Silybum

Abstract: Silybum marianum, commonly known as Milk thistle, is a popular herbal supplement used for the treatment of jaundice and liver cirrhosis worldwide. Here we established methods for somatic embryogenesis and comparative metabolite profiling of the different growth phases during embryogenesis in S. marianum. Highest embryogenic potential was observed for calli previously derived from petiole explants on Schenk and Hildebrandt medium containing 2.5 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 N6-benzyladenine (BA). Somatic embryos (SE) were induced when embryogenic calli with pre-embryoid masses (PEMs) were subcultured on same media as used for induction of embryogenic callus. Highest number of somatic embryos (46 somatic embryo per callus) was observed at 1.5 mg l−1 2,4-D and 1.5 mg l−1 BA, however ½ strength MS medium showed optimal response for maturation followed by germination of somatic embryos at 1.5 mg l−1 GA3. Metabolite profiles from developmental stages of non-embryogenic callus (NEC), PEMs, SE and embryos germinating into intact plantlets (GSE) were obtained using Electro spray ionization mass spectrometry ESI/MS. Principal component analysis (PCA) was carried out to identify key metabolites in different growth phases during somatic embryogenesis. The loading scatter plots enabled the detection of several bin masses responsible for separating samples from different growth stages. Based on the values of % total ions count and average intensity of selected bins in all biological samples, putatively known metabolites were obtained from in-house bin program. Amino acids associated with various biosynthetic pathways like arginine, asparagine and serine were abundantly detected in GSE, while they were detected at decreased intensities in NEC. However, tryptophan was measured with increased signals in SE when compared to other growth phases. Glucose, fructose and fructose-6-phosphate were mostly accumulated in NEC; however they were detected with lowest intensities in GSE. Moreover, sucrose and significant secondary metabolites like cinnamic acid, kaempferol, quercetin, myricetin, linolenic acid, and 5-enolpyruvyl-shikimate-3-phosphate were found at higher amount in SE when compared to other embryogenic phases.

Abstract: Silymarin is a bioactive constituent isolated from milk thistle (Silybum marinum). Since its discovery, silymarin has been considered a gold standard drug in treating ailments related to the liver, resulting from alcohol consumption and viral hepatitis. This hepatoprotective nature of silymarin arises out of antioxidative and tissue-regenerating properties of silymarin. However, several recent studies have established the neuroprotective link of silymarin, too. Thus, the current investigation was aimed at exploring the neuroprotective effect of nanosilymarin (silymarin encapsulated inside collagen-based polymeric nanoparticulate drug delivery system). The study aimed at bringing out the role of nanoparticles in enhancing the therapeutic effect of silymarin against neuronal injury, originating out of oxidative-stress-related brain damages in focal cerebral ischemia. Collagen-based micellar nanoparticles were prepared and stabilized using 3-ethyl carbodiimide-hydrochloride (EDC-Hcl) and malondialdehyde (MDA) as crosslinkers. Nanoparticles were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy techniques, and the size of nanoparticles was found to be around 48 nm. Male albino Wistar rats were pretreated with three different doses of nanosilymarin of 10, 100, and 1,000 μg/kg b.wt and a dose of free silymarin of 100 mg/kg b.wt intraperitoneally (i.p.) for 7 days. Focal cerebral ischemia was induced using the middle cerebral artery occlusion (MCAO) model on the eighth day for 1 h followed by 24 h reperfusion. The animals were then evaluated for neurobehavioral, infarct analysis, biochemical, histopathological, and immunohistochemical studies. All the above parameters showed remarkable improvement in nanosilymarin-treated groups in comparison to the silymarin-treated group. Nanoparticle encapsulation of drug enhanced neuroprotection by increasing drug bioavailability and targeting. Thus, the present study concluded with satisfactory results, showing the critical role played by nanoparticles in improving the neuroprotection at very low drug doses.