A type proanthocyanidin

A type proanthocyanidins are a specific type of proanthocyanidin, which are a class of flavanoid. Proanthocyanidins fall under a wide range of names in the nutritional and scientific vernacular, including oligomeric proanthocyanidins, flavanoids, polyphenols, condensed tannins, and OPCs. Proanthocyanidins were first popularized by French scientist Dr. Jacques Masquelier.[1]

Contents

Distribution in plants

A-type linkage is a less common feature in proanthocyanidins with both 4ß→8 (B-type) and 2ß→O→7 interflavanoid bonds.[2]

Dimers

Other A-type proanthocyanidins can be found in cranberries,[2] in apricots, Prunus armeniaca (ent-epiafzelechin-3-O-p-hydroxybenzoate-(4α→8,2α→O→7)-epiafzelechin) and in peanut skins (epicatechin-(2β→O→7, 4β→8)-ent-epicatechin).[3]

Trimers

An A type proanthocyanidins trimer can be found in Lindera aggregata (epicatechin-(4β→8,2β→O→7)-entcatechin -(4β-8)-catechin).[5] This compound shows cytoprotective action against ethanol-induced gastric injury.[6]

In Ecdysanthera utilis (epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin and epicatechin-(4β→8)-epicatechin-(4β→8,2β→O→7)-epicatechin-(4β→8)-epicatechin) can be found.[7]

Chemistry

B-type procyanidin (catechin dimer) can be converted to A-type procyanidin by radical oxidation.[8]

Health Benefits

Proanthocyanidin A1, A2 and epicatechin-(2β→O→7, 4β→8)-ent-epicatechin possess substantial activity against hyaluronidase.[3]
Proanthancyanidins in Ecdysanthera utilis show immunomodulatory effects.[7]

Urinary Tract Infection Prevention

85-90% of urinary tract infections are caused by E. Coli bacteria.[9] E. Coli use their p type fimbrae to attach to the wall of the urinary tract.[10] A Type proanthocyanidins have been clinically demonstrated to attach to E. Coli fimbriae, preventing the bacteria from attaching to the urinary tract or bladder or urinary wall.[11][12] A Type proanthocyanidins have been demonstrated in vitro to be more effective than other types of proanthocyanidins at adhering to E. Coli and preventing urinary tract infections.[13]

The anti-adhesion activity of A Type Proanthocyanidins in cranberry products has been well established by the aforementioned clinical data. But how well does this anti-adhesion activity translate into prevention of urinary tract infections? A Cochrane Collaboration Review of the body of clinical literature concluded that "there is some evidence to recommend cranberry juice for the prevention of UTIs in women with symptomatic UTIs. The large number of dropouts/withdrawals from some of the trials, however, indicates that cranberry juice may not be acceptable over long periods of time."[14] Another review of cranberry and UTI prevention takes a more skeptical view. The review supports the anti-adhesion of activity of A Type Proanthocyanidins: "evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds" yet asserts that "most clinical trials have had design deficiencies" and points to cranberry products' "adverse events include gastrointestinal intolerance and weight gain (due to the excessive calorie load)."[15] Both reviews agree that the evidence for cranberries (and their anti-adhesion components A Type Proanthocyanidins) and urinary tract infection prevention can be strengthened by better-designed clinical studies.

