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The olive leaf extract exhibits antiviralactivity against viral aemorrhagicsepticaemia rhabdovirus (VHSV)
Abstract
A commercial plant extract derived from olive tree leaf (Olea europaea) (LExt) and its major compound, oleuropein (Ole), inhibited the in vitro infectivity of the viral haemorrhagic septicaemia virus (VHSV), a salmonid rhabdovirus. Incubation of virus with LExt or Ole before infection reduced the viral infectivity to 10 and 30%, respectively. Furthermore, LExt drastically decreased VHSV titers and viral protein accumulation (virucidal effect) in a dose dependent manner when added to cell monolayers 36 h post-infection. On the other hand, both the LExt and Ole were able to inhibit cell-to-cell membrane fusion induced by VHSV in uninfected cells, suggesting interactions with viral envelope. Therefore, we propose that O. europaea could be used as a potential source of promising natural antivirals, which have demonstrated to lack impact on health and environment. In addition, Ole could be used to design other related antiviral agents.
... To search for pharmacological substances of different origins that are effective against fish rhabdoviruses, researchers have extracted several mixtures from marine microalgae, brown alga (Eisenia bicyclis), red alga (Polysiphonia morrowii), algal (Ecklonia cava), fungus (Bacillus subtilis), and herbal or plants, such as the Celosia cristata and Raphanus sativus, olive leaf, Cassia alata, and Phyllanthus acidus [21][22][23][24][25][26][27][28] (Table 1). These extracts have been applied to treat cultured fish cells (in vitro) or inject fish (in vivo) in order to detect their anti-VHSV or anti-IHNV activities, respectively. ...
... Unexpectedly, although the extract mixture from Celosia cristata and Raphanus sativus roots had no effect when added after viral inoculation in fish, it was able to induce the gene expression involved in the innate immune response, which might mediate the antiviral activity of the extracts against VHSV [26]. Recently, two organic mixtures extracted from olive leaf and Cassia alata and Phyllanthus acidus, were confirmed to inhibit cell-to-cell membranes and virus absorption against VHSV and IHNV in vitro [27,28], respectively. Future work should examine the determining compositions and antiviral ingredients in the above-described mixture extracts. ...
Fish rhabdoviruses are harmful single-stranded RNA viruses with high mortality rates which cause considerable economic losses in aquaculture. It is imperative to explore and develop new antiviral compounds against them. In recent years, in addition to inorganic antiviral substances, more than 50 different organic compounds have been confirmed to be effective in the prevention and treatment of rhabdovirus infection and its dissemination in fish. The main types of extracts or agents and their trial designs are here considered for review. This review reveals the reported antiviral activities of extracts from organisms, proteins, lipids, polysaccharides, nucleic acids, coumarin derivatives, arctigenin derivatives, and other antiviral organic molecules against fish rhabdoviruses, respectively. Additionally, their antiviral mechanisms of action include direct virucidal effects, inhibiting virus-induced host cell apoptosis, the blocking of the viral replication cycle, affecting gene expression and innate antiviral immune responses, and so on. This review also gives perspectives on how to comprehensively explore the potential applications of the candidate molecules, which lay the foundation for the future development of new compounds or strategies for the prevention and control of fish rhabdoviruses in aquaculture.
... To find safe and efficient natural antiviral products, Olea europaea extracts were evaluated for their activity against viral haemorrhagic septicaemia virus. Preincubation of the virus with O. europaea extracts before the infection and administration after infection showed in-vitro potency to inhibit viral infectivity in a dose-dependent manner [147]. The authors suggested that O. europaea extracts can directly interact with the viral envelope by interacting with the surface of a phospholipid bilayer [148], enhancing drastic alterations on the membrane surface and, consequently, inhibiting the early fusion steps [147]. ...
... Preincubation of the virus with O. europaea extracts before the infection and administration after infection showed in-vitro potency to inhibit viral infectivity in a dose-dependent manner [147]. The authors suggested that O. europaea extracts can directly interact with the viral envelope by interacting with the surface of a phospholipid bilayer [148], enhancing drastic alterations on the membrane surface and, consequently, inhibiting the early fusion steps [147]. These results indicate that polyphenols and other bioactive compounds isolated from medicinal plants can be used as a promising source of antiviral agents for aquaculture (Fig. 2). ...
This handbook focuses on the use of antibiotic alternatives in poultry and fish feed. Chapters in the book cover a range of natural ingredients in feed and the impacts of these natural feed additives on growth, production, reproduction and health status of poultry and fish. All chapters give a holistic approach to how organic feed additives (herbal plants and their extracts, probiotics, peptides, etc.) can positively impact animal health and production.
Key Features:
- presents 13 chapters contributed by 38 experts and scientists of animal, poultry and fish nutrition, poultry and fish physiology, toxicology, pharmacology, and pathology
- highlights the significance of herbal plants and their extracts and derivatives, cold-pressed and essential oils and fruits by-products
- covers the effects of special ingredients such as immunomodulators, antimicrobial peptides, and probiotics
- provides the reader an updated perspective on the use of additives in poultry and fish industry as growth promoters and their role in developing bacterial resistance to antibiotics
- covers the main poultry species, egg-laying hens, quails, geese, ducks, turkey, and commercial fish
- includes references for advanced readers
This book will be useful for poultry and fish keepers and researchers in animal nutrition, pharmacology, and veterinary sciences. Professionals involved in the poultry and fish feed industry will also find the information useful for product development.
... It contains a significant number of bioactive compounds such as flavonoids, secoiridoids, carotenoids, and phenolic compounds. Olive tree leaf and its active component oleuropein (Ole) were able to inhibit VHSV infection in vitro, and incubation of the virus with LExt or Ole prior to infection reduced viral infectivity to 10% and 30%, respectively [63]. Furthermore, when LExt was added for 36 h after viral infection of cells, LExt sharply reduced VHSV titer and viral protein accumulation in a dose-dependent manner. ...
... It should be noted that the antiviral mechanisms of some of these medicinal plants and active pharmaceutical ingredients have not been confirmed, but are merely inferences made by researchers on the basis of past results. Rhus verniciflua Stokes Flavonoids Inducing apoptosis of cells [47] Celosia cristata and Raphanus sativus Extract Inducing gene expression involved in the innate immune response [57] Licorice (Glycyrrhiza uralensis, GUF) Extract; glycyrrhizin (GL); glycyrrhetinic acid (GLA) Inhibiting the early fusion steps [59] / Curcumin Inhibiting virus entry in cells [61] Olive tree leaf (Olea europaea) (LExt) Extract; oleuropein (Ole) Inactivating virus particles; inhibiting cell-to-cell spread [63] / α-Lipoic acid (LA) Inducing antiviral gene expression; reducing VHSV-induced oxidative stress [65] SVCV / β-Glucose Regulating the innate immune response [76] Herbaspirillum camelliae Selenium Activating IFN-related gene expression [77] Astragalus membranaceus Astragalus polysaccharide (APS) Activating IFN-related gene expression [80] Astragalus membranaceus APS Stimulating the immune response of host; reducing SVCV-induced apoptosis [150] / Palmitic acid (PA) Inhibiting autophagy [81] Psoralea corylifolia Bavachin (BVN) Blocking SVCV-induced apoptosis [84] Bupleurum yinchowense Saikosaponin D (SSD) Reducing SVCV-induced apoptosis [85] Viola philippica Extract Disturbing virus binding, entry, and replication in host cells [129] Glycyrrhiza uralensis (GUF) Extract Impacting the binding of virus particles to cell receptors and the replication of viruses in host cells [130] WSSV Green tea EGCG Inducing gene expression involved in the innate immune response [138,139] Typha angustifolia Naringenin (NAR) Restraining early viral gene replication [140] Pericarpium Citri Reticulatae Hesperidin Improving nonspecific immunity [142] Gardenia jasminoides Extract Blocking viral immediate-early stage gene transcript [143] Gardenia jasminoides Genipin (GN) Attenuating oxidative stress and inflammatory; decreasing signal transducer and activator of transcription gene expression [151] Eucommia ulmoides Geniposidic acid (GPA) Restraining early viral gene replication; promoting apoptosis [144] Pongamia pinnata Bis(2-methylheptyl)phthalate Improving nonspecific immunity [146] Gracilaria tenuistipitata Extract Enhancing the innate immunity [148] Kappaphycus alvarezii Carrageenan Improving nonspecific immunity [152] ...
Aquaculture offers a promising source of economic and healthy protein for human consumption, which can improve wellbeing. Viral diseases are the most serious type of diseases affecting aquatic animals and a major obstacle to the development of the aquaculture industry. In the background of antibiotic-free farming, the development and application of antibiotic alternatives has become one of the most important issues in aquaculture. In recent years, many medicinal plants and their active pharmaceutical ingredients have been found to be effective in the treatment and prevention of viral diseases in aquatic animals. Compared with chemical drugs and antibiotics, medicinal plants have fewer side-effects, produce little drug resistance, and exhibit low toxicity to the water environment. Most medicinal plants can effectively improve the growth performance of aquatic animals; thus, they are becoming increasingly valued and widely used in aquaculture. The present review summarizes the promising antiviral activities of medicinal plants and their active pharmaceutical ingredients against aquatic viruses. Furthermore, it also explains their possible mechanisms of action and possible implications in the prevention or treatment of viral diseases in aquaculture. This article could lay the foundation for the future development of harmless drugs for the prevention and control of viral disease outbreaks in aquaculture.
... Outcomes showed that both extract and oleuropein observed no cellular toxicity as well as after 3 days of treatment with olive leaf extract, level of viral infection was markedly reduced. This information stated the importance of olive extract in the growth of septicemia cause by rhabdovirus[43].Gilling et al. suggested the role of oregano and its active constituent carvacrol (79) against murine norovirus infection. In the work, 4% oregano oil and 0.25%, 0.5% of carvacrol were used to evaluate the antiviral effects against culture media infected with murine norovirus in a 0.25 h, 0.5 h, 1 h, 3 h, 6 h, and 24 h time line. ...
... Predominantly olive fruits and olive oil, but also olive leaves, have been used in traditional medicine to treat cancer, hypertension, arrhythmia and intestinal muscle spasms (Khayyal et al. 2002;Özcan and Matthäus2017) and are thought to be the source of several phytochemicals which have antioxidant, anti-in ammatory, antibacterial (Venditti et al. 2013;Borges et al. 2020), antiviral (Lee-Huang et al. 2003;Micol et al. 2005) and anti-tumor properties (Hamdi et al. 2005;Abaza et al. 2007). ...
Two wild olive subspecies fixed in this research: Olea europaea subsp. europaea var. sylvestris and Olea europaea subsp. laperrinei despite its ecological value, the chemical composition of subsp. laperrinei oil remains unknown, the samples were harvested from the different geographical area. Gas Chromatography-Mass Spectrometry(GC-MS) and Gas Chromatography-flame-ionization detection (GC-FID) analysis of subsp europaea var. sylvestris allowed the identification of 29 compounds oil with Nonanal (11.82%), theaspiranea A (9.81%), 3-hexen-1-ol,benzoate(9.31%) as a major constituents , while the subspecies of the Saharan region were resultedthe identification of 31 compounds where α-pinene (16%) , β-Ocimene (12.82%), dl-Limonene(8.20%) was the main components . The results of the disc diffusion method showed that the two volatile oils have efficient antibacterial activity but, subsp. laperrinei essential oil has a higher range of inhibition, in which P. aeruginosa and B. subtilis showed extreme sensitivity, while the K. pneumoniae bacterium shows great resistance to the two essential oils.
... One of the many components of naturally occurring olive extract (OE) is phenolic compounds, which have been shown to potentially improve cardiovascular health, contain anti-inflammatory properties, provide neuroprotection, and possess antimicrobial activity [6][7][8][9]. Other phytochemicals found in OE are oleuropein and flavonoids; these phytochemicals have been shown to be antioxidants and reduce cancer cell proliferation even at low molecular concentrations [10]. ...
Background
Cervical cancer is the second deadliest for women between the ages of 20 and 39 years. Even with prevention tactics for screening, incident rates and mortality of cervical cancer remain high. Olive has been shown to have many beneficial effects in humans concerning cardiovascular disease and inflammation. Despite these promising benefits, little is known about its effect on cervical cancer. This study examined the effects and mechanism of effects of olive extract (OE) on the HeLa cervical cancer cell line.
Methodology
We utilized clonogenic survival assay, quick cell proliferation assay, and caspase-3 activity to investigate the effect of OE on the proliferation and apoptosis of the cervical cancer cell line HeLa. To investigate the mechanisms behind these findings, Reverse transcription polymerase chain reaction and immunohistochemistry were performed.
Results
OE inhibited the growth and proliferation of HeLa cells. In comparison to the control, the percentage of colonies, as well as the optical density of the cervical cancer cells, was found to be decreased. In addition, the relative activity of caspase-3, a marker for apoptosis, was increased after treatment with OE. The anti-proliferative effect of OE on HeLa cells correlated with the increase of an anti-proliferative molecule p21. However, the pro-apoptotic effect of OE was not correlated with the change in major pro-apoptotic or anti-apoptotic molecules examined in this study.
