2-deoxy-D-glucose inhibition of herpes simplex virus type-1 receptor expression

Growth of HEp-2 cells in 2-deoxy-D-glucose (2-DOG) supplemented media decreased the cells' binding capacity for herpes simplex virus type-1 KOS(HSV-1) but not vesicular stomatitis virus. HEp-2 cells tolerated up to 30 mM 2-DOG, but 2-DOG was toxic for Vero cells over 2 mM. The reduction in binding was maintained for at least 24 h even after careful removal of the inhibitor and growth in normal media. Complete regeneration of the receptor sites on HEp-2 cells was observed 8 h after mild trypsinization of cells grown in either normal or the 2-DOG supplemented media. Specific glycoprotein characteristics of the HSV-1 binding site were indicated by its inactivation upon trypsinization (0.1 mg per 5 X 10(5) cells for 30 s) and blocking by wheat germ agglutinin but not limulin. These results suggest that 2-DOG inhibits the proper expression of cell surface glycoprotein HSV-1 receptor sites on HEp-2 cells.     

Distinctive properties of DNA polymerases induced by herpes simplex virus type-1 and Epstein-Barr virus

The properties of DNA polymerases induced by two human herpesviruses, herpes simplex virus type-1 (HSV-1) and Epstein-Barr virus (EBV), have been compared. The HSV-1 and EBV polymerases can be distinguished from one another by differences in the elution profiles in phosphocellulose and single-stranded DNA cellulose columns. Although both enzymes require monovalent cations for optimum activity, the HSV-1 enzyme requires ammonium sulfate whereas the EBV enzyme activity is inhibited by it; on the other hand, the EBV polymerase requires KCl. Other reaction requirements are also different for the two viral enzymes. Thus, when the EBV DNA polymerase was assayed under conditions optimum for the HSV-1 DNA polymerase, only 15% of its activity was expressed. Differences were also noted in sensitivities of the two viral enzymes to the 5'-triphosphates of nucleoside analogs with antiherpesvirus activity such as BVdU, IVdU, ACV, FIAC and IdUrd. The HSV-1 polymerase was more sensitive than the EBV DNA polymerase to inhibition by phosphonoacetate, phosphonoformate, aphidicolin and N-ethylmaleimide. However, the EBV DNA polymerase was more sensitive than HSV-1 DNA polymerase to heat treatment at 42 degrees C. Thus, the marked differences between the two viral enzymes can be useful in identifying enzyme activities in cells producing the virus and also in studying the biochemical mechanism of action of some of the antiviral agents.     

Direct inactivation of herpes simplex virus type-2 by rat epidermal protein.

Proteins were extracted from corneocytes of skin of 2-day-old rats and fractionated by gel filtration and cation exchange column chromatography. The different protein fractions were tested for direct inactivation of herpes simplex virus infectivity as determined by reduction of plaque formation. The most effective protein fractions against herpes simplex virus were a neutral pH buffer soluble and mol. wts. ranging from 20 K to 30 K. Amino acid composition of the proteins were virtually identical to epidermal histidine-rich proteins. The activity was significantly (P less than 0.001) stronger against type-2 than type-1. The activity was most stable at pH 7.2 and the rate of inhibition increased in a time-dependent manner up to 4 h. The 50% effective dose was estimated as 1.1 micrograms protein/ml.     

土大黄不同提取物对银屑病小鼠模型的作用

目的分别探讨土大黄醇提物、水提物对银屑病小鼠模型的作用。方法采用小鼠鼠尾鳞片表皮模型、盐酸普萘洛尔致小鼠耳部皮肤银屑病样模型,观测土大黄醇提物(2,4和8g·kg-1)、水提物(2,4和8g·kg-1)灌胃给药后,小鼠一般状况、体质量、脾脏及胸腺指数,血清IL-10、IL-17、IL-23水平,尾部及耳部皮肤组织病理学变化。结果土大黄醇提物、水提物(2,4和8g·kg-1)在实验期间小鼠一般状况、体质量变化无明显异常(P>0.05);土大黄醇提物(2和8g·kg-1)、水提物(4和8g·kg-1)能降低小鼠胸腺指数(P<0.05);土大黄醇提物、水提物各剂量组对小鼠血清IL-10、IL-17、IL-23无明显影响(P>0.05);同时,土大黄醇提物、水提物(2,4和8g·kg-1)能促进小鼠尾部鳞片表皮颗粒层形成,能改善对盐酸普萘洛尔致小鼠耳部皮肤银屑病样组织病理学变化。结论土大黄醇提物、水提物均具有治疗实验性银屑病的作用。     

