A new, simple, sensitive, rapid, and accurate isocratic RP-HPLC method was developed and validated for simultaneous analysis of the principal antioxidants of Nigella sativa, i.e., thymoquinone (TQ), carvacrol (CR), and its isomer thymol (THY), in different phytopharmaceuticals. The mobile phase was water-methanol (40 + 60, v/v) at a flow rate of 1.5 mL/min. Quantification was achieved with UV detection at 254 nm, based on peak area. The method was validated for linearity, accuracy, precision, selectivity, and robustness. The proposed method is stability-indicating for determination of TQ in the presence of its degradants. The LOD and LOQ (microg/mL) were, respectively, 0.006 and 0.021 for TQ, 0.002 and 0.006 for CR, and 0.027 and 0.090 for THY. The mean recoveries measured at three concentrations were higher than 99%, with RSD <2%. This analytical method is suitable for quality control of the marker substances in this widely used natural protective and curative remedy.

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The aim of this study was to investigate the stability of three major antioxidants of Nigella sativa: thymoquinone (TQ), carvacrol (CR) and thymol (THY), under different stress conditions using HPLC and LC-MS/MS. Forced degradation for each compound was performed under different conditions, including oxidation, hydrolysis, photolysis and thermal decomposition. The results showed that both CR and THY were stable under the studied conditions, whereas TQ was not affected by acidic, basic and oxidative forced conditions but the effect of light and heat was significant. The degradation products of TQ were further investigated and characterized by LC-MS/MS. HPLC-UV method has been fully validated in terms of linearity and range, the limit of detection and quantitation, precision, selectivity, accuracy and robustness. The method was successfully applied to quantitative analysis of the principal antioxidants of Nigella sativa TQ, CR and THY in different phytopharmaceuticals.

Introduction: This systematic review aims to answer three research questions concerning the management of hereditary multiple osteochondromas of forearm in children: What is the best available evidence for the currently employed surgical procedures? What patient characteristics are associated with better prognosis? What disease characteristics are associated with better prognosis?Methods: We searched the literature using three major databases with no publication date restrictions. To enhance search sensitivity and maintain precision we used keywords/subject terms correlating with patient population, problem and interventions. We used strict inclusion/exclusion criteria to improve validity evidence.Results: The search process yielded 34 eligible studies with a total of 282 patients (315 forearms). We comprehensively analysed study and patient demographics and interventions and outcomes. Eleven studies (32%) had a long-term follow-up and 31 studies (91%) were retrospective. Of the total number of forearms, ulnar lengthening +/− associated procedures was used in 210 forearms (66.7%), isolated osteochondroma excision in 65 forearms (20.6%) and isolated distal radius hemiepiphysiodesis in 15 forearms (4.7%) among others.Discussion: Ulnar lengthening can restore radiologic anatomy, improve appearance and to a lesser extent objective clinical parameters like joint range of motion on the short/intermediate term. Isolated osteochondroma excision can relief pain and satisfy cosmetic concerns occasionally. There is poor evidence to suggest that surgery improves quality of life or function. Predictors of surgical success in regard to patient and disease characteristics remain elusive. Natural history and prospective randomized control studies where the control group receives no treatment should be rethought. They have the potential for bias control and identification of the ideal surgical candidate. The complex interplay between the confounding variables has undermined the capability of most studies to provide well-grounded evidence to support and generalize their conclusions. Valid quality of life scales should supplement objective outcome measures.

A high-performance liquid chromatography method employing diode array detection was developed to determine levels of the major catechins, proanthocyanidin (procyanidin B2), caffeine, thymoquinone and carvacrol and its isomer, thymol, which are present in different natural complex matrices found in commercial products of Camellia sinensis L. and/or Nigella sativa L. Reversed-phase separation was performed on a C18 column by using gradient elution by varying the proportions of solvent A (distilled water containing 0.05% orthophosphoric acid) and solvent B (acetonitrile), with a flow rate of 1.5 mL/min and duration of 31 min. Excellent linearity was observed for all standard calibration curves, and correlation coefficients were above 0.9996. The developed method is efficient, with high reproducibility and sensitivity, and is ideally suited for rapid and routine analysis of principal components in these promising medicinal plants.