References

  1. ^ Fine, AM (2000). "Oligomeric proanthocyanidin complexes: history, structure, and phytopharmaceutical applications". Alternative medicine review 5 (2): 144–51. PMID 10767669. http://www.chiroonline.net/_fileCabinet/opc.pdf. 
  2. ^ a b Neto, CC (2007). "Cranberry and its phytochemicals: a review of in vitro anticancer studies". The Journal of nutrition 137 (1 Suppl): 186S–193S. PMID 17182824. 
  3. ^ a b A-type proanthocyanidins from peanut skins. Hongxiang Lou; Yamazaku Y.; Sasaku T.; Uchida M.; Tanaka H.; Oka S., 1999
  4. ^ Flavonoids and a proanthrocyanidin from rhizomes of Selliguea feei. Baek Nam-In; Kennelly E.J.; Kardono L.B.S.; Tsauri S.; Padmawinata K.; Soejarto D.D.; Kinghorn A.D., Phytochemistry, 1994, vol. 36, no2, pp. 513-518 (19 ref.)
  5. ^ Feng, Zhang Chao; Shi, Sun Qi; Tao, Wang Zheng; Hattori, Masao (2003). "One New A-type Proanthocyanidin Trimer from Lindera aggregata (Sims) Kosterm". Chinese Chemical Letters 14 (10): 1033–6. http://www.imm.ac.cn/journal/ccl/1410/141015-1033-02-781-p4.pdf. 
  6. ^ Cytoprotective Effect of Lindera aggregata Roots Against Ethanol-Induced Acute Gastric Injury. M. Zhu; C. T. Luk; T. H. Lew, Pharmaceutical Biology, Volume 36, Issue 3 July 1998 , pages 222 - 226
  7. ^ a b Immunomodulatory Proanthocyanidins from Ecdysanthera utilis. Lie-Chwen Lin, Yuh-Chi Kuo, and Cheng-Jen Chou, 2002
  8. ^ Conversion of procyanidin B-type (catechin dimer) to A-type: evidence for abstraction of C-2 hydrogen in catechin during radical oxidation. Kazunari Kondo, Masaaki Kurihara, Kiyoshi Fukuhara, Takashi Tanaka, Takashi Suzuki, Naoki Miyata and Masatake Toyoda, Tetrahedron Letters, Volume 41, Issue 4, 22 January 2000, Pages 485-488, doi:10.1016/S0040-4039(99)02097-3
  9. ^ National Kidney and Urologic Diseases Information Clearinghouse (December 2006). "Urinary Tract Infections in Adults". National Institute of Diabetes and Digestive and Kidney Diseases. NIH Publication 07-2097. http://kidney.niddk.nih.gov/Kudiseases/pubs/utiadult/. Retrieved 28 September 2009. 
  10. ^ Bergsten, Göran; Wullt, Björn; Svanborg, Catharina (2005). "Escherichia coli, fimbriae, bacterial persistence and host response induction in the human urinary tract". International Journal of Medical Microbiology 295 (6–7): 487–502. doi:10.1016/j.ijmm.2005.07.008. PMID 16238023. 
  11. ^ Nowack, R; Schmitt, W (2008). "Cranberry juice for prophylaxis of urinary tract infections--conclusions from clinical experience and research". Phytomedicine 15 (9): 653–67. doi:10.1016/j.phymed.2008.07.009. PMID 18691859. 
  12. ^ Foo, LY; Lu, Yinrong; Howell, Amy B.; Vorsa, Nicholi (May 2000). "The structure of cranberry proanthocyanidins which inhibit adherence of uropathogenic P-fimbriated Escherichia coli in vitro". Phytochemistry 54 (2): 173–81. doi:10.1016/S0031-9422(99)00573-7. PMID 10872208. 
  13. ^ Howell, AB; Reed, JD; Krueger, CG; Winterbottom, R; Cunningham, DG; Leahy, M (2005). "A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity". Phytochemistry 66 (18): 2281–91. doi:10.1016/j.phytochem.2005.05.022. PMID 16055161. 
  14. ^ Jepson, RG; Craig, JC; Jepson, Ruth G (2008). Jepson, Ruth G. ed. "Cranberries for preventing urinary tract infections". Cochrane database of systematic reviews (1): CD001321. doi:10.1002/14651858.CD001321.pub4. PMID 18253990. http://www.juxx.com.br/prof_data/materias/2004%20Cranberries%20.pdf. 
  15. ^ Guay, DR (2009). "Cranberry and urinary tract infections". Drugs 69 (7): 775–807. doi:10.2165/00003495-200969070-00002. PMID 19441868. 
A type proanthocyanidins
Dimers : Proanthocyanidin A1 | A2 | Trimers:Cinnamtannin B1 | Selligueain A | Selligueain B | Tetramers: Arecatannin A2
B type proanthocyanidins
Types
Arecatannins (Arecatannin A1 | Arecatannin A3 | Arecatannin B2 | Arecatannin C1)