol and estrone, and provides an alternative embodiment of this invention. This embodiment may further comprise a substance that controls 5-alpha-reductase and its production of DHT.
Other aromatase inhibitors include substituted androstenediones. There is also evidence that aromatase is involved in the production of DHT, which is well known for its negative effects on the prostate and male pattern baldness. An in vitro rat testis cell suspension model was used to investigate the metabolism of tritiated testosterone, dihydrotestosterone, and androstenedione. In the presence of aromatase inhibitors and androstenedione, the metabolism was shifted towards 17-keto forms. This suggests that androstenedione and the derived aromatase inhibitors activate the 17 .beta.-hydroxysteroid-dehydrogenase in a product-activating manner. Thus, aromatase inhibitors may regulate the intratissular levels, not only of estrogens, but also of other hormonally active steroids like DHT and 5-androstenedione. Schroder et al., 31(4B) J. STEROID BIOCHEM. 685-90 (1988).
Because of the usefulness of inhibiting aromatase in breast cancer patients, several synthetic aromatase inhibitors have been developed. See, e.g., U.S. Pat. No. 4,954,446. There are natural substances, however, such as chrysin, that have similar activity. Chrysin is a bioflavonoid found in propolis (bee pollen) and honey that has been demonstrated to be as potent and effective in inhibiting aromatase as the popular pharmaceutical, aminoglutethimide (AG). In aromatase enzyme assays, chrysin, 7,8 benzo-flavone (ANG), AG, flavone and genistein 4'-methyl ether (5,7-dihydroxy-4'-methoxyisoflavone, Biochanin A) were shown to inhibit aromatase. Chrysin and AG inhibited the enzyme by 50% at a concentration of 4.6 .mu.M and 7.4 .mu.M, respectfully, and only ANG had a high I.sub.50 of 0.5 .mu.M. Both Flavone and Biochanin A inhibited aromatase, but to a lesser degree. Campbell et al., 46(3) J. STEROID BIOCHEM. MOL. BIO. 381-88 (1993). In screening for potential chemopreventives against cancer, chrysin was one of the three of flavonoids with the greatest aromatase-inhibiting activity, with an inhibitory concentration (IC) of 1.1 .mu.g/mL. Jeong et al., 22(3) ARCHIVES PHARMA. RES. 309-12 (1999).
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VitaNet®
VitaNet ® Staff
Date:
May 12, 2005 05:14 PM
Author: Darrell Miller
(dm@vitanetonline.com)
Subject: Bee Propolis
Bees create propolis by collecting a resinous sap from trees and then mixing it with wax back at the hive. They use this material much the way people use caulk: to seal their homes. Chemically, propolis is exceedingly complex and contains a rich variety of potent terpenes and benzoic, caffeic, cinnamic,and phenolic acids. It's also high in flavonoids, which by themselves may account for many of the benefits attributed to propolis-and some researchers refer to propolis as a type of flavonoid.
One of the most significant medical journal articles described how the caffeic acids in propolis and honey might prevent colon cancer, which kills some 60,000 Americans each year. Chinthalapally V. Rao, Ph.D., of the American health Foundation, Valhalla, N.Y., reported in Cancer Research (Sept.15,1993; 53:1482-88) that these caffeic acids prevented the formation of precancerous tissue in rats after they were exposed to cancer-causing chemicals.
Most medical articles, however, still point to the value of propolis as a powerful, natural antibiotic. That doesn't mean eating propolis will let you throw away your antibiotics - only that you may not need them quite as often.
Why would bees need substances with broad antibacterial and antiviral properties? Any beekeeper will tell you the answer. Bees are very susceptible to bacterial and viral infections, which can destroy hives the way the bubonic plague ravaged Europe in the 17th century.
Two medical journal articles document the activity of propolis specifically against Staphylococcus aureus, the bacterium that causes dangerous and often deadly surgical infections, blood poisoning, and a type of pneumonia. Five to 10 percent of all patients hospitalized in the United States develop such infections, and S. aureus has become resistant to all but one pharmaceutical antibiotic.
In a Chinese study, researchers found that extracts of propolis - specifically, sinapic, isoferulic, and caffeic acids - inhibited the growth of S. aureus (Qiao Z, China Journal of Chinese Materi Medica, Aug. 1991;16:481-2). A European study reported that ethanol extracts from propolis had a "marked synergistic effect" on the anti-staph activity of two antibiotics, streptomycin and cloxacillin, and a moderate effect on several others (Krol W, Arzneimittel-Forschung, May 1993;43:607-9).
Another scientific investigation discovered that propolis inhibited the activity of several streptococcal bacteria species that cause dental caries.Japanese researchers reported that propolis-fed laboratory fats had far fewer caries than those given a regular diet. Propolis protected specifically against Streptococcus mutans and several other strep species (Ikeno K, Caries research, 1991;25:347-51). These strep species are closely related to the germ that causes strep throat.
Propolis works against bacteria in several ways. One study reported that it prevented bacterial cell division and also broke down bacterial walls and cytoplasm, which is how some prescription antibiotics work (Takaisi-KikuniNB, Planta Medica, June 1994;60:222-7).
Perhaps more remarkable is that propolis acts against viruses, which antibiotics do not. A number of medical journal reports have discussed the role of propolisin fighting upper respiratory infections, such as those caused by the common cold and influenza viruses (Focht J, Arzneimittel-Forschung, Aug. 1993;43:921-3). Other investigators have reported that the cinnamic acid extracts of propolis prevent viruses from reproducing, but they worked best when used during the entire infection (Serkedjieva J, Journal of Natural Products, March 1992;55:294-302).
Underpinning many of the benefits of propolis is that some of its components,like the flavonoids and ethanols, function as antioxidant free-radical scavengers. A study published in the Journal of Ethnopharmacology (Jan. 1994;21:9-13)noted that some of the antioxidant phenols in propolis functioned similarly to vitamin E. In another article, researchers described that propolis had anti-inflammatory properties and that it could also prevent blood clots(Drugs Under Experimental & Clinical Research, 1993; 19:197-203).
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