Stem-leaf saponins from Panax notoginseng (SLSP) comprise numerous PPD-type saponins with diverse pharmacological properties; however, their role in Parkinson's disease (PD), characterized by microglia-mediated neuroinflammation, remains unclear. This study evaluated the effects of SLSP on suppressing microglia-driven neuroinflammation in experimental PD models, including the 1-methyl-4-phenylpyridinium (MPTP)-induced mouse model and lipopolysaccharide (LPS)-stimulated BV-2 microglia. Our findings revealed that SLSP mitigated behavioral impairments and excessive microglial activation in models of PD, including MPTP-treated mice. Additionally, SLSP inhibited the upregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) and attenuated the phosphorylation of PI3K, protein kinase B (AKT), nuclear factor-κB (NFκB), and inhibitor of NFκB protein α (IκBα) both in vivo and in vitro. Moreover, SLSP suppressed the production of inflammatory markers such as interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α) in LPS-stimulated BV-2 cells. Notably, the P2Y2R agonist partially reversed the inhibitory effects of SLSP in LPS-treated BV-2 cells. These results suggest that SLSP inhibit microglia-mediated neuroinflammation in experimental PD models, likely through the P2Y2R/PI3K/AKT/NFκB signaling pathway. These novel findings indicate that SLSP may offer therapeutic potential for PD by attenuating microglia-mediated neuroinflammation.
Animals ; Panax notoginseng/chemistry* ; Saponins/pharmacology* ; Microglia/immunology* ; Mice ; NF-kappa B/immunology* ; Signal Transduction/drug effects* ; Proto-Oncogene Proteins c-akt/immunology* ; Phosphatidylinositol 3-Kinases/genetics* ; Male ; Parkinson Disease/immunology* ; Mice, Inbred C57BL ; Disease Models, Animal ; Plant Leaves/chemistry* ; Neuroinflammatory Diseases/drug therapy* ; Humans

Shengmai formula,composed of Ginseng Radix et Rhizoma,Ophiopogon Radix and Schisandrae Chinensis Fructus,is a classic and famous formula.It is a representative formula for"supplementing qi,nourishing yin,and generating fluid"in Traditional Chinese Medicine theory.To date,a wide range of Shengmai formulae have been developed according to different medical applications,but the quality evaluation standards are at a relatively low level,and most of them only specify the individual components of a single herb,making it difficult to ensure clinical efficacy and safety.At the same time,the physical and chemical identification methods of Shengmai formula have been constantly updated,allowing for greater progress in research on its main chemical components such as saponins,lignans and flavonoids.However,there is little systematic summarization of the chemical components and analytical methods.Based on the existing references,we systematically summarized ginsenosides,ophiopogonins,schisandra lignans,homoisoflavonoids and some other compounds in this paper,as well as the quality standards of Shengmai formulae and their analytical methods in order to aid clinical research and formulation manufacture.