scholarly journals Propolis Extract and Its Bioactive Compounds—From Traditional to Modern Extraction Technologies

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2930
Author(s):  
Jelena Šuran ◽  
Ivica Cepanec ◽  
Tomislav Mašek ◽  
Božo Radić ◽  
Saša Radić ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Geographical Origin ◽  
Research Area ◽  
Mechanisms Of Action ◽  
Bioactive Molecules ◽  
Erk Pathway ◽  
Pharmacological Effects ◽  
Propolis Extract ◽  
Open Research ◽  
Antioxidant Mechanisms

Propolis is a honeybee product known for its antioxidant, anti-inflammatory, anticancer, and antimicrobial effects. It is rich in bioactive molecules whose content varies depending on the botanical and geographical origin of propolis. These bioactive molecules have been studied individually and as a part of propolis extracts, as they can be used as representative markers for propolis standardization. Here, we compare the pharmacological effects of representative polyphenols and whole propolis extracts. Based on the literature data, polyphenols and extracts act by suppressing similar targets, from pro-inflammatory TNF/NF-κB to the pro-proliferative MAPK/ERK pathway. In addition, they activate similar antioxidant mechanisms of action, like Nrf2-ARE intracellular antioxidant pathway, and they all have antimicrobial activity. These similarities do not imply that we should attribute the action of propolis solely to the most representative compounds. Moreover, its pharmacological effects will depend on the efficacy of these compounds’ extraction. Thus, we also give an overview of different propolis extraction technologies, from traditional to modern ones, which are environmentally friendlier. These technologies belong to an open research area that needs further effective solutions in terms of well-standardized liquid and solid extracts, which would be reliable in their pharmacological effects, environmentally friendly, and sustainable for production.

scholarly journals The Potential of the Synthetic Strigolactone Analogue GR24 for the Maintenance of Photosynthesis and Yield in Winter Wheat under Drought: Investigations on the Mechanisms of Action and Delivery Modes

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1223
Author(s):  
Mojde Sedaghat ◽  
Yahya Emam ◽  
Ali Mokhtassi-Bidgoli ◽  
Saeid Hazrati ◽  
Claudio Lovisolo ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Foliar Application ◽  
Mechanisms Of Action ◽  
Bioactive Molecules ◽  
Future Research ◽  
Antioxidant Enzyme Activities ◽  
Synthetic Analog ◽  
Practical Applications ◽  
New Family ◽  
Harsh Environmental Condition

Strigolactones (SLs) have been implicated in many plant biological and physiological processes, including the responses to abiotic stresses such as drought, in concert with other phytohormones. While it is now clear that exogenous SLs may help plants to survive in harsh environmental condition, the best, most effective protocols for treatment have not been defined yet, and the mechanisms of action are far from being fully understood. In the set of experiments reported here, we contrasted two application methods for treatment with a synthetic analog of SL, GR24. A number of morphometric, physiological and biochemical parameters were measured following foliar application of GR24 or application in the residual irrigation water in winter wheat plants under irrigated and drought stress conditions. Depending on the concentration and the method of GR24 application, differentiated photosynthesis and transpiration rate, stomatal conductance, leaf water potential, antioxidant enzyme activities and yield in drought conditions were observed. We present evidence that different methods of GR24 application led to increased photosynthesis and yield under stress by a combination of drought tolerance and escape factors, which should be considered for future research exploring the potential of this new family of bioactive molecules for practical applications.

scholarly journals Plant-Derived Anticancer Compounds as New Perspectives in Drug Discovery and Alternative Therapy

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1109
Author(s):  
Cristina Adriana Dehelean ◽  
Iasmina Marcovici ◽  
Codruta Soica ◽  
Marius Mioc ◽  
Dorina Coricovac ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Alternative Therapy ◽  
Natural Compounds ◽  
Mechanisms Of Action ◽  
Chemotherapeutic Agents ◽  
Biologically Active ◽  
Bioactive Molecules ◽  
Multi Drug Resistance ◽  
Chemopreventive Agents ◽  
Pharmaceutical Agents

