Magterpenes A-C: Three Meroterpenoids with an Unprecedented 6/6/6/6/6 Polycyclic Skeleton Extracted from Magnolia officinalis Rehd. et Wils.

Magterpenes A-C (1-3), three unprecedented meroterpenoids featuring a unique 6/6/6/6/6 polycyclic skeleton, were isolated from the ethanol extract of Magnolia officinalis Rehd. et Wils. The compounds were obtained as racemic mixtures that were completely resolved through chiral columns. Their structures were elucidated by extensive analyses of one-dimensional (1D) and 2D nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, chemical calculations of 1H/13C NMR, and electronic circular dichroism calculations. The compounds were constructed via two Diels-Alder reactions in the proposed biosynthetic pathway. All isolates were evaluated for their nephroprotective and hepatoprotective activities. The results demonstrated that (+)-1 and (-)-1 possessed promising nephroprotective activities in a dose-dependent manner, while (-)-2 and (+)-3 exhibited moderate hepatoprotective activities.

Mailuoning oral liquid ameliorates vasculitis in thromboangiitis obliterans rats via inactivating cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Mailuoning oral liquid (MLN O), one traditional Chinese patent medicine, has a good therapeutic effect on thromboangiitis obliterans (TAO) in clinical practice. However, the underlying mechanism remains unclear. AIM OF THE STUDY: This study aimed to explore the effects and potential mechanisms of MLN O against TAO based on network pharmacology and experimental verification. MATERIALS AND METHODS: Network pharmacology was used to identify the intersectional targets and signaling pathways of MLN O and TAO. In vivo, the TAO model was established by injecting sodium laurate and dihydrotestosterone (DHT) into the femoral arteries of Wistar rats. Rats were given the indicated drugs by intragastric administration (i.g.), intravenous injection (i.v.), or subcutaneous injection (s.c.) per day for 21 days since a week before surgery. In vitro, HUVECs, RAW264.7, and THP-1 cells were stimulated by LPS and DHT to simulate the pathological changes of TAO. The anti-inflammatory, anticoagulant, and immunomodulatory effects of MLN O were evaluated by histological observation, blood biochemical indexes detection, H&E staining, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), qRT-PCR, western blotting and immunofluorescence assays. Furthermore, the vascular ring test was applied to explore the vasodilatory activity of MLN O. RESULTS: MLN O significantly improved the pathological signs in TAO rats through its excellent anti-inflammatory, anticoagulant, immunomodulatory, and vasodilatory effects. Specifically, MLN O alleviated the gangrene and reduced the thrombosis in TAO rats, meanwhile, suppressed the expressions of inflammatory factors and clotting factors, which is related to the inactivations of cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways. However, the superphysiological dose of DHT deteriorated the pathological development of TAO in vitro and in vivo. Moreover, the results of network pharmacology are consistent with the experimental verification. CONCLUSION: Collectively, this study indicates for the first time that MLN O could alleviate TAO by inhibiting cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways, which sheds light on a novel clinical therapeutic strategy for TAO.

Mailuoning oral liquid attenuates convalescent cerebral ischemia by inhibiting AMPK/mTOR-associated apoptosis and promoting CREB/BDNF-mediated neuroprotection.

ETHNOPHARMACOLOGICAL RELEVANCE: Ischemic stroke is divided into acute, subacute and convalescent phases according to the time of onset. Clinically, Mailuoning oral liquid (MLN O) is a traditional Chinese patent medicine for treating ischemic stroke. Previous studies have shown that MLN O could prevent acute cerebral ischemia-reperfusion. However, its underlying mechanism remains unclear. AIM OF THE STUDY: To investigate the relationship between neuroprotection and apoptosis for clarifying MLN O mechanism in the recovery phase of ischemic stroke. MATERIALS AND METHODS: We imitated stroke using middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro models. The infarct volume, neurological deficit scores, HE staining, Nissl staining, TUNEL staining, immunohistochemistry, and Western blot were correspondingly performed to find pathological changes and detect neuronal apoptosis in rat cerebral cortex. The contents of LDH, Cyt-c, c-AMP and BDNF in rat plasma and cerebral cortex were detected by ELISA. Cell viability was measured by CCK8 assay. Cell morphology, Hoechst 33342 staining and Annexin-V-Alexa Fluor 647/PI staining were performed to assess neuronal apoptosis. The expression levels of proteins were evaluated by western blotting. RESULTS: MLN O obviously reduced brain infarct volume and neurological deficit scores in MCAO rats. MLN O inhibited inflammatory cell infiltration and neuronal apoptosis, but promoted gliosis, neuronal survival, and neuroprotection in the cortical region of MCAO rats. Additionally, MLN O decreased the amount of LDH and cytochrome c, while increasing the expression of c-AMP in the plasma and ischemic cerebral cortex of MCAO rats, and promoting the expression of BDNF in the cortical tissue of MCAO rats. Besides, MLN O improved cell viability, restored cell morphology, while attenuating cell damage, inhibiting neuronal apoptosis following OGD/R in PC-12 cells. Moreover, MLN O inhibited apoptosis by suppressing the expression of pro-apoptotic-associated proteins, including Bax, cytochrome c, Cleaved caspase 3 and HIF-1α, whereas accelerating the expression of Bcl-2 in vivo and in vitro. Furthermore, MLN O inhibited the activity of AMP-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR), but activated the signaling pathway of cAMP-response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) in MCAO rats and OGD/R-stimulated PC-12 cells. CONCLUSIONS: These results demonstrated that MLN O inhibited AMPK/mTOR to affect apoptosis associated with mitochondria, leading to improve CREB/BDNF-mediated neuroprotection in the recovery period of ischemic stroke in vivo and in vitro.