Ethanol Extract of Limonium bicolor Improves Dextran Sulfate Sodium-Induced Ulcerative Colitis by Alleviating Inflammation and Restoring Gut Microbiota Dysbiosis in Mice.

Ulcerative colitis (UC) is a kind of inflammatory bowel condition characterized by inflammation within the mucous membrane, rectal bleeding, diarrhea, and pain experienced in the abdominal region. Existing medications for UC have limited treatment efficacy and primarily focus on symptom relief. Limonium bicolor (LB), an aquatic traditional Chinese medicine (TCM), exerts multi-targeted therapeutic effects with few side effects and is used to treat anemia and hemostasis. Nevertheless, the impact of LB on UC and its mechanism of action remain unclear. Therefore, the objective of this study was to investigate the anti-inflammatory effects and mechanism of action of ethanol extract of LB (LBE) in lipopolysaccharide-induced RAW 264.7 macrophages and dextran sulfate sodium (DSS)-induced UC. The results showed that LBE suppressed the secretion of cytokines in LPS-stimulated RAW 264.7 cells in a dose-dependent manner. LBE had protective effects against DSS-induced colitis in mice, decreased the disease activity index (DAI) score, alleviated symptoms, increased colon length, and improved histological characteristics, thus having protective effects against DSS-induced colitis in mice. In addition, it reversed disturbances in the abundance of proteobacteria and probiotics such as Lactobacillus and Blautia in mice with DSS-induced UC. Based on the results of network pharmacology analysis, we identified four main compounds in LBE that are associated with five inflammatory genes (Ptgs2, Plg, Ppar-γ, F2, and Gpr35). These results improve comprehension of the biological activity and functionality of LB and may facilitate the development of LB-based compounds for the treatment of UC.

Effect of piperine on the mitigation of obesity associated with gut microbiota alteration.

An obese mouse model induced by high-fat diet (HFD) feeding was used to reveal the role of piperine in modulating gut microbiota (GM). Piperine was administrated at 20 and 40 mg/kg body weight every day. As a result, piperine at 40 mg/kg significantly decreased body weight, liver weight, perirenal fat weight, and lowered serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, and glucose levels in HFD-fed mice. Additionally, piperine significantly attenuated fatty liver and modulated hepatic mRNA expressions of SREBP-1c, SREBP2, and HMGCR. In perirenal fat, FAS, C/EBPα, MCP1, and IL-6 expressions were significantly downregulated by piperine. 16S rRNA sequencing revealed that piperine elevated GM diversity. The relative abundance of Muribaculaceae and Ruminococcaceae were significantly elevated, while Dubosiella and Enterorhabdus genera were suppressed by piperine. The Pearson correlation analysis showed that the altered phylotypes were highly correlated with obesity phenotypes. These findings suggest that piperine modulates energy homeostasis and inflammation to alleviate obesity associated with GM regulation.

Soluble Polysaccharide Derived from Laminaria japonica Attenuates Obesity-Related Nonalcoholic Fatty Liver Disease Associated with Gut Microbiota Regulation.

In this study, the effects of a polysaccharide derived from Laminaria japonica (LJP) on obesity were investigated in mice fed a high-fat diet (HFD). LJP significantly attenuated obesity-related features, lowering serum triglycerides, glucose, total cholesterol and low-density lipoprotein cholesterol levels. HFD-induced liver steatosis and hepatocellular ballooning were significantly attenuated by LJP. Additionally, LJP was found to significantly modulate hepatic gene expressions of AMPK and HMGCR, which are key regulators of lipid and cholesterol metabolism. We further found that LJP ameliorated HFD-induced gut microbiota (GM) dysbiosis by significantly reducing the obesity-related Firmicutes to Bacteroidetes ratio, meanwhile promoting the growth of Verrucomicrobia at the phylum level. At the genus level, propionate-producing bacteria Bacteroides and Akkermansia were elevated by LJP, which might explain the result that LJP elevated fecal propionate concentration. Taken together, these findings suggest that dietary intake of LJP modulates hepatic energy homeostasis to alleviate obesity-related nonalcoholic fatty liver disease associated with GM regulation.

