The marine environment represents approximately half of the global biodiversity and could provide unlimited biological resources for the production of therapeutic drugs. Marine seaweeds comprise few thousands of species representing a considerable part of the littoral biomass. Extracts of the Cystoseira indica and Cystoseira merica were subjected to phytochemical and cytotoxicity evaluation. The amount of total phenol was determined with Folin-Ciocalteu reagent. Cytotoxicity was characterized by IC50 of human cancer cell lines including MCF-7 (human breast adenocarcinoma), HeLa (cervical carcinoma), and HT-29 (human colon adenocarcinoma) using Sulforhodamin assay. Antioxidant activities were evaluated using 2,2-diphenylpicrylhydrazyl (DPPH) method. The analysis revealed that tannins, saponins, sterols and triterpenes were the most abundant constituents in these Cystoseira species while cyanogenic and cardiac glycosides were the least ones. C. indica had the higher content of total phenolics and also showed higher antioxidant activity. Cytotoxic results showed that both species inhibited cell growth effectively, especially against MCF-7 cell line. The present findings suggest potential pharmacological applications of selected seaweeds but require further investigation and identification of their bioactive principles.

The purpose of the present study was to compare mesoporous and fumed silica nanoparticles (NPs) to enhance the aqueous solubility and oral bioavailability of raloxifene hydrochloride (RH). Mesoporous silica NPs (MSNs) and fumed silica NPs were used by freeze-drying or spray-drying methods. MSNs were obtained with different ratios of cetyltrimethylammonium bromide. Saturation solubility of the NPs was compared with the pure drug. The optimised formulation was characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry. The pharmacokinetic studies were done by oral administration of a single dose of 15 mg/kg of pure drug or fumed silica NPs of RH in Wistar rats. MSNs enhanced the solubility of RH from 19.88 ± 0.12 to 76.5 μg/ml. Freeze-dried fumed silica increased the solubility of the drug more than MSNs (140.17 ± 0.45 μg/ml). However, the spray-dried fumed silica caused about 26-fold enhancement in its solubility (525.7 ± 93.5 μg/ml). Increasing the ratio of silica NPs enhanced the drug solubility. The results of XRD and SEM analyses displayed RH were in the amorphous state in the NPs. Oral bioavailability of NPs showed 3.5-fold increase compared to the pure drug. The RH loaded fumed silica NPs prepared by spray-drying technique could more enhance the solubility and oral bioavailability of RH.

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Self-assembling peptides attract 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...