Special Issue "Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals"

A special issue of Pharmaceuticals (ISSN 1424-8247). This special issue belongs to the section "Natural Products".

Deadline for manuscript submissions: 28 February 2022.

Special Issue Editors

Dr. Dejan Stojković
E-Mail Website
Guest Editor
Mycological laboratory, Department of Plant Physiology, Institute for Biological Research "Siniša Stanković"—National Institute of Republic of Serbia, University of Belgrade, Bulevar despota Stefana 142, 11000 Belgrade, Serbia
Interests: mushrooms; mycomedicines; mycofood
Special Issues and Collections in MDPI journals
Dr. Marina Sokovic
E-Mail Website
Guest Editor
Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
Interests: Microfungi, macrofungi, antimcirobial activity, natural products
Special Issues and Collections in MDPI journals

Special Issue Information

Medicinal plants present a valuable source of chemicals with potential therapeutic properties. They are widely used in traditional medicine as supportive therapeutics for various conditions and diseases. In recent years, there have been extensive studies in the area of medicinal plant research dealing with their various pharmacological effects. Novel research on this subject is necessary, since this is a hot topic field. Many in vitro studies describe the beneficial effects of plants for human health, highlighting promising pharmacological effects.

This thematic issue will cover the biological activity of medicinal plants and isolated compounds. Screening natural preparations for their biological activities is of prime importance, since natural raw material presents an excellent source of pharmaceuticals with a wide variety of different biologically active chemical structures.

The scope of the thematic issue will cover but is not limited to:

  • Chemical characterization of natural preparations;
  • Therapeutic potential of natural matrices in cardiovascular diseases, diabetes, cancer, and neurodegenerative diseases;
  • Antimicrobial activity;
  • Antioxidant activity;
  • Anti-enzymatic activity;
  • Anti-inflammatory activity;
  • Mechanism of pharmacological actions;
  • Structure–activity studies.

Dr. Dejan Stojković
Dr. Marina Sokovic
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Pharmaceuticals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (17 papers)

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Research

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Article
Gardenia jasminoides Attenuates Allergic Rhinitis-Induced Inflammation by Inhibiting Periostin Production
Pharmaceuticals 2021, 14(10), 986; https://doi.org/10.3390/ph14100986 - 28 Sep 2021
Viewed by 391
Abstract
Allergic rhinitis (AR) is a chronic inflammatory condition affecting the nasal mucosa of the upper airways. Herein, we investigated the effects of extracts from Gardenia jasminoides (GJ), a traditional herbal medicine with anti-inflammatory properties, on AR-associated inflammatory responses that cause epithelial damage. We [...] Read more.
Allergic rhinitis (AR) is a chronic inflammatory condition affecting the nasal mucosa of the upper airways. Herein, we investigated the effects of extracts from Gardenia jasminoides (GJ), a traditional herbal medicine with anti-inflammatory properties, on AR-associated inflammatory responses that cause epithelial damage. We investigated the inhibitory effects of water- and ethanol-extracted GJ (GJW and GJE, respectively) in an ovalbumin-induced AR mouse model and in splenocytes, differentiated Th2 cells, and primary human nasal epithelial cells (HNEpCs). Administering GJW and GJE to ovalbumin-induced AR mice improved clinical symptoms including behavior (sneezing and rubbing), serum cytokine levels, immune cell counts, and histopathological marker levels. Treatment with GJW and GJE reduced the secretion of Th2 cytokines in Th2 cells isolated and differentiated from the splenocytes of these mice. To investigate the underlying molecular mechanisms of AR, we treated IL-4/IL-13-stimulated HNEpCs with GJW and GJE; we found that these extracts significantly reduced the production of mitochondrial reactive oxygen species via the uncoupling protein-2 and periostin, a biomarker of the Th2 inflammatory response. Our results suggest that GJ extracts may potentially serve as therapeutic agents to improve the symptoms of AR by regulating the Th2 inflammatory response of the nasal epithelium. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Anti-Cancer Potential of Afzelin towards AGS Gastric Cancer Cells
Pharmaceuticals 2021, 14(10), 973; https://doi.org/10.3390/ph14100973 - 25 Sep 2021
Viewed by 425
Abstract
Afzelin demonstrates anti-inflammatory and anti-cancer properties. Our purpose was to assess its influence on apoptosis, Bax, caspases, MUC1, cancer-related carbohydrate antigens, enzymes participating in their formation, and galectin-3 in AGS gastric cancer cells. A total of 60 and 120 μM afzelin was used [...] Read more.