Effects of loperamide on mechanical allodynia induced by herpes simplex virus type-1 in mice

In the present study, we investigated whether the peripherally acting micro-opioid receptor agonist loperamide would inhibit allodynia in the non-inflamed dermatome of mice with herpetic pain. Subcutaneous (s.c.) injection of loperamide (1 and 3 mg/kg) inhibited allodynia. Local (intraplantar) injection of loperamide (1 and 5 microg/site) also produced an anti-allodynic effect. The peripheral opioid receptor antagonist naloxone methiodide (0.1 mg/kg, s.c.) and the micro-opioid receptor-selective antagonist beta-funaltrexamine (40 nmol/site, intraplantar and 20 mg /kg, s.c.) antagonized the anti-allodynic effects of systemic and local loperamide. Local injection of loperamide into the contralateral hind paw was without effect, suggesting that the effect is mediated through local action, not systemic action. Acute and subacute tolerance did not develop to the anti-allodynic effect of loperamide. In addition, there were no cross-tolerance between local opioids (morphine and loperamide) and systemic morphine. These results suggest that stimulation of peripheral micro-opioid receptors suppresses herpetic allodynia without tolerance development. The non-narcotic micro-opioid receptor agonist loperamide may relieve acute herpetic pain in patients with herpes zoster.     

Evaluation of tTA-mediated gene activation system on human cytomegalovirus and herpes simplex virus type-1 infections

The tetracycline-controlled transactivator (tTA)-mediated gene activation system was examined in virus infected cells to determine its role in the control of gene expression. In the presence of tTA, the gene expression from the tetO-modified minimal promoter was efficiently activated in the uninfected cells, whereas essentially no activation was observed from the only minimal promoter without the seven direct repeats of 42 bp tetO sequences. However, essentially no activation was observed when only the minimal promoter was used, without the seven direct repetitions of the 42 bp tetO sequences. On the other hand, in the infected cells, a substantial background of beta-glucuronidase expression was detected in the absence of tTA, even though tTA stimulated the gene expression by approximately 7-fold. This background expression indicates that the sequences within or nearby tetO are involved in the background stimulation of the gene expression by HCMV and HSV-1. These results suggest that the application of the tTA-mediated gene activation system may not be extremely useful for studying the biological roles of HCMV and HSV genes in the viral replicative cycles, because of the basal activity of the gene expression.     

Antimutagenicity and cytotoxicity of the constituents from the aerial parts of Rumex acetosa

Four anthraquinones isolated for the first time from the aerial parts of Rumex acetosa (Polygonaceae), a Korean and a Japanese medicinal plant, and two synthetic derivatives were examined for their cytotoxicities against five cultured human tumor cell lines, i.e. A549 (non-small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system) and HCY15 (colon), using the Sulfrhodamine-B method in vitro and antimutagenic activities by Ames test with Salmonella typhimurium TA98 and TA100 and SOS chromotest with E. coli PQ37. Among the tested compounds, emodin strongly inhibited the proliferation of each examined tumor cell line with IC50 values ranged from 2.94 to 3.64 microg/ml and showed potent antimutagenic activities with 71.5% and 53.3% at the concentration of 0.1 mg/plate against the mutagens, NPD and sodium azide, respectively. Its antigenotoxic activity was also very effective at the final concentration of 10 microg/reaction tube against the mutagens, MNNG and NQO by SOS chromotest, reducing the induction factors by 19.6% and 43.5%, respectively. The structure-activity correlation study suggests that an additional OH group at C-6 position in the anthraquinone nucleus may play an important role for their cytotoxicities and an introduction of OH- or OCH3 group at C-6 position is necessary for their antimutagenicities.     

