Saussurea costus in nanomedicine: green-synthesized metal nanoparticles and advanced nanosystems for enhanced therapeutic efficacy.

Saussurea costus (S. costus), a medicinal plant widely utilized in traditional Ayurveda, Chinese, and Tibetan medicine, is rich in pharmacologically active compounds, including sesquiterpene lactones, flavonoids, phenolics, and essential oils. Despite its reported antimicrobial, anti-inflammatory, antioxidant, anticancer, and immunomodulatory activities, clinical translation of S. costus remains hindered by its low bioavailability and off-target effects. This review explores the use of nanosystems to address these limitations and enhance the biological performance of S. costus extracts. Metal-based nanoparticles (silver, copper, palladium, magnesium oxide) and other nano-formulations, including polymeric, lipid-based, and inorganic nanoparticles, detailing their synthesis, characterization techniques, and biomedical applications. The integration of S. costus into nanosystems is shown to improve cellular uptake and facilitate prolonged release and superior therapeutic outcomes as supported by several in vitro and in vivo studies. This review highlights the incorporation of Saussurea costus into different nanosystems towards the development of effective nanotherapeutics.