Yes. A Shimano (and Shimano compatible like Microshift) 10 speed brifter would work with a Shimano 8 speed derailleur. Up until recently Shimano kept these things pretty compatible. Then in the move to 11 speed (and 10 speed on MTB gearing), everything got screwed up. Here's an article with some of the numbers:
Art's Cyclery Blog » Science Behind the Magic | Drivetrain Compatibility
You can see that Shimano 6 speed to 10 speed (road) all have the same number for derailleur ratio, which is the magic number in terms of whether the shifter will correctly work with the derailleur.