Vascular mechanisms underlying the hypotensive effect of Rumex acetosa

Context: Rumex acetosa L. (Polygonaceae) is well known in traditional medicine for its therapeutic efficacy as an antihypertensive.

Objective: The study investigates antihypertensive potential of crude methanol extract (Ra.Cr) and fractions of Rumex acetosa in normotensive and hypertensive rat models and probes the underlying vascular mechanisms.

Materials and methods: Ra.Cr and its fractions were tested in vivo on normotensive and hypertensive Sprague-Dawley rats under anaesthesia for blood pressure lowering effect. In vitro experiments on rat and Oryctolagus cuniculus rabbit aortae were employed to probe the underlying vasorelaxant mechanism.

Results: In normotensive rats under anaesthesia, Ra.Cr caused fall in MAP (40?mmHg) at 50?mg/kg with % fall of 27.88?±?4.55. Among the fractions tested, aqueous fraction was more potent at the dose of 50?mg/kg with % fall of 45.63?±?2.84. In hypertensive rats under similar conditions, extract and fractions showed antihypertensive effect at same doses while aqueous fraction being more potent, exhibited 68.53?±?4.45% fall in MAP (70?mmHg). In isolated rat aortic rings precontracted with phenylephrine (PE), Ra.Cr and fractions induced endothelium-dependent vasorelaxation, which was partially blocked in presence of l-NAME, indomethacin and atropine. In isolated rabbit aortic rings pre-contracted with PE and K⁺-(80?mM), Ra.Cr induced vasorelaxation and shifted Ca²⁺ concentration–response curves to the right and suppressed PE peak formation, similar to verapamil, in Ca²⁺-free medium.

Discussion and conclusions: The data indicate that l-NAME and atropine-sensitive endothelial-derived NO and COX enzyme inhibitors and Ca²⁺ entry blocking-mediated vasodilator effect of the extract explain its antihypertensive potential.     

Lactoferricin but not lactoferrin inhibit herpes simplex virus type 2 infection in mice

We have evaluated the potential of bovine lactoferrin and lactoferricin for their ability to prevent and/or treat genital HSV-2 infection in mice. We confirm previous data showing that both lactoferrin and lactoferricin have antiviral properties in vitro and can inhibit HSV-2 infection of GMK cells in a dose-dependent manner. When tested in vivo, lactoferricin but not lactoferrin was also a potent inhibitor of HSV-2 infection. When admixed with virus prior to inoculation, lactoferricin inhibited disease development and significantly reduced the viral load in a genital model of HSV-2 infection in mice. Lactoferrin and lactoferricin were also tested for their ability to stimulate the production of chemokines. Neither of the compounds induced the production of CCL3, CCL5, CXCL1 or CXCL2 by mouse splenocytes in vitro. However, when tested in vivo, both lactoferrin and lactoferricin were able to induce local vaginal production of CCL5. Lactoferrin also induced CXCL2 production. The prophylactic and/or therapeutic effects of lactoferrin or lactoferricin were also tested. But none of the compounds were efficient in blocking HSV-2 infection when given 24 h prior to HSV-2 infection. Lactoferricin however showed promising results as a therapeutic agent and delayed both disease onset by 3 days as well as reducing the viral load almost 15-fold when given as a single dose 24 h post-infection. These data show that lactoferricin can block genital herpes infection in mice, and perhaps also be used for post-infection treatment.     

Resveratrol inhibition of herpes simplex virus replication.

Resveratrol, a phytoalexin, was found to inhibit herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) replication in a dose-dependent, reversible manner. The observed reduction in virus yield was not caused by the direct inactivation of HSV by resveratrol nor inhibition of virus attachment to the cell. The chemical did, however, target an early event in the virus replication cycle since it was most effective when added within 1 h of cell infection, less effective if addition was delayed until 6 h post-infection and not effective if added 9 h post-infection. Resveratrol was also found to delay the cell cycle at S-G2-M interphase, inhibit reactivation of virus from latently-infected neurons and reduce the amount of ICP-4, a major immediate early viral regulatory protein, that is produced when compared to controls. These results suggest that a critical early event in the viral replication cycle, that has a compensatory cellular counterpart, is being adversely affected.     

