Hi. I am not sure to what extent acne scars will improve with natural remedy. But some people 'claim' to have some glow on face with mashed fruit packs, egg white packs and yogurt on face. While these may provide some feel good feel to the skin, I have no scientific studies to prove their benefit in acne scars.
More often acne scars require specific creams and more importantly procedures for definitive treatment. It's like poth holes on the road. Sweeping the road may make it look clean but to have a levelled road you need to fill it with tar. Just the same way, to treat scars you'll need definitive procedures.