Conclusions
Our study suggests that OE inhibits the growth of HeLa cervical cancer cells by upregulation of p21. Further investigation of the effects of OE on cervical cancer and other cancers is warranted by these results.
... The Olea europaea is an important medicinal plant whose leaves have antioxidant, hypoglycemic, antihypertensive, and antimicrobial effects (Wang et al., 2008;Abugomaa and Elbadawy, 2020;Elbadawy et al., 2021). Previous studies on the olive leaf extract reported its antiviral activity against viral hemorrhagic septicemia rhabdovirus and Newcastle disease virus, as it has a lot of polyphenols, especially oleuropein, rutin, verbascoside, apigenin-7-glucoside, and luteolin-7-glucoside, which may be related to these properties (Micol et al., 2005;Salih et al., 2017). Hence, it could be a source of antiviral agents. ...
Infectious bronchitis (IB) is a viral disease that causes serious economic losses in the broiler industry. This study evaluated the effectiveness of Olea europaea leaves and propolis extracts (OLP) mixture at a rate of 400 µg and 100 mg/mL, respectively, in curing IB in broiler chickens. One-day-old Ross broiler chicks were randomized into four groups (G) of twenty-one chicks; G1 (control negative; no infection and treatment); G2 (no infection, treatment only), G3 (control positive; infection only and no treatment), and G4 (infection and treatment) that infected with IBv (10 6 EID50/mL) at 21 days old. The OLP treatment was applied for birds in G2 and G4 at a dose of 0.5 mL/liter drinking water for three successive days. The growth performance, clinical and pathological examinations, and viral shedding were evaluated. The use of the OLP resulted in protection from IB infection through the significant improvement of performance parameters such as weight gain and feed conversion ratio, decrease in mortality rate, lowering disease severity, and rapid recovery from the observed clinical signs (mainly respiratory signs), gross and microscopic lesions in the trachea, lung, and kidneys as compared to those in the positive control (G3). Moreover, the viral shedding in the OLP-treated chicks (G4) was significantly decreased in tracheal and cloacal swabs to a rate less than 3×10 3 IBv genome copy number and became not detectable at 14-days post-infection (dpi) in their cloacal swabs. In conclusion, OLP can potentially display an antiviral effect against IB in broiler chickens. Therefore, adding OLP to the chicken drinking water is recommended to prevent and control IB.
... This reveals that C. citratus infusion composites are capable to reduce inflammation and peripheral pain in vivo (Garcia et al. 2015). However, the inhibition is still high which is may be due to cytotoxicity of the extract (Micol et al. 2005). ...
This study was designed to evaluated the anti-cancerous, antiviral and antibacterial effects of Cymbopogon citratus aqueous leave extracts. Methyl thiazolyl tetrazolium (MTT) staining assay has been applied to detect the cytotoxicity and the antiviral properties against measles virus (MV) using cervical cancer cell line (HeLa). The antibacterial potency of the extract against Staphylococcus aureus (staph. aureus) and Klebsiella pneumoniae (Kleb. pneumoniae) was determined using disc diffusion method by means of agar overlay assay. The results showed that C. Citratus extract effectively destroyed Hela cell line after 72 h of exposure. The half maximal inhibitory concentration (IC50) value for the extract was found to be 500 µg mL-1 which exhibited the concentration of 600 µg mL-1 potent antivirus activity. The extract demonstrated antibacterial potency against Staph. aureus with mean inhibition zone 16.4 mm which was higher than that produced by Kleb. pneumoniae with mean inhibition zone of 10.7 mm. C. citratus was a favourable candidate as a natural herb to treat cervical cancers in vitro, restricted the MV replication and has potent antimicrobial activity against gram-positive and negative bacteria isolated from the respiratory tract.
... Some of these compounds (coumaric, vanillic, protocatechuic, caffeic syringic, ferulic acids, phydroxybenzoic acid) are known for their antimicrobial effect on Pcc. The majority of the compounds identified in the products of O. europaea L. and the leaves of P. lentiscus L. are known for their antimicrobial potential, as shown by the work of Rodriguez-Vaquero et al. (2007) and Bammou et al. (2015) for the different compounds isolated from the leaves of P. lentiscus L. and Micol et al. (2005) for the compounds isolated from the leaves of O. europaea L. ...
... Our previous study reported that OESA has a noticeable effect on the scavenging of free radicals and exhibits high antioxidant activity and a protective effect against lipid peroxidation during Epstein Barr virus lytic cycle induction [15]. Moreover, the antiviral activity of olive leaf extracts towards ILTV virus [50], VHSV virus [51], HIV-1 [52], and HSV-1 was previously reported [16,41]. Complementing these previous studies, we characterized the antiviral effects of OESA and OESY in a HeLa cancer model, demonstrating that treatment with both extracts significantly (p < 0.01) reduced the infectious viral particle production ( Figure 4) affecting viral DNA synthesis ( Figure 5), but the effect was greater for OESA than for OESY. ...
The present study aims to assess the antioxidant and antiviral effectiveness of leaf extracts obtained from Olea europaea L. var. sativa and Olea europaea L. var. sylvestris. The total antioxidant activity was determined via both an ammonium phosphomolybdate assay and a nitric oxide radical inhibition assay. Both extracts showed reducing abilities in an in vitro system and in human HeLa cells. Indeed, after oxidative stress induction, we found that exposition to olive leaf extracts protects human HeLa cells from lipid peroxidation and increases the concentration of enzyme antioxidants such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase. Additionally, OESA treatment affects viral DNA accumulation more than OESY, probably due to the exclusive oleuropein content. In fact, subtoxic concentrations of oleuropein inhibit HSV-1 replication, stimulating the phosphorylation of PKR, c-FOS, and c-JUN proteins. These results provide new knowledge about the potential health benefits and mechanisms of action of oleuropein and oleuropein-rich extracts.
... from olive, Olea polygama and dasyscyphin C (-255.83) from false daisy Eclipta prostrate. Viral haemorrhagic septicaemia virus infection was successfully controlled by oleuropein (Ole), a significant compound in olive tree leaf (Olea europaea) extract (Micol et al., 2005). The antiviral activity of dasyscyphin C extract of leaves of Eclipta prostrata was demonstrated against grouper nervous necrosis virus (GNNV) in vitro (Krishnan et al., 2010). ...
Viral nervous necrosis (VNN), caused by the nervous necrosis virus (NNV), is one of the marine finfish culture’s most
serious viral diseases. There are no successful and proven treatment measures to control this infection. In silico approach
aids in identifying novel antiviral compounds that can be analyzed further to fight VNN infection. The present study
aimed to build a 3D model of the NNV capsid protein by in silico approach and explore the protein-ligand binding of
various commercial and herbal antiviral compounds by molecular docking. The protein sequence NNV capsid protein
was retrieved from the UniProt database and analyzed its structural and functional properties. The homology modelling
was carried out using SWISS-MODEL. The 3D structure of capsid protein was used as a receptor in HEX docking
software against antimicrobial herbal and commercial antiviral compounds taken as ligands. The capsid protein was
soluble, stable, hydrophobic and thermostable. The predicted model’s Z-value was acceptable as it lies within the range of
identical native protein scores. In molecular docking, the top antimicrobial herbal compounds that gave the least E-value
were myricitrin (Myrica nagi) >nimbin (Azadirachta indica) > oleuropein (Olea polygama) and the top commercial compounds
with the least E-value were monensin> bafilomycin A1 > chloroquine. The docking results showed that these herbal
compounds can be used as potential anti-NNV agents in marine aquaculture.
... A commercial plant extract derived from olive tree leaf (Olea europaea), LExt, and its major compound, oleuropein (Ole), inhibited the in vitro infectivity of the viral hemorrhagic septicemia virus (VHSV), a salmonid rhabdovirus. Both the LExt and Ole were able to inhibit cell-to-cell membrane fusion induced by VHSV in uninfected cells, suggesting interactions with viral envelope (Micol et al., 2005). Direkbusarakom et al. (1996) established antiviral activity of 18 herbs (C. ...
Nanotechnology is an area of science, engineering, and technology that deals with nanoscale dimensions and tolerances, specifically the manipulation of single atoms and molecules with diameters ranging from 1 to 100 nm. Carbon-based nanoparticles, ceramic nanoparticles, metal nanoparticles, semiconductor nanoparticles, polymeric nanoparticles, and lipid-based nanoparticles are some of the numerous types of nanoparticles that can be classified on the basis of their size, shape, physical, and chemical properties. Probiotics are live, nonpathogenic bacteria that are given to help maintain microbial balance, particularly in the gastrointestinal tract. These probiotics, which can be found in fermented foods and come in the form of capsules, pills, packets, or powders, are made up of lactic acid bacteria such as Lactobacillus and Bifidobacterium species, as well as Saccharomyces boulardii yeast. The applications of biosynthesis of nanoparticles from marine sources such as marine plants, marine animals, and marine microbes are discussed in this chapter. Probiotics can be found in a variety of forms, including dietary supplements, medicines, and medical foods. For more effective probiotic therapy for microbiota-related ailments, a greater understanding of the interplay between genetic, microbial, and environmental impacts within individuals is expected.
... A commercial plant extract derived from olive tree leaf (Olea europaea), LExt, and its major compound, oleuropein (Ole), inhibited the in vitro infectivity of the viral hemorrhagic septicemia virus (VHSV), a salmonid rhabdovirus. Both the LExt and Ole were able to inhibit cell-to-cell membrane fusion induced by VHSV in uninfected cells, suggesting interactions with viral envelope (Micol et al., 2005). Direkbusarakom et al. (1996) established antiviral activity of 18 herbs (C. ...
Recent Advances in Aquaculture Microbial Technology emphasizes various topics on microbiology related technology for aquaculture development and discusses different types of microbiological applications, thus serving as an all-inclusive reference which consolidates microbial technologies adopted in the field. The book covers the history and development of microbial technology in aquaculture as well as aquaculture microbiology, diversity and the role of microbes in aquaculture systems. In addition, it presents the beneficial microbial communities in aquaculture and varying methods employed to study bacterial association in fish, microbes and fish diseases. This resource will help improve research experiments and accomplishments in the area of aqua-culturally relevant microbial technology, making it useful for researchers and scientists in the field.
... 25,26 Although its antiviral mechanism of action is not fully understood, several studies have been conducted on the antiviral effects of olive leaf extract. [25][26][27][28][29] Active immunity results when exposure to a disease organism triggers the immune system to produce antibodies specific to that disease through natural immunity or vaccine-induced immunity. ...
Objective: During the Coronavirus Disease-2019 (COVID-19) pandemic, in addition to the current measures, the healthy immune system plays an essential role and various natural agents have been recommended to boost innate immunity. The aim of this study was to investigate any association between the potential immunomodulatory activity and drinking olive leaf tea (OLT) in the COVID-19 pandemic. Design: The study was conducted among the workers in a tractor factory where OLT was served in routine. Drinking at least one cup of OLT per day for a minimum of 1 month was the inclusion criteria used in the study. The workers who had a history of vaccination and COVID-19 were excluded from the study, and lymphocyte subsets, interleukin (IL)-2, IFN-γ, COVID-19-specific IgM and IgG levels were analyzed in all the participants to determine the asymptomatic individuals among the participants and compare the immunological parameters. Results: The study was conducted among 336 workers, 183 of them were OLT drinkers and 153 were OLT nondrinkers. The results showed higher values of CD3-/CD16/56 (natural killer [NK]) cells, CD3+/CD16/56 (natural killer T [NKT]) cells, total NK (NK+NKT) cells, and serum IFN-γ, and IL-2 levels in OLT drinkers compared to the nondrinkers. Although all the OLT drinkers and nondrinkers included in the study reported no history of COVID-19, specific COVID-19 IgG levels were found positive in 60% of OLT drinkers and 38% OLT nondrinkers. Conclusions: Peripheral NK and NKT cell values and IL-2 and IFN-γ secretion levels were found higher in the OLT drinking group. There were positive correlations between the OLT drinking frequency and NK cell counts. Moreover, the number of individuals who had "asymptomatic" COVID-19 infection was higher in the OLT drinking group than in the nondrinking cohort. Clinical Trail: The trial has been registered in the ClinicalTrials.gov database (CTR NCT05222347).