Afzelin demonstrates anti-inflammatory and anti-cancer properties. Our purpose was to assess its influence on apoptosis, Bax, caspases, MUC1, cancer-related carbohydrate antigens, enzymes participating in their formation, and galectin-3 in AGS gastric cancer cells. A total of 60 and 120 μM afzelin was used in all experiments. Flow cytometry was applied to determine apoptotic response. Western blotting and RT PCR were used to detect the expression of mentioned factors. Flavonoid at higher concentration revealed slight apoptotic respond. Bax, caspase-3, -8, -9 increased upon afzelin action. Stimulatory effect of the flavonoid on MUC1 cytoplasmic tail and extracellular domain in cell lysates and on MUC1 gene was revealed. MUC1 release into the culture medium was inhibited by the flavonoid. The 60 μM afzelin dose stimulated GalNAcTL5 protein expression and inhibited C1GalT1. ST6GalNAcT mRNA was inhibited by both flavonoid doses. ST3GalT was inhibited by 120 μM afzelin on protein and mRNA level. Lewisa/b protein was reduced by both afzelin concentrations. FUT3 and FUT4 mRNA was inhibited by 120 μM dose of afzelin. Galectin-3 protein increased in cell lysates and decreased in culture supernatant by 60 and 120 μM flavonoid. Galectin-3 gene expression was stimulated by two used concentrations of afzelin in comparison to control. We conclude that afzelin can be considered as the potential anti-cancer agent, supporting conventional cancer treatment. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Chicory Extracts and Sesquiterpene Lactones Show Potent Activity against Bacterial and Fungal Pathogens
Pharmaceuticals 2021, 14(9), 941; https://doi.org/10.3390/ph14090941 - 20 Sep 2021
Viewed by 919
Abstract
Chicory (Cichorium intybus L.) is an important industrial crop cultivated mainly to extract the dietary fiber inulin. However, chicory also contains bioactive compounds such as sesquiterpene lactones and certain polyphenols, which are currently discarded as waste. Plants are an important source of [...] Read more.
Chicory (Cichorium intybus L.) is an important industrial crop cultivated mainly to extract the dietary fiber inulin. However, chicory also contains bioactive compounds such as sesquiterpene lactones and certain polyphenols, which are currently discarded as waste. Plants are an important source of active pharmaceutical ingredients, including novel antimicrobials that are urgently needed due to the global spread of drug-resistant bacteria and fungi. Here, we tested different extracts of chicory for a range of bioactivities, including antimicrobial, antifungal and cytotoxicity assays. Antibacterial and antifungal activities were generally more potent in ethyl acetate extracts compared to water extracts, whereas supercritical fluid extracts showed the broadest range of bioactivities in our assays. Remarkably, the chicory supercritical fluid extract and a purified fraction thereof inhibited both methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Pseudomonas aeruginosa IBRS P001. Chicory extracts also showed higher antibiofilm activity against the yeast Candida albicans than standard sesquiterpene lactone compounds. The cytotoxicity of the extracts was generally low. Our results may thus lead to the development of novel antibacterial and antifungal preparations that are both effective and safe for human use. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Antifungal Activity of Extracts, Fractions, and Constituents from Coccoloba cowellii Leaves
Pharmaceuticals 2021, 14(9), 917; https://doi.org/10.3390/ph14090917 - 10 Sep 2021
Viewed by 625
Abstract
Coccoloba cowellii Britton (Polygonaceae, order Caryophyllales) is an endemic and critically endangered plant species that only grows in the municipality of Camagüey, a province of Cuba. A preliminary investigation of its total methanolic extract led to the discovery of promising antifungal activity. In [...] Read more.
