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The antigens used in vaccines are usually attenuated or inactivated microorganisms, toxoids or purified particles. The purified particles have a better biosecurity but their capacity to generate an immune response is low, therefore vaccines include adjuvants that seek to improve immunogenicity. Unfortunately, adjuvants have side effects so only aluminum salts are currently used as adjuvants. So that this work evaluated an adjuvant of garlic extracts, a plant with immunomodulatory properties, in mice immunized with ovalbumin. To formulate the adjuvant, biotoxicity and cytotoxicity assays with a model of Artemia salina and haemolytic activity were considered respectively. A qualitative phytochemical analysis and quantification of phenolic compounds were carried out and in the immunization scheme 100 μg of antigen with adjuvant were administered at day 1, 50 and 100 μg of antigen on days 14 and 28 respectively. The sacrifice of the animals was done on day 30. Leukocytes and γ globulins were quantified at the beginning and at the end of the experiment. A lethal dose 50% of 1430 μg/mL was calculated for the Garlic extracts, a haemolytic activity of 2.66% and 7.53% was observed (p<0.05) for the concentrations of 10 and 100 μg/mL. And it was only possible to identify the presence of tannins in the aqueous extract of Garlic. With the results obtained, significant differences were observed in leukocyte counts and concentration of γ globulins at the end of the immunization scheme (p<0.05). Concluding that the results with the adjuvant of Garlic at 10 μg/mL concentration were comparable to those found with the adjuvant of aluminum salts. [ABSTRACT FROM AUTHOR]

Dengue fever is a disease with a high mortality rate around the world, which is an important issue for the health authorities of many countries. As a result of this, the search for new drugs that are effective to combat this disease has become necessary. Medicinal plants have been used since ancient times to treat a wide list of diseases, including dengue fever. In this mini-review, 12 medicinal plants with known pharmacological properties are presented, which have been used in studies to evaluate their antiviral activity in vitro tests. Among the chemical agents involved in the antiviral response, found in the alcoholic extracts of these plants, are flavonoids, terpenes and alkaloids, which within the mechanism of action in blocking viral replication are considered entry inhibitors, fusion inhibitors, translation inhibitors and protease inhibitors. The present work shows whether these plants possess antiviral activity and the chemical compounds involved in this response., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: The world's population is still growing, having an impact on the environment and the economic growth of developing countries; so that, there is a particular interest in the development of new fertility control methods, focused on male contraception., Objective: The objective of this study was to evaluate the effect of methanolic extracts of leaf and fruit of Azadirachta indica on sperm quality and testicular histology of Long Evans rats., Methods: Antifertility effects of a methanolic leaf and fruit extracts of A. indica on 24 male rats were investigated. The animals were randomly divided into two control groups and four treatment groups (n=4). Doses of the leaf and fruit extract were given at concentrations of 100 and 200 μg mL-1., Results: A significant decrease in the viability of sperm cells was observed. The leaf extract at a concentration of 200 μg mL-1 inhibited cell viability compared to the negative control (p< 0.001). The percentage of abnormal cells in leaf extract was shown in 100 and 200 μg mL-1, the conditions at which a higher percentage of morphological irregularities of observed (15% and 16% respectively). The results show that there was cellular detachment in the seminiferous epithelium in the experimental groups treated with methanolic extracts. Sperm death was observed without decreasing the number of sperm., Conclusion: The methanolic extracts of Azadirachta indica have a modulating effect on the spermatogenesis of experimental rats through sperm morphological alterations., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Pathogens use multiple mechanisms to disrupt cell functioning in their host and allow pathogenesis. These mechanisms involve communication between the pathogen and the host cell through protein-protein interactions., Methods: Protein-protein interactions chains referred to as signal transduction pathways are the processes by which a chemical or physical signal transmits through a cell as series of molecular events so the pathogen needs to intercept these molecular pathways at few positions to induce pathogenesis such as pathogen viability, infection or hypersensitivity., Results: The pathogen nodes of interception are not necessarily the most immunogenic; so that novel immunogenicity-improvement strategies need to be developed thought a chemical conjugation of the pathogen-carrier nodes to develop an efficient immune response in order to block pathogenesis. On the other hand, if pathogen-carriers are immunogens; toleration ought to be induced by this conjugation avoiding hypersensitivity. Thus, this paper addresses the biological plausibility of plant-phenolics as pathogen-carrier immunogenicity modulator haptens., Conclusion: The plant-phenolic compounds have in their structure functional groups such as hydroxyl, carbonyl, carboxyl, ester, or ether, capable of reacting with the amino or carbonyl groups of the amino acids of a pathogen-carrier to form conjugates. Besides, the varied carbon structures these phenolic compounds have; it is possible to alter the pathogen-carrier related factors that determine the immunogenicity: 1) Structural complexity, 2) Molecular size, 3) Structural heterogeneity, 4) Accessibility to antigenic determinants or epitopes, 5) Optical configuration, 6) Physical state, or 7) Molecular rigidity., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: The immune system is responsible for providing protection to the body against foreign substances. The immune system divides into two types of immune responses to study its mechanisms of protection: 1) Innate and 2) Adaptive. The innate immune response represents the first protective barrier of the organism that also works as a regulator of the adaptive immune response, if evaded the mechanisms of the innate immune response by the foreign substance the adaptive immune response takes action with the consequent antigen neutralization or elimination. The adaptive immune response objective is developing a specific humoral response that consists in the production of soluble proteins known as antibodies capable of specifically recognizing the foreign agent; such protective mechanism is induced artificially through an immunization or vaccination. Unfortunately, the immunogenicity of the antigens is an intrinsic characteristic of the same antigen dependent on several factors., Conclusion: Vaccine adjuvants are chemical substances of very varied structure that seek to improve the immunogenicity of antigens. The main four types of adjuvants under investigation are the following: 1) Oil emulsions with an antigen in solution, 2) Pattern recognition receptors activating molecules, 3) Inflammatory stimulatory molecules or activators of the inflammasome complex, and 4) Cytokines. However, this paper addresses the biological plausibility of two phytochemical compounds as vaccine adjuvants: 5) Lectins, and 6) Plant phenolics whose characteristics, mechanisms of action and disadvantages are addressed. Finally, the immunological usefulness of these molecules is discussed through immunological data to estimate effects of plant phenolics and lectins as vaccine adjuvants, and current studies that have implanted these molecules as vaccine adjuvants, demonstrating the results of this immunization., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)