What natural medicine is used for treating urine infections?

None. Sorry, no natural medicines reliably treat urinary tract infection. UTIs often clear on their own over 2-12 weeks, so if symptoms improve on a natural product, it isn't necessarily because of that treatment; or maybe not a UTI. Meantime you risk serious complications, such as kidney infection (pyelonephritis). Don't mess around with this; see a doctor for diagnosis and antibiotic prescription.