Coccoloba cowellii Britton (Polygonaceae, order Caryophyllales) is an endemic and critically endangered plant species that only grows in the municipality of Camagüey, a province of Cuba. A preliminary investigation of its total methanolic extract led to the discovery of promising antifungal activity. In this study, a bioassay-guided fractionation allowed the isolation of quercetin and four methoxyflavonoids: 3-O-methylquercetin, myricetin 3,3′,4′-trimethyl ether, 6-methoxymyricetin 3,4′-dimethyl ether, and 6-methoxymyricetin 3,3′,4′-trimethyl ether. The leaf extract, fractions, and compounds were tested against various fungi and showed strong in vitro antifungal activity against Cryptococcus neoformans and various Candida spp. with no cytotoxicity (CC50 > 64.0 µg/mL) on MRC-5 SV2 cells, determined by a resazurin assay. A Candida albicans SC5314 antibiofilm assay indicated that the antifungal activity of C. cowellii extracts and constituents is mainly targeted to planktonic cells. The total methanolic extract showed higher and broader activity compared with the fractions and mixture of compounds. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
A Design of Experiment (DoE) Approach to Model the Yield and Chemical Composition of Ajowan (Trachyspermum ammi L.) Essential Oil Obtained by Microwave-Assisted Extraction
Pharmaceuticals 2021, 14(8), 816; https://doi.org/10.3390/ph14080816 - 19 Aug 2021
Viewed by 576
Abstract
Ajowan (Trachyspermum ammi L.) is a spice traditionally used in Middle Eastern medicine and contains a valuable essential oil (EO) exploited in different fields, such as pharmaceutics, agrochemicals and food additives. This EO is mostly characterized by the thymol to which most [...] Read more.
Ajowan (Trachyspermum ammi L.) is a spice traditionally used in Middle Eastern medicine and contains a valuable essential oil (EO) exploited in different fields, such as pharmaceutics, agrochemicals and food additives. This EO is mostly characterized by the thymol to which most of its biological properties are related. Given the economic value of ajowan and its increasing demand across the globe, the extraction method used for its EO is of paramount importance in terms of quality and quantity of the final product. In the present study, we used the design of experiment (DoE) approach to study and optimize the extraction of the ajowan EO using the microwave-assisted extraction (MAE), a novel extraction technique with high efficiency, low energy consumption, short process length and low environmental impact. A two-step DoE (screening followed by surface response methodology) was used to reduce the number of experiments and to improve the cost/benefit ratio. Reliable mathematical models, relating the more relevant EO features with the extraction conditions, were obtained and used to identify the best experimental conditions able to maximize the yield and thymol concentration. The optimized MAE procedure assures an EO with a higher yield and thymol amount compared with the standard hydrodistillation procedure. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Formulation and Evaluation of Helichrysum italicum Essential Oil-Based Topical Formulations for Wound Healing in Diabetic Rats
Pharmaceuticals 2021, 14(8), 813; https://doi.org/10.3390/ph14080813 - 19 Aug 2021
Viewed by 695
Abstract
As proper wound management is crucial to reducing morbidity and improving quality of life, this study evaluated for the first time the wound healing potential of H. italicum essential oil (HIEO) prepared in the form of ointment and gel in streptozotocin-induced diabetic wound [...] Read more.
