The only option I know of is 'user bio/username/name must not contain any invalid words", which you can put things in.
I've been trying this to filter out Arabic and Korean as well, as it seems my account follows lots of users who speak both, and it's not my target audience. It doesn't seem to work as intended a lot of the time
I wonder if a more aggressive filter option would be helpful, like 'Avoid a specific languages' and include a checkbox for the languages contained in profiles you wish to ignore.
Another problem is that for languages which are reversed from english, typing them into the box is problematic because you have to work backwards, so separating characters with comma's gives me a headache.
Here's a list if you wanna use it... after much struggling (But, it hasn't work too well for me so far)
Edit: I think, but I'm not sure, because I don't speak Arabic, but when you combine letters into words they change so you'll never see these characters individually? If anyone speaks/reads it let me know if that's the case.