Inhibition of cartilage degradation and suppression of PGE2 and MMPs expression by pomegranate fruit extract in a model of posttraumatic osteoarthritis

Akhtar N, Khan NM, Ashruf OS, Haqqi TM · Nutrition

A whole-animal result, and oral rather than injected. Total histological score improved in both fed groups (P < 0.01), though the individual scores behind it — Safranin-O loss, structural change, chondrocyte clustering — separated only in the rabbits fed from two weeks before surgery. In both fed groups, cartilage MMP-3, MMP-9 and MMP-13 mRNA fell, aggrecan and COL2A1 mRNA rose, and synovial-fluid IL-6, MMP-13 and PGE2 were lower; plasma PGE2 was not. Synovial IL-1β rose with surgery and the extract did not move it. Apoptosis markers were read off immunostaining without a reported test.

Population

27 male New Zealand White rabbits, 8 months old: six per group with surgically transected anterior cruciate ligaments and three per group sham-operated

Intervention

Whole-fruit pomegranate ethanolic extract, 34 mg/kg/day in drinking water, for 8 weeks after surgery or from 2 weeks before surgery

Comparator

Water alone, and a sham-surgery group

Limitations

Rabbit post-traumatic OA, 8 weeks, six animals per operated group, compared with unpaired t-tests across many endpoints without correction for multiplicity. Both dosing schedules are preventive — the extract started at surgery or before it, and the authors say a trial giving it to an already-damaged joint is the one still missing. From the laboratory that produced most of the pomegranate chondrocyte literature, funded by the National Institutes of Health and the university rather than by a producer. The discussion generalises the histology result to both fed groups where the results section names one, and 34 mg/kg/day of a whole-fruit extract in water is not calibrated to any human intake.