Phytochemical profiling of ethanolic fractions from the stem and root of Tradescantia pallida (Rose) D.R.Hunt by HPLC-DAD and evaluation of their nephroprotective effects against cisplatin-induced nephrotoxicity in Wistar rats

Cisplatin is a potent chemotherapeutic drug that is clinically utilised but is limited by dose-dependent nephrotoxicity linked to oxidative stress, inflammation and apoptosis. Tradescantia pallida (Rose) D.R. Hunt is a medicinal plant with high polyphenolic content, but its nephroprotective activity against renal toxicity induced by cisplatin has not been extensively studied. The aim of the study was to establish the bioactive compounds of the separate ethanolic fractions of stem and root of T. pallida by high-performance liquid chromatography with diode-array detection (HPLC-DAD) and to assess the nephroprotective activity of the fractions in a rat model of cisplatin-induced nephrotoxicity. In the phytochemical identification, the retention time and the UV spectra of the identified compounds were compared to those of the authenticated reference standards, catechin, esculetin, p-coumaric acid, ferulic acid, morin, cyanidin and luteolin. Cisplatin was used to induce nephrotoxicity and the animals were given single dose of the stem or root ethanolic fractions apart, with the reference drug being silymarin. To study the nephroprotective activities of both parts of the plants against the renal injury caused by cisplatin, the renal function biomarkers and histopathological changes were evaluated. In the root fraction, five major compounds were identified: catechin, esculetin, p-coumaric acid, ferulic acid and morin. In the stem fraction, seven major compounds were identified: five of which were also detected in the root fraction, in addition to luteolin and cyanidin. Good linear relationships (R² > 0.999) were obtained for the calibration curves. Serum creatinine and blood urea levels were reduced significantly after treatment with T. pallida fractions and renal histopathological damage was remarkably ameliorated. The results suggest that the nephroprotective effect of T. pallida might be linked to its polyphenolic compounds, which in combination have an overall antioxidant, anti-inflammatory and anti-apoptotic impact on cisplatin-induced oxidative stress, inflammation and apoptosis. In general, the ethanolic fractions of the stem and root showed good nephroprotective activity with the decrease in elevated renal function markers and decrease in histopathological damage after cisplatin treatment.