Baculovirus expressed herpes simplex virus type 1 glycoprotein C protects mice from lethal HSV-1 infection.

A recombinant baculovirus (vAc-gC1) was constructed that expresses the glycoprotein C (gC) gene of herpes simplex virus type 1 (HSV-1). When Sf9 cells were infected with this recombinant, a protein that was smaller in size than authentic HSV-1 gC was detected by Western blotting using anti-gC polyclonal antibody. The recombinant gC was susceptible to tunicamycin, partially resistant to Endo-H, and was found on the membrane of Sf9 cells. Antibodies raised in mice to recombinant gC reacted with gC from HSV-1 infected cells and neutralized the infectivity of HSV-1 in vitro. Immunized mice were protected from lethal challenge with HSV-1.     

Anti-herpes simplex virus type-1 flavonoids and a new flavanone from the root of Limonium sinense

From the root of Limonium sinense (Girard) Ktze a new (2R,3S)-3,5,7,4'-tetrahydroxy-3',5'-dimethoxyflavanone was isolated and named isodihydrosyringetin (3), together with nine other known compounds, (-)-epigallocatechin 3-O-gallate (1), samarangenin B (2), myricetin (4), myricetin 3-O-alpha-rhamnopyranoside (5), quercetin 3-O-alpha-rhamnopyranoside (6), (-)-epigallocatechin (7), gallic acid (8), N-trans-caffeoyltyramine (9), and N-trans-feruloyltyramine (10). All of them were examined for their inhibitory effects on herpes simplex virus type-1 (HSV-1) replication in Vero cells. Both compounds 1 and 2 exhibited potent inhibitory activities in HSV-1 replication. Comparison of the IC50 values indicated that compounds 1 and 2 had higher inhibitory activities than the positive control acyclovir (38.6 +/- 2.6 vs. 55.4 +/- 5.3 microM, P < 0.001; 11.4 +/- 0.9 vs. 55.4 +/- 5.3 microM, P < 0.0005). Cytotoxicity was unlikely involved because no cell deaths were observable in the Vero cells following 5 day treatments with compound 1 or 2.     

Treatment of herpes simplex virus infections

Herpes simplex virus (HSV) types 1 and 2 are ubiquitous organisms that cause infections in human populations throughout the world. The clinical manifestations of HSV infections are varied, ranging from asymptomatic disease to life-threatening illness in neonates and immunocompromised hosts. This article will review the common presentations for HSV disease and the current recommendations for the treatment of these infections. A detailed summary of the antiviral drugs used to treat HSV infections is also presented.     

单纯疱疹病毒性脑炎的治疗

脑炎是一种以脑实质受累为主的中枢神经系统感染性疾病,其感染源包括病毒、细菌、真菌、立克次体、螺旋体、寄生虫等。感染的途径有：①血行感染：病原体经呼吸道或皮肤粘膜进入血液后,随血液入颅;②直接感染：病原体通过头面部外伤或感染向颅内蔓延;③逆行感染：病原体沿神经干逆行进入颅内。     

Oncolytic herpes simplex virus type 1 and host immune responses

The use of oncolytic herpes simplex virus type 1 (HSV-1) is a promising strategy for cancer treatment. Accumulating evidence indicates that, aside from the extent of replication capability within the tumor, the efficacy of an oncolytic HSV-1 depends on the extent of induction of host antitumor immune responses. Ways to modify the host immune responses toward viral oncolysis include expression of immunostimulatory molecules using oncolytic HSV-1 as a vector and co-administration of reagents that modulate immune reactions. Viral propagation may be enhanced via temporary suppression of innate immune responses. Elucidation of the role of the host immune system in oncolytic HSV-1 therapy is the key to establishing the approach as a useful clinical means for cancer treatment.