Browsing by Subject "Silymarin"

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    Alterations in the silymarin metabolism in transgenic Silybum marianum cultured cells by the heterologous expression of the Arabidopsis thaliana V-myb myeloblastosis viral oncogene homolog transcription factor MYB12 and Cicer arietinum chalcone synthase
    (Elsevier, 2020-11-01) Villar, David; Palazón, Javier; Corchete, Purificación; Almagro Romero, Lorena; Biología Vegetal
    Silymarin (Sm), the main bioactive principle of Silybum marianum (L.) Gaernt. fruits, has strong antihepatotoxic properties and also exhibits antitumor and antiviral activity. This flavonolignan complex is synthesized from the flavonoid precursor taxifolin, which undergoes an oxidative coupling with the monolignol coniferyl alcohol. Attempts to produce Sm in plant cell suspensions have met with limited success, probably due to insufficient flux into the flavonoid branch pathway of Sm biosynthesis. In this study, it was attempted to increase Sm production in in vitro cultures of S. marianum by genetically engineering the flavonoid pathway. Using Agrobacterium tumefaciens strain C58C1, S. marianum cell suspension cultures were transformed either with the Arabidopsis thaliana transcription factor AtMYB12 (V-myb myelo-blastosis viral oncogene homolog) (MYB) or with a chalcone synthase (CHS) gene from Cicer arietinum. A double transformant was also generated by introducing the CaCHS gene in AtMYB12-expressing cultures. The ectopic expression of AtMYB12 in cultures activated some of the genes involved in the flavonoid pathway, notably chalcone isomerase (CHI) and flavonoid 3′-hydroxylase (F3’H), whereas the secondary metabolites al-tered by the inserted gene were chlorogenic acid glycoside derivatives. Expression of CaCHS in the cultures led to the production of the flavanone naringenin (Ng), which accumulated as glycosides. The simultaneous ex-pression of AtMYB12-CaCHS resulted in the production of lower amounts of chlorogenic derivatives but similar levels of Ng glycosides compared with the CaCHS lines. Both CaCHS lines and the double transformant could be maintained over prolonged subcultures without Ng production losses, confirming long-term and stable CaCHS transgene expression. In no case did the inserted genes have a discernable effect on Sm production compared with the un-transformed cultures, neither under control culture conditions or in cultures elicited with MeJA.
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    Histological and immunohistochemical effects of L-arginine and silymarin on TNBS-induced inflammatory bowel disease in rats
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Al-Drees, Abdul Majeed; Khalil, Mahmoud Salah
    Inflammatory bowel disease (IBD) is a chronic disease that affects quality of life. Various mediators are involved in IBD pathogenesis including inducible nitric oxide synthase (iNOS), nuclear factor kappa B (NF-κB), cytochrome c, heat shock protein 70 (HSP70) and tumor necrosis factor (TNF)-α. L-Arginine (L-Arg) can be depleted in IBD, and silymarin inhibits neutrophil infiltration, NF-κB, and TNF-α, which have crucial roles in inducing IBD. This study aimed to investigate whether silymarin and L-Arg supplementation decreases IBD progression in trinitrobenzinesulfonic acid (TNBS)-induced colitis. Fifty adult male albino rats were randomized into five groups (10 animals per group): Group I rats orally received 10 mg silymarin/100 g body weight once daily; Group II rats orally received 2 mg L-Arg/100 g body weight once daily; Group III rats rectally received 0.85 mL TNBS in 50% ethanol to induce colitis; Group IV rats were treated similar to group III and, on recovery from anesthesia, received silymarin as described for group I; and Group V rats were treated similar to group III and, on recovery from anesthesia, received L-Arg as described for group II. On day 7, the rats were anesthetized, and blood samples were collected to determine the serum concentrations of TNF-α. Laparotomy and total colectomy were performed for macroscopic, histological, and immunohistochemical investigations. The results showed that silymarin and L-Arg macroscopically and microscopically ameliorated TNBS-induced colitis; significantly decreased the serum levels of TNFα; inhibited the colonic expression of iNOS, NF-κB, and cytochrome c; and increased expression of HSP70. Our results suggest that these complementary medicines could be used to supplement current treatments for IBD.