Missouri Snakeroot (commonly Aristolochia serpentaria or Polygala senega, sometimes called Seneca snakeroot) has a history of use in traditional herbal medicine, particularly among Native American and early European settlers in North America. It was historically employed as a remedy for a variety of ailments, including respiratory issues, snakebites, and occasionally for kidney-related complaints.

With respect to kidney infections (pyelonephritis), the use of Missouri Snakeroot is justified primarily by tradition, not by scientific evidence. Historical texts and ethnobotanical records sometimes mention its use for "urinary troubles" or as a general tonic, but clear, consistent documentation specifically for treating kidney infections is sparse. There are no high-quality clinical studies or pharmacological data to validate its effectiveness or safety for this condition. Furthermore, some species of Aristolochia contain aristolochic acids, which are now known to be nephrotoxic (damaging to the kidneys) and carcinogenic, making their use potentially dangerous, especially for individuals with kidney issues.

In summary, Missouri Snakeroot's reputation for supporting or treating kidney infections is rooted in traditional use rather than scientific validation. Its evidence rating is low (1 out of 5), reflecting anecdotal and historical references without modern research support. Due to possible toxicity concerns, its use is generally not recommended for kidney health today.