Progress in Identification of UDP-Glycosyltransferases for Ginsenoside Biosynthesis.

Ginsenosides, the primary pharmacologically active constituents of the Panax genus, have demonstrated a variety of medicinal properties, including anticardiovascular disease, cytotoxic, antiaging, and antidiabetes effects. However, the low concentration of ginsenosides in plants and the challenges associated with their extraction impede the advancement and application of ginsenosides. Heterologous biosynthesis represents a promising strategy for the targeted production of these natural active compounds. As representative triterpenoids, the biosynthetic pathway of the aglycone skeletons of ginsenosides has been successfully decoded. While the sugar moiety is vital for the structural diversity and pharmacological activity of ginsenosides, the mining of uridine diphosphate-dependent glycosyltransferases (UGTs) involved in ginsenoside biosynthesis has attracted a lot of attention and made great progress in recent years. In this paper, we summarize the identification and functional study of UGTs responsible for ginsenoside synthesis in both plants, such as Panax ginseng and Gynostemma pentaphyllum, and microorganisms including Bacillus subtilis and Saccharomyces cerevisiae. The UGT-related microbial cell factories for large-scale ginsenoside production are also mentioned. Additionally, we delve into strategies for UGT mining, particularly potential rapid screening or identification methods, providing insights and prospects. This review provides insights into the study of other unknown glycosyltransferases as candidate genetic elements for the heterologous biosynthesis of rare ginsenosides.

Pien-Tze-Huang alleviates CCl4-induced liver fibrosis through the inhibition of HSC autophagy and the TGF-ß1/Smad2 pathway.

Ethnopharmacological relevance: Pien-Tze-Huang (PZH)-a traditional Chinese medicine (TCM) compound-has been employed to treat various liver inflammation and tumors for over 10 decades. Interestingly, most of the pharmacological effects had been validated and explored toward liver ailment along with pro-inflammatory conditions and cancer at the cellular and molecular level to date. Aim of the study: The present study aimed to investigate the therapeutic effect of PZH on autophagy and TGF-ß1 signaling pathways in rats with liver fibrosis and hepatic stellate cell line (HSC). Materials and methods: Male SD rats with carbon tetrachloride (CCl4)-induced liver fibrosis were used as the animal model. Next, PZH treatment was given for 8 weeks. Afterward, the therapeutic effects of PZH were analyzed through a hepatic tissue structure by hematoxylin-eosin (H&E), Van Gieson (VG) staining, and transmission electron microscopy (TEM), activity of ALT and AST by enzyme-associated immunosorbent assay as well. Subsequently, mRNA and protein expression were examined by quantitative polymerase chain reaction (qPCR), Western blotting, and immunohistochemistry (IHC). Then, the cell vitality of PZH-treated HSC and the expression of key molecules prevailing to autophagy were studied in vitro. Meanwhile, SM16 (a novel small molecular inhibitor which inhibits TGFß-induced Smad2 phosphorylation) was employed to confirm PZH's effects on the proliferation and autophagy of HSC. Results: PZH pharmacologically exerted anti-hepatic fibrosis effects as demonstrated by protecting hepatocytes and improving hepatic function. The results revealed the reduced production of extracellular collagen by adjusting the balance of matrix metalloproteinase (MMP) 2, MMP9, and tissue inhibitor of matrix metalloproteinase 1 (TIMP1) in PZH-treated CCl4-induced liver fibrosis. Interestingly, PZH inhibited the activation of HSC by down-regulating TGF-ß1 and phosphorylating Smad2. Furthermore, PZH down-regulated yeast Atg6 (Beclin-1) and microtubule-associated protein light chain 3 (LC3) toward suppressing HSC autophagy, and PZH exhibited similar effects to that of SM16. Conclusion: To conclude, PZH alleviated CCl4-induced liver fibrosis to reduce the production of extracellular collagen and inhibiting the activation of HSC. In addition, their pharmacological mechanisms related to autophagy and TGF-ß1/Smad2 signaling pathways were revealed for the first time.

Gualou Guizhi Granule Suppresses LPS-Induced Inflammatory Response of Microglia and Protects against Microglia-Mediated Neurotoxicity in HT-22 via Akt/NF-κB Signaling Pathways.