... Some sources of medicinal plants in aquaculture include (Aloe vera) Kim et al. (1999), almond (Terminalia catappa) Chitmanat et al. (2005), basil flower (Ocimum sanctum) Peraza-Gómez et al. (2011), caraway seed meal (CarumcarviL.) (Ahmad and Abdel-Tawwab, 2011), cinnamon (Cinnamomum zeylanicum) , garlic (Allium sativum) (Aly and Mohamed, 2010; ginger (Zingiber officinale) Talpur et al., 2013), American ginseng (Panax quinquefolium) (Abdel-Tawwab, 2012), green tea (Camellia sinensis) (Abdel-Tawwab et al., 2010;Hwang et al., 2013), Arabic coffee bean (Coffee arabica) (Abdel-Tawwab, 2015), guava (Psidium guajava) (Direkbusarakom, 2004), heartleaf moonseed (Tinospora cordifolia) (Sudhakaran et al., 2006), olive tree leaf (Oleaeuropaea) (Micol et al., 2005), papaya leaf (Penaflorida, 1995), peppermint (Mentha piperita) (Mousavi et al., 2011), purple coneflower (Echinacea purpurea) (Aly and Mohamed, 2010) quillajasaponins (Quillaja saponaria) (Francis et al., 2005), seaweeds (Sargassum spp.) Immanuel et al., 2010) tulsi (Ocimum sanctum) .More than 60 different medicinal-plant species have been studied for the improvement of fish health and disease management in aquaculture etc. (Bulfon et al., 2015). ...
Medicinal plants have been known as immunostimulants for thousands of years. The application of medicinal plants as natural and innocuous compounds has potential in aquaculture as an alternative to antibiotics and immunoprophylactics. The growing interest in these plants has increased worldwide because they are easy to prepare, cheap and have little or no side effects on animals and the environment. A wide range of medicinal plants such as herbs, spices, seaweeds, herbal medicines, herbal extracted compounds, traditional Chinese medicines and commercial plant-derived products have been studied in various aquatic animals. The whole plant or its parts viz. roots, leaves, seeds, flowers or extract compounds can be used. The extraction process is simple, with ethanol and methanol being commonly used. Various chemicals used to extract compounds may lead to different degrees of effects on aquatic animals. Application methods can be either single or in combination, or even in a mixture with other immunostimulants, via water routine or feed additives and enrichment, where single administrations are as practical as combinations. The dosages and duration of time varies and the optimal levels have not been considered. Medicinal plants show their main properties as growth promoters, immune enhancers, where they act as antibacterial and antiviral agents to the host immune system. Unfortunately, the mechanisms are not fully understood. Therefore, most authors did not recommend that their results be used directly, while suggestions are proposed for further investigations.
... The plant extract Cynodon dactylon prevented WSSV infection without mortality and without evidence of white spot disease in 2% respectively and 40% mortality in 1% in black tiger shrimp [72]. The salmonid rhabdovirus, the viral hemorrhagic septicemia, was controlled with plant extracts derived from olive leaves and its main compound, oleuropein [73]. In addition, the ethanolic extracts of Piper guineese (fruit) and Xylopia aethiopica (seeds) were active against Candida albicans and B. subtilis, E. coli, Salmonella typhi and P. vulgaris. ...
Fish from the aquaculture industry will continue to be one of the mainstays in meeting human animal protein needs. Various global challenges face the aquaculture industry. Starting from the issue of environmental degradation, water pollution, conversion of agricultural land and aquaculture, to diseases attacks and the use of antibiotics to control fish pests and diseases. The presence of antibiotics and insecticides in food is no longer acceptable. Therefore, it is necessary to find an environmentally friendly solution for this disease and disturbance of water and environmental pollution. The use of natural ingredients in the form of medicinal plants to increase fish immunity and treat infectious diseases is a promising option. Water and environmental pollution are increasingly inevitable and the use of plants for the bioremediation process is the right choice. This paper presents a review of research on the use of several plant species that may be used for the purposes of improvement of fish immunity, enhancement of antimicrobial activity, replacement of the role of antibiotics, improvement of fish growth, improvement of feed conversion, and water quality improvement of polluted waters.
... Substantial research has been conducted to search for useful herbal medicines or to isolate and identify active compounds from these herbs for the prevention and control of viral diseases [30]. For example, Micol et al. found that extracts from olive tree leaf (Olea europaes) inhibited the in vitro infectivity of VHSV, a salmonid rhabdovirus [31]. Furthermore, extracts from Punica granatum [32], emodin, and barbaloin [33] have been reported to show anti-rhabdovirus activity. ...
Micropterus salmoides rhabdovirus (MSRV) is a primary viral pathogen in largemouth bass aquaculture, which leads to tremendous economic losses yearly. Currently, there are no approved drugs for the treatment and control of this virus. Our previous studies screened the herb Magnolia officinalis from many traditional Chinese medicines, and we isolated and identified magnolol as its main active compound against multiple rhabdoviruses, including MSRV. On the basis of the structure–activity relationship and pharmacophore model of magnolol, two new magnolol derivatives, namely, hydrogenated magnolol and 2,2′-dimethoxy-magnolol, were designed and synthesized. Their anti-MSRV activities were systematically investigated both in vitro and in vivo. By comparing the half-maximal inhibitory concentration (IC50), it was found that hydrogenated magnolol possessed a higher anti-MSRV activity than magnolol and 2,2′-dimethoxy-magnolol, with an IC50 of 13.37 μM. Furthermore, hydrogenated magnolol exhibited a protective effect on the grass carp ovary (GCO) cell line by reducing the cytopathic effect induced by MSRV. Further studies revealed that hydrogenated magnolol did not directly impact virions or interfere with MSRV adsorption. It worked within the 6–8 h of the phase of virus replication. In vivo treatment of MSRV infection with magnolol and hydrogenated magnolol showed that they significantly improved the survival rate by 44.6% and 62.7%, respectively, compared to MSRV-infected groups. The viral load measured by the expression of viral glycoprotein in the organs including the liver, spleen, and kidney also significantly decreased when fish were intraperitoneally injected at a dose of 20 mg/kg. Altogether, the structural optimization of magnolol via hydrogenation of the propylene groups increased its anti-MSRV activity both in vitro and in vivo. These results may provide a valuable reference for anti-MSRV drug discovery and development in aquaculture.
... Thus, oleuropein stable binding with TLR-4 and POP will not only limit neuro-COVID effects but pave the way for treatment strategies against other neurological disorders as well. Oleuropein is known for its antiviral activity and reported to inhibit fusion and infectivity of viruses [22,23,55,56]. In 2019, phenolic compounds of virgin olive oil showed TLR4/NLRP3 modulating potential to curb inflammatory response on brain cells [57]. ...
The association of COVID-19 with neurological complications is a well-known fact, and researchers are endeavoring to investigate the mechanistic perspectives behind it. SARS-CoV-2 can bind to Toll-like receptor 4 (TLR-4) that would eventually lead to α-synuclein aggregation in neurons and stimulation of neurodegeneration pathways. Olive leaves have been reported as a promising phytotherapy or co-therapy against COVID-19, and oleuropein is one of the major active components of olive leaves. In the current study, oleuropein was investigated against SARS-CoV-2 target (main protease 3CLpro), TLR-4 and Prolyl Oligopeptidases (POP), to explore oleuropein potency against the neurological complications associated with COVID-19. Docking experiments, docking validation, interaction analysis, and molecular dynamic simulation analysis were performed to provide insight into the binding pattern of oleuropein with the three target proteins. Interaction analysis revealed strong bonding between oleuropein and the active site amino acid residues of the target proteins. Results were further compared with positive control lopinavir (3CLpro), resatorvid (TLR-4), and berberine (POP). Moreover, molecular dynamic simulation was performed using YASARA structure tool, and AMBER14 force field was applied to examine an 100 ns trajectory run. For each target protein-oleuropein complex, RMSD, RoG, and total potential energy were estimated, and 400 snapshots were obtained after each 250 ps. Docking analyses showed binding energy as −7.8, −8.3, and −8.5 kcal/mol for oleuropein-3CLpro, oleuropein-TLR4, and oleuropein-POP interactions, respectively. Importantly, target protein-oleuropein complexes were stable during the 100 ns simulation run. However, an experimental in vitro study of the binding of oleuropein to the purified targets would be necessary to confirm the present study outcomes.
... Oleuropein has exhibited many pharmacological effects including anti-oxidant [8], antimicrobial [11], anti-viral [44], neuroprotective, cardioprotective [45], hypoglycemic properties [46]. Furthermore, oleuropein also had anti-ischemic [47], anti-inflammatory [19] and hypolipidemic [48] effects. ...
... Acar-Tek and Ağagündüz (2020) and Sánchez- Gutiérrez et al. (2021) confirmed that traditional herbal medicines rely on the utilization of olive leaves to avoid and get relief from numerous illnesses, particularly in the Mediterranean countries. For example, leaves are utilized due to their antimicrobial (Pereira et al. 2007), antioxidant (Skrget et al. 2005), hypotensive (Khayyal et al. 2002), gastroprotective (Dekanski et al. 2009), hypoglycemic (Al-Azzawie and Alhamdani 2006), antiatherosclerotic (Wang et al. 2008), antiviral (Micol et al. 2005), antiarrhythmic (Somova et al. 2004), antitumor (Abaza et al. 2007), and antiinflammatory properties (Pieroni et al. 1996), and insulin sensitizing (González-Hedström et al. 2021) and antiproliferative activity (Goulas et al. 2009). The reported biological activities of the leaf extract have been related to specific phenolic compounds characteristic of the Olea genus. ...
Olea europaea L. (olive, Oleaceae) constitutes a source of many bioactive compounds, which have recognized benefits for both human health and technological purposes. The present article was carried out to evaluate the biological activity of oleuropein (an ester of 2-(3,4-dihydroxyphenyl) ethanol (hydroxytyrosol) which has the oleosidic skeleton that is common to the secoiridoid glucosides of Oleaceae). It occurred in leaf extracts of the four olive cultivars (Chemlali, Manzanilla, Picaul and Toffahi) as a source for some anticancer and antioxidant agents and their consequences on the action of Hordeum vulgare (barley). The total phenolic and flavonoid compounds were extracted from olive leaves by ethanol 95% then analyzed by high-performance liquid chromatography (HPLC). The study evaluates the anticancer activity of the ethanolic extract of olive leaves against breast and hepatocellular carcinoma cells showing high values. Also, the extract exhibited highly consequence on the antioxidant potentiality of barley which was assessed using the diphenyl picryl hydrazyl method (DDPH). These results pave the way for utilization of olive leaves as a source of natural anticancer and antioxidant agents.
... However, the use of antioxidants and antimicrobials provides an effective way for preservation of meat products against spoilage. Nowadays, an increased interest has been focused towards plant-based extract as a source of phenolic antioxidant, antimicrobial, antiviral and antiinflammatory (13, 45). It has been reported that adding olive leaf extract (OLE) at a rate of 1, 2 and 3%, led to retarted significantly (p < 0.01) oxidative rancidity of lamb patties stored at 4c° for 12 days by 52.3, 36.5 and 26.17%, respectively as compared with control.Total plate count, psychrophilic count and coliform bacteria decreased significantly (p < 0.01) with the addition of this extract (11). ...
The aim of this experiment was to evaluate the effect of adding different levels of each of olive leaf extract (OLE) and thyme leaf extract (TLE) and their combination in some physicochemical, microbial, and sensory characteristic of lamb patties stored either at 4c° for 12 days or at -18c° for 120 days. Results revealed that there are a steady rise (p<0.01) in oxidative rancidity, microbial count and free fatty acid in control and treated samples with increasing time in both storage periods. Also, a significant (p<0.01) reduction in TBA, microbial count and free fatty acid was observed in samples treated with OLE, TLE and their combination. Moreover, it was found that addition of 1% OLE and 1% OLE +0.05%TLE are more effective against formation of TBA and microbial count, respectively. Sensory characteristics were highest in patties treated with 0.05% TLE and the lowest was noticed in samples treated with 1% OLE.
... This suggests that the OESA treatment has a protective effect against the EBV lytic cycle induction. These results reflect previous studies which reported the antiviral activity of olive leaf extract preparations towards ILTV virus [42], VHSV virus [43], HIV-1 [44], and HSV-1 [45]. Recently, we showed the antiviral effect of OESA against HSV-1. ...
Citation: Ben-Amor, I.; Gargouri, B.; Attia, H.; Tlili, K.; Kallel, I.; Musarra-Pizzo, M.; Sciortino, M.T.; Pennisi, R. In Vitro Anti-Epstein Barr Virus Activity of Olea europaea L. Leaf Extracts. Plants 2021, 10, 2445. https:// Abstract: Olea europaea L. var. sativa (OESA) preparations are widely used in traditional medicine in the Mediterranean region to prevent and treat different diseases. In this research, olive extracts derived from the leaves of the OESA tree have been screened for antioxidant activity by two methods: the DPPH free radical scavenging assay (DPPH) and the Ferric reducing antioxidant power (FRAP) assay. The DPPH assay showed that OESA possesses a stronger antioxidant activity (84%) at 1 mg/mL while the FRAP method showed a strong metal ion chelating activity (90%) at 1 mg/mL. The low IC 50 values, obtained by two different methods, implies that OESA has a noticeable effect on scavenging free radicals comparable to standards. During EBV infection, the free radicals increased triggering lipid oxidation. Therefore, the monitoring of the secondary lipid peroxidation products was done by measuring malonaldehyde (MDA) and conjugated dienes (DC). The simultaneous treatment of Raji cells with OESA and TPA, as an inductorof the lytic cycle, generated a significant decrease in MDA levels and DC (p < 0.05). Besides, Raji cells simultaneously exposed to TPA and OESA exhibited a percentage of EBV-positive fluorescence cells lower than TPA treated cells (**** p < 0.0001). This suggests that OESA treatment has a protective effect against EBV lytic cycle induction.
