Green tea affects thermogenesis via synergistically acting in concert with its caffeine content, and the addition of 300mg EGCG to 200mg caffeine can increase the thermic response to food more than 200mg caffeine.  Caffeine is able to increase noradrenaline levels in the body, which is synergistic with EGCG's ability to inhibit the enzyme catechol-o-methyl transferase (COMT)  which degrades catecholamines like noradrenaline  and methylates polyphenols. The end result of the pairing is higher levels of catecholamines induced by caffeine, and this synergism seems to be equipotent at various dosages of EGCG.  Caffeine also inhibits the phosphodiesterase enzyme, which degrades cAMP. It appears that this pathway (catechol-o-methyltransferase inhibition) may be active in vivo . 
Based on the mechanism of action, the use of prostaglandin-mediated NSAIDs, including Celebrex, may delay or prevent rupture of ovarian follicles, which has been associated with reversible infertility in some women. Published animal studies have shown that administration of prostaglandin synthesis inhibitors has the potential to disrupt prostaglandin mediated follicular rupture required for ovulation. Small studies in women treated with NSAIDs have also shown a reversible delay in ovulation. Consider withdrawal of NSAIDs, including Celebrex, in women who have difficulties conceiving or who are undergoing investigation of infertility.