Genus Gentiana: A review on phytochemistry, pharmacology and molecular mechanism.

ETHNOPHARMACOLOGICAL RELEVANCE: As the largest genus of Gentianaceae family, the Gentiana genus harbors over 400 species, widely distributed in the alpine areas of temperate regions worldwide. Plants from Gentiana genus are traditionally used to treat a wide variety of diseases including easing pain dispelling rheumatism, and treating liver jaundice, chronic pharyngitis and arthritis in China since ancient times. In this review, a systematic and constructive overview of the traditional uses, phytochemistry, molecular mechanisms, toxicology and pharmacological activities of the researched species of genus Gentiana is provided. MATERIALS AND METHODS: The used information in this review is based on various databases (PubMed, Science Direct, Wiley online library, Wanfang Data, Web of Science) through a search using the keyword "Gentiana" in the period of 1981-2019. Besides, other ethnopharmacological information was acquired from Chinese herbal classic books and Chinese pharmacopoeia 2015 edition. RESULTS: The plants from Gentiana genus have a long tradition of various medicinal uses in Europe and Asia. Phytochemical studies showed that the main bioactive components isolated from this genus includes iridoids xanthones and flavonoids. These compounds and extracts isolated from this genus show a wide range of protective activities including hepatic protection, gastrointestinal protection, cardiovascular protection, immunomodulation, joint protection, pulmonary protection, bone protection and reproductive protection. Molecular mechanism studies also indicated several potential therapeutic targets in the treatment of certain diseases by plants from this genus. Besides, natural products from this plant show no significant animal toxicity, cytotoxicity or genotoxicity. CONCLUSION: This review summarized the traditional medicinal uses, phytochemistry, pharmacology, toxicology and molecular mechanism of genus Gentiana, providing references and research tendency for plant-based drug development and further clinical studies.

Thymoquinone Attenuates Acetaminophen Overdose-Induced Acute Liver Injury and Inflammation Via Regulation of JNK and AMPK Signaling Pathway.

Thymoquinone (TQ) is a main aromatic component of Nigella sativa L. seeds or Agastache rugosa (Fisch. & C.A.Mey.) Kuntze. The protective mechanism of TQ against acute liver injury induced by acetaminophen (APAP), however, remains unclear. We aimed to investigated the hepato-protective mechanism of TQ on the development of APAP-induced acute liver injury. Male kunming mice were pretreated with TQ or N-acetylcysteine (NAC) before a single APAP injection. Human Chang liver cells were incubated with TQ, SP600125 or AICAR in presence of APAP for 24 h. TQ pretreatment reduced levels of serum aminotransferases and increased hepatic glutathione and glutathione peroxidase activities via inhibiting CYP2E1 expression. TQ inhibited JNK, ERK and P38 phosphorylation induced by APAP. Meanwhile, TQ inhibited PI3K/mTOR signaling activation and activated AMPK phosphorylation. Moreover, TQ prevented APAP-induced hepatocytes apoptosis regulated by Bcl-2 and Bax. Furthermore, TQ inhibited STAT3 phosphorylation on APAP-induced acute liver injury. In addition, TQ significantly inhibited P2X7R protein expression and IL-1 ß release. APAP-enhanced JNK phosphorylation and APAP-suppressed AMPK phosphorylation were also observed in Chang liver cells, and these changes were recovered by pretreatment with TQ, SP600125 and AICAR. Our findings suggest that TQ may actively prevent APAP-induced acute liver injury, and the effect may be mediated by JNK and AMPK signaling pathways.

Oligomeric proanthocyanidin derived from grape seeds inhibited NF-κB signaling in activated HSC: Involvement of JNK/ERK MAPK and PI3K/Akt pathways.

In current study, we aimed to reveal the potential antifibrotic effects of oligomeric proanthocyanidin (OPC) from grape seeds on lipopolysaccharide (LPS)-activated, HSC-T6, a rat hepatic stellate cell line. HSC-T6 cells were treated with OPC 1h prior to LPS, and then incubated for indicated time. OPC inhibited cells viability of HSC-T6 cells and decrease protein expression of collagen I, α-smooth muscle actin (α-SMA), tissue inhibitors of metalloproteinases I (TIMP-1) on LPS-induced HSC-T6 cells. OPC also significantly inhibited phosphorylation of LPS-stimulated phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). Furthermore, OPC pretreatment blocked LPS-triggered nuclear factor-kappa B (NF-κB) translocation from cytosol to nuclear. OPC, as well as specific inhibitors of NF-κB, PI3K and JNK could effectively inhibited α-SMA and collagen I expression. In conclusion, we demonstrated that the anti-fibrotic mechanism of OPC might be involved the inhibition of HSC activation and transdifferentiation by suppressing NF-κB activation through JNK/ERK MAPK and PI3K/Akt phosphorylation. Thus, OPC possesses the potential inhibitory property of HSC activation through NF-κB modulation involving MAPK-PI3K/AKT pathways.