Ameliorative Effect of Aqueous and Hydroalcoholic Extracts of Scrophularia striata Boiss. on Murine Model of Experimental Colitis.

Background: Scrophularia striata Boiss. (S. striata) is a flowering plant with several therapeutic properties including antiinflammatory, antioxidant, antimicrobial, and wound-healing activity. Regarding the side effects of drugs conventionally used for inflammatory bowel disease (IBD) treatment, we investigated the anticolitis properties of aqueous (SSAE) and hydroalcoholic (SSHE) extracts of S. striata on experimental colitis. Materials and Methods: The colitis was induced using acetic acid (3%) and 2 h before ulcer induction, each group of rats received orally three doses (150, 300, and 600 mg/kg, p.o.) of SSAE or SSHE for the next 5 days. Dexamethasone (1 mg/kg, i.p.) and mesalazine (100 mg/kg, p.o.) were used as reference drugs. Different parameters including weight of colon/height, ulcer index, total colitis index, levels of myeloperoxidase (MPO) and malondialdehyde (MDA) were investigated. Results: Total phenolic contents were 4.3 ± 0.2 and 7.1 ± 0.4 mg/g equivalent to gallic acid for SSAE and SSHE respectively. Three applied doses of SSHE and the highest dose of SSAE (600 mg/kg) could reduce all the macroscopic and pathologic indices of colitis and the levels of MPO and MDA. Two lesser doses of SSAE (150, 300 mg/kg) however, couldn't diminish the histopathologic features of colitis and the values of MPO and MDA. Conclusions: S. striata, especially SSHE, which also contained more phenolic compounds, had an ameliorating effect on ulcerative colitis and possibly exerts this effect through its antioxidant, antiinflammatory and wound healing properties. Further investigations are required to introduce this plant as a novel alternative herbal drug for colitis treatment.

Morphological studies of self-assembled cyclotides extracted from Viola odorata as novel versatile platforms in biomedical applications.

Self-assembling peptides have attracted researchers' attention recently. They are classified as biomedical materials with unique properties formed in response to environmental conditions. Cyclotides are macrocyclic plant-derived peptides containing 28-37 amino acids that have the ability to self-assemble. Herein, we investigated the effect of pH, time, and temperature on the self-assembling properties of the cyclotides extracted from Viola odorata. For this purpose, the cyclotides were dispersed in aqueous trifluoroacetic acid at pH 2, 4, or 6 and incubated at 25 or 37 °C for 1, 2, 3, 5, 7 or 10 days, and the morphology of the self-assembled structures was identified by optical microscopy, polarized optical microscopy, scanning electron microscopy, transmission electron microscopy, and fluorescence microscopy. At pH 2 and 4, the self-assembly process of cyclotides comprises a number of steps, starting with the formation of spherical peptide nanostructures followed by hierarchically assembled nanotubes, and then shifting to nanofibers after 10 days. At pH 6, amorphous structures were produced even after 10 days. The temperature also could affect the self-assembly mechanism of the cyclotides. At 25 °C, the spherical peptide micelles formed firstly and then merged to form nanotubes, while at 37 °C the cyclotides showed crystallization followed by an increase in length with time. The fluorescence microscopy images showed that the nanotubes could efficiently entrap the hydrophobic molecules of coumarin. This comparative study on the self-assembly of the cyclotides extracted from Viola odorata is the first example exploring the capacity of these cyclotides to adopt precise nanostructures. The nanotubes and nanofibers obtained with these cyclotides might find interesting applications in drug delivery and tissue engineering.

Isolation of Cinnamic Acid Derivatives from the Bulbs of Allium tripedale.

BACKGROUND: Allium genus with 750 species is the most diverse genus in the Amaryllidaceae family. Historically, Allium species have been used as medicinal plants, especially for prevention and treatment of cardiovascular diseases and considered as valuable sources of phytonutrients. Phytochemical investigation of Allium tripedale, locally called "Anashq," which is an edible plant of the "Zagros" region (west of Iran) was conducted in the present study. MATERIALS AND METHODS: Air-dried bulbs of the plant were extracted in a four-step extraction method with increasing polarity using hexane, chloroform, chloroform-methanol (9:1), and methanol. Chloroform-methanol (9:1) extract was fractionated by medium-pressure liquid chromatography on a RP-18 column using a linear gradient solvent system of H2O to MeOH. Phenolic-rich fractions were subjected to the final isolation and purification of the constituents by reversed-phase high-performance liquid chromatography method. Structure elucidation of the compounds was performed through comprehensive methods including 1D-and 2D-NMR and mass spectroscopy. RESULTS: Two cinnamic acid derivatives were isolated from the bulbs of A. tripedale; using spectroscopic methods, their chemical structures were determined as 6,7-dimethoxy N-trans-caffeoyltyramine (1) and N-trans-feruloyltyramine (2). CONCLUSION: Cinnamic acid derivatives are pharmacologically active phenolic compounds, which have been isolated from different Allium species. Isolation of these compounds from A. tripedale is reported for the first time in this study and could be used as a chemical basis for explanation of the plant biological and pharmacological activities.