Quercetin is not associated with PPH, to the best of my knowledge. Rather, it’s dasatanib, which is a prescription drug used primarily in the treatment of cancer. Dasatnib is an oral oral Brc Abl tyrosine kinase inhibitor. It was U.S. FDA approved in 2006, however because of its high cost, there is not a lot of experience with it.
I don’t know if dasatanib+quercetin will be effective in humans at doses that are “safe”, or even if reducing the burden of senescent cells will extend lifespan. However, as you point out, it is likely that reducing the number of senescent cells will improve the health-span. Moreover, if this combo works topically, or as an oral-topical combination then it may substantially rejuvenate the skin. Senescent and hyperplasia cells in skin are a major cause of skin aging. I suppose I should patent this idea, because whoever develops AND successfully markets the first truly effective skin anti-aging cream/nostrum is going to be richer than Bill and Melinda Gates, LOL! Photodamaged cells form large colonies of both senescent and actinic (hyperplastic) cells. A recently developed UV photography technique shows just how bad, how early, and how nearly invisible this pathology is:
There are several treatments to eliminate the actinic fraction of these photodamaged areas, most notably the cytotoxic chemotherapeutic agent 5-fluorouracil, administered as a 5% cream. The 5-FU causes inflammatory necrosis of the actinic cells, as can be seen in the photos below:
This red, raw inflammatory response starts after a few days of application. The recommended duration of treatment is 3-4 weeks and the redness persists for a couple of weeks following the cessation of Tx. Once Tx is complete, the risk of skin cancer is greatly reduced, most of the hyperpigmented, freckled, liver-spotted areas are gone, and the skin generally looks much younger. However, you have to go around looking like the people in the photos above for onto two months: http://ift.tt/1EMJTw1 to say, many patients simply refuse to have this Tx! [As a relevant aside, age spots or liver spots are NOT due to lipofuscin containing cells, nor are they remediated by centrophenoxine.]
There is another Tx for actinic keratosis which does not cause this inflammatory response, imiquimod, which is a topical medication that up-regulates a variety of cytokines that provoke a nonspecific immune response (interferons, natural killer cells) and a specific immune response (T cells). It is applied 2-3 times a week for up to 4 months, although generally one month of Tx is sufficient, with the notable downside being that it costs about $800 for a course of treatment.
If you look at the photos above, it makes you wonder what the interior of our aging/aged bodies look like with respect to senescent cells. It should also give pause to the systemic application of dasatinib+quercetin without first evaluating the effect of inducing apoptotic death in a significant fraction of the body’s cells locally. This is in part why I suggest a cutaneous trial, first.
Since I discovered the ability of imiquimod to selectively destroy actinic cells in the skin, I’ve thought about the possibility of finding a way to do the same thing with senescent cells systemically. Dasatinib+quercetin may be the answer. Even if it can only be used topically, that may prove advantageous from a cosmetic standpoint – which is no small thing.