Effects of Inducible Nitric Oxide Synthase (iNOS) Gene Knockout on the Diversity, Composition, and Function of Gut Microbiota in Adult Zebrafish.

The gut microbiota constitutes a complex ecosystem that has an important impact on host health. In this study, genetically engineered zebrafish with inducible nitric oxide synthase (iNOS or NOS2) knockout were used as a model to investigate the effects of nos2a/nos2b gene single knockout and nos2 gene double knockout on intestinal microbiome composition and function. Extensive 16S rRNA sequencing revealed substantial changes in microbial diversity and specific taxonomic abundances, yet it did not affect the functional structure of the intestinal tissues. Notably, iNOS-deficient zebrafish demonstrated a decrease in Vibrio species and an increase in Aeromonas species, with more pronounced effects observed in double knockouts. Further transcriptomic analysis of the gut in double iNOS knockout zebrafish indicated significant alterations in immune-related and metabolic pathways, including the complement and PPAR signaling pathways. These findings underscore the crucial interplay between host genetics and gut microbiota, indicating that iNOS plays a key role in modulating the gut microbial ecology, host immune system, and metabolic responses.

Discovery of a Novel Benzothiadiazine-Based Selective Aldose Reductase Inhibitor as Potential Therapy for Diabetic Peripheral Neuropathy.

Aldose reductase 2 (ALR2), an activated enzyme in the polyol pathway by hyperglycemia, has long been recognized as one of the most promising targets for complications of diabetes, especially in diabetic peripheral neuropathy (DPN). However, many of the ALR2 inhibitors have shown serious side effects due to poor selectivity over aldehyde reductase (ALR1). Herein, we describe the discovery of a series of benzothiadiazine acetic acid derivatives as potent and selective inhibitors against ALR2 and evaluation of their anti-DPN activities in vivo. Compound 15c, carrying a carbonyl group at the 3-position of the thiadiazine ring, showed high potent inhibition against ALR2 (IC50 = 33.19 nmol/L) and ∼16,109-fold selectivity for ALR2 over ALR1. Cytotoxicity assays ensured the primary biosafety of 15c. Further pharmacokinetic assay in rats indicated that 15c had a good pharmacokinetic feature (t1/2 = 5.60 h, area under the plasma concentration time curve [AUC(0-t)] = 598.57 ± 216.5 µg/mL * h), which was superior to epalrestat (t1/2 = 2.23 h, AUC[0-t] = 20.43 ± 3.7 µg/mL * h). Finally, in a streptozotocin-induced diabetic rat model, 15c significantly increased the nerve conduction velocities of impaired sensory and motor nerves, achieved potent inhibition of d-sorbitol production in the sciatic nerves, and significantly increased the paw withdrawal mechanical threshold. By combining the above investigations, we propose that 15c might represent a promising lead compound for the discovery of an antidiabetic peripheral neuropathy drug.

NEP010, a novel compound with minor structural modification from afatinib, exhibited significantly improved antitumor activity.

Non-small cell lung cancer (NSCLC) is classified into many subclasses according to the specific kinase mutations. The most common mutation is epidermal growth factor receptor (EGFR) somatic mutation, which has promoted the development of several novel drugs (Tyrosine kinase inhibitors, TKIs). Although various TKIs are recommended as targeted therapy for NSCLC with EGFR mutations in NCCN guidelines, not all patients respond equally to the recommended TKIs, which lead to series of novel compound under development to satisfy actual clinical needs. Based on the structure of afatinib, a marketed drug recommended as the first-line therapy for patients with EGFR mutation, NEP010 was synthesized with structural modification. The antitumor efficacy of NEP010 on mouse tumor xenograft models with different EGFR mutations was determined. Results showed that with minor structural modifications on afatinib, the inhibitory effect of NEP010 on EGFR mutant tumors was significantly improved. Pharmacokinetics test was adopted, and compared with afatinib, the increased tissue exposure of NEP010 may be the potential factor responsible for the increased efficacy. Furthermore, tissue distribution test showed a high concentration of NEP010 in the lung which happens to be the target organ of NEP010 in clinical practice. In conclusion, data obtained suggested that NEP010 has an increased anti-tumor effect via improving pharmacokinetics, and may provide a potent therapeutic option for the patients with EGFR mutation of NSCLC in the future.

Hydroxysafflor yellow A alleviates myocardial ischemia/reperfusion in hyperlipidemic animals through the suppression of TLR4 signaling.