... Oleuropein (OP) is the most abundant polyphenol in olives and olive leaves, conferring the bitter principal taste and the resistance against the development of oil rancidity (Visioli et al., 1998;Guinda et al., 2015). During years, oleuropein intake has been correlated with several pharmacological properties, including anti-cancer, hepatoprotective, neuroprotective, antiviral, and anti-inflammatory effects (De La Puerta et al., 1999;Micol et al., 2005;Daccache et al., 2011;Park et al., 2011). ...
Oleuropein (OP) is a polyphenol present in drupes and leaves of olive tree with health benefits and, as antioxidant, potentiality to alter gluten functionality. Effects of OP inclusion to wheat flour (0.01% and 0.02% on flour weight basis) on dough rheology and breadmaking performance, and bread features were investigated. Farinograph, uniaxial extension and shear rheometry (oscillatory and creep-recovery) were applied. Doughs containing OP were stronger, more elastic, and less sticky indicating the ability of OP to act as flour improver. The strengthening effect of OP on gluten led to the increase in bread volume and softer crumb compared to control. A lower crumb density of bread with the addition of OP was related to a higher in vitro glycaemic response. An increase in the antioxidant capacity of bread made with the phenolic compound was also found.
... The plant extract Cynodon dactylon prevented WSSV infection without mortality and without evidence of white spot disease in 2% respectively and 40% mortality in 1% in black tiger shrimp [72]. The salmonid rhabdovirus, the viral hemorrhagic septicemia, was controlled with plant extracts derived from olive leaves and its main compound, oleuropein [73]. In addition, the ethanolic extracts of Piper guineese (fruit) and Xylopia aethiopica (seeds) were active against Candida albicans and B. subtilis, E. coli, Salmonella typhi and P. vulgaris. ...
Fish from the aquaculture industry will continue to be one of the mainstays in meeting human animal
protein needs. Various global challenges face the aquaculture industry. Starting from the issue of
environmental degradation, water pollution, conversion of agricultural land and aquaculture, to
diseases attacks and the use of antibiotics to control fish pests and diseases. The presence of
antibiotics and insecticides in food is no longer acceptable. Therefore, it is necessary to find an
environmentally friendly solution for this disease and disturbance of water and environmental
pollution. The use of natural ingredients in the form of medicinal plants to increase fish immunity and
treat infectious diseases is a promising option. Water and environmental pollution are increasingly
inevitable and the use of plants for the bioremediation process is the right choice. This paper presents
a review of research on the use of several plant species that may be used for the purposes of
improvement of fish immunity, enhancement of antimicrobial activity, replacement of the role of
antibiotics, improvement of fish growth, improvement of feed conversion, and water quality
improvement of polluted waters.
... W badaniach in vitro wykazano, że podawanie oleuropeiny 36 godz. przed inkubacją z wirusem posocznicy krwotocznej zmniejsza zakaźność o 30%, hamowało również fuzję wirusa do komórek niezakażonych (51). ...
The olive tree is a long-lived plant, mentioned already in Greek mythology and the Bible. Currently most plantations is concentrated in the Mediterranean and the Middle East. The fruit of the olive ripens in favorable climatic conditions for about 5 months. Half of the fruit's content is water, the other ingredients are mainly: oil, carbohydrates, cellulose, phenolic compounds, proteins and inorganic compounds. This compound belongs to the terpenes secoids, it is a glucoside of the ester of elenolic acid and 3,4-dihydroxyphenylethanol. It is found in many genera of the Oleaceae and Gentianaceae families. Oleuropein and hydroxytyrosol are responsible for the sharp and bitter taste of the oil.
... Olive trees were historically referred to as the "king of trees" because olive leaf extract (OLE) has been shown to be beneficial to humans since ancient times. The beneficial functional and nutritional effects of OLE include antibacterial, antiviral, antifungal, and antioxidant activities (Bisignano et al., 1999;Markin et al., 2003;Micol et al., 2005;Pereira et al., 2007). In addition, OLE has been shown to support the immune system, provide cardioprotection, lower blood pressure, as well as improve diabetes, cancer, and arthritis (Susalit et al., 2011;de Bock et al., 2013;Cabarkapa et al., 2016;Gouvinhas et al., 2017;Xu et al., 2018;Ruzzolini et al., 2020). ...
Listeria monocytogenes is a regulated foodborne pathogen that is known to cause listeriosis, a disease associated with high mortality rates in humans. Olive leaf extract (OLE) has been shown to act as a plant antimicrobial and inhibit the growth of pathogens, such as L. monocytogenes , although its mode of action has not been defined. To help identify the cellular mechanisms important for conveying these beneficial traits, RNA-Seq was used to study the transcriptome of L. monocytogenes upon exposure to a sublethal level of OLE. Results obtained from cells cultured both with and without OLE at two different time points (3.5-h and 24-h) revealed 661 genes that were differentially expressed. Of the differentially expressed genes (DEGs) identified, transcription was altered for 171 genes in response to the 3.5-h OLE treatment while 490 genes were altered in response to the 24-h OLE treatment. These DEGs included but were not limited to genes encoding for signal transduction, ATP-binding cassette (ABC) transporters, and the phosphotransferase system. Interestingly, several virulence-related genes were downregulated including an ABC transporter permease previously shown to negatively regulate biofilm formation, genes involved in flagella assembly and binding/entry into host cells as well as those regulating acid resistance suggesting that OLE may decrease the virulence potential of L. monocytogenes . Furthermore, quantitative reverse-transcription PCR was used to validate the data obtained via RNA-Seq. Our study provides insight into the mode of action of OLE treatment against L. monocytogenes and may aid in identifying synergetic strategies to inhibit L. monocytogenes in food.
Currently, in addition to the use of olive oil in cosmetics, the use of olive-derived bioactives and their incorporation into cosmetics is a growing trend. The olive oil industry produces vast quantities of by-products, such as olive mill wastewater, olive pomace and leaves from which new ingredients may be obtained for cosmetic use. In this way, by-products are revalorized, which contributes to the implementation of a sustainable economy or upcycling. This review intends to provide a detailed overview of the different extraction techniques reported in order to obtain the bioactive compounds of cosmetic value that can be found in olive by-products: fatty acids, tocopherols, polyphenols, phytosterols and squalene. Different extraction techniques are presented, including some traditional techniques (solid–liquid extraction) and more novel or “greener” ones: ultrasound, microwave, supercritical extraction, pressurized fluids and deep eutectic solvents. Additionally, different applications of olive by-products in skin care products are explored: emollient, antioxidant, anti-age, anti-inflammatory, antiviral, antifungal and antibacterial, and the perspective of consumers is also considered since they increasingly demand products formulated with natural ingredients.
Olive leaves are an immense source of antioxidant and antimicrobial bioactive constituents. This study investigated the effects of dietary incorporation of olive leaf extract (OLE) on the growth performance, hematobiochemical parameters, immune response, antioxidant defense, histopathological changes, and some growth- and immune-related genes in the common carp (Cyprinus carpio). A total of 180 fish were allocated into four groups with triplicate each. The control group received the basal diet without OLE, while the other three groups were fed a basal diet with the OLE at 0.1, 0.2, and 0.3%, respectively. The feeding study lasted for 8 weeks, then fish were challenged with Aeromonas hydrophila. The results revealed that the group supplied with the 0.1% OLE significantly exhibited a higher final body weight (FBW), weight gain (WG%), and specific growth rate (SGR) with a decreased feed conversion ratio (FCR) compared to the other groups (p < 0.05). An increase in immune response was also observed in the fish from this group, with higher lysosome activity, immunoglobulin (IgM), and respiratory burst than nonsupplemented fish, both before and after the A. hydrophila challenge (p < 0.05). Similarly, the supplementation of the 0.1% OLE also promoted the C. carpio's digestive capacity pre- and post-challenge, presenting the highest activity of protease and alkaline phosphatase (p < 0.05). In addition, this dose of the OLE enhanced fish antioxidant capacity through an increase in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and decreased hepatic lipid peroxidation end products (malondialdehyde—MDA), when compared to the control group, both pre- and post-infection (p < 0.05). Concomitantly with the superior immune response and antioxidant capacity, the fish fed the 0.1% OLE revealed the highest survival rate after the challenge with A. hydrophila (p < 0.05). A significant remarkable upregulation of the hepatic sod, nrf2, and protein kinase C transcription levels was detected as a vital approach for the prevention of both oxidative stress and inflammation compared to the infected unsupplied control group (p < 0.05). Interestingly, HPLC and UPLC-ESI-MS/MS analyses recognized that oleuropein is the main constituent (20.4%) with other 45 compounds in addition to tentative identification of two new compounds, namely oleuroside-10-carboxylic acid (I) and demethyl oleuroside-10-carboxylic acid (II). These constituents may be responsible for the OLE exerted potential effects. To conclude, the OLE at a dose range of 0.66–0.83 g/kg w/w can be included in the C. carpio diet to improve the growth, antioxidant capacity, and immune response under normal health conditions along with regulating the infection-associated pro-inflammatory gene expressions, thus enhancing resistance against A. hydrophila.
Nowadays, theoretical chemistry has experienced a great advance in the search for drugs for the treatment of various human and animal pathologies. Although it is expected that medicinal plants constitute a great source for the research of compounds, the present study has been carried out to provide a list of important plants that can be explored in the research of antiviral compounds. The main objective is to search for medicinal plant(s) that can be used to treat various viral pathologies; in other words, the search for broad spectrum antiviral plants. Thus, several articles of synthesis, original research, systematic review on antiviral plants from different countries are consulted in this study. A total of 694 species of medicinal plants from 152 families were extracted from the literature against 17 virus families including Adenoviridae, Alloherpesviridae, Arteriviridae, Birnaviridae, Coronaviridae, Flaviviridae, Herpesviridae, Nimaviridae, Orthomyxoviridae, Papillomaviridae, Parvoviridae, Picornaviridae, Poxviridae, Reoviridae, Retroviridae, Togaviridae. The most cited families of plants are Fabaceae (11.38%), Lamiaceae (5.90%), Asteraceae (5.61%), Rubiaceae (3.45%) and Euphorbiaceae (3.02%). The three (3) most cited species that can treat several viral diseases are Allium sativum, Azadirachta indica and Zingiber officinale. These plants can be a starting point for antiviral drug research and the compounds already isolated from these plants can be subject to molecular docking in order to explore their antiviral potential.
Aquaculture is an important source of high‐quality protein and plays a crucial role in ensuring global food security. However, viral diseases have caused significant damage to aquaculture production, making it necessary to develop effective measures to treat them. Although drugs are commonly used to treat viral diseases, recent studies have shown that crude extracts of medicinal plants and their active ingredients have potential applications in the treatment of aquatic viral diseases. Furthermore, natural small molecule compounds from herbs could be used as lead compounds to develop more potent anti‐aquatic virus derivatives. As such, there is an urgent need to develop and apply drugs for the treatment of viral disease outbreaks in aquaculture. In this review, we summarize previous studies on the efficacy of different agents used as antiviral drugs in aquaculture, with a focus on their protective effects. Additionally, we highlight the potential of active natural compounds isolated from medicinal plants, which could serve as lead compounds for developing aquatic‐specific drugs. However, the relationship between the structure of a compound and its antiviral activity in aquaculture has not been clearly elucidated, posing a challenge for further drug optimisation. Therefore, this study also analyses the structure–activity relationship of several reported lead compounds and their derivatives in aquaculture, providing a reference for subsequent drug development efforts.
Leaves of the Olea europaea L. species are frequently utilized in both folk and modern medicine.In nowadays are strongly valuable for their beneficial effects to treat a multitude of bacterial and inflammation-type diseases, two wild olive subspecies fixed in this research: the widespread Mediterranean Olea europaea subsp. europaea var. sylvestris and the endemic Olea europaea subsp. laperrinei from Saharan region, Despite its ecological value, the chemical composition of subsp. laperrinei oil remains unknown, the samples were harvested from the different geographical area. Gas Chromatography-Mass Spectrometry(GC-MS) and Gas Chromatography-flame-ionization detection (GC-FID) analysis of subsp europaea var. sylvestris allowed the identification of 29 compounds oil with Nonanal (11.82%), Theaspiranea A (9.81%), 3-hexen-1-ol,benzoate(9.31%), β-damascenone (6.87%), α-pinene (6.32%), Farnesol (6.10%) as a major constituents, while the subspecies of the Saharan region were resultedthe identification of 31 compounds where α-pinene (16%), β-Ocimene (12.82%), dl-Limonene(8.20%), Nonanal (8.18%), was the main components .The Monoterpene hydrocarbons represented the most abundant class in the two essential oils samples. The results of the disc diffusion method showed that the two volatile oils have efficient antibacterial activity but, subsp. laperrinei essential oil has a higher range of inhibition, in which P. aeruginosa and B. subtilis showed extreme sensitivity, while the K. pneumoniae bacterium shows great resistance to the two essential oils. These results demonstrated the medicinal value of olive leaves, as well as the impact of climate on the volatiles produced.
