22) Osteoarthritis and Cartilage 15: December 2007


  1. Oshima D. Amiel J. Theodosakis

Purpose:Osteoarthritis (OA) is a joint disease characterized bya degenerative change of articular cartilage and underlying sub-chondral  bone  and  often  accompanied by  inflammation.  MSM,a  dietary supplement composed of  about 34% sulfur  and self-affirmed  as  GRAS  (generally  recognized  as  safe)  in  the  U.S.,is most utilized for treating osteoarthritis. A recent study by Kimet. al., OA & Cart, 2006, showed clinical effectiveness of MSMsupplementation at 3 gm BID x 12 weeks compared to placebo.The  objective  of  our  study  was  to  examine  the  effect  of  MSMat  varying  concentrations  on  cultured  human  healthy  and  os-teoarthritic chondrocytes in vitro with  a focus  on catabolic andanabolic markers.Methods:Human cartilage tissues were obtained from 22 knees,72 hrs postmortem from donors with different grades of OA. Weused the Outerbridge classification (Grades I – IV), Grade I forintact surface; Grade II for minimal fibrillation; Grade III for overtfibrillation;  and  Grade  IV  for  erosion  of  the  articular  cartilagesurface.  Following  gross  assessment  of  the  donor  knees,  thefollowing  knees  were  studied  for  Grade  I  (n=6)  (aged  23-38);Grade  II  (n=9) (aged 50-77); for  Grade  III  (n=5) (aged 32-70);and  Grade  IV  (n=2)  (aged  70-93).  Cartilage  tissues  were  har-vested from femoral condyles and tibial plateaus, the matrix wasdissolved with collagenase; the chondrocytes were then culturedfor 2 weeks in culture media without MSM. After reaching con-fluence, the chondrocytes were harvested and 2 x 105cells in10 ml culture medium with varying concentrations of MSM (0, 1,3, 6, 12, and 60μg/ml) were cultured in 100 mm (in-diameter)plates at 37°C in 5% CO2for 3 days. The concentrations wereestimated  to  correspond  to  human,  oral  dosing  at  between  0and  30  grams  of  MSM  per  day.  mRNA  expression  of  variousmarkers by RT-PCR including: TNF-alpha, IL-1, MMP-1, MMP-3,and MMP-13 was also determined for each OA grade and eachconcentration of MSM or control. Anabolic pathways examinedincluded  proteoglycan  synthesis  (by  a  pulse  chase  analysis  of35SO4  incorporation)  and  chondrocyte  mRNA  expressions  ofType-II  collagen  and  aggrecan.  A  one-way  ANOVA  was  per-formed to establish the level of statistical significance.Results:In Grade II OA chondrocytes treated with MSM at theconcentration  of  12μg/ml,  there  was  a  strong  trend  for  MSMto reduce the mRNA expression of inflammatory markers: TNF-alpha (-33%, p=0.08) and IL-1 (-29%, p=0.08) when compared tolower concentrations of MSM and control. These results did notapply for OA chondrocytes of Grade III or IV. MSM did not showan increase in proteoglycan synthesis in cultured chondrocytesor  an  increase  of  cartilage  matrix  production  in  normal  andosteoarthritic chondrocytes at the mRNA level.Conclusions:MSM  might  have  an  ability  to  protect  articularcartilage in early OA by reducing expression of inflammatory cy-tokines, i.e. TNF-alpha & IL-1. The effective concentration of 12μg/ml MSM correlates with the dosage used in a recent clinicaltrial.