Mulberry Leaf Extract Alleviates Staphylococcus aureus-Induced Conjunctivitis in Rabbits via Downregulation of NLRP3 Inflammasome and Upregulation of the Nrf2 System and Suppression of Pro-Inflammatory Cytokines.

INTRODUCTION: Mulberry (Morus alba L.) leaves are widely used in traditional Chinese medicine for their antioxidant, anti-inflammatory, antibacterial, anti-obesity, antidiabetic, antiatherosclerotic, and anticancer properties. The current study aimed to investigate the effect of mulberry leaf extract (MLE) on Staphylococcus aureus (S. aureus)-induced conjunctivitis (5 × 109 colony-forming units, 0.5 mL/eye) in a rabbit model. METHODS: Rabbits were treated with MLE (5 mL/kg·d-1 and 10 mL/kg·d-1), 0.9% saline, pearl bright eye (PBE) drops, or erythromycin eye ointment (EEO) group for 5 days. The ocular infection symptoms, bacterial negative conversion rate, and conjunctival histopathological changes of rabbits in each group were observed. The expression of caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain, NOD-like receptor leucine-rich pyrin domain-containing protein 3 (NLRP3), interleukin (IL)-18, IL-6, IL-1ß, TNFα, Keap1, and nuclear factor erythroid 2-related factor 2 (Nrf2) in conjunctival tissue of rabbits were detected by quantitative real-time reverse transcription PCR and/or Western blot analysis. RESULTS: The results showed that MLE treatment significantly reduced the clinical sign scores of conjunctivitis, alleviated clinical signs, and decreased bacterial load, and histological damage in a time- and dose-dependent manner was compared to that in the control group. The antibacterial and anti-inflammatory activities of MLE (10 mL/kg·d-1) were similar to those of the positive control drug PBE and EEO. In addition, MLE significantly decreased the levels of pro-inflammatory cytokines, downregulated the NLRP3 inflammasome, and upregulated the Nrf2 system. CONCLUSIONS: MLE is effective in alleviating S. aureus-induced conjunctivitis in rabbits, and this mechanism is associated with the inhibition of the NLRP3 inflammasome and activation of the Nrf2 system to regulate pro-inflammatory signaling.

Protective effects of quercetin and crocin in the kidneys and liver of obese Sprague-Dawley rats with Type 2 diabetes: Effects of quercetin and crocin on T2DM rats.

Quercetin and crocin are the main active constituents of Eucommia and Gardenia species, respectively. This study was conducted to explore the effects of quercetin and crocin on fat reduction and renal fibrosis and the relationship of these compounds with autophagy. First, a model of high-fat diet- and streptozotocin-induced type 2 diabetes was established and then subjected model animals to 8 weeks of metformin, quercetin and crocin gavage. Then, a high glucose-induced rat mesangial cells (RMCs) model was established, and these cells were cocultured with quercetin and crocin. The results showed that quercetin and crocin can decrease fasting blood glucose levels, reduce fat accumulation in the liver, alleviate renal fibrosis, and reduce blood lipid levels. Quercetin and crocin increased autophagy-related protein (LC3, Atg5, Beclin-1 and p-AMPK) levels in the liver and decreased autophagy-related protein (LC3, Atg5, Beclin-1 and p-AMPK) levels in the kidneys. Moreover, quercetin and crocin inhibited the excessive proliferation of RMCs induced by high-glucose (HG) conditions, decreased autophagy-related protein (LC3, Atg5, Beclin-1 and p-AMPK) levels, and decreased TGF-ß1 expression. Importantly, cotreatment with quercetin and crocin had a more significant effect than treatment with either compound alone. These results suggest that combined administration of quercetin and crocin can more significantly reduce blood glucose/lipid levels and improve renal fibrosis than administration of either compound alone and that AMPK-dependent autophagy might be involved in this process. Eucommia ulmoides Oliv. and Gardenia could be developed as drugs for Type 2 diabetes treatment.

Synergistic effect of phytochemicals on cholesterol metabolism and lipid accumulation in HepG2 cells.

