Answer
If a point charge is negative and it moves to a region of higher potential, then the electric potential energy decreases.
Work Step by Step
The expression for electric potential is $V = \frac{k~q_1}{r}$
The expression for electric potential energy is $U = \frac{k~q_1~q_2}{r}$
If the point charge $q_2$ is negative and it moves to a region of higher potential, then $U$ becomes more negative. That is, the electric potential energy decreases.
