Someone on the LEF forum had posted this a while ago.
 
http://tinyurl.com/yarm7t
 
Hot-water extracts from adzuki beans (Vigna angularis) stimulate not only melanogenesis in cultured mouse B16 melanoma cells but also pigmentation of hair color in C3H mice.Itoh T, Furuichi Y.  
Imuraya Confectionary Co., Ltd., Mie, Japan. chuken@imuraya.co.jp
 
A hot-water extract of adzuki was obtained by boiling beans of adzuki (Vigna angularis). This hot-water extract was fractionated using HP-20 column chromatography. Its distilled water fraction (WEx) was found to stimulate tyrosinase activity in cultured mouse B16 melanoma cells and hair color pigmentation in C3H mice. At concentrations of 1-3 mg/ml, WEx stimulated melanogenesis without inhibiting cell growth. During this effect, WEx activated tyrosinase-inducing activity in the cells, but did not activate tyrosinase, which exists at an intracellular level. In this study, WEx increased cyclic adenosine-3',5'-monophospate (cAMP) content in the cells and protein kinase A (PKA) activity, and stimulated translocation of cytosolic protein kinase C (PKC) to the membrane-bound PKC. These results suggest that the addition of WEx activates the adenylcyclase and protein kinase pathways and, as a result, stimulates melanogenesis. WEx was found to have pigmentation activity on hair color in C3H mice. It might be useful in anti-graying, protecting human skin from irradiation.
 
PMID: 15914904 [PubMed - indexed for MEDLINE]
 

 
 
Update:  
Adzuki beans may inhibit the adhesion, invasion, and metastasis of melanoma cells!
 
http://tinyurl.com/yhsay7
 
 

Quote from bmwballa   on 10/15/06 at 15:55:13:

 
LOL!  I see the next spa treatment:
"Adzuki bean soak: Soak in a luxurious tub of Adzuki beans and emerge with a golden tan!"
 

Excellent, but how are you going to get a strong enough concentration?  What did they use in the study precisely?
 
Good luck, I think it's one of the better possibilities for sure.
 
Personally, I'm gonna consume large amounts of Astralagus, and am surprised no one has tried this yet as it doesn't have the high oral risks of forskolin and at a few studies show it increases melanin.
 
Also, it's good for immunity, and tanning is intimately involved with immunity. In fact, there are strong theories that tanning is all about body immunity actually.  
 
Anybody notice any difference in their immunity while on Melanotan?  Wouldn't be surprised if it was modulate at all.

make sure to keep us up to date with your results! Sounds promising...