Rare ginsenosides (Rk1 > Rg5, Rh2
Ginsenosides are natural bioactive compounds extracted from ginseng plants, belonging to a class of triterpenoid saponins linked to sugar chains (Chopra et al., 2023). Based on their skeletal structures, they can be classified into dammarane type and oleanane type categories (Shi et al., 2019). To date, over 100 ginsenosides have been isolated and identified from Panax species, including both PGs and RGs. PGs are directly extracted from ginseng and are characterized by their large molecular weight, typically containing multiple sugar moieties, and low bioavailability (Gantait et al., 2020). RGs, which are usually obtained through transformation technologies such as microbial fermentation or enzymatic processing of primary ginsenosides, exhibit reduced molecular weight, enhanced lipophilicity, and significantly improved bioavailability (Fan et al., 2024). Ginsenosides are known for their anti-inflammatory and antioxidant properties, showing great potential in protecting against auditory injury. Studies have demonstrated that various PGs (such as Rh1 and Rc) can alleviate cisplatin-induced auditory damage through pathways such as antioxidant stress reduction, anti-inflammatory effects, and anti-apoptosis