Green tea polyphenol treatment is chondroprotective, anti-inflammatory and palliative in a mouse post-traumatic osteoarthritis model

Leong DJ, Choudhury M, Hanstein R, Hirsh DM, Kim SJ, Majeska RJ, Schaffler MB, Hardin JA, Spray DC, Goldring MB, Cobelli NJ, Sun HB · Arthritis Research & Therapy

Structure and pain measured in the same animals, six per group. At 4 and 8 weeks the EGCG mice had less Safranin O loss, less cartilage erosion and lower OARSI scores (2.1 against 6.5 at 8 weeks), with reduced aggrecan and type II collagen cleavage epitopes and reduced MMP-13 and ADAMTS5 staining in articular cartilage, plus lower MMP-1, -3, -8, -13, ADAMTS5, IL-1β and TNF-α mRNA. Of the three pain readouts, only distance travelled in the open field recovered; rearing and von Frey tactile sensitivity did not differ from vehicle.

Population

C57BL/6 mice after destabilization of the medial meniscus or sham surgery

Intervention

EGCG 25 mg/kg daily by intraperitoneal injection for 4 or 8 weeks

Comparator

Vehicle

Limitations

Delivered by intraperitoneal injection, not by drinking, so it bypasses the absorption question entirely. A 2019 correction replaced two figure panels, and in 2022 the US Office of Research Integrity found that the senior author had falsified data in NIH grant applications, in part by reusing and relabelling image panels from this paper; the paper itself has not been retracted. Funded by NIAMS and the Arthritis Foundation.