Japecanga (Smilax japecanga) is a plant traditionally used in Brazilian folk medicine and in other parts of South America. Its roots have been utilized for various ailments, including as a diuretic and for supporting the urinary tract and kidney functions. The reputation of Japecanga as a kidney-supportive herb is primarily based on ethnobotanical reports and traditional knowledge passed down through generations. In these traditions, decoctions or infusions of the root are taken to help flush out the kidneys, alleviate inflammation, and manage symptoms of urinary tract infections.

Despite its longstanding traditional use, there is limited scientific research directly evaluating the efficacy or safety of Japecanga for kidney support. Most available information consists of anecdotal reports and ethnopharmacological surveys, with very few peer-reviewed studies investigating its bioactive compounds or pharmacological effects in the context of kidney health. Some preliminary investigations suggest that related Smilax species contain saponins and flavonoids with potential anti-inflammatory and diuretic properties, but these findings cannot be directly extrapolated to Japecanga without further specific research.

In summary, the use of Japecanga for kidney support is primarily justified by traditional knowledge rather than by robust scientific validation. Its efficacy and safety remain to be established by clinical studies.