As proper wound management is crucial to reducing morbidity and improving quality of life, this study evaluated for the first time the wound healing potential of H. italicum essential oil (HIEO) prepared in the form of ointment and gel in streptozotocin-induced diabetic wound models in rats. After creating full-thickness cutaneous wounds, forty-eight diabetic rats were divided into six groups: (1) negative control; (2) positive control; (3) ointment base; (4) gel base; (5) 0.5% HIEO ointment (6) 0.5% HIEO gel. Wound healing potential was determined by the percentage of wound contraction, hydroxyproline content, redox status, and histological observation. A significant decrease in the wound size was observed in animals treated with HIEO formulations compared with other groups. The HIEO groups also showed a higher level of total hydroxyproline content, and more pronounced restitution of adnexal structures with only the underlying muscle defect indicating the incision site. Hence, our results legitimate the traditional data of the pro-healing effect of HIEO because HIEO in both formulations such as gel and ointment exhibited the significant wound repairing effect in the incision wound model. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
A High-Content Screen for the Identification of Plant Extracts with Insulin Secretion-Modulating Activity
Pharmaceuticals 2021, 14(8), 809; https://doi.org/10.3390/ph14080809 - 17 Aug 2021
Viewed by 856
Abstract
Bioactive plant compounds and extracts are of special interest for the development of pharmaceuticals. Here, we describe the screening of more than 1100 aqueous plant extracts and synthetic reference compounds for their ability to stimulate or inhibit insulin secretion. To quantify insulin secretion [...] Read more.
Bioactive plant compounds and extracts are of special interest for the development of pharmaceuticals. Here, we describe the screening of more than 1100 aqueous plant extracts and synthetic reference compounds for their ability to stimulate or inhibit insulin secretion. To quantify insulin secretion in living MIN6 β cells, an insulin–Gaussia luciferase (Ins-GLuc) biosensor was used. Positive hits included extracts from Quillaja saponaria, Anagallis arvensis, Sapindus mukorossi, Gleditsia sinensis and Albizia julibrissin, which were identified as insulin secretion stimulators, whereas extracts of Acacia catechu, Myrtus communis, Actaea spicata L., Vaccinium vitis-idaea and Calendula officinalis were found to exhibit insulin secretion inhibitory properties. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were used to characterize several bioactive compounds in the selected plant extracts, and these bioactives were retested for their insulin-modulating properties. Overall, we identified several plant extracts and some of their bioactive compounds that may be used to manipulate pancreatic insulin secretion. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources
Pharmaceuticals 2021, 14(5), 414; https://doi.org/10.3390/ph14050414 - 28 Apr 2021
Cited by 1 | Viewed by 745
Abstract
Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides [...] Read more.
Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Identification of Anti-Inflammatory and Anti-Proliferative Neolignanamides from Warburgia ugandensis Employing Multi-Target Affinity Ultrafiltration and LC-MS
Pharmaceuticals 2021, 14(4), 313; https://doi.org/10.3390/ph14040313 - 01 Apr 2021
Cited by 1 | Viewed by 591
Abstract
Previous reports have illustrated that the incidence and mortality of cancer are increasing year by year worldwide. In addition, the occurrence, development, recurrence and metastasis of cancer are closely related to inflammation, which is a kind of defensive response of human body to [...] Read more.