BACKGROUND: Crocin (CRO), chlorogenic acid (CGA), geniposide (GEN), and quercetin (QUE) are all natural compounds with anti-obesity properties, in particular, hypolipidemic effects, which have been widely used for the treatment of obesity-related metabolic diseases. However, it is not yet known whether these compounds interact synergistically. Here, we investigated the effects and molecular mechanisms of CRO, CGA, GEN, QUE, and a combination of all four compounds (CCGQ), on lipid accumulation in human hepatoma (HepG2 cells). METHODS: The optimal concentration of CRO, CGA, GEN, QUE to stimulate HepG2 cells proliferation was determined using MTT assay. HepG2 cells were pretreated with 10 µmol/L simvastatin, 1 µmol/L CRO, 30 µmol/L CGA, 10 µmol/L GEN, 10 µmol/L QUE, and CCGQ (a combination of 1 µmol/L CRO, 30 µmol/L CGA, 10 µmol/L GEN, and 10 µmol/L QUE) for 24 or 48 h. Oil red O staining and extracellular TC and TG levels were detected. The RT-PCR was used to observe on cholesterol metabolism-related gene expression. Immunocytochemistry and western-blot assayed the 3-hydroxy-3-methylglutaryl-coenzyme (HMGCR) protein expression in HepG2 cells. RESULTS: Compared to those of control, we demonstrated that treating HepG2 cells for 48 h with CCGQ resulted in a strong synergistic effect, causing a marked decrease in lipid deposition in comparison to individual treatments, in both triglyceride and total cholesterol (CRO, 5.74- and 1.49-folds; CGA, 3.38- and 1.12-folds; GEN, 4.04- and 1.44-folds; QUE, 3.36- and 1.24-folds; simvastatin, 5.49- and 1.83-folds; and CCGQ, 7.75- and 2.20-folds), and Oil red O staining assays. In addition, CCGQ treatment increased ATP-binding cassette transporter (ABCA1), cholesterol 7α-hydroxylase (CYP7A1), and AMP-activated protein kinase 2α (AMPKα2) mRNA expression, while decreasing sterol regulatory element binding protein 2 (SREBP2), and liver X receptor alpha (LXRα) mRNA expression. Notably, CCGQ was more effective in decreasing HMGCR expression than the individual treatments. CONCLUSION: The CCGQ combination has potential, both as a complementary therapy for hyperlipemia, and in preventing further obesity-related complications.

In vitro evaluation of ruthenium complexes for photodynamic therapy.

BACKGROUND: Photodynamic therapy (PDT) is a promising anti-tumor treatment strategy. Photosensitizer is one of the most important components of PDT. In this work, the anticancer activities of PDT mediated by six new ruthenium porphyrin complexes were screened. The mechanisms of the most efficacious candidate were investigated. METHODS: Photocytotoxicity of the six porphyrins was tested. The most promising complex, Rup-03, was further investigated using Geimsa staining, which indirectly detects reactive oxygen species (ROS) and subcellular localization. Mitochondrial membrane potential (MMP), cell apoptosis, DNA fragmentation, c-Myc gene expression, and telomerase activities were also assayed. RESULTS: Rup-03 and Rup-04 had the lowest IC50 values. Rup-03 had an IC50 value of 29.5±2.3µM in HepG2 cells and 59.0±6.1µM in RAW264.7 cells, while Rup-04 had an IC50 value of 40.0±3.8µM in SGC-7901 cells. The complexes also induced cellular morphological changes and impaired cellular ability to scavenge ROS, and accumulated preferentially in mitochondria and endoplasmic reticulum. Rup-03 reduced MMP levels, induced apoptosis, and repressed both c-Myc mRNA expression and telomerase activity in HepG2 cells. CONCLUSIONS: Among six candidates, Rup-03-mediated PDT is most effective against HepG2 and RAW264.7, with a similar efficacy as that of Rup-04-mediated PDT against SGC-7901 cells. Repression of ROS scavenging activities and c-Myc expression, which mediated DNA damage-induced cell apoptosis and repression of telomerase activity, respectively, were found to be involved in the anticancer mechanisms of Rup-03.