METHODS: A rapid, specific, reversed phase, HPLC-UV method with an isocratic elution of acetonitrile and 2% v/v acetic acid (40% : 60% v/v) (pH 2.6) at a flow rate of 1.3 mL/minutes, a column temperature of 35°C, and ultraviolet (UV) detection at 370 nm was developed. The method was validated and applied to the quantification of different types of market available Chinese medicine extracts, pills and tablets.
RESULTS: The method allowed simultaneous determination of quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin in the concentration ranges of 0.00488 ─ 200 μg/mL, 0.625 ─ 320 μg/mL, 0.07813 ─ 320 μg/mL and 0.03906 ─ 320 μg/mL, respectively. The limits of detection and quantification, respectively, were 0.00488 and 0.03906 μg/mL for quercetin, 0.62500 and 2.50000 μg/mL for bisdemethoxycurcumin, 0.07813 and 0.31250 μg/mL for demethoxycurcumin, and 0.03906 and 0.07813 μg/mL for curcumin. The percent relative intra day standard deviation (% RSD) values were 0.432 ─ 0.806 μg/mL, 0.576 ─ 0.723 μg/mL, 0.635 ─ 0.752 μg/mL and 0.655 ─ 0.732 μg/mL for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and those for intra day precision were 0.323 ─ 0.968 μg/mL, 0.805 ─ 0.854 μg/mL, 0.078 ─ 0.844 μg/mL and 0.275 ─ 0.829 μg/mL, respectively. The intra day accuracies were 99.589% ─ 100.821%, 98.588% ─ 101.084%, 9.289% ─ 100.88%, and 98.292% ─ 101.022% for quercetin, bisdemethoxycurcumin, demethoxycurcumin and curcumin, respectively, and the inter day accuracy were 99.665% ─ 103.06%, 97.669% ─ 103.513%, 99.569% ─ 103.617%, and 97.929% ─ 103.606%, respectively.
CONCLUSION: The method was found to be simple, accurate and precise and is recommended for routine quality control analysis of commercial Chinese medicine products containing the flour flavonoids as their principle components in the extracts.
METHODS: A cross-sectional study was conducted in 320 students from urban and rural secondary schools. The participants were randomly selected via multi-stage sampling. They completed the Malay versions of the Children's Depression Inventory (CDI) and Beck Scale for Suicide Ideation (BSS).
RESULTS: The prevalence of depressive symptoms was 26.2%. On binary logistic regression analysis, variables with significant association with depressive symptoms were race (P = 0.028), type of class (P < 0.001), mother's education level (P = 0.036), type of housing (P = 0.036), parents' marital status (P = 0.012), alcohol intake (P = 0.005), stealing (P < 0.001) and history of disciplinary record (P = 0.005). Variables that remained significant on multivariable logistic regression were type of class (P = 0.004), parents' marital status (P = 0.017) and stealing (P < 0.001). Students from the Arts stream (OR, 2.43) with parents who were separated, divorced or widowed (OR, 3.13) and who had experience of stealing (OR, 3.27) were predicted to be at risk of developing depressive symptoms. There was a significant correlation between total CDI score and total BSS score (P < 0.001).
CONCLUSIONS: The prevalence of depressive symptoms in adolescents was high. Depressive symptoms are significantly correlated with suicidal ideation. Greater collaboration between the education and health agencies is essential for mental health promotion in schools and early detection of depression, especially in at-risk adolescents.