Shaoyao Gancao decoction alleviates the central hyperalgesia of recurrent NTG-induced migraine in rats by regulating the NGF/TRPV1/COX-2 signal pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Shaoyao Gancao Decoction (SGD) is well known as an effective prescription for analgesia composed of two herbs, and is noted as traditional Chinese medicine morphine. It is widely used in various conditions causing pain, including migraine. However, there is currently no research exploring the mechanism of action in the treatment of migraines. AIM OF THE STUDY: The current research was devised to determine the underlying regulatory mechanism of SGD, by verifying its role in the NGF/TRPV1/COX-2 signal pathway. MATERIALS AND METHODS: The active components in SGD were identified by UHPLC-MS. A migraine model was prepared by subcutaneous (s.c.) injection of nitroglycerin (NTG) into the neck to detect migraine-like behavior, orbital hyperalgesia threshold changes, and the therapeutic effect of SGD. The mechanism of SGD in remedying migraine was studied through transcriptome sequencing (RNA-seq), which was further validated utilizing Elisa, Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting (WB) experiments. RESULTS: In the SGD chemical composition analysis, 45 components were identified including gallic acid, paeoniflorin and albiforin. In the behavioral experiments, SGD treatment significantly decreased the score of migraine-like head scratching in the NTG-induced migraine model (Mod) rats, while the hyperalgesia threshold increased outstandingly on days 10, 12, and 14 (P < 0.01, P < 0.001 or P < 0.0001). In migraine biomarkers experiment, compared with the Mod group, the 5-hydroxytryptamine (5-HT) contents were outstandingly enhanced by SGD treatment, while nitric oxide (NO) contents were markedly declined (P < 0.01). In the RNA-seq test, the down-regulated genes of SGD inhibiting hyperalgesia migraine included the neurotrophic factor (NGF) and transient receptor potential vanillic acid subfamily protein 1 receptor (TRPV1). The down-regulation pathway is the inflammatory mediator regulation of TRP channels. In gene set enrichment analysis (GSEA), SGD decreased the over-expression of protooncogene tyrosine-protein kinase Src (SRC) and TRPV1 in this pathway, and the two genes clustered at its lower end, with similar functions. PPI network results show that NGF interacts with TRPV1. Further verification shows that when compared with Mod group, the plasma cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) protein expression levels and the dura mater calcitonin gene-related peptide (CGRP), extracellular signal-regulated kinase (ERK), p-ERK, SRC and NGF protein expression levels in the SGD group were remarkably decreased (P < 0.01, P < 0.001 or P < 0.0001), and the expression level of TRPV1 protein showed a downward trend (P = 0.06). The expression levels of COX-2, NO, CGRP, TRPV1, SRC and NGF mRNA in the dura mater was overtly down-regulated (P < 0.05, P < 0.01 or P < 0.001). CONCLUSIONS: SGD has a significant inhibitory effect on the NGF/TRPV1/COX-2 signaling pathway that mediates central hyperalgesia migraine, thus suggesting the molecular mechanism of SGD in improving the symptoms of migraine may be related to the central hyperalgesia neurotransmitter that regulates the pathogenesis of migraine.

EDTA-enhanced phytoremediation of heavy metals from sludge soil by Italian ryegrass (Lolium perenne L.).

Landscaping of sludge is a kind of recycling disposal, but the potential heavy metal risks limit its application. In this paper, the sludge soil was remediated by ryegrass, and the effect of ethylene diamine tetraacetic acid (EDTA) was studied through pot experiments. Italian ryegrass was planted in the sludge soil treated with six gradients concentrations of 0, 1, 2, 3, 4, 5 mmol kg-1 of EDTA, and the planting conditions were kept the same. After 45 days of planting, compared with the control group (without EDTA treated), the application of 1-5 mmol kg-1 EDTA decreased ryegrass biomass by 2-43%, reduced soil pH value by 0.21-0.34 unit, and reduced 4.1-9.7% capacity of exchange cation, but increased 1.4-8.6% soil organic matter. After growing ryegrass, the contents of heavy metals decreased by 10% for Cu, 15% for Zn, 6% for Ni, 14% for Cd and 44% for Pb; and after spraying EDTA decreased again by 33% for Cu, 31% for Zn, 56% for Ni, 24% for Cd, and 68% for Pb. In ryegrass, the uptake heavy metals were enhanced, and bio-concentration factor of Cu, Zn, Ni, Cd, and Pb of EDTA treated groups were 1.9, 1.6, 4.1, 2.7, and 4.8 times of the control group, respectively. However, EDTA only significantly increased transfer factor values of Cu and Zn, and made bio-extraction factor value of Cu greater than 1. The remediation factor values were used to comprehensive assess accumulation capacity of heavy metals by ryegrass under EDTA treating, and they ordered in Zn > Cu > Ni > Cd > Pb, and the best dose was 2 mmol kg-1 EDTA. Prediction models for bio-concentration factor were established by using stepwise multiple linear regression, explaining 94.9-99.3% of the corresponding elements with soil organic matter, EDTA dosage, and/or pH value (p < 0.005). This paper provided effective heavy metals remediation data for municipal sludge landscape and the prediction models.