Bioavailable constituents/metabolites of pomegranate (Punica granatum L) preferentially inhibit COX2 activity ex vivo and IL-1beta-induced PGE2 production in human chondrocytes in vitro

Shukla M, Gupta K, Rasheed Z, Khan KA, Haqqi TM · Journal of Inflammation (London)

Tests whether anything that reaches the blood is still active. Ellagic acid appeared in plasma 2 hours after a 34 mg/kg dose, the equivalent of 175 mL of juice. Post-dose plasma cut IL-1β-induced PGE2 and nitric oxide in chondrocytes where pre-dose plasma did not, and inhibited COX-2 by 38.8% against 12.3% for pre-dose plasma. COX-1 inhibition was 21.5% against 14.9%; the results text calls that significant and the figure legend says COX-1 was not, so the selective-for-COX-2 claim rests on the larger COX-2 number.

Population

Six rabbits, four dosed and two controls; plasma taken before and 2 hours after oral pomegranate extract and applied to rabbit chondrocytes and to purified COX enzymes

Intervention

Plasma collected after oral pomegranate fruit extract

Comparator

Plasma collected before dosing

Limitations

Rabbit plasma and rabbit chondrocytes, not human, despite a title that says human chondrocytes; an ex-vivo readout that shows bioactive material circulates after a dose, not that a joint is protected. NIH-funded.