[Lotus]

I like astaxanthin, it's stronger antioxidant than CoQ10, just don't take it with saw palmetto or you might be lowering estrogen. Btw, most carentoids inhibit 5 alpha reductase...(as well), red pigmented fruits and vegetables inhibit 5 alpha reductase.

As listed, second messengers improve the biosynthesis of hormones, so does ATP (Adenosine triphosphate, and Astaxanthin works quite well for this ), G protein-coupled estrogen receptors (GPER), activation of GPER comes from estrogen, which is the result of adenylyl cyclase and cAMP-dependent signaling.

Astaxanthin inhibits DHT, free radicals, cancer, radiation, diabetes and protects DNA.. Maybe 8-12 mg is too much, the study demostrated (in vitro) .3 mg was to inhibit DHT @ 99% (type II most likely). I found in further studies that astaxanthin inhibits DHT while promoting T. In other words, an ideal scenario for pro-aromatase (increased estrogen), though incombination with a pro-aromatase. So, maybe 2mg -4mg would be a good starting dose. 

A preliminary investigation of the enzymatic inhibition of 5alpha-reduction and growth of prostatic carcinoma cell line LNCap-FGC by natural astaxanthin and Saw Palmetto lipid extract in vitro.

J Herb Pharmacother. 2005;5(1):17-26.
Abstract
Inhibition of 5alpha-reductase has been reported to decrease the symptoms of benign prostate hyperplasia (BPH) and possibly inhibit or help treat prostate cancer. Saw Palmetto berry lipid extract (SPLE) is reported to inhibit 5alpha-reductase and decrease the clinical symptoms of BPH. Epidemiologic studies report that carotenoids such as lycopene may inhibit prostate cancer. In this investigation the effect of the carotenoid astaxanthin, and SPLE were examined for their effect on 5alpha-reductase inhibition as well as the growth of prostatic carcinoma cells in vitro. These studies support patent #6,277,417 B1. The results show astaxanthin demonstrated 98% inhibition of 5alpha-reductase at 300 microg/mL in vitro. Alphastat, the combination of astaxanthin and SPLE, showed a 20% greater inhibition of 5alpha-reductase than SPLE alone n vitro. A nine day treatment of prostatic carcinoma cells with astaxanthin in vitro produced a 24% decrease in growth at 0.1 mcg/mL and a 38% decrease at 0.01 mcg/mL. SPLE showed a 34% decrease at 0.1 mcg/mL.
CONCLUSIONS: Low levels of carotenoid astaxanthin inhibit 5alpha-reductase and decrease the growth of human prostatic cancer cells in vitro. Astaxanthin added to SPLE shows greater inhibition of 5alpha-reductase than SPLE alone in vitro.

PMID 16093232 [PubMed - indexed for MEDLINE]

Anti-cancer potential of flavonoids: recent trends and future perspectives
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3824783/