Plant-based extracts possess biological potential due to their high content of phytochemicals. Nevertheless, photosynthetic pigments (e.g., chlorophylls) that are also present in plant extracts could produce undesirable pro-oxidant activity that might cause a negative impact on their eventual application. Herein, the phenolic content of olive leaf (OLE) and green tea (GTE) extracts was assayed, and their antioxidant and anticancer activities were evaluated before and after the removal of chlorophylls. Regarding phenolic content, OLE was rich in hydroxytyrosol, tyrosol as well as oleuropein, whereas the main compounds present in GTE were gallocatechin, epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate, and caffeine. Interestingly, fresh extracts’ antioxidant ability was dependent on phenolic compounds; however, the elimination of chlorophyll compounds did not modify the antioxidant activity of extracts. In addition, both OLE and GTE had high cytotoxicity against HL-60 leukemic cell line. Of note, the removal of chlorophyll pigments remarkably reduced the cytotoxic effect in both cases. Therefore, our findings emphasize the remarkable antioxidant and anticancer potential of OLE and GTE and suggest that chlorophylls are of paramount importance for the tumor-killing ability of such plant-derived extracts.
Research of new bioactive compounds from natural raw materials, the by-products of the olive tree, attracts considerable attention due to their high potential as a source of useful molecules. The therapeutic virtues of olive tree by-products have been known since antiquity, it is mainly olive oil, and leaves are the most used in traditional medicine and recently in phytotherapy. The beneficial effects on human health of these two derivatives are multiple: antioxidants, hypoglycemic, antimicrobial, and anticancer. Although studies on the biological activities of other olive by-products (pruning wood, oil mill waste, and pomace) remain limited, these by-products are characterized by their richness in bioactive molecules. Indeed, studies have shown that the biological potentialities are related to the presence of monounsaturated fatty acids (especially oleic acid: C18:1) as well as other bioactive compounds such as tocopherols, carotenoids, phospholipids, and phenolic compounds (hydroxytyrosol, tyrosol, and oleuropein). Moreover, phytosterols are among the most interesting molecules of these coproducts that need to be studied in depth. This brief overview presents state of research on useful bioactive compounds from olive tree by-products.
Ethnopharmacological relevance: Sauropus androgynus is a medicinal shrub used for the treatment of fever in ethnomedical traditions in various Southeast Asian countries.
Aim of the study: This study was aimed to identify antiviral principles from S. androgynus against Chikungunya virus (CHIKV), a major mosquito-borne pathogen that re-emerged in the last decade, and to unravel their mechanism of action.
Materials and methods: Hydroalcoholic extract of S. androgynus leaves was screened for anti-CHIKV activity using cytopathic effect (CPE) reduction assay. The extract was subjected to activity guided isolation and the resultant pure molecule was characterized by GC-MS, Co-GC and Co-HPTLC. The isolated molecule was further evaluated for its effect by plaque reduction assay, western blot and immunofluorescence assays. In silico docking with CHIKV envelope proteins and molecular dynamics simulation (MD) analyses were used to elucidate its possible mechanism of action.
Results: S. androgynus hydroalcoholic extract showed promising anti-CHIKV activity and its active component, obtained by activity guided isolation, was identified as ethyl palmitate (EP), a fatty acid ester. At 1 μg/mL, EP led to 100% inhibition of CPE and a significant 3-log10 reduction in CHIKV replication in Vero cells at 48 h post-infection. EP was highly potent with an EC50 of 0.0019 μg/mL (0.0068 μM) and a very high selectivity index. EP treatment significantly reduced viral protein expression, and time of addition studies revealed that it acts at the stage of viral entry. A strong binding to the viral envelope protein E1 homotrimer during entry, thus 58 preventing viral fusion, was identified as a possible mechanism by which EP imparts its antiviral effect.
Conclusions: S. androgynus contains EP as a potent antiviral principle against CHIKV. This justifies the use of the plant against febrile infections, possibly caused by viruses, in various ethnomedical systems. Our results also prompt more studies on fatty acids and their derivatives against emerging viral diseases.
Surprisingly little overlap has been found in the studies of the several hundred plant and herb species with promise as new antiviral medicines. Given the rise in migration, international travel, and urbanization today, viral infections are one of the leading causes of disease around the world. Researchers are looking to the plant world as a source of potential novel antiviral treatments due to the numerous adverse effects of synthetic medicines and the growing problem of resistance. For their various therapeutic purposes, a large number of biologically active compounds have been discovered. Over the past few decades, thorough research into phytochemicals’ antiviral properties has gained relevance. This chapter demonstrates the abundance of potentially beneficial medicinal plants and herbs that are only waiting to be assessed and used for therapeutic applications against genetically and functionally varied plant and viral families.
Olive oil production is a significant source of economic profit for Mediterranean nations, accounting for around 98 percent of global output. Olive oil usage has increased dramatically in recent years, owing to its organoleptic characteristics and rising knowledge of its health advantages. The culture of olive trees and the manufacture of industrial and table olive oil produces enormous volumes of solid waste and dark liquid effluents, involving olive leaves, pomace, and olive oil mill wastewaters. These by-products cause an economic issue for manufacturers and pose major environmental concerns. As a result, partial reuse, like other agronomical production wastes, is a goal to be achieved. Because these by-products are high in bioactive chemicals, which, if isolated, might denote components with significant added value for the food, cosmetic, and nutraceutical sectors, indeed, they include significant amounts of beneficial organic acids, carbohydrates, proteins, fibers, and phenolic materials, which are distributed differently between the various wastes depending on the olive oil production method and table olive agronomical techniques. However, the extraction and recovery of bioactive materials from chosen by-products is a significant problem of their reasonable value, and rigorous detection and quantification are required. The primary aims of this review in this context are to outline the vital bioactive chemicals in olive by-products, evaluate the main developments in extraction, purification, and identification, and study their uses in food packaging systems and safety problems.
Disease outbreaks have resulted in significant losses in aquaculture. Antibiotics, although typically effective in treating fish diseases, can accumulate in the environment as antibiotic residues or in fish tissues over time, leading to the growth of antibiotic-resistant strains. Vaccines are often too costly and time-consuming for widespread use in fish farms, and each vaccine is effective only against one form of pathogen. For thousands of years, medicinal plants have been used as immunostimulants. Aquaculture may benefit from the use of medicinal plants as natural and safe compounds as an alternative to antibiotics and immunoprophylactics. Since they are simple to prepare, inexpensive, and have few undesirable effects on animals and the climate, there has been a surge in interest in these plants around the world. Herbs, seaweeds, herbal extract compounds, spices, commercial plant-derived products, and traditional herbs are all sources of medicinal plants. Active compounds such as alkaloid, terpenoid, pigments, polyphenol, quinone, lectin, tannins, essential oils, and polypeptide compounds have been shown to have antimicrobial properties, the ability to promote growth and strengthen the immune system, as well as stimulate appetite and possess antistress properties in fish, and others are effective alternatives to antibiotics, chemicals, and vaccines. They are often used as a source of nutrition for fish.
A oliveira (Olea europaea) é uma árvore característica da Região Mediterrânea, conhecida mundialmente pelo seu fruto, a azeitona. É um dos cultivos mais antigos, principalmente devido a fácil adaptação às adversidades ambientais. No estado do Rio Grande do Sul, seu cultivo teve início em 1948 e vem apresentando grande destaque. Entre outros compostos produzidos pela oliveira, os fenólicos, especialmente os polifenóis hidroxitirosol e a oleuropeína, demonstraram ação antimicrobiana in vitro, porém existem poucos relatos sobre a atividade antifúngica. O objetivo desta revisão foi relatar a atividade antimicrobiana de O. europaea e comparar os resultados dos testes realizados com as distintas variedades e extratos. Foram selecionados onze trabalhos publicados entre os anos de 2000 e 2018. Os experimentos avaliados neste estudo permitiram concluir que os diferentes extratos da oliveira, preparados através de uma extração simples, apresentaram uma satisfatória atividade antimicrobiana in vitro. A variedade Arbequina e o método de difusão em ágar foram os mais utilizados nos experimentos analisados. Os extratos da oliveira têm demonstrado resultados promissores relacionados a efeitos anti-inflamatórios, antioxidantes e antimicrobianos. Estudos in vivo são necessários para confirmar a atividade terapêutica dos diversos compostos da árvore.
Objective: Complementary and alternative medicine (CAM) has an increasing usage in the last decades throughout the world. Herbal medicine, the most preferred CAM, is used in the treatment of various disorders by approximately eighty percent of the world's population. In this study, it was aimed to determine the antiviral activity and wound healing potential of a special herbal oil blend prepared from Olea europaea, Nigella sativa and Rosmarinus officinalis that has been used for centuries in Middle and East Anatolia. Materials and Methods: The nontoxic concentration of herbal blend was determined by MTS assay. This concentration was investigated for its wound healing potential using in vitro scratch assay. A scratch was made on cultured keratinocyte cell layer and the herbal blend was added to medium. Pictures of cells were taken at different time points. The antiviral activity was determined using Adenovirus type 5 and Poliovirus type 1. Virus titer was calculated by Spearman-Karber method. Results: The nontoxic concentration of the blend was found to show statistically higher wound healing rate in compare to control group at the end of 12, 24 and 36 hours. According to antiviral efficacy test, four log of reduction in virus titer was seen, which meant that the mixture was quite effective against the viruses used in the study. Conclusion: The study shows that the special herbal blend speed up wound healing rate and it also has antiviral activity.
Abstract
The present study aimed to investigate the potential
protective effects of the aqueous extract of olive leaf
against hepato-renal toxicity induced by sodium nitrite in
male rabbits by studying some physiological, biochemical,
and histological changes. 24 adult male rabbits were used
in this study and divided into 4 groups (6 rabbits for each),
and treated daily for 8 weeks as follows: the first group
served as a control, the 2nd group received orally the
aqueous extract of the olive leaf at a dose of 2.21
ml/kg/BW by gavage tube, the 3rd group received a feed
containing sodium nitrite at a concentration of 0.4%, the
4th group received orally the aqueous extract of the olive
leaf at a dose of 2.21 ml/kg/BW by gavage tube and
received a feed containing sodium nitrite at a concentration
of 0.4%. At the end of the experiment, blood was drawn
from the rabbit's ear vein in all groups for assessment of
serum biochemical parameters, and specimens from the
liver and kidney of rabbits were collected for histological
examination. The results obtained from this study showed
a significant increase (P<0.001) in the serum activities of
liver enzymes (ALT, AST, ALP, and GGT), and
concentrations of urea, creatinine, uric acid, sodium, and
potassium ions, while there was a significant decrease
(P<0.001) in serum concentrations of total protein and
albumin, and there was no significant difference (P>0.05)
in serum the concentration of globulin and the ratio of
albumin/globulin in the group treated with sodium nitrite
only when compared with the control group. The group
treated with sodium nitrite+the aqueous extract of olive
leaf recorded a significant decrease (P<0.01) in the serum
activities of liver enzymes (ALT, AST, ALP, and GGT),
and concentrations of urea, uric acid, and sodium, and
potassium ions, and creatinine at (P<0.05), while it
showed a significant increase (P<0.01) in the serum
concentrations of total protein and albumin, and there was
no significant difference (P>0.05) in serum the
concentration of globulin and the ratio of albumin/globulin, in this group when compared with that
of sodium nitrite only. Histological sections of the liver of
the sodium nitrite treated group revealed that hepatocytes
appeared a cloudy swelling, and their cytoplasm contained
fatty and/or hydropic vacuoles. Also, dilatation and
congestion in the central vein and portal vein, thickening
of the lining of the central vein, the walls of the portal
vein, bile ducts, and hepatic artery, and narrowing in the
blood sinusoids with the presence of red blood cells, in
addition, the presence of leukocytic infiltration and
fibrosis in the portal area. While histological sections of
the kidney of the sodium nitrite treated group revealed
shrinkage of the renal glomeruli and dilatation in
Bowman's capsules, congestion, and hemorrhage in the
blood vessels near the Malpighian corpuscles, and an
increase in the thickness of its wall. Presence of protein
casts in the lumen of renal tubules, hemorrhage, dilatation
and leukocytic infiltration between the urinary tubules, as
well as the presence of necrosis and vacuolation in the
cytoplasm of the cells lining the urinary tubules, as well as
the presence of edema in some places in the renal cortex.
While histological examination findings of sodium nitrite
+ an aqueous olive leaf extract-treated group revealed an
improvement in liver and kidney tissues. In conclusion,
according to the results obtained from this study that the
aqueous extract of the olive leaf at a dose of 2.21
ml/kg/BW/day has a protective effect against hepato-renal
toxicity induced by sodium nitrite in male rabbits.
