Cloning and molecular characterization of the ORF5 gene from a PRRSV-SN strain from Southwest China.

To monitor the genetic variation of PRRSV, the ORF5 gene of the PRRSV-SN strain found in Suining City, Sichuan Province, was cloned and sequenced. The results showed that the PRRSV-SN strain was a highly pathogenic PRRSV (HP-PRRSV) variant strain with the North American (NA) genotype. Homology analysis showed that the ORF5 gene of the PRRSV-SN isolate shared 89.4% (86.5%) nucleotide (amino acid) sequence similarity with the North American strain VR-2332, 98.8% (96%) similarity with JXA1, and 63.8% (57.7%) similarity with the European type representative strain Lelystad virus. Phylogenetic analysis showed that PRRSV-SN belongs to the NA genotype and has the same subtype as other highly pathogenic PRRSV strains. Amino acid sequence analysis showed that compared with the VR2332 strain, PRRSV-SN has different degrees of variation in the signal peptide, transmembrane region (TM), primary neutralizing epitope (PNE), non-neutral epitopes and N-glycosylation sites. Antigenicity analysis showed that the PRRSV-SN ORF5 gene products and JXA1 have similar antigenic characteristics, and the antigenic epitopes are mainly located in aa30-39, aa50-60, aa128-141, aa146-155 and aa161-183 regions. In contrast, the antigenic characteristics of PRRSV-SN are quite different from those of the VR2332 strain. The main differences were that the PRRSV-SN strain was significantly narrower than the VR2332 strain in the aa30-39 and the aa50-60 regions but was significantly wider in the aa136-141 region. The results of this study showed that the epidemic strains that cause PRRSV outbreaks in the farm are still mainly JXA1 variants, but due to the more frequent use of live vaccine immunizations, the genes of the PRRSV epidemic strain still show constant variation. Vaccination with live PRRSV should be reduced, and surveillance of PRRSV strains should be enhanced.

Total alkaloids from the rhizomes of Ligusticum striatum: a review of chemical analysis and pharmacological activities.

Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., is a geoauthentic TCM herb distributed in Sichuan province of China that possesses efficacy in promoting blood circulation, removing blood stasis and alleviating pain. Rhizome Chuanxiong total alkaloids (RCXTAs) are one of the major characteristic constituents of RCX with the effects of antimigraine, neuroprotective, cardioprotective and other cardiovascular and cerebrovascular diseases. Over the past years, rapid development of technology has advanced some aspects of RCXTAs. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of RCXTAs, and to highlight new challenges.

Nucleoside alkaloids with anti-platelet aggregation activity from the rhizomes of Ligusticum striatum.

Two new (1-2) and six known (3-8) nucleoside alkaloids were isolated from the rhizomes of Ligusticum striatum DC. Compounds 1 and 2 (liguadenosines A and B) were unusual N-10 substituted adenosine derivatives. Their structures were elucidated by extensive spectroscopic analyses and ECD calculation. Most of them significantly inhibited the abnormal increase in platelet aggregation induced by ADP at concentrations of 50 and 100 µM. Particularly, the inhibitory effect of 3 was equivalent to aspirin.

Alkaloids from the rhizomes of Ligusticum striatum exert antimigraine effects through regulating 5-HT1B receptor and c-Jun.

ETHNOPHARMACOLOGICAL RELEVANCE: Migraine is a prevalent, complex, painful, and disabling neurovascular disorder that places an enormous social and economic burden on patients. Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., has been widely used in the clinic for the treatment of migraine for centuries in China. Total alkaloids (TAs) are considered to be important effective ingredients of L. striatum, especially for cardiovascular and cerebrovascular diseases. However, there has been no study published, to date, reporting the antimigraine effects of TAs from RCX (RCXTAs). AIM OF THE STUDY: The present study was designed to evaluate the antimigraine effects of RCXTAs and explore the underlying mechanisms in an experimental migraine rat model. MATERIALS AND METHODS: RCXTAs were prepared in accordance with our previous optimized preparation process. A nitroglycerin-induced migraine model in rats and a reserpine-induced migraine model in mice were established to investigate the effects of RCXTAs on monoamine neurotransmitters in brain tissue, including 5-hydroxytryptamine (5-HT) and its metabolite (5-HIAA). Migraine rats or mice were divided into six groups as follows: control; model; zolmitriptan (1.67 mg/kg); and low-, medium-, and high-dose RCXTAs (12.5, 25, and 50 mg/kg, respectively). The levels of 5-HT and 5-HIAA in the brains of rats and mice were determined by using the enzyme-linked immunosorbent assay method. Pathological changes in the brains of migraine rats were examined by immunohistochemistry. The protein expression of 5-HT1B receptor, c-Fos, and c-Jun in the periaqueductal gray (PAG) of migraine rats was measured by Western blot. RESULTS: After preventive administration of RCXTAs to the nitroglycerin-induced migraine rats, the levels of 5-HT and 5-HIAA in the brain tissue were generally upregulated in all three RCXTA dose groups, a finding that was similar to that observed in the control group. Additionally, the 5-HT and 5-HIAA levels were significantly increased in the medium- and high-dose RCXTA groups when compared with the model group (p < 0.01). Therapeutical administration of RCXTAs to reserpine-induced migraine mice also inhibited the reduction of 5-HT and 5-HIAA in the brain (p < 0.01). Both immunohistochemistry and Western blot tests showed that RCXTAs pretreatment has significantly upregulated 5-HT1B receptor expression and downregulated c-Jun expression in the nitroglycerin-induced migraine rats. CONCLUSIONS: RCXTAs exerted significant preventive and therapeutic effects on migraine via increasing the levels of 5-HT and 5-HIAA. Upregulation of the expression of monoamine neurotransmitter 5-HT1B receptor and downregulation of the expression of c-Jun were the possible mechanisms.

Acaricidal activity of extracts of neem (Azadirachta indica) oil against the larvae of the rabbit mite Sarcoptes scabiei var. cuniculi in vitro.

The acaricidal activity of the petroleum ether extract, the chloroform extract and the acetic ether extract of neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi larvae was tested in vitro. A complementary log-log (CLL) model was used to analyze the data of the toxicity tests. The results showed that at all test time points, the petroleum ether extract demonstrated the highest activity against the larvae of S. scabiei var. cuniculi, while the activities of the chloroform extract and the acetic ether extract were similar. The activities of both the petroleum ether extract and the chloroform extract against the larvae showed the relation of time and concentration dependent. The median lethal concentration (LC50) of the petroleum ether extract (1.3 microL/mL) was about three times that of the chloroform extract (4.1 microL/mL) at 24 h post-treatment. At the concentrations of 500.0 microL/mL, the median lethal time (LT50) of the petroleum ether extract and the chloroform extract was 8.4 and 9.6 h, respectively.