Dual Mechanisms of Plant-Derived Phytochemicals in Renal Protection and Tissue Remodeling

Abstract

The dual therapeutic mechanisms of plant-derived phytochemicals—specifically flavonoids, saponins, tannins, and alkaloids—in both renal protection against drug-induced injury and tissue remodeling through collagen synthesis. The central hypothesis posited that these compound classes exert organ-specific effects through overlapping molecular pathways, including antioxidant, anti-inflammatory, and anti-apoptotic signaling, while also modulating extracellular matrix dynamics. Our results demonstrated that flavonoids and saponins primarily protect against nephrotoxicity induced by cisplatin, gentamicin, and doxorubicin through suppression of oxidative stress (e.g., reduced malondialdehyde, restored superoxide dismutase and glutathione), inhibition of tumor necrosis factor-alpha and nuclear factor-kappa B signaling, and modulation of caspase-3 and Bax/Bcl-2 ratio. However, a critical counterexample emerged: certain flavonoids, such as tangeretin and nobiletin, inhibited the multidrug and toxin extrusion protein 1 transporter, thereby reducing renal cisplatin excretion and exacerbating nephrotoxicity in vivo. For tissue remodeling, tannins (e.g., ellagitannins from Phyllanthus muellerianus) stabilized collagen and stimulated fibroblast activity, while saponins, particularly ginsenosides, enhanced type I collagen synthesis through Smad signaling and promoted wound contraction in rat models. Alkaloids played a supportive anti-inflammatory and antimicrobial role, though direct evidence for collagen quantification was limited. This work contributes a mechanistic framework for the dual applications of phytochemicals, highlighting both therapeutic potential and context-dependent risks, thereby informing future development of plant-based strategies for nephroprotection and wound healing.