Neuroprotection by plumbagin involves BDNF-TrkB-PI3K/Akt and ERK1/2/JNK pathways in isoflurane-induced neonatal rats.

OBJECTIVES: This study was designed to assess the effects of plumbagin on isoflurane-induced neurotoxicity. METHODS: Neonatal Sprague Dawley rat pups were treated with plumbagin (50, 100 or 150 mg/kg body weight, orally) from postnatal day 2. The pups on postnatal day 7 were subjected to isoflurane (0.75%) exposure for 6 h. Neuronal apoptosis in the hippocampal tissues was detected by TUNEL assay and FluroJade B staining following isoflurane exposure. Protein expressions were analysed by immunoblotting. RT-PCR was performed to assess mRNA levels of brain-derived neurotrophic factor (BDNF) and TrkB. KEY FINDINGS: We observed reduced apoptosis in hippocampal CA1, CA3 and dentate gyrus regions along with severely reduced pro-apoptotic factors (Bad, Bax and cleaved caspase-3) expression and raised levels of Bcl-2, Bcl-xL, survivin, xIAP and cIAPs (cell survival proteins) in plumbagin supplemented rats. Decrease in the levels of JNK, phospho-JNK, c-Jun and phospho-c-Jun with enhanced ERK1/2 levels was observed on plumbagin pretreatment. Down-regulated PI3K/Akt signalling following isoflurane was activated by plumbagin as evidenced by raised PI3K/Akt pathway proteins - mTORc1, Akt, phospho-Akt, GSK-3ß, phospho-GSK-3ß, PTEN and NF-κBp65 in the hippocampal tissues as detected by Western blotting. The mRNA levels were enhanced on plumbagin supplementation. CONCLUSIONS: Plumbagin exerted its neuroprotective effects by effectively suppressing isoflurane-induced neuronal apoptosis via regulating BDNF-TrkB-PI3/Akt and ERK/JNK signalling.

[Characterization of Phosphorus Forms in Organic Composts and Their Effects on Leaf Phosphorus Content of Castanea mollissima in Chinese Chestnut Producing Area].

Characterization of the forms of phosphorus (P) in four organic composts including compost of hulls and leaves of Castanea mollissima, edible fungi residues, corn stalks and chicken manure (BYZ), compost of edible fungi residues and chicken manure(ZF), composts of hulls and leaves of C. mollissima, edible fungi residues and chicken manure (BZ1 and BZ2) in Chinese chestnut producing area was conducted by sequential P fractionation developed by Dou et al. Field trial was conducted to study the effects of compost application on leaf phosphorus content of Castanea mollissima. The results showed that total phosphorus content(TP) of organic composts ranked as follows:BZ1(10.61 g·kg-1) > ZF(9.03 g·kg-1) > BYZ(8.56 g·kg-1) > BZ2(7.68 g·kg-1), and the inorganic phosphorus(Pi) accounted for 62.88%-73.62% of the total phosphorus in the organic composts. The content and proportion of HCl-P in the total fractionated phosphorus(Prt) was the highest among P forms in ZF, while that of H2O-P was the highest in BYZ, BZ1 and BZ2. The content of NaOH-P was very low in all the composts. Active H2O-Por NaHCO3-P had the highest inorganic phosphorus proportion(89.17%-96.00%) of all the P forms. The major Piforms in BZ2 were H2O- and HCl-extractable P fractions, while H2O-Pi, HCl-Pi and NaHCO3-Pi were major Pi forms in BYZ, BZ1 and ZF. Residual-P was the predominant organic phosphorus form, and BZ2 showed the highest Residual-P proportion of the total fractionated phosphorus(Prt) among all the composts. Leaf phosphorus contents per unit area of Castanea mollissima by field trial on the added phosphorus-equivalent basis were expressed as:BZ2>BZ1>BYZ>ZF>CK. Increment of leaf phosphorus content per unit area in Julyand per month on average showed positive relationship with the content and proportion of H2O-Pi in the total fractionated phosphorus of composts, which presumably played a key role in leaf phosphorus absorption of C. mollissima measured in the year of deep concentrated fertilization. The results suggested that composts of hulls and leaves of C. mollissima, edible fungi residues and chicken manure (BZ2) was a good choice in given area for aerobic composting raw material system in which organic wastes from Chinese chestnut industry accounted for 80% (hulls and leaves of Castanea mollissima and edible fungi residues accounted for 60% and 20% respectively), which had a high proportion of H2O-Pi and organic Residual-P pool and led to the highest leaf phosphorus content of C. mollissima.

[Determination the Change of Main Trace Elements in the Ovary with Self- and Cross-Pollination of Chinese Chestnut by ICP-MS].

Castanea mollissima Blume has potential as an non-wood forest trees that have been cultivated for thousands of years in China. In order to elucidate the trace elements of chestnut ovary, the major trace elements of self- and cross-pollination chestnut ovary were determined by inductively coupled plasma mass spectrometry. The results showed that self- and cross-pollination 5-50 d, six trace elements trends showed fluctuations. After cross-pollination 20 d, the content of Ca was up to 6.50 mg x g(-1), while the self-pollination 10 d, the content of Ca reached up to 7.77 mg x g(-1). After cross- and self-pollination pollination 30 d, the content of Mg were highest, 4.19 and 4.69 mg x g(-1), respectively. After cross-pollination 5 d, the content of Zn reached the highest, 0.038 7 mg x g(-1), while self-pollination 10d the content of Zn was 0.039 9 mg x g(-1). After self- and cross-pollination 35 d, the content of Fe were 0.022, 0.019 mg x g(-1), respectively. After cross- and self-pollination 20 d, the content of Cu were 0.056, 0.045 mg x g(-1), respectively. After self-pollination 40d, the content of Mn reaching the highest was 1.204 mg x g(-1), while cross-pollination 30 d, the content of Mn reached its maximum 0.845 mg x g(-1). The results can provide a reference for spraying fertilizer on the ovary development, thereby improving chestnut production.