Previous reports have illustrated that the incidence and mortality of cancer are increasing year by year worldwide. In addition, the occurrence, development, recurrence and metastasis of cancer are closely related to inflammation, which is a kind of defensive response of human body to various stimuli. As an important medicinal plant in Africa, Warburgia ugandensis has been reported to have certain anti-inflammatory and anti-proliferative activities, but its specific components and mechanisms of action remain elusive. To tackle this challenge, affinity ultrafiltration with drug targets of interest coupled to high-performance liquid chromatography-mass spectrometry (AUF-HPLC-MS/MS) could be utilized to quickly screen out bioactive constituents as ligands against target enzymes from complex extracts of this plant. AUF-HPLC-MS/MS with four drug targets, i.e., cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), topoisomerase I (Top I) and topoisomerase II (Top II) were used to rapidly screen and characterize the anti-inflammatory and anti-proliferative natural ligands from W. ugandensis, and the resulting potential active compounds as ligands with specific binding affinity to COX-2, 5-LOX, Top I and Top II, were isolated with modern separation and purification techniques and identified with spectroscopic method like NMR, and then their antiinflammatory and anti-proliferative activities were tested to verify the screening results from AUF-HPLC-MS/MS. Compounds 1 and 2, which screened out and identified from W. ugandensis showed remarkable binding affinity to COX-2, 5-LOX, Top I and Top II with AUF-HPLC-MS/MS. In addition, 1 new compound (compound 3), together with 5 known compounds were also isolated and identified from W. ugandensis. The structure of compound 3 was elucidated by extensive 1D, 2D NMR data and UPLC-QTOF-MS/MS. Furthermore, compounds 1 and 2 were further proved to possess both anti-inflammatory and anti-proliferative activities which are in good agreement with the screening results using AUF-HPLC-MS/MS. This work showcased an efficient method for quickly screening out bioactive components with anti-inflammatory and anti-proliferative activity from complex medicinal plant extracts using AUF-HPLC-MS/MS with target enzymes of interest, and also demonstrated that neolignanamides (compounds 1 and 2) from W. ugandensis would be the active components responsible for its anti-inflammatory and anti-proliferative activity with the potential to treat cancer and inflammation. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
In Vitro Effects of Low Doses of β-Caryophyllene, Ascorbic Acid and d-Glucosamine on Human Chondrocyte Viability and Inflammation
Pharmaceuticals 2021, 14(3), 286; https://doi.org/10.3390/ph14030286 - 23 Mar 2021
Viewed by 1191
Abstract
β-caryophyllene (BCP), a plant-derived sesquiterpene, has been reported to have anti-inflammatory and antioxidant effects. The purpose of this study is to evaluate the effects of BCP in combination with ascorbic acid (AA) and d-glucosamine (GlcN) against macrophage-mediated inflammation on in vitro primary [...] Read more.
β-caryophyllene (BCP), a plant-derived sesquiterpene, has been reported to have anti-inflammatory and antioxidant effects. The purpose of this study is to evaluate the effects of BCP in combination with ascorbic acid (AA) and d-glucosamine (GlcN) against macrophage-mediated inflammation on in vitro primary human chondrocytes. Changes in cell viability, intracellular ROS generation, gene expression of pro-inflammatory mediators, metalloproteinases (MMPs), collagen type II and aggrecan were analyzed in primary human chondrocytes exposed to the conditioned medium (CM) of activated U937 monocytes and subsequently treated with BCP alone or in combination with AA and GlcN. The CM-induced chondrocyte cytotoxicity was reduced by the presence of low doses of BCP alone or in combination with AA and GlcN. The exposure of cells to CM significantly increased IL-1β, NF-κB1 and MMP-13 expression, but when BCP was added to the inflamed cells, alone or in combination with AA and GlcN, gene transcription for all these molecules was restored to near baseline values. Moreover, chondrocytes increased the expression of collagen type II and aggrecan when stimulated with AA and GlcN alone or in combination with BCP. This study showed the synergistic anti-inflammatory and antioxidative effects of BCP, AA and GlcN at low doses on human chondrocyte cultures treated with the CM of activated U937 cells. Moreover, the combination of the three molecules was able to promote the expression of collagen type II and aggrecan. All together, these data could suggest that BCP, AA and GlcN exert a chondro-protective action. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Communication
A Novel Pro-Melanogenic Effect of Standardized Dry Olive Leaf Extract on Primary Human Melanocytes from Lightly Pigmented and Moderately Pigmented Skin
Pharmaceuticals 2021, 14(3), 252; https://doi.org/10.3390/ph14030252 - 11 Mar 2021
Viewed by 697
Abstract
Benolea® (EFLA®943) is a standardized dry olive leaf extract (DOLE) considered safe for food consumption and has demonstrated superior pharmaceutical benefits such as antioxidant, anti-obesity, and anti-hypertensive activities. However, there is no study on its effects on melanogenesis yet. Disruption [...] Read more.