Neuroinflammation plays a crucial part in the commencement and advancement of ischemic stroke. Gualou Guizhi granule (GLGZG) is known to well exhibit neuroprotective effect, but it is not known whether GLGZG can regulate the inflammatory process at the cellular level in BV2 microglia cells and protect against microglia-mediated neurotoxicity in neurons. Herein, we aimed to investigate the anti-inflammatory effects of GLGZG on BV2 microglia cells and protection against microglia-mediated neurotoxicity in neurons. Methods. The cell model of neuroinflammation was constructed by lipopolysaccharide (LPS) to observe the effect of GLGZG in the presence or absence of GLGZG. The production of nitric oxide (NO), inflammatory mediators, was detected. Moreover, potential mechanisms associated with the anti-inflammatory effect, such as inhibition of microglial activation and nuclear factor kappa B (NF-κB), were also investigated. In addition, to prove whether GLGZG protects against microglia-mediated neurotoxicity, neuronal HT-22 cells were cultured in the conditioned medium. And cell survivability and neuronal apoptosis of HT-22 were evaluated. Results. It was found that a main regulator of inflammation, NO, is suppressed by GLGZG in BV2 microglial cells. Moreover, GLGZG dose dependently decreased the mRNA and protein levels of inducible NO synthase (iNOS) in LPS-stimulated BV2 cells. Additionally, GLGZG inhibited the expression and secretion of proinflammatory cytokines in BV2 microglial cells. Also, GLGZG inhibited LPS-activated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in BV2 microglial cells at the intracellular level. GLGZG significantly affected Akt phosphorylation: phosphorylated forms of Akt increased. To check whether GLGZG protects against microglia-mediated neurotoxicity, neuronal HT-22 cells were incubated in the conditioned medium. GLGZG showed a neuroprotective effect by promoting cell survivability and suppressing neuronal apoptosis. Conclusions. GLGZG exerted its potential effects on suppressing inflammatory responses in LPS-induced BV2 cells by regulating NF-κB and Akt pathways. In addition, GLGZG could protect against microglia-mediated neurotoxicity in HT-22.

Compound GDC, an Isocoumarin Glycoside, Protects against LPS-Induced Inflammation and Potential Mechanisms In Vitro.

Compound 3R-(4'-hydroxyl-3'-O-ß-D-glucopyranosyl phenyl)-dihydro isocoumarin (GDC) is a natural isocoumarin, recently isolated from the stems of H. paniculiflorum. However, we know little about the effects of GDC on rheumatoid arthritis (RA). This study aims to investigate the protective effects and potential mechanisms of GDC against LPS-induced inflammation in vitro. Fibroblast-like synoviocytes (FLSs) obtained from synovial tissue of rats were induced by lipopolysaccharide (LPS) and treated with GDC. Cell viability was determined by mitochondrial-respiration-dependent3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. Secretion of various inflammatory mediators was analyzed by ELISA and RayBio® Rat Cytokine Antibody Array. Potential mechanisms that are associated with anti-inflammatory effect were examined by Western blot. Results showed that GDC significantly inhibited the production of tumor necrosis factor alpha (TNF-α) and interleukin- (IL-) 6 induced by LPS. GDC also reduced the expression of inducible nitric oxide synthase (iNOS), TNF-α, IL-6, and IL-1ß, as well as proinflammatory cytokines such as activin A, ciliary neurotrophic factor (CNTF), fractalkine, IFN-γ, IL-4, and TIMP-1. Moreover, GDC inhibited LPS-induced phosphorylation of extracellular regulated protein kinases (ERK1/2), p38 mitogen-activated protein kinases (p38), c-Jun N-terminal kinase (JNK), and IκB. And GDC also blocked NF-κBp65 nuclear translocation. All the results suggested that the protective effects of GDC against LPS-induced inflammation in vitro may be related with NF-κB and JNK signaling pathway.

Apoptosis Effects of Dihydrokaempferol Isolated from Bauhinia championii on Synoviocytes.

Bauhinia championii (Benth.) Benth. is a traditional medicinal plant used in China to treat rheumatoid arthritis (RA), especially in She ethnic minority group. This study focused on the active constituents from the rattan of B. championii (Benth.) Benth., which possess potential apoptosis effects. A conventional phytochemical separation method for the isolation of compounds from the ethyl acetate extract of B. championii was developed. The procedure involved extraction, liquid-liquid partitioning with ethyl acetate, and subsequent compound purification, respectively. Additionally, cell viability of dihydrokaempferol found abundantly in it was evaluated in vitro by MTS, and the antiapoptosis effect was evaluated by annexin V/PI staining (Flow Cytometry Analysis) and western blot. The results showed that nine flavonoids, and five other compounds, were isolated from the ethyl acetate extract of B. championii and were identified as ß-sitosterol (1), 5,6,7,3',4',5'-hexamethoxyflavone (2), 3',4',5,7-tetrahydroxyflavone (3), 5,7,3',4',5'-pentamethoxyflavone (4), 4'-hydroxy-5,7,3',5'-pentamethoxyflavone (5), apigenin (6), liquiritigenin (7), 5, 7-dihydroxylcoumarin (8), 3',4',5,7, -pentamethoxyflavone (9), n-octadecanoate (10), lupine ketone (11), dibutylphthalate (12), dihydrokaempferol (13), and 5,7,3',5'-tetrahydroxy-6-methylflavanone (14). Among these compounds, 5-14 were isolated for the first time from B. championii. In addition, apoptosis effects of abundant dihydrokaempferol were evaluated in vitro. Dihydrokaempferol exhibited inhibitory effects on the proliferation of synoviocytes. Furthermore, dihydrokaempferol promoted Bax and Bad expression, as well as the cleavage of caspase-9, caspase-3, and PARP. Meanwhile, it inhibited Bcl-2 and Bcl-xL expression. These findings indicate that dihydrokaempferol isolated from the ethyl acetate extract of B. championii effectively promotes apoptosis, which is an important process through suppression of apoptotic activity. The results are encouraging for further studies on the use of B. championii in the treatment of RA.