No italics are necessary in your example. You're making a direct quote of the verse and its translation.
It would be right to italicise a foreign word when it's used as though it were an English word, say in something like
In this book, one pāda goes "Vadhikaraste ma phaleshu" or "It is your duty to help others."
...and in that case, where you are italicising Sanskrit, you could italicise the Sanskrit phrase.
[I'm not sure that pāda is the right word, but it serves the purpose for this answer. The phrase "Karmanye vadhikaraste Ma Phaleshu Kadachana" consisting of two pādas appears in the Bhagavad Gita. If there's a better word please feel free to edit it in.]