Benolea® (EFLA®943) is a standardized dry olive leaf extract (DOLE) considered safe for food consumption and has demonstrated superior pharmaceutical benefits such as antioxidant, anti-obesity, and anti-hypertensive activities. However, there is no study on its effects on melanogenesis yet. Disruption in the sequence of steps in melanogenesis can lead to hypopigmentary disorders which occur due to reduced production or export of pigment melanin in the skin. There is a need for safe and nontoxic therapeutics for the treatment of hypopigmentation disorders. Herein, we studied the effects of DOLE over a concentration range of 10–200 µg/mL on melanin synthesis and melanin secretion in B16F10 mouse melanoma cells and MNT-1 human melanoma cells and validated our results in primary human melanocytes (obtained from lightly pigmented (LP) and moderately pigmented (MP) cells) as well as their cocultures with keratinocytes. The capacity of melanocytes to export melanosomes was also estimated indirectly by the quantitation of melanocyte dendrite lengths and numbers. Our results show that DOLE significantly enhanced levels of extracellular melanin in the absence of effects on intracellular melanin, demonstrating that this plant extract’s pro-melanogenic activity is primarily based on its capacity to augment melanin secretion and stimulate melanocyte dendricity. In summary, our preliminary results demonstrate that DOLE may hold promise as a pro-pigmenting agent for vitiligo therapy and gray hair treatment by its exclusive and novel mechanism of functioning as a dendrite elongator. Further studies to elucidate the mechanisms of action of the pro-melanogenic activity and effects of DOLE on melanosome export as well as the last steps of melanogenesis are warranted. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Chemical Composition, Larvicidal Activity, and Enzyme Inhibition of the Essential Oil of Lippia grata Schauer from the Caatinga Biome against Dengue Vectors
Pharmaceuticals 2021, 14(3), 250; https://doi.org/10.3390/ph14030250 - 10 Mar 2021
Cited by 1 | Viewed by 958
Abstract
Insect resistance and environmental pollution are among the drawbacks of continuous use of synthetic insecticides against the vectors of dengue, Aedesaegypti and Aedes albopictus. The objective of this study was to analyze the composition of the essential oil of Lippia grata [...] Read more.
Insect resistance and environmental pollution are among the drawbacks of continuous use of synthetic insecticides against the vectors of dengue, Aedesaegypti and Aedes albopictus. The objective of this study was to analyze the composition of the essential oil of Lippia grata Schauer collected from plants, in three periods of the year, to compare the larvicidal activity and enzymatic inhibition of the dengue vectors. The oilsanalyzed by gas chromatography coupled to mass spectrometry (GC-MS), presented thymol and 1,8-cineole, as the main constituents, in all three periods. This composition was different from that found in previous studies of the species from different places, thus, suggesting a new chemotype of Lippia grata. Larvicidal tests were performed at concentrations of 100, 75, 50, 25, and 12.5 μg.mL−1 and the essential oil from the rainy season showed the best results, with LC50 of 22.79 μg.mL−1 and 35.36 μg.mL−1 against Ae. aegypti and Ae. albopictus, respectively; this result was better than other reports. In the rainy period, however, there was a greater variety of components, which led to a better larvicidal effect, possibly due to synergistic action with minor constituents. Total proteins, amylases, and acetylcholinesterase of both species were inhibited by the oils. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Carnosic Acid Induces Apoptosis and Inhibits Akt/mTOR Signaling in Human Gastric Cancer Cell Lines
Pharmaceuticals 2021, 14(3), 230; https://doi.org/10.3390/ph14030230 - 08 Mar 2021
Cited by 1 | Viewed by 667
Abstract
Gastric cancer is among the most common malignancies worldwide. Due to limited availability of therapeutic options, there is a constant need to find new therapies that could target advanced, recurrent, and metastatic gastric cancer. Carnosic acid is a naturally occurring polyphenolic abietane diterpene [...] Read more.
