1. Osteoarthritis (OA) is the most common type of degenerative
joint disease. It is characterised by pain and decreased
mobility1.
It results from injury to articular cartilage. Articular cartilage
functions as a load bearer and prevents friction between joints,
allowing pain-free movement. It has a complex structure and
organisation that allows it to perform its functions1,2.
Cartilage has an abundant extracellular matrix (ECM) with
minimal cells, no direct vascular, neural and lymphatic supply.
This reduces the capacity for self-repair.
It is divided into superficial, middle, deep and calcified zones.
Each zone has its identifiable cell organisation, water and
extracellular matrix molecule content and mechanical
properties. Thus, making it difficult to mimic using tissue
engineering as a form of treatment2.
There is currently no cure. Current treatments like NSAIDs only
alleviate pain but have adverse side effects. Consequently a
natural occurring compound that has anti-inflammatory
properties with minimal side effects is required for treating OA3.
Genistein, a soy isoflavone has anti-inflammatory properties.
This summarises the potential action of genistein in articular
cartilage. Anti-inflammatory effects of genistein have been
shown in several studies. Genistein might be the relevant
compound as a potential treatment for OA3,4.
• Investigate the effect of genistein on tissue regeneration of
articular chondrocytes
• Investigate the role of genistein on accumulation of collagen
type II in articular chondrocytes
Gratitude to Tshwane University of Technology for their financial contribution, Mrs F. Bierman for technical assistance,
Prof F Dakora for the donation of compound and fellow post-grads for support.
Figure 3: Stained histology sections of articular
cartilage from the medial condyle of a 3-month old
pig reveal the size and arrangement of
chondrocytes. Magnification (5x). Scale bar 200 μM.
Figure 1: Schematic representation of the experimental design
Figure 5: Apoptotic effects of genistein on
chondrocytes from the superficial and middle zone.
The cells are distributed into Viable (N), Necrotic
(N), Early apoptotic (EA) and Late apoptotic stages.
The high viability correlated with cell toxicity results
done with Xcelligence system (not shown).
Figure 1:
1.PAETZOLD, H., GOEPFERT, C., HUBER, G., HOENIG, E., PORTNER, R., SCHILLING, A.F., MEENEN, N.M. & MORLOCK, M.M. 2012. The development
of the collagen fibre network in tissue-engineered cartilage constructs in vivo. Engineered cartilage reorganises fibre network. European Cells & Materials, 23
2. MOTAUNG, S.C.K.M, DI CESARE, P.E. & REDDI, A.H. 2011. Differential response of cartilage oligomeric matrix protein (COMP) to morphogens of bone
morphogenic protein/transforming growth factor- β family in the surface, middle and deep zones of articular cartilage. J Tissue Eng Med, 5
3.KUMAR, S. & PANDEY, A.K. 2013. Chemistry and biological activities of flavonoids: An overview. The Scientific World Journal, doi:10.1155/2013/162750
4.TADAISHI, M., NISHIDE, Y., TOUSEN, Y., KRUGER, M.C. & ISHIMI, Y. 2014. Cooperative effects of soy isoflavones and carotenoids on osteoclast
formation. J. Clin. Biochem. Nutr., 54(2)
Even though genistein cannot be claimed to cure OA, the bioactivity and safety
of this compound revealed in this study is appealing. It was found that collagen
type II in the superficial zone was up-regulated by 5, 15 and 25 ᶙM, while the
middle zone was up-regulated by 15 ᶙM genistein. Genistein revealed its
biphasic effect on the expression of collagen type II in articular chondrocytes
and its possible potential role in osteoarthritis. Future investigations include the
combination of TGF-β3 and IL-β1 with genistein in a 4 and 7 day study.
Figure 2: Porcine knee
collected within 24 hours
of slaughter at the local
abattoir and dissected.
Figure 4: Graphic
representation of Cell
cycle analysis of cells
from the superficial and
middle zone. The graph
indicates that most cells
are in the growth phase.