Didymin alleviates metabolic dysfunction-associated fatty liver disease (MAFLD) via the stimulation of Sirt1-mediated lipophagy and mitochondrial biogenesis.

BACKGROUND: Metabolic dysfunction-associated fatty liver disease (MAFLD) is one of the most prevalent metabolic syndromes worldwide. However, no approved pharmacological treatments are available for MAFLD. Chenpi, one kind of dried peel of citrus fruits, has traditionally been utilized as a medicinal herb for liver diseases. Didymin is a newly identified oral bioactive dietary flavonoid glycoside derived from Chenpi. In this study, we investigated the therapeutic potential of Didymin as an anti-MAFLD drug and elucidated its underlying mechanisms. METHODS: High-fat diet (HFD)-induced MAFLD mice and alpha mouse liver 12 (AML12) cells were utilized to evaluate the effects and mechanisms of Didymin in the treatment of MAFLD. Liver weight, serum biochemical parameters, and liver morphology were examined to demonstrate the therapeutic efficacy of Didymin in MAFLD treatment. RNA-seq analysis was performed to identify potential pathways that could be affected by Didymin. The impact of Didymin on Sirt1 was corroborated through western blot, molecular docking analysis, microscale thermophoresis (MST), and deacetylase activity assay. Then, a Sirt1 inhibitor (EX-527) was utilized to confirm that Didymin alleviates MAFLD via Sirt1. Western blot and additional assays were used to investigate the underlying mechanisms. RESULTS: Our results suggested that Didymin may possess therapeutic potential against MAFLD in vitro and in vivo. By promoting Sirt1 expression as well as directly binding to and activating Sirt1, Didymin triggers downstream pathways that enhance mitochondrial biogenesis and function while reducing apoptosis and enhancing lipophagy. CONCLUSIONS: These suggest that Didymin could be a promising medication for MAFLD treatment. Furthermore, its therapeutic effects are mediated by Sirt1.

[Effects of baicalin and other Chinese herbal monomer on androgen receptor mRNA expression in SZ95 sebocytes].

OBJECTIVE: To determine the effects of Chinese herbal monomers such as baicalin, berberine, and matrine on the androgen receptor (AR) mRNA expression in SZ95 sebocytes in vitro and to explore the possible mechanism of using traditional Chinese medicines to treat acne. METHODS: SZ95 sebocytes were cultured and then treated with berberine, baicalin, matrine, and 13-cis-retinoic acid for 24 hours. Reverse transcription polymerase chain reaction was applied to detect the changes of AR. RESULT: AR mRNA was downregulated by 13-cis-retinoic acid of 1 x 10(-5) mol/L and 1 x 10(-6) mol/L, and by baicalin of 1 x 10(-4) mol/L (P < 0.05). CONCLUSION: 13-cis-retinoic acid and baicalin may exert antiandrogenitic action by inhibiting AR mRNA expression in human sebocytes.

[Sebaceous glands and acne].

New studys on the sebaceous glands in recent years have facilitated the further understanding and treatment of acne vulgaris. This article summarizes the advancements in the relationship between sebaceous glands and acne, with focus on androgen metabolism in skin, abnormal lipids secretion, and immunology of sebaceous gland cells.

[A de nono I462S mutation in the KRT6A gene is associated with pachyonychia congenita type I].

OBJECTIVE: To analyze the KRT6A gene mutation and mutating patterns in a sporadic Chinese patient with Pachyonychia congenita (PC)-1 so as to provide a basis for gene diagnosis and genetic counseling of this disorder. METHODS: Genomic DNA was extracted from whole blood by standard methods from a female patient with PC-1 and her parents, and from 50 normal, unrelated individuals. Primers for specific amplification of the structural KRT6A gene without co amplification of homologous genes were designed and synthesized. All exons of the gene and their flanking intronic sequences were amplified using polymerase chain reaction (PCR) and subjected to automatic DNA sequencing. The mutation was confirmed by Mbo I restriction digestion of the KRT6A-specific PCR products. RESULTS: Direct sequencing of the PCR products revealed a novel heterozygous missense mutation, I462S in the KRT6A gene, which resulted from T to G transversion at nucleotide 1385 (1385T > G) in exon 7 was detected in the patient. This mutation would result in the substitution of Isoleucine by Serine at codon 462 (I462S) located in the end 2B domain of keratin 6A. No such mutation was found in the patient's parents by sequencing of PCR products and this mutation was confirmed in the patient and excluded from both parents and 50 normal, unrelated controls by restriction analysis of PCR fragments using Mbo I enzyme. CONCLUSIONS: A de novo missense mutation in the KRT6A gene, I462S, has been found in a sporadic PC-1 patient. The identification of this novel mutation in the KRT6A gene provides further evidence that mutation in the KRT6A gene causes PC-1 phenotype.