Hyperlipidemia aggravates myocardial ischemia/reperfusion (MI/R) injury through stimulating excessive inflammatory response. Therefore, blockade of inflammatory signal is a potential therapeutic management for MI/R complicated with hyperlipidemia. Hydroxysafflor yellow A (HSYA, a monomer extracted from Carthamus tinctorius L.), was studied in this article to address that the regulation of inflammatory signal would alleviate MI/R combined with hyperlipidemia injury. High-fat diet induced hyperlipidemia worsened MI/R mediated heart injury (elevation of infarct size, CK-MB and LDH activity), activated TLR4 over-expression in hearts, released inflammatory cytokines (LPS, TNF-α and IL-1ß) excessively. HSYA administration suppressed the over-expression of TLR4 and alleviated heart damage caused by MI/R complicated with hyperlipidemia. Furthermore, HSYA had little influence on MI/R injury in TLR4-knockout mice, which indicated that HSYA protected MI/R through TLR4 inhibition. In vitro, hypoxia/reoxygenation (H/R) coexisting with LPS model in neonatal rat ventricular myocytes (NRVMs) induced serious damage compared with H/R injury to NRVMs. HSYA decreased excessive secretion of inflammatory cytokines, down-regulated over-expression of TLR4 and NF-κB in H/R + LPS injured NRVMs. In conclusion, HSYA alleviated myocardial inflammatory injury through suppressing TLR4, offering an alternative medication for MI/R associated with hyperlipidemia.

Cardioprotective activity of iron oxide nanoparticles.

Iron oxide nanoparticles (IONPs) are chemically inert materials and have been mainly used for imaging applications and drug deliveries. However, the possibility whether they can be used as therapeutic drugs themselves has not yet been explored. We reported here that Fe2O3 nanoparticles (NPs) can protect hearts from ischemic damage at the animal, tissue and cell level. The cardioprotective activity of Fe2O3 NPs requires the integrity of nanoparticles and is not dependent upon their surface charges and molecules that were integrated into nanoparticles. Also, Fe2O3 NPs showed no significant toxicity towards normal cardiomyocytes, indicative of their potential to treat cardiovascular diseases.

The molecular insight into the antihyperuricemic and renoprotective effect of Shuang Qi gout capsule in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Shuang-Qi gout capsule, a traditional Chinese medicine prescription, has been used in the treatment of, gout arthritis, arthralgia and inflammation. Since renal urate overload associated with severe disability including gout, elimination of excess renal uric acid is highly essential. Therefore, in this study we evaluated the antihyperuricemic and the renoprotective effect of the Shuang Qi gout capsule (SQ) with elucidation of its mechanism. MATERIALS AND METHODS: We assessed the antihyperuricemic activity of SQ on urinary and serum uric acid, creatinine, blood urea nitrogen, fractional excretion of uric acid (FEUA) and glomerular filtration rate of creatinine and uric acid in potassium oxonate (PO) - induced mice as well as in non-induced mice. To illuminate the mechanism of antihyperuricemic activity, we investigated renal transport activity and the expression of mRNA levels in PO-induced and non-induced mice by western blot and RT-PCR methods. RESULTS: SQ showed significant reduction in serum uric acid, creatinine and blood urea nitrogen levels and marked elevation of urine uric acid, creatinine and FEUA levels only in hyperuricemic mice. Furthermore, SQ could recover the altered expressions of proteins and mRNA levels of all the main renal transporters significantly in dose dependent manner. CONCLUSIONS: SQ could effectively regulate the main renal transporters denoted its denote probable antihyperuricemic mechanism of SQ and its dose dependent uricosuric effect. In addition, SQ attenuated the deleterious effects of hyperuricemia with renal dysfunction. Thus SQ could be a potent antihyperuricemic agent which can perform as a safer and effective agent in the management of hyperuricemia via regulating the renal transporters.

The effect of multidrug resistance modulator HZ08 on pharmacodynamics and pharmacokinetics of adriamycin in xenograft-nude mice.

To overcome MDR (multidrug resistance) of cancer mediated by P-gp (P-glycoprotein) has become a key strategy to improve the survival rate in clinic. Therefore, it is imperative to develop advanced modulators that have no side effects or interactions with cytotoxic drugs. HZ08, which acts as a P-gp inhibitor, shows a notable reverse effect with low cytotoxicity in vitro. Based on the previous results, the goal of this experiment is to elucidate the effect of HZ08 on pharmacodynamics and pharmacokinetics of adriamycin in tumor-bearing nude mice. Several criterions and methods, such as tumor weight and volume, in vivo imaging, western blot, immunohistochemistry as well as ATPase hydrolysis assay were selected to evaluate the reversing activity and mechanism of HZ08 on MDR; Furthermore, fluorescence detection assay was applied to determine the distribution of adriamycin in the blood and tissues. This study revealed that HZ08 potentiated the anti-tumor activity of adriamycin but with little effect on the expression of P-gp in vivo. Adriamycin accumulation in tumor was enhanced by HZ08 via ATPase activity inhibition. In addition, HZ08 did not alter the pharmacokinetic characteristic of adriamycin in plasma or tissues. In conclusion, HZ08 showed dramatic MDR reversing activity and had no influence on the pharmacokinetics of adriamycin.