Introduction: For decades, viral diseases have been treated using medicinal plants and herbal practices in the northern part of Nigeria. Though scarcely investigated, these medicinal plants could serve as potential sources for novel antiviral drugs against emerging and remerging viral diseases. Therefore, this study is aimed at investigating the medicinal practices and plants used to treat emerging and re-emerging viral diseases including hepatitis, poliomyelitis, monkeypox, smallpox, yellow fever, Lassa fever, meningitis, and COVID-19 in some northern states; Katsina, Kebbi, Kwara and Sokoto states. Method: Administered questionnaires and oral interviews were used to collect information on medicinal plants, method of preparation of herbal formulations, diagnosis, and treatment of viral diseases. Medicinal plants were collected, botanically identified, and assigned voucher numbers. The plant names were verified using www. theplantlist.org, www.worldfloraonline.org and the international plant names index. Result: A total of 280 participating herbal medicine practitioners (HMPs) mentioned 131 plants belonging to 65 families. Plant parts such as roots, bark, leaf, seed, and fruit were prepared as a decoction, concoction, infusion, or ointment for oral and topical treatment of viral diseases. Moringa oleifera (75.3%), Elaeis guineensis Jacq. (80%), and Acacia nilotica (70%) were the most frequently mentioned plants in Kebbi, Kwara and Sokoto states, respectively. Conclusion: The study revealed scarcely investigated and uninvestigated medicinal plants used to treat hepatitis, poliomyelitis, monkeypox, smallpox, yellow fever, Lassa fever, meningitis, and COVID-19. Future studies should be conducted to determine the antiviral potency and isolate novel bioactive agents from these plants against viral diseases.
Natural products, along with food, clothes, and shelter, serve as the basis of treatment since the dawn of human civilization; while the modern medicine has developed over the years by observational and scientific efforts from ancient traditions. Impressive array of bioactivities with minimum or no toxicity was reported with diverse botanicals against several chronic and difficult-to-treat diseases when most synthetic drugs showed unacceptable side effects. A whole range of viral diseases including Dengue, Ebola, drug-resistant Herpes, HIV/AIDS, Japanese Encephalitis, Rabies, SARS, and recent pandemic of SARS Coronavirus-2 need effective prophylactic or therapeutic agents. Considerable research carried out for last few decades on the Pharmacognosy, chemistry; pharmacology and therapeutics of traditionally used medicines of diverse cultures forced most pharmaceutical companies to renew their strategies of drug discovery, from ‘synthetic to green chemistry’, against different stages of virus infection cycle or host-virus interaction where no effective vaccine or drugs exist. Thus, plants or phytochemicals having potentials of preventing or inhibiting viral infection cycle need to studied in-depth with the purity, safely and potency including their standardization, isolation, efficacy, mechanism of action, along with adverse effect on the host to reduce the time and cost of drug discovery. This updated review will portray the in-depth scientific knowledge and steps for the development of nature-based solutions against genetically and functionally diverse viral diseases from age-old traditional medicines.
The objective of this research work is to demonstrate the ecologically friendly fabrication of gold nanoparticles (OL-Au NAPs) using the biomolecules of Olea europaea leaf extract. Several spectroscopic approaches were utilized to analyze green fabricated OL-Au NAPs efficiently. OL-Au NAPs were investigated against two different bacteriological strains for antibacterial and biofilm inhibition efficacy. The MTT technique was used to determine the cytotoxic activity against MCF-7 cancerous cells, which was expressed as a percentage of viable cells. The biocompatibility of the synthesized NAPs was evaluated further by incubating them for 24 hours with hMSC and 293T cell lines. The results indicated that synthesized OL-Au NAPs effectively suppressed proliferation and biofilm formation in all tested bacteria. Their antibacterial activity was statistically equivalent to that of standard antibiotics (p > 0.05). In silico molecular docking studies confirmed that OL-Au NAPs can also bind and inhibit important S. aureus proteins involved in the cell wall and fatty acid biosynthesis pathways. Moreover, they outperformed plant leaf extract and CH-Au NAPs in terms of cytotoxic effects on MCF-7 cancerous cells. Green fabricated OL-Au NAPs seemed more biocompatible with 293T and hMSC cells than CH-Au NAPs. The promising biological properties of the OL-Au NAPs may be a result of the NAPs' properties interacting with the adsorbed bioactive molecules from plant leaf extract. As a consequence of this study, synthesized OL-Au NAPs may be a potential choice for their numerous pharmacological and nutritional properties. This discovery will also open the road for the creation of nontoxic nanomaterials with extra biologic properties obtained from plants.
The COVID-19 pandemic has provided an opportunity for repurposing of drugs, including complex, natural drugs, to meet the global need for safe and effective antiviral medicines which do not promote multidrug resistance nor inflate medical costs. The author herein describes his own repurposing of herbal tinctures, previously prepared for oncology, into a possibly synergistic, anti-COVID 41 “herb” formula of extracts derived from 36 different plants and medicinal mushrooms. A method of multi-sample in vitro testing in green monkey kidney vero cells is proposed for testing the Hypothesis that even in such a large combination, antiviral potency may be preserved, along with therapeutic synergy, smoothness, and complexity. The possibility that the formula’s potency may improve with age is considered, along with a suitable method for testing it. Collaborative research inquiries are welcome.
This study focuses on the variation of the contents, chemical profiling and biological activities among fresh and dried leaves essential oils of Olea europaea L. Chemlali cultivar. The essential oils (EO) of the fresh and shade dried leaves of O. europaea were obtained by hydro-distillation and analyzed by gas chromatography-mass spectrometry. Antimicrobial activities were assessed by the evaluation of MICs and MCCs standards. Both oils showed significant quantitative and qualitative differences in their chemical composition. Indeed, 25 and 47 components were identified in the fresh and shade dried leaves essential oils, respectively. The fresh leaves essential oils were dominated by α-farnesene (17.85 %) and β-maaliene (17.16 %) while n-hexadecanoic acid (7.44% ) was the major component of shade dried leaves essential oils. Moderate antioxidant activity was shown for both essential oils. The essential oils of dried leaves exhibited higher antimicrobial activity with MICs values ranging between 1 and 2 mL L⁻¹ and MFCs ranging between 1 and 4 mL L⁻¹, whereas the MBCs of oils of fresh leaves ranged between 3.25 and 26 mL L⁻¹, and MFCs ranged between 3.25 and 6.5 mL L⁻¹. The detected reduction in the viability of standard bacteria, higher than 5 log units within a contact time of 5 min, was obtained by 0.75 % (v/v) dried and 1.25 % (v/v) fresh leaves essential oils. Concentrations of 3 % (v/v) dried and 6 % (v/v) fresh leaves essential oils resulted in a reduction in viability higher than 4 log units for the standard fungi, within a contact time of 5 min.
Aromatik halkasında bir veya daha fazla hidroksil grubu içeren bileşikler fenolik madde olarak adlandırılmaktadır. Fenolik maddeler bitkilerin meyve, sebze, yaprak, tohum, çiçek, gövde ve dallarında bulunmaktadır. Fenolik maddeler antioksidan özelliklerine bağlı olarak antikanserojen, antimutajenik, antimikrobiyal aktivite göstermektedir ve insan sağlığı ile yakından ilişkilidir. Zeytin, zeytin yaprağı ve zeytinyağı fenolik içerikleri ile önemli bileşiklerdir. Oleuropein, zeytin meyvesinin olgunlaşmadan önceki döneminde bol miktarda bulunan, meyve olgunlaştıkça miktarı azalan ve meyveye acı tat veren bir maddedir. Kuersetin; lahanalar, soğan, kırmızı üzüm ve çayda bol miktarda bulunan polifenolik bir flavonoiddir. Diyette en fazla bulunan flavonoid olan kuersetin diyet suplemanları, yiyecek ve içeceklere acı tat veren bir maddedir. Çalışmalar, oleuropein ve kuersetinin organizmadaki zararlı maddelerin hücre yapısını bozarak sağlık için olumlu etkiye sahip olduğunu göstermektedir. COVID-19 koronavirüs ailesinin son tanımlanan türlerinden biridir. Tedavi ve korunma yöntemi bulunmayan hastalığa karşı insanlar çeşitli çözümler denemektedir. Bu bağlamda başvurulan yollardan önemli bir tanesi de fenolik bileşiklerdir. Bu çalışmada, dünya genelinde birçok insanın hayatını kaybetmesine neden olan COVID-19’ a karşı oleuropeinin ve kuersetinin etkinliğinin belirlenmesi amaçlanmaktadır.
The rhabdovirus causing viral haemorrhagic septicemia (VHS), an important disease of salmonids, induced formation of large syncytia in fish cell monolayers by cell fusion. For maximal percentage of fusion, not only was a pH of 5.6 needed but also a temperature of at least 14 degrees C. The fusion was dependent on the G protein of VHSV as shown by inhibition of fusion with specific anti-G polyclonal and monoclonal antibodies. Part of the region of the G protein involved in fusion was mapped to amino acids 82 to 109 because anti-peptide antibodies binding to that region also inhibited fusion. The fusion assay described here can be useful for studying the functionality of the G protein of fish rhabdoviruses in the early steps of infection and this information can, in turn, help to designing effective vaccination and/or therapeutic strategies against fish rhabdoviruses. The described fusion assay could also be applied to other fish rhabdoviruses such as infectious haematopoietic necrosis virus (IHNV) and spring viraemia of carp virus (SVCV).
Trials to determine the efficacy of trifloxystrobin (75 and 100 g ai/ha) and azoxystrobin (100 g ai/ha), on the control of black Sigatoka disease caused by Mycosphaerella fijiensis Morelet (M. fijiensis), in small randomized plots of banana and plantain treated from the ground and in commercial banana fields treated from the air, were carried out between 1997 and 1999. Trifloxystrobin at 75 g ai/ha showed a similar efficacy to propiconazole at 100 g ai/ha and benomyl at 150 g ai/ha and was superior to azoxystrobin (100 g ai/ha). Azoxystrobin show a similar efficacy to propiconazole against M. fijiensis populations sensitive to DMIs. The ED50 (ascospore germinative test) of five wild type M. fijiensis populations of different localities to azoxystrobin were between 0.03 and 0.8 μg/ml. Results suggest that monitoring for strobilurin resistance may be conducted using 5 μg/ml as the threshold concentration.
The oligomerization state of the rabies virus envelope glycoprotein (G protein) was determined using electron microscopy and sedimentation analysis of detergent solubilized G. Most of the detergents used in this study solubilized G in a 4 S monomeric form. However, when CHAPS was used, G had a sedimentation coefficient of 9 S. This high sedimentation coefficient allowed its further separation from M1 and M2. Using electron microscopy of negatively stained samples, we studied the morphology of G on virus and after detergent extraction. End-on views of G on virus clearly showed triangles consisting of three dots indicating the trimeric nature of native G. End-on views of CHAPS-isolated G showed very similar triangles confirming that, using this detergent, G was solubilized in its native trimeric structure. Electron microscopy also showed that G had a "head" and a "stalk" and provided the basis for a low-resolution model of the glycoprotein structure.
To evaluate the genetic diversity of viral haemorrhagic septicaemia virus (VHSV), the sequence of the glycoprotein genes (G) of 11 North American and European isolates were determined. Comparison with the G protein of representative members of the family Rhabdoviridae suggested that VHSV was a different virus species from infectious haemorrhagic necrosis virus (IHNV) and Hirame rhabdovirus (HIRRV). At a higher taxonomic level, VHSV, IHNV and HIRRV formed a group which was genetically closest to the genus Lyssavirus. Compared with each other, the G genes of VHSV displayed a dissimilar overall genetic diversity which correlated with differences in geographical origin. The multiple sequence alignment of the complete G protein, showed that the divergent positions were not uniformly distributed along the sequence. A central region (amino acid position 245-300) accumulated substitutions and appeared to be highly variable. The genetic heterogeneity within a single isolate was high, with an apparent internal mutation frequency of 1.2 x 10(-3) per nucleotide site, attesting the quasispecies nature of the viral population. The phylogeny separated VHSV strains according to the major geographical area of isolation: genotype I for continental Europe, genotype II for the British Isles, and genotype III for North America. Isolates from continental Europe exhibited the highest genetic variability, with sub-groups correlated partially with the serological classification. Neither neutralizing polyclonal sera, nor monoclonal antibodies, were able to discriminate between the genotypes. The overall structure of the phylogenetic tree suggests that VHSV genetic diversity and evolution fit within the model of random change and positive selection operating on quasispecies.
Antibody linear epitopes of the glycoprotein G (gpG) of the viral haemorrhagic septicaemia virus (VHSV), a rhabdovirus of salmonids, were mapped by pepscan using overlapping 15-mer peptides covering the entire gpG sequence and ELISA with polyclonal and monoclonal murine and polyclonal trout antibodies. Among the regions recognized in the pepscan by the polyclonal antibodies (PAbs) were the previously identified phosphatidylserine binding heptad-repeats (Estepa & Coll 1996; Virology 216:60-70) and leucocyte stimulating peptides (Lorenzo et al. 1995; Virology 212:348-355). Among 17 monoclonal antibodies (MAbs), only 2 non-neutralizing MAbs, 110 (aa 139-153) and IP1H3 (aa 399-413), could be mapped to specific peptides in the pepscan of the gpG. Mapping of these MAbs was confirmed by immunoblotting with recombinant proteins and/or other synthetic peptides covering those sequences. None of the neutralizing MAbs tested reacted with any of the gpG peptides. Previously mapped MAb resistant mutants in the gpG did not coincide with any of the linear epitopes defined by the pepscan strategy, suggesting the complementarity of the 2 methods for the identification of antibody recognition sites.