Despite the recent advances in the field of chemically synthetized pharmaceutical agents, nature remains the main supplier of bioactive molecules. The research of natural products is a valuable approach for the discovery and development of novel biologically active compounds possessing unique structures and mechanisms of action. Although their use belongs to the traditional treatment regimes, plant-derived compounds still cover a large portion of the current-day pharmaceutical agents. Their medical importance is well recognized in the field of oncology, especially as an alternative to the limitations of conventional chemotherapy (severe side effects and inefficacy due to the occurrence of multi-drug resistance). This review offers a comprehensive perspective of the first blockbuster chemotherapeutic agents of natural origin’s (e.g. taxol, vincristine, doxorubicin) mechanism of action using 3D representation. In addition is portrayed the step-by-step evolution from preclinical to clinical evaluation of the most recently studied natural compounds with potent antitumor activity (e.g. resveratrol, curcumin, betulinic acid, etc.) in terms of anticancer mechanisms of action and the possible indications as chemotherapeutic or chemopreventive agents and sensitizers. Finally, this review describes several efficient platforms for the encapsulation and targeted delivery of natural compounds in cancer treatment

Wavelets as activation functions in Neural Networks

2021 ◽  
pp. 1-11
Author(s):  
Oscar Herrera ◽  
Belém Priego
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
High Performance ◽  
Research Area ◽  
Experimental Results ◽  
Activation Functions ◽  
Hyperbolic Tangent ◽  
Open Research ◽  
Bounded Functions

Traditionally, a few activation functions have been considered in neural networks, including bounded functions such as threshold, sigmoidal and hyperbolic-tangent, as well as unbounded ReLU, GELU, and Soft-plus, among other functions for deep learning, but the search for new activation functions still being an open research area. In this paper, wavelets are reconsidered as activation functions in neural networks and the performance of Gaussian family wavelets (first, second and third derivatives) are studied together with other functions available in Keras-Tensorflow. Experimental results show how the combination of these activation functions can improve the performance and supports the idea of extending the list of activation functions to wavelets which can be available in high performance platforms.

scholarly journals Natural products with therapeutic potential in melanoma metastasis

2015 ◽  
Vol 32 (8) ◽  
pp. 1170-1182 ◽  
Author(s):  
A. AlQathama ◽  
J. M. Prieto
Keyword(s):  
Natural Products ◽  
Cancer Treatment ◽  
Therapeutic Potential ◽  
Melanoma Cells ◽  
Mechanisms Of Action ◽  
Melanoma Metastasis ◽  
Pharmacological Effects ◽  
Cytotoxic Compounds

Natural products continue to provide lead cytotoxic compounds for cancer treatment but less attention has been given to antimigratory compounds. We here systematically and critically survey more than 30 natural products with direct in vitro and in vivo pharmacological effects on migration and/or metastasis of melanoma cells and chart the mechanisms of action for this underexploited property.

scholarly journals General Characteristics of Adjuvants and Their Mechanism of Action (Part 1)

2020 ◽  
Vol 20 (4) ◽  
pp. 245-256
Author(s):  
N. A. Alpatova ◽  
Zh. I. Avdeeva ◽  
S. L. Lysikova ◽  
O. V. Golovinskaya ◽  
L. A. Gayderova
Keyword(s):  
Molecular Mechanisms ◽  
Research Area ◽  
Mechanisms Of Action ◽  
Vaccine Antigen ◽  
Infectious Agents ◽  
Effective Protection ◽  
Is Development ◽  
Defensive Mechanisms ◽  
Structure And Activity ◽  
New Vaccines

One of priority issues of the present-day healthcare system is development of new vaccines and improvement of existing ones due to decreasing immunocompetence of the population, emergence of new infections and reemergence of old ones which were previously thought to be under control. Adjuvants have proven to be integral and important components of modern vaccines, as they enhance immune response to the vaccine antigen. However, despite a lot of effort put into their development, only a small number of adjuvants are currently used in clinical practice.The aim of the study was to systematise literature data on the adjuvants’ mechanisms of action, their specific structure, composition, and stimulation effects that mediate their immunoadjuvant properties. The paper summarises data on adjuvants used as components in licensed vaccines, describes their characteristics, analyses molecular mechanisms of their action in order to establish correlation between their structure and activity, which is important for the development of more efficacious and safe adjuvants. The paper cites advanced developments aimed at enhancing stimulation effects of existing adjuvants. It concludes by stating that the key research area aimed at improving vaccination efficacy is the study of mechanisms that contribute to the development of effective protection against infectious agents, as well as analysis of how to use adjuvants to stimulate the body’s defensive mechanisms, primarily by impacting the innate immunity.

