Antifungal activity of cinnamaldehyde against Fusarium sambucinum involves inhibition of ergosterol biosynthesis.

AIMS: In this study, the antifungal effect of cinnamaldehyde against Fusarium sambucinum and its underlying mechanisms were determined. METHODS AND RESULTS: Minimum inhibitory concentration and minimal fungicidal concentration of cinnamaldehyde were 3 and 4 mmol l-1 on spore germination and colony development assays in vitro, respectively. Furthermore, the lesion diameter of potato tubers and tuber slices inoculated with F. sambucinum was reduced by 76·9 and 69% after treatment with 4 mmol l-1 cinnamaldehyde. Cytometric analyses revelled that cinnamaldehyde significantly affected the integrity of cell membrane firstly, then decreased mitochondrial membrane potential and induced the accumulation of intracellular reactive oxygen species. Meanwhile, high-performance liquid chromatography results indicated that 3 mmol l-1 cinnamaldehyde could reduce the ergosterol content by 67·94%. This effect was accompanied by a down-regulation of ERG11, ERG6 and ERG4 which were involved in ergosterol biosynthesis. CONCLUSION: Theses results suggest that cinnamaldehyde exerts strong antifungal activity against F. sambucinum, probably by affecting the ergosterol biosynthetic processes what leads to the disruption of cell membrane integrity. SIGNIFICANCE AND IMPACT OF THE STUDY: Cinnamaldehyde is a predominant constituent and key flavour compound of cinnamon essential oil. It has been used as a food additive and flavorant. It is expected to be a novel and safe fungicide for controlling dry rot in potato tubes.

Ginsenoside Rg1 attenuates lipopolysaccharide-induced inflammatory responses via the phospholipase C-γ1 signaling pathway in murine BV-2 microglial cells.

BACKGROUND AND PURPOSE: Microglial activation plays an important role in neurodegenerative diseases by producing an array of proinflammatory enzymes and cytokines. Ginsenoside Rg1 (Rg1), a well-known Chinese herbal medicine, has been well recognized for its anti-inflammatory effect. This study sought to determine the anti-inflammatory effects of Rg1 and its underlying mechanisms in lipopolysaccharide (LPS)-stimulated murine BV-2 microglial cells. EXPERIMENTAL APPROACH: Murine BV-2 microglial cells were treated with Rg1 (10, 20, and 40 µM) and/or LPS (1 µg·ml(-1)). The mRNA and protein levels of proinflammatory proteins and cytokines were analysed by RT-PCR assay and double immunofluorescence labeling, respectively. Phosphorylation levels of mitogen-activated protein kinases (MAPKs) cascades, inhibitor κB-α (IκB-α) and cyclic AMP- responsive element (CRE)-binding protein (CREB) were measured by western blot. U73122 (5 µM), a specific phospholipase C (PLC) inhibitor, was used to determine if PLC signaling pathway might be involved in Rg1's action on activated BV-2 cells. KEY RESULTS: Pretreatment with Rg1 significantly attenuated the LPS-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and nuclear factor-κB (NF-κB) in BV-2 cells. U73122 blocked the effects of Rg1 on LPS-induced microglial activation. In addition, PLC-γ1 inhibition partially abolished the inhibitory effect of Rg1 on the phosphorylation of IκB-α, CREB, extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK). CONCLUSION AND IMPLICATIONS: This investigation demonstrates that Rg1 significantly attenuates overactivation of microglial cells by repressing expression levels of neurotoxic proinflammatory mediators and cytokines via activation of PLC-γ1 signaling pathway.

Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China.

The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr bp). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by 'bunding' to maintain crop yields. The site's exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr bp. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment.

The effect of neferine on foam cell formation by anti-low density lipoprotein oxidation.

Oxidatively modified low density lipoprtein (LDL) plays an important role in atheroslerosis (AS) development. To investigate the role of neferine (Nef) in anti-LDL oxidation and foam cell formation, the lipoprotein was derived and subjected to three different treatments: N-LDL (normal LDL), Cu2+ + LDL and Cu2+ + Nef + LDL. The LDLs were put at 25 degrees C for 24 h and the thiobarbituric acid reactive substance (TBARS) values were determined. They were 0.57 +/- 0.2, 6.01 +/- 0.22 and 2.26 +/- 0.13 nmol/mg protein, respectively. The difference was very significant (P < 0.01) for each two groups by t test. Mouse peritoneal macrophage (M phi) were exposed to 50 micrograms protein/ml of Cu2+ + LDL and Cu2+ + Nef + LDL at 37 degrees C for 60 h. The tryglyceride (TG) and total cholesterol (TC) content in M phi were assayed. The results showed that Cu2+ + LDL was more efficient than Cu2+ + Nef + LDL in stimulating lipid accumulation in M phi (P < 0.001). The study demonstrated that Nef could inhibit Cu(2+)-mediated LDL oxidation and thereby inhibiting macrophage-derived foam cell formation.

Determination of strychnine and brucine by capillary zone electrophoresis.

A procedure for quantitative estimation of strychnine and brucine in the extracts of Strychnos nux-vomica seeds by capillary zone electrophoresis (CZE) was developed. The buffer solution used was 10mM phosphate buffer-MeOH (9:1), pH 2.5. The linear calibration range was 0.01-0.15 mg/ml. This method is useful for the qualitative and quantitative determination of strychnine and brucine in plant drug samples, as well as in human plasma.