A marine isolate of viral haemorrhagic septicaemia virus (VHSV) (860/94) was passaged in triplicate through sequential batches of rainbow trout via an intra-peritoneal infection route, without amplification in tissue culture. Following 5 passages, the VHSV glycoprotein gene was amplified directly from fish tissue homogenates and the consensus sequence compared to that of the original tissue culture isolate. Virus was also recovered directly from pools of kidney and spleen material after 5 passage events, and its virulence compared to that of unpassaged material by intra-peritoneal infection. Following passage in rainbow trout, isolate 860/94 exhibited a higher virulence for rainbow trout than unpassaged material. Sequence comparisons identified no difference in the consensus sequence of the glycoprotein gene following in vivo passage. The mechanisms responsible for the observed increase in virulence of isolate 860/94 following passage in rainbow trout thus remain unknown. The possibility that viral isolates may exhibit an increased virulence following passage in novel host species does, however, have important implications with regard to the epidemiology of this important fish pathogen.
The fusion-related properties of segments p9, p3, p4, and p9 + p2 surrounding the p2 phospholipid-binding domain of the protein
G (pG) of the salmonid rhabdovirus of viral hemorrhagic septicemia (VHS) (Nuñez, E., Fernandez, A. M., Estepa, A., Gonzalez-Ros,
J. M., Gavilanes, F., and Coll, J. M. (1998)Virology 243, 322–330; Estepa, A., and Coll, J. M. (1996) Virology 216, 60–70), have been studied at neutral and fusion (low) pH values by using its derived peptides. Cell-to-cell fusion,
translocation of phosphatidylserine, and inhibition of fusion of pG-transfected cells defined the p9 + p2 (fragment 11, sequence
56–110) as a fragment with higher specific activity for anionic phospholipid aggregation than the previously reported p2.
While fragment 11, p2, and p3 showed interactions with anionic phospholipids, p9 and p4 showed no interactions with any phospholipids.
When added to a cell monolayer model at low pH, fragment 11 induced pH-dependent cell-to-cell fusion and translocated phosphatidylserine
from the inner to the outer leaflet of the membrane. At low pH and in the presence of anionic phospholipids, fragment 11 showed
more than 80% β-sheet conformation (IR and CD spectroscopies). Finally, anti-fragment 11 antibodies inhibited low pH-dependent
pG-transfected cell-to-cell fusion. All of the data support the conclusion that fragment 11 is a primary determinant of some
of the viral cell fusion events in VHSV.
Six secoiridoid glucosides, lucidumoside C (1), oleoside dimethylester (2), neonuezhenide (3), oleuropein (4), ligustroside (5) and lucidumoside A (6), isolated from the fruits of Ligustrum lucidum (Oleaceae), were examined in vitro for their activities against four strains of pathogenic viruses, namely herpes simplex type I virus (HSV-1), influenza type A virus (Flu A), respiratory syncytial virus (RSV) and parainfluenza type 3 virus (Para 3). Antiviral activities were evaluated by the cytopathic effect (CPE) inhibitory assay. The purpose was to check if the antioxidative potency of these glucosides correlated with their antiviral potency. Results showed that none of the glucosides had any significant activity against HSV-1 and Flu A. Oleuropein, however, showed significant antiviral activities against RSV and Para 3 with IC50 value of 23.4 and 11.7 microg/ml, respectively. Lucidumoside C, oleoside dimethylester and ligustroside showed potent or moderate antiviral activities against Para 3 with IC50 values of 15.6-20.8 microg/ml. These results also documented that the anti-oxidative potency of these secoiriodoid glucosides was not directly related to their antiviral effects.
To search for enhancers and/or inhibitors of viral haemorrhagic septicaemia virus (VHSV, a salmonid rhabdovirus) infectivity, a total of 51 peptides from a pepscan of viral envelope protein G, a recombinant peptide from protein G (frg11) and 80 peptide mixtures from an alpha-helix-favoured combinatorial library were screened. However, contrary to what occurs in many other enveloped viruses, only peptides enhancing rather than inhibiting VHSV infectivity were found. Because some of the enhancer pepscan G peptides and frg11 were derived from phospholipid-binding or fusion-related regions identified previously, it was suggested that enhancement of virus infectivity might be related to virus-cell fusion. Furthermore, enhancement was significant only when the viral peptides were pre-incubated with VHSV at the optimal low pH of fusion, before being adjusted to physiological pH and assayed for infectivity. Enhancement of VHSV infectivity caused by the pre-incubation of VHSV with peptide p5 (SAAEASAKATAEATAKG), one of the individual enhancer peptides defined from the screening of the combinatorial library, was independent of the pre-incubation pH. However, it was also related to fusion because the binding of p5 to protein G induced VHSV to bypass the endosome pathway of infection and reduced the low-pH threshold of fusion, thus suggesting an alternative virus entry pathway for p5-VHSV complexes. Further investigations into VHSV enhancer peptides might shed some light on the mechanisms of VHSV fusion.
Rabbit neutrophil peptide-1 (NP-1), a prototypic α-defensin, protects cells in vitro from infection by clinical and laboratory
isolates of herpes simplex virus type 2 (HSV-2). Incubation of concentrated virus stocks for 1 h with noncytotoxic concentrations
of NP-1 reduces subsequent infection by >98%. Pretreating cells with NP-1 for 1 h prior to inoculation with untreated virus
also prevents infection. NP-1, a cationic peptide, does not compete with viral envelope glycoproteins for binding to cellular
heparan sulfate receptors, but it prevents viral entry. No VP16, a major viral tegument protein, is transported to the cell
nucleus in the presence of NP-1. Infectious center assays demonstrate that NP-1 also inhibits cell-to-cell viral spread. Thus,
NP-1 prevents virally mediated fusion events, entry, and cell-to-cell spread. This unique mechanism of anti-HSV activity,
coupled with established antibacterial and possible anti-human immunodeficiency virus type 1 activities of defensins, render
this family of compounds excellent candidates for further development as topical microbicides.
The anti-HIV-1 activity of aromatic herbs in Labiatae was evaluated in vitro. Forty five extract from among 51 samples obtained from 46 herb species showed significant inhibitory effects against HIV-1 induced cytopathogenicity in MT-4 cells. In particular, the aqueous extracts of Melissa officinalis, a family of Mentha x piperita "grapefruit mint," Mentha x piperita var. crispa, Ocinum basilicum cv "cinnamon," Perilla frutescens var. crispa. f. viridis, Prunella vulgaris subsp. asiatica and Satureja montana showed potent anti-HIV-1 activity (with an ED of 16 mu g/ml). The active components in the extract samples were found to be water-soluble polar substances, not nonpolar compounds such as essential oils. In addition, these aqueous extracts inhibited giant cell formation in co-culture of Molt-4 cells with and without HIV-1 infection and showed inhibitory activity against HIV-1 reverse transcriptase.
The main reaction products obtainable by the hydrolysis of commercially available oleuropein by hyperthermophilic beta -glycosidase were purified and structurally characterized by UV and H-1 and C-13 NMR analyses. Their antioxidant activity, in particular their capacity to inhibit the fatty acid peroxidation rate, was studied. The molecular structures assigned revealed the presence of two elenolic acid forms presenting different antioxidant abilities closely correlated to their molecular structures, as well as an unstable elenolate which is a rearrangement product of the oleuropein aglycon. This molecule, under the reaction conditions (pH 7.0, 60 degreesC) required for beta -glycosidase activity, rapidly gives rise to 3,4-dihydroxy-phenylethanol (hydroxytyrosol).
Oleuropein and hydroxytyrosol, two phenolic compounds contained in olives and olive oil, are known to possess several biological properties, many of which may be related, partially at least, to their antioxidant and free radical-scavenger ability. Hence, together with their scavenging activity against the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test), we have investigated the antioxidative effect of oleuropein and hydroxytyrosol in a model system consisting of dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (DPPC/LA LUVs) and a water-soluble azo compound as a free radical generator (LP–LUV test). The results obtained were also interpreted in the light of biophenol interactions, studied by differential scanning calorimetry (DSC), with dimyristoylphosphatidylcholine (DMPC) vesicles as a biological membrane model. Our results obtained in the DPPH and LP–LUV tests confirm the good scavenger activity and antioxidant effect of oleuropein and hydroxytyrosol. However, while both compounds exhibit comparable effectiveness in the DPPH test (hydroxytyrosol being slightly more active than oleuropein), oleuropein seems, in the LP–LUV test, a better antioxidant than hydroxytyrosol. Besides oleuropein shows a better antioxidant activity in the membranous system than in homogenous solution. Furthermore, oleuropein, but not hydroxytyrosol, interacts with DMPC vesicles, causing shifts, toward lower values, of the calorimetric peak temperature (Tm), associated to the gel to liquid-crystal phase transition, typical for DMPC multilayers. The hypothesis will be discussed that hydroxytyrosol can serve as scavenger of aqueous peroxyl radicals near the membrane surface, while oleuropein acts also as a scavenger of chain-propagating lipid peroxyl radicals within the membranes.
A description of the types of viral vaccines that are being developed for fish is presented in this review. All three types of vaccines, i.e. killed, attenuated, and subunit vaccines, have worked to some extent in fish under controlled laboratory conditions. However, with the exception of a killed vaccine for spring viremia of carp, there are no commercially available viral vaccines for fish. The introduction of these vaccines to aquaculture will require an understanding of immune recognition in fish and the development of cost-effective ways of producing a safe, immunogenic vaccine. A review of available information on vaccines for infectious pancreatic necrosis virus, viral hemorrhagic septicemia virus, infectious hematopoietic necrosis virus, spring viremia of carp virus, and channel catfish virus is presented. These are the main viruses that have been investigated for vaccine development. Very little information is available on vaccines for other viral diseases of fish.
A cell line, named Epithelioma papulosum cyprini (EPC) and originating from carp epidermal herpes virus-induced hyperplastic lesions, was esta blished and has now given rise to more than 80 subcultures. It grows within a wide temperature range (15–33°C), survives between 7 and 10°C for several months without alterations in its further virus susceptibility and growth characteristics, and degenerates at 37°C. Its karyotype is 2n=96. It propagates most of the systemic infection viruses of the fish families Salmonidae, Cyprinidae, Anguillidae and Esocidae, as well as Indiana-type vesicular stomatitis virus.
With increasing interest in novel descriptors of hedonic-sensory (HS) and functional (F) quality, scientific documentation of the dietary habits associated with the Mediterranean Aliment Culture (MAC) lifestyle, shows low risk for many chronic diseases. This has been interpreted as the F effect of widespread plant antioxidant intake. The antioxidant and antimicrobial activity of some of the most typical biophenols (BPs) contained in table olives (TOs) and olive oil, such as extra virgin olive oil (EVOO), was revealed through biomimetic experiments on the scavenging effects of chain-propagating lipid peroxyl radicals within membranes, and for human skin protection. Dietary intake of TO and EVOO BPs might lower the risk of degenerative diseases and microbial infections for consumers, Homo consumans (Hc). MAC foodstuffs, also referred to as ‘life-stage foods’, could emerge as ‘F products’, engineered to tackle the specific dietary requirements of the aged population.
The purpose of this study was to identify the main phenolic compounds present in an olive leaf extract (OL) in order to delineate the differential antioxidant activities of these compounds through the extent of their abilities to scavenge the ABTS+ radical cation and to clarify the structural elements conferring antioxidant capacity in aqueous systems. The results show that the relative abilities of the flavonoids from olive leaf to scavenge the ABTS+ radical cation are influenced by the presence of functional groups in their structure, mainly the B-ring catechol, the 3-hydroxyl group and the 2,3-double bond conjugated with the 4-oxo function. For the other phenolic compounds present in OL, their relative abilities to scavenge the ABTS+ radical cation are mainly influenced by the number and position of free hydroxyl groups in their structure. Also, both groups of compounds show synergic behaviour when mixed, as occurs in the OL.
Plants in the Mediterranean basin, such as vine and olive trees, have developed an array of antioxidant defences to protect themselves from environmental stress. Accordingly, the incidence of coronary heart disease and certain cancers is lower in the Mediterranean area, where olive oil is the dietary fat of choice. As opposed to other vegetable oils, extra virgin olive oil, which is obtained by physical pressure from a whole fruit, is rich in phenolic components that are responsible for the particular stability of the oil. We have investigated the scavenging actions of some olive oil phenolics, namely hydroxytyrosol and oleuropein, with respect to superoxide anion generation, neutrophils respiratory burst, and hypochlorous acid. The low EC50s indicate that both compounds are potent scavengers of superoxide radicals and inhibitors of neutrophils respiratory burst: whenever demonstratedin vivo,these properties may partially explain the observed lower incidence of CHD and cancer associated with the Mediterranean diet.
