Phytochemical constituents,biological activities,and health‐promoting effects of the genus Origanum

Origanum species are mostly distributed around the Mediterranean, Euro‐Siberian, and Iran‐Siberian regions. Since time immemorial, the genus has popularly been used in Southern Europe, as well as on the American continent as a spice now known all over the world under the name “oregano” or “pizza‐spice.” Origanum plants are also employed to prepare bitter tinctures, wines, vermouths, beer, and kvass. The major components of Origanum essential oil are various terpenes, phenols, phenolic acids, and flavonoids with predominant occurrence of carvacrol and thymol (with reasonable amounts of p‐cymen and ‐terpinene) or of terpinene‐4‐ol, linalool, and sabinene hydrate. Many species of Origanum genus are used to treat kidney, digestive, nervous, and respiratory disorders, spasms, sore throat, diabetes, lean menstruation, hypertension, cold, insomnia, toothache, headache, epilepsy, urinary tract infections, etc. Origanum essential oil showed potent bioactivities owing to its major constituents' carvacrol, thymol, and monoterpenes. Several preclinical studies evidenced its pharmacological potential as antiproliferative or anticancer, antidiabetic, antihyperlipidemic, anti‐obesity, renoprotective, antiinflammatory, vasoprotective, cardioprotective, antinociceptive, insecticidal, and hepatoprotective properties. Its nanotechnological applications as a promising pharmaceutical in order to enhance the solubility, physicochemical stability, and the accumulation rate of its essential oils have been investigated. However, Origanum has been reported causing angioedema, perioral dermatitis, allergic reaction, inhibition of platelet aggregation, hypoglycemia, and abortion. Conclusive evidences are still required for its clinical applications against human medical conditions. Toxicity analyses and risk assessment will aid to its safe and efficacious application. In addition, elaborate structure–activity studies are needed to explore the potential use of Origanum‐derived phytochemicals as promising drug candidates.     

Recombinant prion protein induces a new transmissible prion disease in wild-type animals

Prion disease is a neurodegenerative malady, which is believed to be transmitted via a prion protein in its abnormal conformation (PrP^Sc). Previous studies have failed to demonstrate that prion disease could be induced in wild-type animals using recombinant prion protein (rPrP) produced in Escherichia coli. Here, we report that prion infectivity was generated in Syrian hamsters after inoculating full-length rPrP that had been converted into the cross-β-sheet amyloid form and subjected to annealing. Serial transmission gave rise to a disease phenotype with highly unique clinical and neuropathological features. Among them were the deposition of large PrP^Sc plaques in subpial and subependymal areas in brain and spinal cord, very minor lesioning of the hippocampus and cerebellum, and a very slow progression of disease after onset of clinical signs despite the accumulation of large amounts of PrP^Sc in the brain. The length of the clinical duration is more typical of human and large animal prion diseases, than those of rodents. Our studies establish that transmissible prion disease can be induced in wild-type animals by inoculation of rPrP and introduce a valuable new model of prion diseases.     

Comparative Study of Tumor Targeting and Biodistribution of pH (Low) Insertion Peptides (pHLIP<Superscript>®</Superscript> Peptides) Conjugated with Different Fluorescent Dyes

Purpose

Acidification of extracellular space promotes tumor development, progression, and invasiveness. pH (low) insertion peptides (pHLIP^® peptides) belong to the class of pH-sensitive membrane peptides, which target acidic tumors and deliver imaging and/or therapeutic agents to cancer cells within tumors.

Procedures

Ex vivo fluorescent imaging of tissue and organs collected at various time points after administration of different pHLIP^® variants conjugated with fluorescent dyes of various polarity was performed. Methods of multivariate statistical analyses were employed to establish classification between fluorescently labeled pHLIP^® variants in multidimensional space of spectral parameters.

Results

The fluorescently labeled pHLIP^® variants were classified based on their biodistribution profile and ability of targeting of primary tumors. Also, submillimeter-sized metastatic lesions in lungs were identified by ex vivo imaging after intravenous administration of fluorescent pHLIP^® peptide.

Conclusions

Different cargo molecules conjugated with pHLIP^® peptides can alter biodistribution and tumor targeting. The obtained knowledge is essential for the design of novel pHLIP^®-based diagnostic and therapeutic agents targeting primary tumors and metastatic lesions.

     

Host factors mediating HIV-1 replication

Human immunodeficiency virus type 1(HIV-1) infection is the leading cause of death worldwide in adults attributable to infectious diseases. Although the majority of infections are in sub-Saharan Africa and Southeast Asia, HIV-1 is also a major health concern in most countries throughout the globe. While current antiretroviral treatments are generally effective, particularly in combination therapy, limitations exist due to drug resistance occurring among the drug classes. Traditionally, HIV-1 drugs have targeted viral proteins, which are mutable targets. As cellular genes mutate relatively infrequently, host proteins may prove to be more durable targets than viral proteins. HIV-1 replication is dependent upon cellular proteins that perform essential roles during the viral life cycle. Maraviroc is the first FDA-approved antiretroviral drug to target a cellular factor, HIV-1 coreceptor CCR5, and serves to intercept viral–host protein–protein interactions mediating entry. Recent large-scale siRNA and shRNA screens have revealed over 1000 candidate host factors that potentially support HIV-1 replication, and have implicated new pathways in the viral life cycle. These host proteins and cellular pathways may represent important targets for future therapeutic discoveries. This review discusses critical cellular factors that facilitate the successive steps in HIV-1 replication.     

Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish

Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17alpha-ethinylestradiol (EE(2)). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor alpha (ERalpha) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE(2) had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERalpha mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells.     

A critical role for CD63 in HIV replication and infection of macrophages and cell lines

HIV infection typically involves interaction of Env with CD4 and a chemokine coreceptor, either CCR5 or CXCR4. Other cellular factors supporting HIV replication have also been characterized. We previously demonstrated a role for CD63 in early HIV infection events in macrophages via inhibition by anti-CD63 antibody pretreatment. To confirm the requirement for CD63 in HIV replication, we decreased CD63 expression using CD63-specific short interfering RNAs (siRNA), and showed inhibition of HIV replication in macrophages. Surprisingly, pretreatment with CD63 siRNA not only silenced CD63 expression by 90%, but also inhibited HIV-1 replication in a cultured cell line (U373-MAGI) which had been previously shown to be insensitive to CD63 monoclonal antibody inhibition. Although the anti-CD63 antibody was previously shown to inhibit early HIV infection events only in macrophages, we now show a potential role for CD63 in later HIV replication events in macrophages and cell lines. Further delineation of the role of CD63 in HIV replication may lead to development of novel therapeutic compounds.