Have you looked at wikipedia yet? (many of these articles are available translated into other languages if you don't want to read the English versions), look on the Wikipedia sidebar to the left of the article.
Interleukin 6 - Interleukins help regulate a bunch of inflammatory and immune responses. IL6 in particular is involved in the fever response and helps promote bone remodelling by osteoclast induction. It doesn't seem to have a direct effect or major role in depression or mood.
Angiotensin-converting enzyme - is an enzyme that helps convert angiotensin I to its active form, angiotensin II, which is a vasoconstrictor and increases blood pressure. Drugs that inhibit that enzyme ("
ACE inhibitors") help reduce blood pressure and are a popular treatment in the USA for congestive heart failure. Not much direct impact on mood here.
Oxytocin receptor /
Oxytocin - oxytocin is a hormone that helps mediate social bonding and empathy, and is involved in human group dynamics (feelings of care, love, kindness). I don't think it's directly related to depression or mood exactly but it does have an effect on social interactions and peer bonding. It's also a hormone that is released in labour to help the uterus contract and expel the baby. It's suspected that part of why MDMA and its analogues cause empathy is oxytocin release through 5HT1
A receptor activation, and also why partial 5-HT1
A agonists like
buspirone help social anxiety/fear reduction, to an extent. By no means is it a miracle cure though, but it's significant enough of an effect to be recommended as a treatment for some conditions.
I must warn you that if this thread degenerates into you ignoring everything anyone says and simply playing "20 Dumb Biochemistry Questions" I'm going to close it up. If you're looking for a miracle drug to turn your life around and magically switch the "gene for depression" off then you're wasting your time. I'm not going to have this become a repeat of the last thread.