I appreciate the reply. Each of these looks well or partially supported.
Hi I urge you to describe source material. While I am looking around this moment
Metformin
Note SHR are hypertensive mice, my perception is that there is also a normal mouse longevity pubmed PMID.
PMID 18728386
Here we show the chronic treatment of female outbred SHR mice with metformin (100 mg/kg in drinking water) slightly modified the food consumption but decreased the body weight after the age of 20 months, slowed down the age-related switch-off of estrous function, increased mean life span by 37.8%, mean life span of last 10% survivors by 20.8%,
First, SHR mice are not hypertensive: you're (understandably) confusing them with SHR rats ("SHR" in this context means "Spontaneously Hypertensive Rat"). SHR mice are a line of outbred mice derived from Swiss-derived albino mice in the former Czechoslovakia.
As to the report: as you can see in the free full text, the weights of the treated animals suddenly dropped as compared to the controls starting at the time when treatment began (Fig. 1), and ate less IAC starting shortly before (Fig. 2), so Occam's razor says that any results are likely crypto-CR. Additionally, these animals were miserably short-lived -- controls and treatment group alike (Table 3). This tells you (as many studies do) that metformin can often help miserably-short-lived animals live somewhat closer to the normal life of a genetically-intact, well-nourished, well-husbanded animal who is not living in an infested colony; it tells you nothing at all about taking on the degenerative aging process.
Deprenyl
Chronic treatment of Syrian hamsters with low-dose selegiline increases life span in females but not males.
PMID: [9258898 - corrected (MR)]]
Abstract
... Selegiline (0.05 mg/kg) significantly increased life span in female Syrian hamsters, but not in males. In contrast, MAO-B was inhibited equally in both sexes by about 40%... Female control hamsters had a shorter life span than male controls. Interestingly, this sex difference disappeared in the selegiline-treated animals. ...
If it increases lifespan in females but not males, one has to question its likely efficacy as an anti-aging intervention -- or, of course, its utility to half the population. IAC, the literature on deprenyl and lifespan is all over the place; eg, in PMID: 11104356, "Eighteen month old rats were treated with 1 mg/kg s.c. deprenyl 3 times per week for 13 months. At the age of 31 months, treated rats showed a greater mortality rate with three of 12 rats surviving, while in saline-treated control animals seven of 12 animals survived."
Please see this post on deprenyl, and this re-analysis of the DATATOP trial, which originally fueled much of the early belief that deprenyl is neuroprotective: "Selegiline treatment had independent effects as a predictor of death at 8 year follow-up with a hazard ratio of 2.54 (95% CI 1.51, 4.25) but had beneficial effects on disability with a hazard ratio of 0.363 (95% CI 0.132, 0.533) and depression with a hazard ratio of 0.372 (95% CI 0.12, 0.552)."
Entersorption
Effect of enterosorption on animal lifespan.
Frolkis VV1, Nikolaev VG, Paramonova GI, Shchorbitskaya EV, Bogatskaya LN, Stupina AS, Kovtun AI, Sabko VE, Shaposhnikov VM, Muradian KK, et al.
Author information
Abstract
Experiments were performed on Wistar male rats, starting from the 28th month of age. The effect of dietary sorbent (non coated nitrogen-containing carbon administered as 10 day courses at 1 month intervals in dosage of 10 ml/kg) on lifespan and a number of biological indices were studied. Enterosorption resulted in the increase of mean and maximal lifespan by 43 and 34% respectively....
PMID: 2479433
Somewhere in my piles of papers I have a copy of this. I last looked at it almost a decade ago, and don't recall why, but it was easy to determine that this study was meaningless and should be ignored -- so I subsequently have.