Gardenia jasminoides Extract GJ-4 Alleviates Memory Deficiency of Vascular Dementia in Rats through PERK-Mediated Endoplasmic Reticulum Stress Pathway.

Endoplasmic reticulum stress (ERS) is involved in the pathological process of vascular dementia (VD). GJ-4 is extracted from Gardenia jasminoides J. Ellis and has been reported to have protective roles in ischemia-related brain damage. However, the role of GJ-4 in ERS has not been elucidated. We established a VD rat model through bilateral common carotid arteries occlusion (2-VO). The rats were intragastrically administrated with GJ-4 (10, 25, and 50[Formula: see text]mg/kg) and nimodipine (10[Formula: see text]mg/kg). Data from a Morris water maze test showed that GJ-4 could significantly alleviate learning and memory deficits in VD rats. Nissl and cleaved caspase-3 staining revealed that GJ-4 can inhibit apoptosis and thus exert a protective role in the brain of 2-VO rats. Western blot results suggested that GJ-4 significantly reduced ERS-related protein expression and inhibited apoptosis through suppression of the PERK/eIF2[Formula: see text]/ATF4/CHOP signaling pathway. For in vitro studies, the oxygen-glucose deprivation (OGD) SH-SY5Y model was employed. Western blot and Hoechst 33342/PI double staining were utilized to explore the effects of crocetin, the main active metabolite of GJ-4. Like GJ-4 in vivo, crocetin in vitro also decreased ERS-related protein expression and inhibited the activation of the PERK/eIF2[Formula: see text]/ATF4/CHOP signaling pathway. Thus, crocetin exerted similar protective roles on OGD challenged SH-SY5Y cells in vitro. In summary, GJ-4 and crocetin reduce the ERS in the brain of VD rats and SY5Y cells subjected to OGD and inhibit neuronal apoptosis through suppression of the PERK/eIF2[Formula: see text]/ATF4/CHOP pathway, suggesting that GJ-4 may be useful for the treatment of VD.

Presegetane diterpenoids from Euphorbia sieboldiana as a new type of anti-liver fibrosis agents that inhibit TGF-ß/Smad signaling pathway.

Seven new diterpenoids, eupholenes A-G (1-7), including two presegetanes (1 and 2), four jatrophanes (3-6), and one paraliane (7), along with 19 known analogues (8-26) were obtained by anti-liver fibrosis bioassay-guided isolation of Euphorbia sieboldiana. Their structures were elucidated by extensive spectroscopic data analyses, chemical methods, ECD calculations, and single-crystal X-ray diffractions. Euphorbesulin A (10), a presegetane diterpenoid (5/9/5 ring system), was identified as a promising anti-liver fibrosis agent that could inhibit the expressions of fibronectin (FN), α-smooth muscle actin (α-SMA), and collagen I in TGF-ß1-stimulated LX-2 cells at a micromolar level. Mechanistic study revealed that 10 suppressed liver fibrosis via inhibition of TGF-ß/Smad signaling pathway, and its potential target was TGF-ß type I receptor. These findings suggested that presegetane diterpenoid could serve as a new type of structural motif in future anti-liver fibrosis drug development.

Highly modified nor-clerodane diterpenoids from Croton yanhuii.

Phytochemical investigation of the leaves and twigs of Croton yanhuii led to the isolation of seven highly modified nor-clerodane diterpenoids (1-7), including three new ones, croyanoids A-C (1-3), along with four known analogues (4-7). Compound 1 incorporates a 5,12-epoxy ring, forming a unique cage-like, 6/6/6/5-fused tetracyclic ring system. Their structures were established by extensive spectroscopic analysis, and the absolute configurations of 1-4 were determined by a combination of circular dichroism (CD) analysis and single-crystal X-ray diffraction. All compounds were tested in an array of bioassays, but were inactive. Crotoeurin A (7), a nor-clerodane dimer with a high yield of 0.2‰ isolated in current study, was considered as a chemotaxonomic marker for this species.