Improvement of OA (test in human)
In a normal knee joint, the "articular cartilage" at the edge of the femur and the tibia work as a cushion, and its main component; type II collagen plays an important role. However, when a knee joint suffered osteoarthritis(OA), degradation of components of the articular cartilage caused by injury or aging that are associated with meniscus injury or ligament rupture leads to abrasion and collapse of the cartilage, and eventually it causes outgrowth of bones around the joint (osteophyte formation) and disorder of joint functions (decreasing of sliding and cushioning functions), with accompanying synovitis.
In contrast, we verified the effect on reduction of cartilage destruction in OA by oral ingestion of CTP-containing collagen by using OA model rabbit. Accordingly, we expected the same effect (reduction of various symptoms of human OA) through oral ingestion of CTP-containing collagen. We performed a clinical trial on some patients of OA based on "Japanese Knee Osteoarthritis Measure (JKOM)" and "findings by a doctor".
Test for promotion of healing of OA in human
1) Methods
From 120 Japanese men and women having knee pain at the age of 35 to 70, 95 people were chosen in the primary screening (whose RA test results were negative and also JKOM evaluation score were relatively high). In the secondary screening, 66 people from this group were chosen based on findings by a doctor. Those subjects were assigned to 3 groups (according to test samples : placebo, 2g of CTP-containing collagen, and 4g of CTP-containing collagen) so that each group had approximately the same average age and score of JKOM evaluation, and they took specified samples once a day for 10 successive weeks. The evaluation was performed according to JKOM evaluation scores (questionnaire survey to subjects) and findings by a doctor before and 5 weeks/10weeks after the sample ingestions.
2) Results
All 3 groups improved their scores in every item including "Level of knee pain (Indicated by Visual Analogue Scale called VAS)" in JKOM evaluation after 10 weeks. The 2 g CTP (ingestion) group showed almost the same result as the placebo group, but the 4 g CTP (ingestion) group showed superior improvement effects as in the figure below. In findings by a doctor which was regarded as a more objective evaluation, the 2 g CTP group and the placebo group showed significant reduction of "tenderness" after 10 weeks, but the 4 g CTP group had already showed this result after 5 weeks, and obtained further improvement after 10 weeks. Regarding "existence state of hydropst", there was no change in the placebo group, but there were significant improvements in the 2 g CTP group after 5 and 10 weeks and in the 4 g CTP group after 10 weeks. Also, in �Friction sound�, significant improvements were found only in the 2 g and the 4 g CTP groups after 5 and 10 weeks. That is to say, we could observe a significant difference between the placebo and the CTP-containing collagen groups.
Figure) The ratio of each score against 0 week (before ingestion of CTP-containing collagen)
3) Discussion
As a result of the clinical trial in humans targeted at OA patients, in JKOM evaluation, we found that the 4g CTP group had superior improvement effects than the placebo group even though the placebo brought unexpected effects. In findings by a doctor, the 2g CTP and the 4g CTP groups showed apparently improving effects in comparison with the placebo group. Therefore, it was confirmed that CTP-containing collagen could help improvement of OA.
