Cordycepin protects against β-amyloid and ibotenic acid-induced hippocampal CA1 pyramidal neuronal hyperactivity

Cordycepin exerts neuroprotective effects against excitotoxic neuronal death. However, its direct electrophysiological evidence in Alzheimer's disease (AD) remains unclear. This study aimed to explore the electrophysiological mechanisms underlying the protective effect of cordycepin against the excitotoxic neuronal insult in AD using whole-cell patch clamp techniques. β-Amyloid (Aβ) and ibotenic acid (IBO)-induced injury model in cultured hippocampal neurons was used for the purpose. The results revealed that cordycepin significantly delayed Aβ + IBO-induced excessive neuronal membrane depolarization. It increased the onset time/latency, extended the duration, and reduced the slope in both slow and rapid depolarization. Additionally, cordycepin reversed the neuronal hyperactivity in Aβ + IBO-induced evoked action potential (AP) firing, including increase in repetitive firing frequency, shortening of evoked AP latency, decrease in the amplitude of fast afterhyperpolarization, and increase in membrane depolarization. Further, the suppressive effect of cordycepin against Aβ + IBO-induced excessive neuronal membrane depolarization and neuronal hyperactivity was blocked by DPCPX (8-cyclopentyl-1,3-dipropylxanthine, an adenosine A₁ receptor-specific blocker). Collectively, these results revealed the suppressive effect of cordycepin against the Aβ + IBO-induced excitotoxic neuronal insult by attenuating excessive neuronal activity and membrane depolarization, and the mechanism through the activation of A₁R is strongly recommended, thus highlighting the therapeutic potential of cordycepin in AD.

Chemical studies on alkaloids of Chinese medicinal herbs Daphniphyllum macropodum / 中国中药杂志

<p><b>OBJECTIVE</b>To study the alkaloids of the Chinese medicinal herbs Daphniphyllum macropodum for in search for new bioactive substances.</p><p><b>METHOD</b>The CHCl3 extract of D. macropodum was subjected to repeated column chromatography on silica gel to afford four pure compounds (1-4). Their structures were determined on the basis of detailed spectroscopic analysis and comparison with the data reported in the literature.</p><p><b>RESULT</b>The four known compounds were isolated and elucidated as Daphniphyllum alkaloids with different carbon skeletons, namely longistylumphylline A (1), deoxycalyciphylline B (2), daphnicyclidin B (3) and H (4), respectively.</p><p><b>CONCLUSION</b>All compounds were isolated from the titled plant for the first time. The discovery of daphnicyclidin B (3) and H (4) further confirmed the biogenetic relationship between the two compounds and the previously reported macropodumines A-C, found in the same plant.</p>

Progress of researches on the allergens Ara h 1, Ara h 2 and Ara h 3 from peanut / 生物医学工程学杂志

Peanut is one of the most popular foods in the world due to its high nutrition; however, it contains multiple seed storage proteins which are identified as allergens and hence are the most common cause of life-threatening, IgE-mediated anaphylaxis among the hypersensitive individuals. Three peanut proteins, Arachis hypogaea allergy 1, 2, 3 (Ara h 1, Ara h 2 and Ara h 3), which have the common biochemical characteristics like resistance to proteases and heat, are considered as the major allergens because they are recognized by serum IgE from a peanut-allergic patient population. The linear IgE-binding epitopes in the allergens lay the foundation of the anaphylaxis in the peanut-allergic individuals. Peanut allergy is often a life-long problem, so many investigators are focusing on decreasing clinical reactivity. In this review, the latest advances in the researches on biochemical characteristics, structure and function of the three major allergens were described and particular attention was given to the immunity properties of the three allergens. The future research directions were also discussed.

Three kinds of internal fixations for treatment of complex tibial plateau fractures: a comparative biomechanical study / 中华创伤杂志

Objective To evaluate the biomechanism of three kinds of internal fixations in treatment of complex tibial plateau fractures. Methods Eighteen human antiseptic cadaver tibial plateau specimens were used to make models of complex tibial plateau fracture (type Ⅵ fractures of Schatzker classification). The models were fixated with a lateral Golf-buttress plate (GP), modified dual plate (a lateral Golf-buttress plate plus a medial five-hole one-third tubular antiglide plate) (DP) or a lateral locking compression plate (LCP) respectively to compare strength, rigidity and stability of different fixation methods. Results The biomechanical strength, rigidity and stability in DP group and LCP group were better than those in GP group (P<0.05), while there was no statistical difference between LCP group and DP group (P>0.05). Conclusions Locking compression plate and modified dual plate are fairly ideal internal fixators for treatment of complex tibial plateau fractures. In the meantime, locking compression plate emphasizes conservation of soft tissues and blood supply, can better meet the requirement of the biological fixation of fracture and is the most ideal internal fixator at present.