COX-2 enzymes are normally found in the immune cells (eg. neutrophils,
macrophages, immuno-globulins, T-cells, Natural-Killer cells, etc.) &
inflammatory cells (eg. mast cells, platelets, etc). BUT they also
exist in the kidneys, and are induced by low-sodium levels or
sodium-loss (as in Addison's Disease) and/or the use of
ACE-inhibitors, as by hypertensives. Do the natural COX-2 inhibitors,
as found in in plant & herbal sources like Vits. E & C, flavonoids,
bromelain, ginger, salicylates, curcumin, resveratrol, genistein,
kaempferol, quercetin, rescorcinol, boswellia, & Devil's Claw REDUCE
RENAL FUNCTION(S)by inhibiting the COX-2 enzymes that exist in the
kidneys, or are these COX-2 enzymes specific to the kidneys impervious
or insensitive to these inhibitors?

You may want to raise your price. You're asking for a great deal here,
and a $5 fee isn't likely to attract the medically-savvy professional
researchers.

Any drug which inhibits cox-2 in the inflammatory cells will also
inhibit it in the kidney, thus raising the spectre of renal failure. 
This is also true for the mixed cox-1/cox-2 inhibitors such as aspirin
(or willow bark for that matter), ibuprofen, naproxen, etc...

I was unable to find any specific studies on the substances that you
mention with regard to cox-2/renal failure.

synarchy

Patients with the problems I mentioned (Addison's Disease, Na-loss or
salt-restricted diet or ACE-inhibitors) are routinely warned not to
take COX-2 inhibitors, but all those natural sources of COX-2
inhibitors I mentioned are NOT proscribed, & neither do their
monographs contain any such caveats or restrictions.  If anything,
hypertensives on low-Na diets do quite well on many of these
naturally-sourced phyto-compounds. So, why don't their COX-2
inhibitory properties shut down renal functions? I'm not after
educated guesses here, but some hard evidence (preferably in the form
of radomised-placebo-controlled clinical  trial data) as to whether
anyone has found them to be harmful to the kidneys of people in this
sub-category. [As for broad-spectrum, non-specific COX-1&2 inhibition,
we already know WHATEVER the circumstances, they are highly
gastro-duodeno-toxic & renal-compromising (COX-1 MAKES PGE2 which
regulates renal perfusion and gastro-dudeno mucosal maintenance)].
I'll up the ante to 20 bucks if anyone has the right answer for me.