In vitro studies have shown the antimicrobial effects of green tea catechins and their synergistic effects with trimethoprim–sulfamethoxazole against Escherichia coli. Green tea is made from non-fermented leaves of Camellia sinensis L. It has anti-inflammatory, antiarthritic, antibacterial, antiangiogenic, antioxidative, antiviral, and neuroprotective effects. A recent study, published in Complementary Therapies in Clinical Practice, assessed the efficacy of green tea as an adjunctive therapy to standard antimicrobial treatment in women with acute uncomplicated cystitis. This was a blinded randomized trial wherein 70 patients received four 500 mg capsules of green tea or starch (placebo) daily for three days along with trimethoprim–sulfamethoxazole. The presence of acute uncomplicated cystitis symptoms was recorded and urinalysis was performed. Women in the green tea group had a statistically significant reduction in the prevalence of cystitis symptoms and a statistically significant improvement in the urinalysis results after 3 days of treatment. Green tea was found to be an effective adjunctive treatment option to trimethoprim–sulfamethoxazole in treating acute uncomplicated cystitis in women.

Majority of the health benefits of green tea are attributed to its polyphenolic compounds, especially catechins. There is a need to look for medicinal plants to treat UTIs as many women with UTIs prefer home remedies and do not seek medical help immediately. Green tea seems to be one such herb with potential benefit in treating acute uncomplicated cystitis.