Several medicinal foods abound in traditional medicine with antioxidant potentials that could be of importance for the management of several diseases but with little or no scientific justification to substantiate their use. Thus, the objective of this study was the assessment of the antioxidant effect of two leave extracts of Solanum nigrum L. (SN), which is a medicinal plant member of the Solanaceae family, mainly used for soup preparation in different parts of the world. Then methanolic/water (80:20) (SN1) and water (SN2) leaves extracts were prepared. The total polyphenolic content and the concentration of phenolic acids and flavones compounds were determined. In order to verify whether examined extracts were able to restore the oxidative status, modified by glutamate in primary cultures of astrocytes, the study evaluated the glutathione levels, the intracellular oxidative stress, and the cytotoxicity of SN1 and SN2 extracts. Both extracts were able to quench the radical in an in vitro free cellular system and restore the oxidative status in in vitro primary cultures of rat astroglial cells exposed to glutamate. These extracts prevented the increase in glutamate uptake and inhibited glutamate excitotoxicity, which leads to cell damage and shows a notable antioxidant property.

A simple high-performance liquid chromatography method using a diode array detector (DAD) is developed for the simultaneous analysis of five major catechins: (+)-catechin (C), (−)-epicatechin (EC), (−)-gallocatechin (GCT), (−)-epigallocatechin (EGC), (−)- epigallocatechin gallate (EGCG), and the phenolic plant metabolites gallic acid (GA) and rutin (RT) in lyophilized extracts of Cistus species. The optimal analytical conditions are investigated to obtain the best resolution and the highest UV sensitivity for the quantitative detection of catechins. The optimized conditions (acetonitrile-phosphate buffer 50mM, pH 2.5, gradient elution system on a C₁₈ reversed-phase column with a flow rate of 1 mL/min and UV absorbance at 210 nm) allowed a specific and repeatable separation of the studied analytes to be achieved. All compounds are successfully separated within 32 min. Calibration curves are linear in the 2–50 µg/mL range for GCT, C, and EGCG and in the 5–50 µg/mL range for GA, EGC, EC, and RT. The limit of detection values ranged from 0.24 to 0.74 µg/mL. The limit of quantitation limit values ranged from 0.77 to 1.94 µg/mL. The validated method is applied to the determination of the specific phytochemical markers GA, GCT, C, and RT in Cistus incanus and Cistus monspeliensis lyophilised extracts. The recovery values ranged between 78.7% and 98.2%. The described HPLC method appears suitable for the differentiation and determination of the most common catechins together with the glycoside rutin and the phenolic compound gallic acid and can be considered an effective and alternative procedure for the analyses of this important class of natural compounds.

1-(2,5-Dihydroxyphenyl)-2-bromoethanone (2,5-DBE) has been used as an electroactive labelling reagent for high performance liquid chromatographic (HPLC) analysis of chenodeoxycholic acid impurity in pharmaceutical formulations of ursodeoxycholic acid. The preparation of this reagent has been performed in a single step by bromination of 2,5-dihydroxyacetophenone (2,5-DAP), with remarkable improvement as regards the synthesis previously reported. Several experiments have been performed in order to give maximum conversion of the bile acids to their electroactive esters. The determination of the derivatized compounds has been carried out on an Adsorbosphere column with a methanol-acetonitrile-acetate buffer eluent and detected by a porous graphite electrode set at an oxidation potential of + 0.6 V. The high sensitivity and specificity shown by this novel method allows the determination of low concentrations of the cited impurity in capsule and tablet formulations containing the above therapeutic agent.