The inhibitory and combinative mechanism of HZ08 with P-glycoprotein expressed on the membrane of Caco-2 cell line.

Recently, the research and development of agents to reverse the phenomenon of multidrug resistance has been an attractive goal as well as a key approach to elevating the clinical survival of cancer patients. Although three generations of P-glycoprotein modulators have been identified, poor clearance and metabolism render these agents too toxic to be used in clinical application. HZ08, which has been under investigation for several years, shows a dramatic reversal effect with low cytotoxicity. For the first time, we aimed to describe the interaction between HZ08 and P-glycoprotein in Caco-2 cell line in which P-glycoprotein is overexpressed naturally. Cytotoxicity and multidrug resistance reversal assays, together with flow cytometry, fluorescence microscopy and siRNA interference as well as Caco-2 monolayer transport model were employed in this study to evaluate the interaction between HZ08 and P-glycoprotein. This study revealed that HZ08 was capable of reversing adriamycin resistance mediated by P-glycoprotein as a result of intracellular enhancement of adriamycin accumulation, which was found to be superior to verapamil. In addition, we confirmed that HZ08 suppressed the transport of Rhodamine123 in the Caco-2 monolayer model but had little effect on P-glycoprotein expression. The transport of HZ08 was diminished by P-glycoprotein inhibitors (verapamil and LY335979) and its accumulation was increased via siRNA targeting MDR1 in Caco-2 cells. Furthermore, considering the binding site of P-glycoprotein, verapamil performed as a competitive inhibitor with HZ08. In conclusion, as a P-glycoprotein substrate, HZ08 inhibited P-glycoprotein activity and may share the same binding site of verapamil to P-glycoprotein.

Anti-inflammatory and antinociceptive effects of Chinese medicine SQ gout capsules and its modulation of pro-inflammatory cytokines focusing on gout arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: Shuang-Qi gout capsule is a traditional Chinese medicine prescription, which has been used in the treatment of joint pain, inflammation and gout arthritis. This study evaluates anti-inflammatory and antinociceptive effects of Shuang-Qi gout capsule and its modulation of pro-inflammatory cytokines with special reference to gout arthritis. MATERIALS AND METHODS: Anti-inflammatory effect of Shuang-Qi gout capsule was investigated bymice tail-flick response, acetic acid induced writhing response, Xylene-induced auricle inflammation and the hind paw volume of the monosodium urate (MSU) crystal induced rats with different time durations. To investigate the effects on gout arthritis, ankle joint of rats induced by MSU crystals and assessed for edema and histopathological changes. In vitro, prepared serum was incubated with urate crystal induced HUVE cells and the release of TNF-α and IL-1ß determined by ELISA. RESULTS: Shuang-Qi gout capsule showed significant and dose dependent anti-inflammatory effect via reducing edema and pain, throughout all the models. The high dose of Shuang-Qi gout capsule and Indomethacin significantly attenuated the edema. Histopathological results showed that high and medium dose of Shuang-Qi gout capsule and Indomethacin reduced gouty joint inflammatory features, while the high dose of Shuang-Qi gout capsule showed a better therapeutic effect. High and medium dose of Shuang-Qi gout capsule significantly reduced the release of TNF-α and IL-1ß (p<0.05). CONCLUSION: Shuang-Qi gout capsule can effectively inhibit the inflammation, analgesia, through the modulation of emission of pro-inflammatory cytokines and the curative effect is dose dependent. Conversely, these MSU induced in vivo and in vitro studies of Shuang-Qi gout capsule suggest that, Shuang-Qi gout capsule may be a potential agent for treatment in gouty arthritis.

HZ08 inhibits the multi-drug resistance on multiple sites as the substrate of p-glycoprotein.

Overexpression of p-glycoprotein (p-gp) leads to the production of multi-drug resistance (MDR) which could discharge various anti-tumor chemicals with structural heterogeneity. HZ08, a novel tetrahydroisoquinoline derivate, was discovered to modulate the MDR. What was confirmed is its definite inhibition of multi-drug resistance caused by p-gp and its promotion for the intracellular cytotoxins accumulation in the previous study. In order to explore whether HZ08 is the substrate of p-gp and on which sites it exerts its function, RNAi to mdr1 was introduced and the interaction between HZ08 and some classic agents (verapamil, rhodamine 123) with clearly binding sites was also investigated. Experimental results revealed that HZ08 is the most probable substrate of p-gp and may share the same modulation sites located at the p-gp with verapamil. Data obtained also indicated that there is a common binding site shared by rhodamine 123 and HZ08, but negative competition showed between HZ08 and adriamycin. In conclusion, HZ08 may be the substrate of p-gp and acts as a multiple target modulator to invert the efflux function of p-gp.