title: Protection against LPS-induced cartilage inflammation and degradation provided by a biological extract of Mentha spicata.
abstract: BACKGROUND
  A variety of mint [Mentha spicata] has been bred which over-expresses Rosmarinic acid (RA) by approximately 20-fold. RA has demonstrated significant anti-inflammatory activity in vitro and in small rodents; thus it was hypothesized that this plant would demonstrate significant anti-inflammatory activity in vitro. The objectives of this study were: a) to develop an in vitro extraction procedure which mimics digestion and hepatic metabolism, b) to compare anti-inflammatory properties of High-Rosmarinic-Acid Mentha spicata (HRAM) with wild-type control M. spicata (CM), and c) to quantify the relative contributions of RA and three of its hepatic metabolites [ferulic acid (FA), caffeic acid (CA), coumaric acid (CO)] to anti-inflammatory activity of HRAM.
  
  
  METHODS
  HRAM and CM were incubated in simulated gastric and intestinal fluid, liver microsomes (from male rat) and NADPH. Concentrations of RA, CA, CO, and FA in simulated digest of HRAM (HRAMsim) and CM (CMsim) were determined (HPLC) and compared with concentrations in aqueous extracts of HRAM and CM. Cartilage explants (porcine) were cultured with LPS (0 or 3 microg/mL) and test article [HRAMsim (0, 8, 40, 80, 240, or 400 microg/mL), or CMsim (0, 1, 5 or 10 mg/mL), or RA (0.640 microg/mL), or CA (0.384 microg/mL), or CO (0.057 microg/mL) or FA (0.038 microg/mL)] for 96 h. Media samples were analyzed for prostaglandin E2 (PGE2), interleukin 1beta (IL-1), glycosaminoglycan (GAG), nitric oxide (NO) and cell viability (differential live-dead cell staining).
  
  
  RESULTS
  RA concentration of HRAMsim and CMsim was 49.3 and 0.4 microg/mL, respectively. CA, FA and CO were identified in HRAMsim but not in aqueous extract of HRAM. HRAMsim (> or = 8 microg/mL) inhibited LPS-induced PGE2 and NO; HRAMsim (> or = 80 microg/mL) inhibited LPS-induced GAG release. RA inhibited LPS-induced GAG release. No anti-inflammatory or chondroprotective effects of RA metabolites on cartilage explants were identified.
  
  
  CONCLUSIONS
  Our biological extraction procedure produces a substance which is similar in composition to post-hepatic products. HRAMsim is an effective inhibitor of LPS-induced inflammation in cartilage explants, and effects are primarily independent of RA. Further research is needed to identify bioactive phytochemical(s) in HRAMsim.
authors.affiliation: Dept Plant Agriculture, University of Guelph, Ontario, Canada. wpearson@ovc.uoguelph.ca
authors.forename: Wendy
authors.initials: W
authors.lastname: Pearson
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Fletcher
authors.forename: Laima S
authors.initials: LS
authors.lastname: Kott
authors.forename: Mark B
authors.initials: MB
authors.lastname: Hurtig
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D001947:Breeding; D002109:Caffeic Acids / Q000494:pharmacology; D002356:Cartilage / Q000187:drug effects* / Q000378:metabolism; D002934:Cinnamates / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D003373:Coumaric Acids / Q000494:pharmacology; D053630:Depsides / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D004063:Digestion; D015232:Dinoprostone / Q000378:metabolism; D005750:Gastric Juice; D005838:Genotype; D006025:Glycosaminoglycans / Q000378:metabolism*; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000517:prevention & control*; D008070:Lipopolysaccharides; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D031337:Mentha spicata / Q000737:chemistry* / Q000235:genetics; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D009249:NADP; D009569:Nitric Oxide / Q000378:metabolism; D010936:Plant Extracts / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D012639:Seeds; D013552:Swine; D000097123:Rosmarinic Acid
chemical_list: D000893:Anti-Inflammatory Agents; D002109:Caffeic Acids; D002934:Cinnamates; D003373:Coumaric Acids; D053630:Depsides; D015232:Dinoprostone; D006025:Glycosaminoglycans; D008070:Lipopolysaccharides; D009249:NADP; D009569:Nitric Oxide; D010936:Plant Extracts; D000097123:Rosmarinic Acid; C020341:glucosaminoglycans; C004999:ferulic acid; C040048:caffeic acid
references.citation: Mol Nutr Food Res. 2007 Aug;51(8):1020-30
references.pmid: 17639996
references.citation: Transplantation. 2003 May 27;75(10):1758-60
references.pmid: 12777871
references.citation: Pak J Biol Sci. 2007 Feb 15;10(4):637-40
references.pmid: 19069549
references.citation: Nahrung. 2003 Aug;47(4):261-4
references.pmid: 13678266
references.citation: Z Naturforsch C J Biosci. 2006 May-Jun;61(5-6):351-6
references.pmid: 16869492
references.citation: J Vet Pharmacol Ther. 2007 Dec;30(6):523-33
references.pmid: 17991220
references.citation: J Photochem Photobiol B. 2006 Sep 1;84(3):167-74
references.pmid: 16631374
references.citation: Bosn J Basic Med Sci. 2008 Aug;8(3):254-8
references.pmid: 18816259
references.citation: Toxicol In Vitro. 2009 Apr;23(3):386-92
references.pmid: 19159670
references.citation: Drug Metab Dispos. 2004 Jun;32(6):647-60
references.pmid: 15155557
references.citation: Phytother Res. 2004 Jul;18(7):561-5
references.pmid: 15305317
references.citation: Curr Drug Metab. 2006 Aug;7(6):661-75
references.pmid: 16918318
references.citation: Ceska Slov Farm. 2007 Jul;56(4):165-73
references.pmid: 17969314
references.citation: Eur J Med Chem. 2009 Jan;44(1):312-21
references.pmid: 18423943
references.citation: Life Sci. 2004 Jan 9;74(8):935-68
references.pmid: 14672753
references.citation: Antimicrob Agents Chemother. 2007 Sep;51(9):3367-70
references.pmid: 17576830
references.citation: Osteoarthritis Cartilage. 2008 Apr;16(4):489-97
references.pmid: 17923423
references.citation: Free Radic Res. 2005 Sep;39(9):995-1003
references.pmid: 16087481
references.citation: Nat Prod Res. 2007 Nov;21(13):1133-44
references.pmid: 17987492
references.citation: Phytomedicine. 2004 Sep;11(6):490-7
references.pmid: 15500259
references.citation: Free Radic Res. 2006 Feb;40(2):223-31
references.pmid: 16390832
references.citation: J Vet Pharmacol Ther. 2008 Jun;31(3):268-71
references.pmid: 18471150
references.citation: Life Sci. 2004 May 28;75(2):165-78
references.pmid: 15120569
references.citation: Eur J Med Res. 1998 Dec 16;3(12):539-45
references.pmid: 9889172
references.citation: Am J Vet Res. 2008 Dec;69(12):1560-8
references.pmid: 19046001
references.citation: Mol Cells. 2008 Dec 31;26(6):583-9
references.pmid: 18799930
references.citation: Food Chem Toxicol. 2001 Sep;39(9):907-18
references.pmid: 11498267
references.citation: Mutat Res. 2008 Dec 8;657(2):150-4
references.pmid: 18926924