Organic cation transporter 1 (OCT1) is located in the sinusoidal membrane of human hepatocytes. It mediates the uptake of hydrophilic organic cationic drugs in hepatocytes and thus determine their systemic concentrations. OCT1 has a broad spectrum of structurally diverse substrates like metformin, sumatriptan, trospium, and fenoterol. Recent cryo-EM data suggested that Y361, E386, and R439, referred to as the YER motif, could be important for transport. Building on this, we used extensive functional analyses to investigate the general function, and the substrate-specific effects of the YER motif. We determined the activity of the Y361A, E386A, and R439A mutants for fifteen OCT1 substrates. Extended mutagenesis revealed the negative charge of E386 and the positive charge of R439 as essential for the transport of all substrates tested. Charge reversal mutants, E386R-R439E, did not restore transport activity, suggesting that at least one of the two amino acids is involved in additional interactions essential for transport. Y361 exhibited substrate-specific effects. The Y361A mutant transported fenoterol, but not pirbuterol or other beta₂-adrenergic drugs with only one aromatic ring. MD simulations suggested that substrates with aromatic or lipophilic characteristics may compensate for the missing aromatic ring at position 361. Only tryptophan at codon 361 efficiently rescued the transport of the Y361A mutant supporting hydrogen bound interaction with E386 and R439. Our study confirms that the YER motif is essential for OCT1 transport and points to Y361 as a lever that interacts with E386 and R439 to trigger the closing of the binding pocket of human OCT1.

2024-12-01·JOURNAL OF ETHNOPHARMACOLOGY

Toxicological profiling of methanolic seed extract of Abutilon indicum (L.) Sweet: in-vitro and in-vivo analysis

Article

作者: Saha, Tilak ; Islam, Rejuan ; Kumar, Anoop ; Ray, Arpita ; Deb, Arijit ; Dutta, Debojit ; Sarkar, Sagar ; Ghosh, Supriyo ; Dutta, Ankita ; Ghosh, Amlan Jyoti ; Bahadur, Min

ETHNOPHARMACOLOGICAL RELEVANCE:

Abutilon indicum, a shrub of the Malvaceae family, is found abundantly in tropical countries like India. A. indicum is widely used for its high medicinal properties. Traditionally, A. indicum seed powder is consumed to treat piles, constipation, chronic cystitis, gonorrhea, gleet, and pregnancy-related problems. Despite having numerous medicinal properties and widespread traditional use of A. indicum seeds, scientific validation, and toxicity studies have yet to be documented.

AIMS OF THE STUDY:

The primary objective of this study is to conduct a comprehensive study on phytochemical profiling, in-vitro cytotoxicity, mutagenicity, and in-vivo acute and sub-acute toxicity, and genotoxicity on animal models of methanolic extract of A. indicum seed (MAS).

MATERIALS AND METHODS:

The qualitative analysis of MAS was explored through FTIR and HR LC-MS. For in-vitro cytotoxicity, the HEK-293 cell line was used, and the TA100 (Staphylococcus typhimurium) bacterial strain was used for the Ames mutagenicity test. A single oral dose of 250, 500, 1000, or 2000 mg/kg body weight of MAS was given to each male and female rat for acute toxicity study and observed for 14 days for any toxicity signs. In the sub-acute toxicity study, 250, 500, or 1000 mg/kg body weight of MAS was administered orally to each rat for 28 days. The experimental animals were weighed weekly, and general behavior was monitored regularly. After 28 days of the experiment, the rats were sacrificed, and different serum biochemical, hematological, and histological analyses were performed. The blood samples of different doses of MAS were used for genotoxicity study through comet assay.

RESULTS:

FTIR analysis found different functional groups, which indicated the presence of phenolics, flavonoids, and alkaloids. HR LC-MS analysis depicts several components with different biological functions. The cell cytotoxicity and Ames mutagenicity results showed minimal toxicity and mutagenicity up to a certain dose. The acute toxicity study conducted in Wistar albino rats demonstrated zero mortality among the animals, and the LD₅₀ value for seed extract was determined to be 2000 mg/kg body weight. Sub-acute toxicity assessments indicated that the administration of seed extract resulted in no adverse effects at dosages of 250 and 500 mg/kg body weight. However, at higher doses, specifically 1000 mg/kg body weight, the liver of the experimental rats exhibited some toxic effects. In the genotoxicity study, minimal DNA damage was found in 250 and 500 mg/kg doses, respectively, but slightly greater DNA damage was found in 1000 mg/kg doses in both male and female rats.

CONCLUSIONS:

The consumption of A. indicum seed powder is deemed safe; however, doses exceeding 500 mg/kg body weight may raise concerns regarding use. These findings pave the path for the creation of innovative medicines with improved efficacy and safety profiles.

2024-11-13·JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

Metagenomics and Untargeted Metabolomics Analysis Revealed the Probiotic and Postbiotic Derived from Lactiplantibacillus plantarum DPUL F232 Alleviate Whey Protein-Induced Food Allergy by Reshaping Gut Microbiota and Regulating Key Metabolites

Article

作者: Zhu, Xuemei ; Guo, Zihao ; Mu, Guangqing ; Feng, Lu ; Yao, Wenpu

Postbiotics have emerged as a promising alternative to probiotics. However, it remains unclear whether postbiotics can exert regulatory effects on intestinal flora and metabolism as probiotics. Thus, we investigated the effects of probiotic and postbiotic in rats with whey protein-induced food allergy, which demonstrated that postbiotic intervention effectively alleviated allergy symptoms, reduced serum immunoglobulin E (IgE) and mast cell protease-1 (mMCP-1) levels, and regulated the type helper 1 cell/2 cell (Th1/Th2) balance in both serum and spleen. Metagenomic analysis revealed that postbiotics induced more significant changes in intestinal flora. Untargeted metabolomics analysis showed that both probiotics and postbiotics significantly up-regulated various differential metabolites, which were negatively correlated with immune indices, including malvidin-3-glucoside, 3,4-dihydroxymandelic acid, nicotinamide, triterpenoids, pirbuterol, and 4-hydroxybenzoic acid. This study confirms that postbiotics can alleviate food allergies and regulate intestinal flora and metabolites, which provides a valuable reference for the use of postbiotics in mitigating allergic diseases through gut microbiota and metabolite modulation.

100 项与醋酸吡布特罗相关的药物交易

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