Gastric cancer is among the most common malignancies worldwide. Due to limited availability of therapeutic options, there is a constant need to find new therapies that could target advanced, recurrent, and metastatic gastric cancer. Carnosic acid is a naturally occurring polyphenolic abietane diterpene derived from Rosmarinus officinalis and reported to have numerous pharmacological effects. In this study, the cytotoxicity assay, Annexin V-FITC/PI, caspases 3, 8, and 9, cell cycle analysis, and Western blotting were used to assess the effect of carnosic acid on the growth and survival of human gastric cancer cell lines (AGS and MKN-45). Our findings showed that carnosic acid inhibited human gastric cancer cell proliferation and survival in a dose-dependent manner. Additionally, carnosic acid is found to inhibit the phosphorylation/activation of Akt and mTOR. Moreover, carnosic acid enhanced the cleavage of PARP and downregulated survivin expression, both being known markers of apoptosis. In conclusion, carnosic acid exhibits antitumor activity against human gastric cancer cells via modulating the Akt-mTOR signaling pathway that plays a crucial role in gastric cancer cell proliferation and survival. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Up-Regulated Vitamin D Receptor by Pelargonium sidoides Extract EPs® 7630 Contributes to Rhinovirus Defense in Bronchial Epithelial Cells
Pharmaceuticals 2021, 14(2), 172; https://doi.org/10.3390/ph14020172 - 22 Feb 2021
Cited by 1 | Viewed by 777
Abstract
EPs®7630, extracted from Pelargonium sidoides, reduces the severity of viral upper respiratory tract infections. Vitamin D also improves anti-viral host defense through similar signaling pathways. This study assessed if EPs®7630 modifies vitamin D receptor (VDR) expression and function [...] Read more.
EPs®7630, extracted from Pelargonium sidoides, reduces the severity of viral upper respiratory tract infections. Vitamin D also improves anti-viral host defense through similar signaling pathways. This study assessed if EPs®7630 modifies vitamin D receptor (VDR) expression and function by human bronchial epithelial cells. Bronchial epithelial cells were incubated with EPs®7630 over 48 h before calcitriol stimulation and/or infection with Rhinovirus (RV)-16. Protein expression was determined by Western-blotting. Intracellular signaling of mitogen activated protein kinases (MAPK) was studied by chemical inhibitors. The anti-viral effect was assessed by immunofluorescence for RV-16 protein. EPs®7630 upregulated VDR expression through Erk1/2 MAPK and thereby increased the cell’s sensitivity to calcitriol. Compared ton untreated cells, the shift of the VDR into the nucleus at 5.3 times lower calcitriol concentration. EPs®7630 increased Erk1/2 MAPK signaling, but reduced p38 phosphorylation, and had no effect on Jun N-terminal kinase (JNK). EPs®7630 improved the anti-viral effect of vitamin D on RV-16 infection by 2.1 folds compared to vitamin D alone or to untreated cells. Furthermore, EPs®7630 improved the differentiation of epithelial cells by upregulating E-cadherin expression through Erk1/2. In conclusion, EPs®7630 increased host defense against Rhinovirus infection by upregulating the VDR and the differentiation of epithelial cells. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Flavones, Flavonols, and Glycosylated Derivatives—Impact on Candida albicans Growth and Virulence, Expression of CDR1 and ERG11, Cytotoxicity
Pharmaceuticals 2021, 14(1), 27; https://doi.org/10.3390/ph14010027 - 30 Dec 2020
Cited by 3 | Viewed by 1025
Abstract
Due to the high incidence of fungal infections worldwide, there is an increasing demand for the development of novel therapeutic approaches. A wide range of natural products has been extensively studied, with considerable focus on flavonoids. The antifungal capacity of selected flavones (luteolin, [...] Read more.
