A new type of sandwich electrochemiluminescence (ECL) immunosensor dependent on ECL resonance energy transfer (ECL-RET) to achieve sensitive detection of procalcitonin (PCT) has been designed. In brief, carbon nanotubes (CNT) and Au-nanoparticles-functionalized graphitic carbon nitride (g-C3N4–CNT@Au) and CuO nanospheres covered with polydopamine (PDA) layer (CuO@PDA) were synthesized and applied as ECL donor and receptor, respectively. g-C3N4–CNT nanomaterials were in situ prepared on the basis of π–π conjugation, and the CNT content in the composite were optimized to achieve a strong and stable ECL signal. At the same time, Au nanoparticles were used to functionalize g-C3N4–CNT to further increase the ECL intensity and the loading amount of primary antibody (Ab1). Moreover, CuO@PDA was first used to successfully quench the ECL signal of g-C3N4–CNT@Au. Under the optimum experimental conditions, the linear detection range for PCT concentration was within 0.0001–10 ng mL–1 and the detection limit was 25.7 fg mL–1 (S/N = 3). Considering prominent specificity, reproducibility, and stability, the prepared immunosensor was used to assess recovery rate of PCT in human serum according to the standard addition method and the result was satisfactory. In addition, it is worth mentioning that a novel ECL-RET pair of g-C3N4–CNT@Au (donor)/CuO@PDA (acceptor) was first developed, which offered an effective analytical tool for sensitive detection of biomarkers in early disease diagnostics.

Natural products with non-toxic and environmentally friendly properties are good resources for skin-whitening cosmetic agents when compared to artificial synthetic chemicals. Here, we investigated the effect of glyceollin produced to induce disease resistance responses of soybean to specific races of an incompatible pathogen, phytophthora sojae, on melanogenesis and discussed their mechanisms in melanin biosynthesis. We found that glyceollin inhibits melanin synthesis and tyrosinase activity in B16 melanoma cells without cytotoxicity. To elucidate the mechanism of the effect of glyceollin on melanogenesis, we conducted western blot analysis for melanogenic enzymes such as tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2. Glyceollin inhibited tyrosinase and TRP-1 protein expression. Additionally, glyceollin effectively inhibited intracellular cAMP levels in B16 melanoma cells stimulated by α-melanocyte stimulating hormone (α-MSH). These results suggest that the whitening activity of glyceollin may be due to the inhibition of cAMP involved in the signal pathway of α-MSH in B16 melanoma cells. [BMB reports 2010; 43(7): 461-467]

Pseudoginsenoside-F11 (PF11), a component of Panax quinquefolism (American ginseng), plays a lot of beneficial effects on disorders of central nervous system. In this paper, the neuroprotective effect of PF11 on Parkinson's disease (PD) and the possible mechanism were investigated in a rat PD model. PF11 was orally administered at 3, 6, and 12 mg/kg once daily for a period of 2 weeks before and 1 week after the unilateral lesion of left medial forebrain bundle (MFB) induced by 6-hydroxydopamine (6-OHDA). The results showed that PF11 markedly improved the locomotor, motor balance, coordination, and apomorphine-induced rotations in 6-OHDA-lesioned rats. The expression of tyrosine hydroxylase (TH) in substantia nigra (SN) and the content of extracellular dopamine (DA) in striatum were also significantly increased after PF11 treatment. Moreover, significant reduction in the levels of striatal extracellular hydroxyl radical (∙OH), detected as 2,3- and 2,5-dihydroxy benzoic acid (2,3- and 2,5-DHBA), and increase in the level of striatal extracellular ascorbic acid (AA) were observed in the PF11-treated groups compared with 6-OHDA-lesioned rats. Taken together, we propose that PF11 has potent anti-Parkinson property possibly through inhibiting free radical formation and stimulating endogenous antioxidant release.

Glyceollins, produced to induce disease resistance responses against specific species, such as an incompatible pathogen Phytophthora sojae in soybeans, have the potential to exhibit anti-inflammatory activity in RAW 264.7 cells. To investigate the anti-inflammatory effects of elicited glyceollins via a signaling pathway, we studied the glyceollin signaling pathway using several assays including RNA and protein expression levels. We found that soybean glyceollins significantly reduced LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, as well as the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) via the suppression of NF-κB activation. Glyceollins also inhibited the phosphorylation of IκBα kinase (IKK), the degradation of IκBα, and the formation of NF-κB-DNA binding complex in a dose-dependent manner. Furthermore, they inhibited pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-18, but increased the generation of the anti-inflammatory cytokine IL-10. Collectively, the present data show that glyceollins elicit potential anti-inflammatory effects by suppressing the NF-κB signaling pathway in RAW 264.7 cells.

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