Development of propolis nanoparticles for the treatment of bovine mastitis: in vitro studies on antimicrobial and cytotoxic activities

2019 ◽  
Vol 99 (4) ◽  
pp. 713-723 ◽  
Author(s):  
Gabriela Tasso Pinheiro Machado ◽  
Maria Beatriz Veleirinho ◽  
Letícia Mazzarino ◽  
Luiz Carlos Pinheiro Machado Filho ◽  
Marcelo Maraschin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Encapsulation Efficiency ◽  
Average Particle Size ◽  
Physical Stability ◽  
Bovine Mastitis ◽  
Total Phenolic ◽  
Cytotoxic Activities ◽  
Average Particle ◽  
Propolis Extract

This study describes the development of propolis nanoparticles (PNP) to treat bovine mastitis. Three PNP prepared with varying concentrations of propolis (5% and 7%, w/v) and the surfactants [poloxamer (1%, 3%, and 4%, w/v) and soy lecithin (0.25%, 0.7%, and 1%, w/v)]. PNP were characterized according to their size, polydispersity, zeta potential, pH, morphology, and physical stability. PNP were evaluated for their in vitro antimicrobial and cytotoxic effects. PNP obtained were spherical with a monodisperse distribution (polydispersity index < 0.2) and an average particle size between 181 and 201 nm. Stability studies showed that PNP were stable over 150 d. The encapsulation efficiency of total phenolic content varied between 73% and 91%. The chromatographic profile of phenolic compounds from PNP showed selective encapsulation efficiency according to the polarity of compounds. All PNP showed antimicrobial activity against Staphylococcus aureus with a minimum inhibitory concentration ranging from 156 to 310 μg mL−1. The IC50 (the concentration responsible for reduction of cellular viability by half) for epithelial cells of bovine mammary gland (MAC-T, mammary alveolar cell-T) varied from 122.2 to 268.4 μg mL−1. Results showed that PNP represent a promising nanocarrier for high concentrations of propolis extract in a stable aqueous medium, while, at the same time, presenting antimicrobial activity accompanied by moderate cytotoxicity to the MAC-T cells.

Pharmacological Properties of Curcumin

2020 ◽  
pp. 235-248
Author(s):  
Anuradha Singh
Keyword(s):  
Clinical Trial ◽  
Natural Product ◽  
Mechanisms Of Action ◽  
Clinical Settings ◽  
Pharmacological Properties ◽  
Pharmacological Effects ◽  
The Poor ◽  
Cellular Factors

Curcumin, the polyphenol natural product, is a constituent of the traditional medicine known as turmeric. Extensive research over the last 50 years has indicated that this polyphenol displays potent pharmacological effects by targeting many critical cellular factors through a diverse array of mechanisms of action. However, there are some obstacles that prevent this wonder molecule to be effective in clinical settings and limit its use to topical applications only. Curcumin has recently been classified as both PAINS (panassay interference compounds) and an IMPS (invalid metabolic panaceas) candidate. Due to likely false activity of curcumin in vitro and in vivo has resulted unsuccessful clinical trial of curcumin against several disease. The chapter will review the essential medicinal chemistry of curcumin as well as envisage a compilation and discussion on the poor bioavailability of curcumin.

scholarly journals Snake Venom: Any Clue for Antibiotics and CAM?

2005 ◽  
Vol 2 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Deivy Clementino de Lima ◽  
Paula Alvarez Abreu ◽  
Cícero Carlos de Freitas ◽  
Dilvani Oliveira Santos ◽  
Rodrigo Oliveira Borges ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Alternative Medicine ◽  
Complementary And Alternative Medicine ◽  
Snake Venom ◽  
Biological Effects ◽  
Mechanisms Of Action ◽  
Snake Venoms ◽  
Commercial Use ◽  
Naturally Occurring ◽  
Complementary And Alternative

Lately several naturally occurring peptides presenting antimicrobial activity have been described in the literature. However, snake venoms, which are an enormous source of peptides, have not been fully explored for searching such molecules. The aim of this work is to review the basis of antimicrobial mechanisms revealing snake venom as a feasible source for searching an antibiotic prototype. Therefore, it includes (i) a description of the constituents of the snake venoms involved in their main biological effects during the envenomation process; (ii) examples of snake venom molecules of commercial use; (iii) mechanisms of action of known antibiotics; and (iv) how the microorganisms can be resistant to antibiotics. This review also shows that snake venoms are not totally unexplored sources for antibiotics and complementary and alternative medicine (CAM).

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