Due to the high incidence of fungal infections worldwide, there is an increasing demand for the development of novel therapeutic approaches. A wide range of natural products has been extensively studied, with considerable focus on flavonoids. The antifungal capacity of selected flavones (luteolin, apigenin), flavonols (quercetin), and their glycosylated derivatives (quercitrin, isoquercitrin, rutin, and apigetrin) along with their impact on genes encoding efflux pumps (CDR1) and ergosterol biosynthesis enzyme (ERG11) has been the subject of this study. Cytotoxicity of flavonoids towards primary liver cells has also been addressed. Luteolin, quercitrin, isoquercitrin, and rutin inhibited growth of Candida albicans with the minimal inhibitory concentration of 37.5 µg/mL. The application of isoquercitrin has reduced C. albicans biofilm establishing capacities for 76%, and hyphal formation by yeast. In vitro treatment with apigenin, apigetrin, and quercitrin has downregulated CDR1. Contrary to rutin and apigenin, isoquercitrin has upregulated ERG11. Except apigetrin and quercitrin (90 µg/mL and 73 µg/mL, respectively inhibited 50% of the net cell growth), the examined flavonoids did not exhibit cytotoxicity. The reduction of both fungal virulence and expression of antifungal resistance-linked genes was the most pronounced for apigenin and apigetrin; these results indicate flavonoids’ indispensable capacity for further development as part of an anticandidal therapy or prevention strategy. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Article
Additive Effect of a Combination of Artocarpus lakoocha and Glycyrrhiza glabra Extracts on Tyrosinase Inhibition in Melanoma B16 Cells
Pharmaceuticals 2020, 13(10), 310; https://doi.org/10.3390/ph13100310 - 14 Oct 2020
Cited by 5 | Viewed by 1040
Abstract
Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show tyrosinase inhibitory activity and melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of tyrosinase and reduction of melanin [...] Read more.
Artocarpus lakoocha (Al) and Glycyrrhiza glabra (Gg) extracts have been reported to show tyrosinase inhibitory activity and melanin pigment reduction. This is the first study to assess the combination of Al and Gg extracts in enhancing inhibition of tyrosinase and reduction of melanin pigments. Al and Gg extracted by maceration in 70% and 95% ethanol were analyzed for oxyresveratrol and glabridin using Ultra High Performance Liquid Chromatography. Extracts of Al and Gg singly and combinations of Al95 and Gg95 were tested for cytotoxicity, tyrosinase inhibitory activity, and reduction of melanin pigments in melanoma B16 cells. Al95 had higher antioxidant, tyrosinase inhibitory activity and reduced more melanin pigments in B16 cells compared to Al70, and exhibited higher levels of oxyresveratrol. Gg95 inhibited oxidative stress and mushroom tyrosinase better than Gg70, and exhibited higher levels of glabridin. Combinations of Al95 and Gg95 at various ratios (concentration of 0.1 mg/mL) were not cytotoxic to B16 cells. Interestingly, Al95 and Gg95 combined at a ratio 9:1 reduced melanin pigment up to 53% in B16 cells. This combination of Al95 and Gg95 extracts exhibited the additive effect of reducing melanin pigments by suppressing the expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR) and tyrosinase-related protein-2 (TRP-2) in B16 cells. The combination of Al and Gg extracts could be developed as skin care products for hyperpigmentation treatment. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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Review

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Review
Phytochemicals from Plant Foods as Potential Source of Antiviral Agents: An Overview
Pharmaceuticals 2021, 14(4), 381; https://doi.org/10.3390/ph14040381 - 19 Apr 2021
Cited by 3 | Viewed by 1447
Abstract
To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow [...] Read more.
To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review focuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioavailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these reasons, a continuous systematic exploration of plant foods and their phytochemicals is necessary for the development of new antiviral agents capable of saving lives and improving their well-being. Full article
(This article belongs to the Special Issue Natural Pharmacons: Biologically Active Plant Based Pharmaceuticals)
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