Total Synthesis and Anti-Inflammatory Bioactivity of (-)-Majusculoic Acid and Its Derivatives.

The first total synthesis of marine natural product, (-)-majusculoic acid (1) and its seven analogs (9-15), was accomplished in three to ten steps with a yield of 3% to 28%. The strategy featured the application of the conformational controlled establishment of the trans-cyclopropane and stereochemical controlled bromo-olefination or olefination by Horner-Wadsworth-Emmons (HWE) reaction. The potential anti-inflammatory activity of the eight compounds (1 and 9-15) was evaluated by determining the nitric oxide (NO) production in the lipopolysaccharide (LPS)-induced mouse macrophages RAW264.7. (-)-Majusculoic acid (1), methyl majusculoate (9), and (1R,2R)-2-((3E,5Z)-6-bromonona-3,5-dien-1-yl)cyclopropane-1-carboxylic acid (12) showed significant effect with inhibition rates of 33.68%, 35.75%, and 43.01%, respectively. Moreover, they did not show cytotoxicity against RAW264.7 cells, indicating that they might be potential anti-inflammatory agents.

Insoluble dietary fiber derived from brown seaweed Laminaria japonica ameliorate obesity-related features via modulating gut microbiota dysbiosis in high-fat diet-fed mice.

Gut microbiota (GM) is considered to play an important role in obesity. Additionally, the impact of dietary fiber (DF) consumption on GM has been well established. Brown seaweeds are known to be a rich source of DF. However, the effect of insoluble DFs (IDFs) alone from brown seaweed on obesity and GM remains to be determined. This study investigated the effect of IDFs prepared from Laminaria japonica Aresch on high-fat diet (HFD)-induced obesity and GM dysbiosis in mice. Although HFD-induced body weight gain was not significantly attenuated by the IDF treatment, HFD-induced liver injury was ameliorated, and the HFD-elevated serum cholesterol concentration and glucose level of obese mice were significantly lowered. IDF treatment significantly modulated the GM composition disturbed by the HFD. It was found that 5% IDFs restored the GM to a very similar composition to that in the normal mice. The relative abundance of Akkermansia genus was decreased by >300-fold in HFD-fed mice, and it was fully restored by 5% IDF administration. Akkermansia muciniphila, a short-chain fatty acid producer, was identified as a marker species in both control and high-dose IDF groups. Furthermore, IDFs significantly restored the HFD-reduced acetate and propionate levels in the cecal content. In conclusion, the beneficial effect of IDFs derived from L. japonica on obesity was confirmed in mice, and the underlying mechanism may be associated with the modulation of GM composition, possibly through the enrichment of Akkermansia.

Synthesis and Biological Evaluation of Analogues of Butyrolactone I as PTP1B Inhibitors.

In recent years, a large number of pharmacologically active compounds containing a butenolide functional group have been isolated from secondary metabolites of marine microorganisms. Butyrolactone I was found to be produced by Aspergillus terreus isolated from several marine-derived samples. The hypoglycemic activity of butyrolactone I has aroused our great interest. In this study, we synthesized six racemic butenolide derivatives (namely BL-1-BL-6) by modifying the C-4 side chain of butyrolactone I. Among them, BL-3 and BL-5 improved the insulin resistance of HepG2 cells and did not affect the proliferation of RIN-m5f cell line, which indicated the efficacy and safety of BL-3 and BL-5. Furthermore, BL-3, BL-4, BL-5, and BL-6 displayed a significant protein tyrosine phosphatase 1B (PTP1B) inhibitory effect, while the enantiomers of BL-3 displayed different 50% percentage inhibition concentration (IC50) values against PTP1B. The results of molecular docking simulation of the BLs and PTP1B explained the differences of biological consequences observed between the enantiomers of BL-3, which supported BLs as PTP1B inhibitors, and also indicated that the chirality of C-4 might influence the inhibitory effect of the BLs. Our findings provide a novel strategy for the development of butyrolactone derivatives as potential PTP1B inhibitors for the treatment of type 2 diabetes mellitus.

