First, a lot of people here claim that AC is safer because of muscle reaction i.e. that one has some time to let go, whereas with DC this wouldn't be possible.
This is true, but having a current running through your body for some time isn't directly going to kill you. It depends on the time and magnitude of the current and on the path it takes.
Generally, the body can manage DC currents for longer than AC currents with the same peak value. Why? Because of ventricular fibrillation. At 60Hz, this is very likely to occur, and also the cause of death when looking at current levels far below the 'instant fry' level. Have a look at IEC60479.
For much higher (kHz) range frequencies, the situation changes in favor of AC, due to the fact that the current will choose to flow on the surface of the body and not through it. It will still give you nasty burns, but you're much more likely to survive. .................
For the 380V choice, it is advantageous wrt to 48V because of efficiency; Modern medium to high power supplies are mostly made with a boost PFC, upconverting the voltage to a DC bus of around 400-500V, followed by some kind of bridge converter (forward, ahb, LLC). Now, we can take out the PFC stage and rectifier, and also simplify the EMI filter stage - this will take out somewhere around 5% of the loss power while reduce power supply cost and increasing reliability.