Lycofargesiines A-F, further Lycopodium alkaloids from the club moss Huperzia fargesii.

Six undescribed Lycopodium alkaloids (LAs) comprising four lycodine-type (lycofargesiines A-D), one lycopodine-type (lycofargesiine E), and a phlegmarine-type (lycofargesiine F), together with 16 known ones were isolated from the club moss Huperzia fargesii. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD) analysis, and density functional theory (DFT) calculations. (7S,8R,12R,13R)-Lycofargesiine A is a rare naturally occurring LA possessing an exocyclic double bond between C-15 and C-16, with ring A being a rare 2,3-dihyropyridone motif. Lycofargesiine D is an uncommon lycodine-type alkaloid featuring a unique N-acetylated tetrahydropyridinyl segment (ring A), whereas lycofargesiine F is the first phlegmarane-type LA bearing two nitrone moieties. In addition to the isolated huperzine A in this study, another two isolates (lycofargesiine C and 16-hydroxyhuperzine A) were also found to show inhibitory activities against acetylcholinesterase (AChE), with IC50 values of 8.63 and 5.18 µM, respectively.

Antifungal activity of osthol in vitro and enhancement in vivo through Eudragit S100 nanocarriers.

In vitro interaction of osthol (Ost) and fluconazole (FLC) was investigated against 11 fluconazole-resistant clinical isolates of Candida albicans. Synergistic activities were determined using the checkerboard microdilution assay. The results of agar diffusion test confirmed the synergistic interaction. We used an enteric material Eudragit S100 for preparation of Ost nanoparticle (Ost-NP) to improve the oral bioavailability, biological activity of Ost. The physicochemical characteristics of Ost-S100-NP revealed Ost-S100-NP with mean particle size of 55.4±0.4 nm, encapsulation efficiency of 98.95±0.06%, drug loading efficiency of 23.89±0.25%, yield of 98.5±0.1% and a polydispersity index (PDI) of 0.165. As the Ost concentration-time curve showed, Ost-S100-NP can increase the plasma concentration and relative bioavailability of Ost compared with Ost-suspension by oral administration. In vivo, Ost-S100-NP enhanced the therapeutic efficacy of Ost against FLC-resistant C. albicans in immunosuppressed candidiasis mice model. The available information strongly suggests that Ost-S100-NP may be used as a promising compound against drug-resistant fungi.

Kaempferol induces autophagic cell death of hepatocellular carcinoma cells via activating AMPK signaling.

In the present study, we demonstrate that Kaempferol inhibited survival and proliferation of established human hepatocellular carcinoma (HCC) cell lines (HepG2, Huh-7, BEL7402, and SMMC) and primary human HCC cells. Kaempferol treatment in HCC cells induced profound AMP-activated protein kinase (AMPK) activation, which led to Ulk1 phosphorylation, mTOR complex 1 inhibition and cell autophagy. Autophagy induction was reflected by Beclin-1/autophagy gene 5 upregulation and p62 degradation as well as light chain 3B (LC3B)-I to LC3B-II conversion and LC3B puncta formation. Inhibition of AMPK, via AMPKα1 shRNA or dominant negative mutation, reversed above signaling changes. AMPK inhibition also largely inhibited Kaempferol-induced cytotoxicity in HCC cells. Autophagy inhibition, by 3-methyaldenine or Beclin-1 shRNA, also protected HCC cells from Kaempferol. Kaempferol downregulated melanoma antigen 6, the AMPK ubiquitin ligase, causing AMPKα1 stabilization and accumulation. We conclude that Kaempferol inhibits human HCC cells via activating AMPK signaling.

Acute temperature and cadmium stress response characterization of small heat shock protein 27 in large yellow croaker, Larimichthys crocea.

Small heat shock proteins (sHSPs) are a group of molecular chaperones and play a crucial role in cell response to various stresses. In this study, we cloned and sequenced a small heat shock protein 27 (LcHSP27) cDNA from large yellow croaker, Larimichthys crocea. The full-length cDNA of LcHSP27 was 1227 bp, including a 5'-terminal untranslated region (UTR) of 54 bp, a 3'-terminal UTR of 561 bp and an open reading frame (ORF) of 612 bp encoding a polypeptide of 203 amino acids. Three conserved phosphorylation sites of serine were identified in the deduced LcHSP27 amino acid sequence at positions 15, 91 and 95 respectively, and a typical α-crystallin domain was at positions 96-193. Phylogenetic analysis revealed that LcHSP27 was categorized together with the HSP27 obtained from other fish. And a closer phylogenetic relationship of HSP27 was found with HSP22, then HSP30. Quantitative real-time reverse transcription PCR (qRT-PCR) analysis indicated the strongest expression of LcHSP27 in heart. However, expression of LcHSP27 in other examined tissues including muscle, brain, liver, spleen, kidney, gill, and blood was very weak. The impact of temperature and cadmium (Cd(2+)) stress on LcHSP27 expression was tested in liver and brain. The results showed that the levels of LcHSP27 expression increased significantly after low temperature (19°C) and high temperature (27°C and 31°C) stress both in liver and brain. And low temperature stress induced a higher LcHSP27 expression in liver. More important, LcHSP27 expression showed a dramatic up-regulation after a combined stress of temperature and cadmium (p<0.05). These results reveal that HSP27 may play an important role in the large yellow croaker response to temperature and cadmium stress.

Oxidative stress potentiated by diallylsulfide, a selective CYP2E1 inhibitor, in isoniazid toxic effect on rat primary hepatocytes.

Isoniazid (INH), one of the first-line antituberculosis drugs, has potential liver toxicity. Mechanisms reported by previous studies mainly focused on oxidative stress. In the present study, we investigated acute effects of diallylsulfide (DAS), a selective CYP2E1 inhibitor, on reduced glutathione (GSH) and reactive oxygen species (ROS) levels in rat primary hepatocytes treated with INH. In cultures treated with INH for 1, 4, 8h, significant loss of GSH content and decrease of ROS levels were observed. Moreover, when hepatocytes were co-treated with INH and 1mM DAS, accelerated GSH depletion and increased ROS production appeared. Further more, rat primary hepatocytes survival rates decreased significantly in cultures treated with INH together with DAS than in cultures treated with INH alone after 24h. In conclusion, DAS could potentiate INH toxic effect and this is the first study reporting the effect of DAS on oxidative stress in INH-induced hepatocytotoxicity.