Analgesia Effect of Enteric Sustained-Release Tetrodotoxin Pellets in the Rat.

Tetrodotoxin (TTX) was identified as a latent neurotoxin that has a significant analgesia effect. It was rapidly absorbed and excreted in rat after intramuscular (i.m.) injection. To maintain the effect, frequent injections were required. The enteric sustained-release TTX pellets with sucrose pellets as a drug carrier was prepared by fluidized bed spray irrigation, coated in sequence with Eudragit NE30D as a sustained-release layer, hydroxypropyl methylcellulose (HPMC) as a barrier layer and Eudragit L30D-55 as an enteric coating. TTX in the pellets could be sustained released for 12 h in dissolution test. In vivo, TTX pellets reached Cmax at 5 h, and t1/2 was 14.52 ± 2.37 h after intragastrically (i.g.) administration in rat. In acetic acid induced writhing test in rat, the pellets at the dosages of 20, 40, 60 and 80 µg·kg-1 produced analgesic effect at about 1.5 h to 9 h and the strongest effect was at about 3 h to 6 h. Simultaneously, the LD50 of the enteric sustained-release TTX pellets was 840.13 µg·kg-1, and the ED50 was about 30 µg·kg-1. Thus, the therapeutic index was about 25. The enteric sustained-release TTX pellets with absolute analgesia effect and greatly enhanced safety was prepared.

Combination Formulation of Tetrodotoxin and Lidocaine as a Potential Therapy for Severe Arrhythmias.

Severe arrhythmias-such as ventricular arrhythmias-can be fatal, but treatment options are limited. The effects of a combined formulation of tetrodotoxin (TTX) and lidocaine (LID) on severe arrhythmias were studied. Patch clamp recording data showed that the combination of LID and TTX had a stronger inhibitory effect on voltage-gated sodium channel 1.5 (Nav1.5) than that of either TTX or LID alone. LID + TTX formulations were prepared with optimal stability containing 1 µg of TTX, 5 mg of LID, 6 mg of mannitol, and 4 mg of dextran-40 and then freeze dried. This formulation significantly delayed the onset and shortened the duration of arrhythmia induced by aconitine in rats. Arrhythmia-originated death was avoided by the combined formulation, with a decrease in the mortality rate from 64% to 0%. The data also suggests that the anti-arrhythmic effect of the combination was greater than that of either TTX or LID alone. This paper offers new approaches to develop effective medications against arrhythmias.

Effect of Tetrodotoxin Pellets in a Rat Model of Postherpetic Neuralgia.

Postherpetic neuralgia (PHN) is nerve pain caused by a reactivation of the varicella zoster virus. Medications are used to reduce PHN but their use is limited by serious side effects. Tetrodotoxin (TTX) is a latent neurotoxin that can block neuropathic pain, but its therapeutic index is only 3⁻5 times with intravenous or intramuscular injection. Therefore, we prepared oral TTX pellets and examined their effect in a rat model of PHN induced by resiniferatoxin (RTX). Oral TTX pellets were significantly effective at preventing RTX-induced mechanical and thermal allodynia, and similar to pregabalin. Moreover, oral administration of TTX pellets dose-dependently inhibited RTX-induced PHN compared with intramuscular administration of TTX injection. We also studied the pharmacokinetic profile of TTX pellets. Our results showed that the blood concentration of TTX reached a maximum plasma concentration (Cmax) at around 2 h, with an elimination half-life time (t1/2) of 3.23 ± 1.74 h after intragastric administration. The median lethal dose (LD50) of TTX pellets was 517.43 µg/kg via oral administration to rats, while the median effective dose (ED50) was approximately 5.85 µg/kg, and the therapeutic index was 88.45. Altogether, this has indicated that oral TTX pellets greatly enhance safety when compared with TTX injection.