The antiviral activity of natural phloroglucinols and of synthesized mono- and diacylphloroglucinols, and 2,6-diacyl-4,4-dialkylcyclohexa-1,3,5-triones was investigated. A correlation between the acyl chain length and inhibitory activity against vesicular stomatitis virus (VSV) was observed. Potent antiviral activity was found in di-isovalerylphoroglucinol. 2,6-Diacyl-4,4-dialkylcyclohexa-1,3,5-triones inhibited replication of the virus with low cytotoxicity.
The effect of different concentrations of calcium elenolate (molecular weight, 522.22) in varying conditions of assay on the DNA polymerase activity of purified Moloney leukaemia virus [MuLV(M)] was determined as reported earlier6'7 (Fig. 1).
The gene encoding the envelope glycoprotein of a recent Danish isolate of a salmonid rhabdovirus, viral haemorrhagic septicaemia virus (VHSV) has been cloned and sequenced at the cDNA level. When compared with the deduced sequence of a French isolate of VHSV, it was noted that there were 13 amino acid substitutions in the Danish virus. Amino acid homologies with the glycoprotein of a North American salmonid rhabdovirus (infectious haematopoietic necrosis virus) indicate a high degree of structural similarity between the two fish rhabdovirus glycoproteins. Results from partial enzymatic deglycosylation of the viral protein indicate that all four NXT/S sites found in the sequence are N-glycosylated in the virus. The glycoprotein, without the N-terminal leader sequence and C-terminal hydrophobic anchor segment, was expressed in Escherichia coli as a factor Xa protease-cleavable fusion protein. The purified and renatured viral part of the recombinant protein was able to elicit VHSV-specific antibodies and neutralizing antibody activity in serum when injected into rainbow trout.
The binding of labeled phosphatidylserine (PS) to a collection of synthetic 15-mer peptides covering full-length glycoprotein G (G) of viral hemorrhagic septicemia virus (VHSV), a salmonid rhabdovirus, showed three dominant overlapping reactive peptides. This major PS-binding region was contained in a 28-mer peptide (p2; aa 82-109) with consecutive hydrophobic amino acid a-d heptad repeats (putative amphipathic alpha-helix) and 2 carboxy-terminal arginines. This 28-mer peptide showed a 10-fold higher apparent specific activity for PS binding than the 15-mer peptides. Binding to PS was also detected with virion-purified protein G but was not detected with other viral proteins. The highest apparent specific activity for PS binding was found with purified VHSV particles by both solid-phase and liquid assays. In contrast to the pH-independent PS binding to peptide p2, binding to virions was optimal at pH 5.6. PS binding to purified VHSV was greatly reduced by protease or detergent treatments that removed protein G, by treatment at pH 7.6, or by anti-p2 mouse antibodies at pH 5.6. The PS-binding region seems to be related to viral-host cell fusion since anti-p2 mouse antibodies inhibited VHSV-infected cell to cell fusion (fusion from within) and the pH profile of the VHSV-infected cell to cell fusion was similar to the pH profile of PS binding to VHSV. Comparative analysis showed that sequences similar to the major PS-binding domain of VHSV were also present in other fish rhabdoviruses and in rabies and vesicular stomatitis viruses.
An enzyme-immunohistochemical procedure was employed to facilitate neutralization/diagnostic tests for viral haemorrhagic septicaemia virus (VHSV), a significant pathogen in trout farms throughout Europe. The method described can be used for trout or mice antibodies; increases speed (1 day), simplicity, and minimizes the use of reagents compared to other neutralization assays. Furthermore, the test requires a minimum handling of the cell cultures under sterile conditions, decreasing frequent contamination due to the non-sterile conditions of the fish pathological samples. Foci of 5-20 infected epithelioma papillosum carp (EPC) cells are detected and counted with an inverted microscope in under 16 h after infection of EPC monolayers using a high titre anti-N VHSV monoclonal antibody (MAb) 2C9. MAb 2C9 recognizes different viral haemorrhagic septicaemia virus serotypes and VHSV isolates from different host species (trout, salmon and barbel) and Spanish geographical locations. The high titre and specificity of MAb 2C9 favour its conjugation to peroxidase and also make it possible to use in direct immunoperoxidase staining of the VHSV infected EPC monolayers. This neutralization/immunoperoxidase assay should improve diagnostics that use currently agarose or methylcellulose plaque reduction neutralization assays.
Extracts of dried flowers from Calendula officinalis were examined for their ability to inhibit the human immunodeficiency virus type 1 (HIV-1) replication. Both organic and aqueous extracts were relatively nontoxic to human lymphocytic Molt-4 cells, but only the organic one exhibited potent anti-HIV activity in an in vitro MTT/tetrazolium-based assay. In addition, in the presence of the organic extract (500 micrograms/mL), the uninfected Molt-4 cells were completely protected for up to 24 h from fusion and subsequent death, caused by cocultivation with persistently infected U-937/HIV-1 cells. It was also found that the organic extract from Calendula officinalis flowers caused a significant dose- and time-dependent reduction of HIV-1 reverse transcription (RT) activity. An 85% RT inhibition was achieved after a 30 min treatment of partially purified enzyme in a cell-free system. These results suggested that organic extract of flowers from Calendula officinalis possesses anti-HIV properties of therapeutic interest.
The anti-HIV-1 activity of aromatic herbs in Labiatae was evaluated in vitro. Forty five extract from among 51 samples obtained from 46 herb species showed significant inhibitory effects against HIV-1 induced cytopathogenicity in MT-4 cells. In particular, the aqueous extracts of Melissa officinalis, a family of Mentha x piperita "grapefruit mint," Mentha x piperita var. crispa, Ocimum basilicum cv "cinnamon," Perilla frutescens var. crispa f. viridis, Prunella vulgaris subsp. asiatica and Satureja montana showed potent anti-HIV-1 activity (with an ED of 16 microg/ml). The active components in the extract samples were found to be water-soluble polar substances, not nonpolar compounds such as essential oils. In addition, these aqueous extracts inhibited giant cell formation in co-culture of Molt-4 cells with and without HIV-1 infection and showed inhibitory activity against HIV-1 reverse transcriptase.
Folk medicinal plants are potential sources of useful therapeutic compounds including some with antiviral activities. Extracts prepared from 10 South American medicinal plants (Baccharis trinervis, Baccharis teindalensis, Eupatorium articulatum, Eupatorium glutinosum, Tagetes pusilla, Neurolaena lobata, Conyza floribunda, Phytolacca bogotensis, Phytolacca rivinoides and Heisteria acuminata) were screened for in vitro antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. The most potent inhibition was observed with an aqueous extract of B. trinervis, which inhibited HSV-1 replication by 100% at 50-200 micrograms/mL, without showing cytotoxic effects. Good activities were also found with the ethanol extract of H. acuminata and the aqueous extract of E. articulatum, which exhibited antiviral effects against both DNA and RNA viruses (HSV-1 and VSV, respectively) at 125-250 micrograms/mL. The aqueous extracts of T. pusilla (100-250 micrograms/mL), B. teindalensis (50-125 micrograms/mL) and E. glutinosum (50-125 micrograms/mL) also inhibited the replication of VSV, but none of the extracts tested had any effect on poliovirus replication.
Ethanolic and aqueous extracts of seven plant species used in the traditional medicine of Bolivia have been tested for their antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV), and poliovirus type 1. The aqueous extracts of most of the species investigated showed antiviral activity. Two of these plants-namely, Satureja boliviana and Baccharis genistelloides-were active against two different viruses-HSV-1 and VSV.
In order to find antiviral substances from basidiomycetes, two water soluble substances, GLhw and GLlw, and eight methanol soluble substances, GLMe-1-8, were prepared from carpophores of Ganoderma lucidum. These substances were examined for their activities against five strains of pathogenic viruses such as herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), influenza A virus (Flu A) and vesicular stomatitis virus (VSV) Indiana and New Jersey strains in vitro. Antiviral activities were evaluated by the cytopathic effect (CPE) inhibition assay and plaque reduction assay. Five substances, GLhw, GLMe-1, -2, -4 and -7 significantly inhibited the cytopathic effects of HSV and VSV. In the plaque reduction assay, GLhw inhibited plaque formation of HSV-2 with 50% effective concentrations (EC50) of 590 and 580 microg/ml in Vero and HEp-2 cells, and its selectivity indices (SI) were 13.32 and 16.26. GLMe-4 did not exhibit cytotoxicity up to 1000 microg/ml, while it exhibited potent antiviral activity on the VSV New Jersey strain with an SI of more than 5.43. These results indicate the possibility of development of antiviral agents from basidiomycetous fungi.
Epidemiological studies have shown that the incidence of heart disease and certain cancers is lower in the Mediterranean region. This has been attributed to the high consumption of olive oil in the Mediterranean diet, which contains polyphenolic compounds with antioxidant activity. Although many in vitro studies have been performed to elucidate mechanisms by which these compounds may act, there are virtually no data relating to their fate after ingestion. Therefore, we decided to investigate the intestinal absorption of one of the major olive oil polyphenolics, oleuropein. To do this, a novel in situ intestinal perfusion technique was developed, and the absorption of oleuropein was studied under both iso-osmotic and hypotonic luminal conditions. Oleuropein was absorbed, with an apparent permeability coefficient (P:(app)) of 1.47 +/- 0.13 x 10(-6) cm/s (+/-SE) observed under iso-osmotic conditions. The mechanism of absorption is unclear but may involve transcellular transport (SGLT1) or paracellular movement. Under hypotonic conditions, the permeability of oleuropein was significantly greater (5.92 +/- 0.49 x 10(-6) cm/s, P: < 0.001). This increase is thought to be due to an increase in paracellular movement facilitated by the opening of paracellular junctions in response to hypotonicity. Overall, we determined that the olive oil polyphenolic oleuropein can be absorbed, albeit poorly, from isolated perfused rat intestine. Therefore, it is possible that it or its metabolites may confer a positive health benefit after the consumption of olive oil, most likely via an antioxidant mechanism.
In the course of our search for plant natural products as antiviral agents, extracts of ten plants from the Iberian Peninsula were tested for antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. Aqueous extracts of five of these medicinal plants, namely Nepeta nepetella (150-500 microg/mL), Nepeta coerulea (150-500 microg/mL), Nepeta tuberosa (150-500 microg/mL), Dittrichia viscosa (50-125 microg/mL) and Sanguisorba minor magnolii (50-125 microg/mL), showed a clear antiviral activity against two different DNA and RNA viruses, i.e. HSV-1 and VSV. Only the medicinal plant Dittrichia viscosa was active against an additional virus, poliovirus type 1.
A preparation of water soluble components (EA) was made from carpophores of Elfvingia applanata (Pers.) Karst and its in vitro antiviral activity on vesicular stomatitis virus [(Indiana serotype, VSV(IND)] was investigated by plaque reduction assay. EA exhibited potent antiviral activity on VSV(IND) growth and negligible cytotoxicity on Vero cells, 50% effective concentration (EC50) of 104 microg/ml and 50% cytotoxic concentration (CC50) of 3,793 microg/ml, respectively. Selectivity index (SI, CC50/EC50) of EA on Vero cell and VSV(IND) was about 36.5. EA did not display either a direct virucidal effect on VSV(IND) or induction of antiviral substance by Vero cells upon its treatment. Thus, the mode of antiviral activity of EA was studied at steps of viral adsorption onto cell. When both EA and virus were added to cell monolayers, titer of cell-free virus in culture supernatant increased in ca. 30-40% compared with that of control group and titer of cell-associated virus was 60-100% higher than that of control group. These results suggested that antiviral activity of EA on VSV(IND) might be due to the hindrance of viral entry to cells at either endocytosis or loss of envelope.
A rhabdoviral disease occurred in farmed populations of market sized Japanese flounder (hirame) Paralichthys olivaceus in the Seto Inland Sea of Japan in 1996. The causative agent was identified as viral hemorrhagic septicemia virus (VHSV) based on morphological, immunological, and genetic analyses. Diseased fish that were artificially injected with a representative virus isolate showed the same pathological signs and high mortality as observed in the natural outbreak. This is the first report of an outbreak of VHSV infection in cultured fish in Japan. Clinical signs of diseased fish included dark body coloration, an expanded abdomen due to ascites, congested liver, splenomegaly, and a swollen kidney. Myocardial necrosis was most prominent and accompanied by inflammatory reactions. Necrotic lesions also occurred in the liver, spleen and hematopoietic tissue, and were accompanied by circulatory disturbances due to cardiac failure. Hemorrhagic lesions did not always appear in the lateral musculature. Transmission electron microscopy revealed many rhabdovirus particles and associated inclusion bodies containing nucleocapsids in the necrotized myocardium. The histopathological findings indicated that the necrotizing myocarditis could be considered a pathognomonic sign of VHSV infection in Japanese flounder.