Honokiol Dimers and Magnolol Derivatives with New Carbon Skeletons from the Roots of <i>Magnolia officinalis</i> and Their Inhibitory Effects on Superoxide Anion Generation and Elastase Release

<div><p>Two honokiol dimers, houpulins A and B (<b>1</b> and <b>2</b>), and two magnolol derivatives, houpulins C and D (<b>3</b> and <b>4</b>), were isolated and characterized from an ethanol extract obtained from the roots of <i>Magnolia officinalis</i>. The chemical structures were determined based on spectroscopic and physicochemical analyses, which included 1D and 2D NMR, as well as mass spectrometry data. These four oligomers possess new carbon skeletons postulated to be biosynthesized from the coupling of three or four C₆-C₃ subunits. In addition, the new oligomers were evaluated for inhibition of superoxide anion generation and elastase release, and houpulin B (<b>2</b>) was identified as a new anti-inflammatory lead compound.</p></div

[Ca²⁺]_i to return to half of the peak value (<i>t</i>_1/2) by compound 2.

<p>[Ca²⁺]_i to return to half of the peak value (<i>t</i>_1/2) by compound 2.</p

Plausible biosynthetic pathway to 1 and 2.

<p>Plausible biosynthetic pathway to 1 and 2.</p

Inhibitory effects of <b>1</b>–<b>4</b> on superoxide anion generation and elastase release by human neutrophils in response to FMLP/CB.

a<p>Concentration necessary for 50% inhibition. Results are presented as the mean ± S.D. (n = 3).</p>***<p>P<0.001 compared with the control value.</p>b<p>Alone induced superoxide generation by human neutrophils.</p>c<p>Sorafenib, a tyrosine kinase inhibitor, was used as a positive control.</p

Compound 2 did not alter activation of ERK, p38 MAPK, JNK, and Akt.

<p>Compound 2 did not alter activation of ERK, p38 MAPK, JNK, and Akt.</p

Physiologic parameters before (preocclusion) and after (postocclusion) permanent middle cerebral artery occlusion (PMCAO) between animals pretreated with magnolol versus vehicle (PEG 400)-treated controls.

<p>Physiologic data obtained from control and pre-treated animal groups are represented as the mean±standard deviation (SD). Hct – hematocrit; Gluc - blood glucose; MABP - mean arterial blood pressure; HR - heart rate; <i>n</i> – number of animals. All animals were maintained at 37±0.5°C. Paired Students’ <i>t</i> tests were used to evaluate the response to a change in conditions, and one-way Analysis of Variance (one-way ANOVA) with Dunnett’s <i>posthoc</i> comparison was used to evaluate differences between groups. The symbol * and <b>†</b> mean <i>P<</i>0.05, compared to preischemic and control data, respectively.</p

Application of flow cytometry for evaluating clinical prognosis and histopathological grade of human glioma

<p><b>Objectives:</b> Flow cytometry was applied to predict the biological parameters of tumor behavior based on the DNA content distribution of tumors. We used flow cytometry to determine the number of cell cycles for the characterization of intracranial gliomas and its possible prognostic role.</p> <p><b>Methods:</b> Flow cytometric analysis of the DNA content was performed for 37 fresh operative glioma specimens. The expression of Ki-67 in glioma specimens was detected using immunohistochemistry staining. The check points of G2/M-phase fractions, cyclin B, and pCdk1 (Y15) were analyzed using Western immunoblotting.</p> <p><b>Results:</b> Compared to low-grade (grade I/II) gliomas, significant differences in the Ki-67, cyclin B, G2/M-phase, and S+G2/M-phase expressions were found in high-grade (grade III/IV) gliomas. Furthermore, receiver operating characteristic (ROC) analysis indicated optimal cutoff points for the G2/M-phase and S+G2/M-phase fractions of 13.47 and 17.26%, respectively, which can be used to differentiate cases with low- and high-grade gliomas. Additionally, both G2/M-phase and S+G2/M-phase fractions had significant association with the expression of Ki-67 in the gliomas. The gliomas were classified by the DNA content. We found that patients with high-grade glioma had worse survival rate than patients with low-grade glioma. Meanwhile, ROC curve analysis gave cutoffs for G2/M-phase of 9.4% and for S+G2/M-phase fractions of 15.04% as best predicting survival. The patients with glioma had poor survival when the levels of G2/M-phase and S+G2/M-phase were more than 9.4 and 15.04%, respectively. In contrast, no significant association between the DNA content of glioma patients and their age, tumor recurrence, and tumor size was found.</p> <p><b>Discussion:</b> Our results indicate that flow cytometry analysis for G2/M-phase and S+G2/M-phase fractions can be used for tumor grading for rapidly differentiating low- from high-grade gliomas.</p

Neurobehavioral scores and body weight loss obtained after permanent middle cerebral artery occlusion (pMCAO) in each pretreatment group in the study.

<p>Data are represented as the mean±standard deviation (S.D.). <i>n</i> – number of animals.</p>*<p>means <i>P</i><0.05, compared to control data, respectively.</p

The changes of core temperatures obtained after vehicle or magnolol treatment in rats subjected to permanent middle cerebral artery occlusion (PMCAO) in the study.

<p>Data are represented as the mean±standard deviation (S.D.). <i>n</i> – number of animals.</p>*<p>means <i>P</i><0.05, compared to control data, respectively.</p

Magnolol attenuated glutamate-induced rises in the intracellular calcium, [Ca²⁺](i), inflow and cell swelling in cultured neurons.

<p>(A) Ratio image detection for [Ca²⁺](i) concentrations showed that magnolol at 0.1 µM, but not at 0.01 and 1 µM, effectively inhibited the rises of [Ca²⁺](i) induced by glutamate exposure. (B) Time-course differential interference contrast (DIC) photomicrographs of cultured neurons showed that magnolol at 0.1–1 µM attenuated the glutamate-induced cell swelling over time. *<i>P</i><0.05 vs controls, and <i>n</i> = 6–7 per group.</p