Oleanane- and Ursane-Type Triterpene Saponins from Centella asiatica Exhibit Neuroprotective Effects

Abstract

Six new pentacyclic triterpenoid saponins, centelloside F (1), centelloside G (2), 11-oxo-asiaticoside B (3), 11-oxomadecassoside (4), 11(β)-methoxy asiaticoside B (5), and 11(β)-methoxy madecassoside (6), along with seven known ones, asiaticoside (7), asiaticoside B (8), madecassoside (9), centellasaponin A (10), isoasiaticoside (11), scheffoleoside A (12), and centelloside E (13), were separated from the 80% MeOH extract of the whole plant of Centella asiatica, which has been used as a medicinal plant and is now commercially available as a diatery supplement in many countries. Compounds 1 and 2, 3 and 4, and 5 and 6 are three pairs of isomers with oleanane-or ursane-type triterpenes as aglycones. The chemical structures of the new triterpene saponins were fully characterized by extensive analysis of their nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry data. The protective effects of compounds 1−13 on PC12 cells induced by 6-OHDA were screened, and compound 3 displayed the best neuroprotective effect, with 91.75% cell viability at the concentration of 100 μM. Moreover, compound 3 also attenuated cell apoptosis and increased the mRNA expression of antioxidant enzymes, including superoxide dismutase and catalase. Additionally, compound 3 activated the phosphatidylinositol 3-kinase/Akt pathway, including PDK1, Akt, and GSK-3β. These findings suggested that triterpene saponins from C. asiatica were worthy of further biological research to develop new neuroprotective agents.

Variation of Triterpenic Acids in 12 Wild Syzygium formosum and Anti-Inflammation Activity on Human Keratinocyte HaCaT

“…This subtropical tree has very large and relatively thick leaves that contains large amounts of secondary metabolites. Among various phytochemicals, TAs were considered as major products based on the previous research on the chemical composition of S. formosum leaves, and many reports on the biological activities of TAs are available [7,9,15,16]. It is well known that secondary metabolites are affected by environmental factors as well as genetic backgrounds.…”

Ethnobotany, phytochemistry, pharmacology, and toxicity of Centella asiatica (L.) Urban: A comprehensive review

“…In addition, the compound terminated cell apoptosis, improved the mRNA expression of antioxidant enzymes and facilitated the activation of the phosphatidylinositol 3‐kinase/Akt pathway viz. PDK1, Akt, and GSK‐3β (Wu et al, 2020). Long‐term potentiation (LTP) (6 weeks) using C. asiatica extract (100 mg kg −1 ) before induction of The nucleus basalis of Meynert (NBM) lesion and Alzheimer's showed neuroprotection and enhanced memory in a rat model of Alzheimer's disease (Doulah, Mahmoodi, & Borujeni, 2020).…”

Antioxidant, Anti-Aging and Organ Protective Effects of Total Saponins from Aralia taibaiensis

“… 14–16 Many studies have shown that triterpene saponins such as asiaticoside B, madecassoside and parkioside A can react with free radicals and prevent further development of free radical chain reactions, thus exerting antioxidant effects. 17 , 18 Previous reports described that TSAT exhibited superior DPPH radical scavenging activity to single saponins, as well as good antioxidant capacity against lipid peroxidation in rat liver microsomes, and was shown to have superior antioxidant effects to ginseng, schisandra and other saponins. 14 , 15 In addition, TSAT also attenuated D-gal-induced liver damage in aging rats through its antioxidant effect.…”