Chemical Profiling and Biological Evaluation of Nepeta baytopii Extracts and Essential Oil: An Endemic Plant from Turkey

Molecular background of the diverse metabolic profiles in leaves and inflorescences of naked catmint (Nepeta nuda L.)

Nepeta nuda L. shares a typical secondary chemistry with other Nepeta species (fam. Lamiaceae), characterized by the tendency to intensively produce monoterpenoid iridoids, whereas the phenylpropanoid chemistry is steered towards the production of a caffeic acid ester, rosmarinic acid. Combining complementary state-of-the-art analytical techniques, N. nuda metabolome was here comprehensively characterized in the quest for the organ-specific composition of phenolics and terpenoids that possess well-defined functions in plant-biotic interactions as well as therapeutic potential. N. nuda inflorescences showed generally higher constitutive levels of specialized metabolites, as compared to leaves, and the composition of major iridoids and phenolics in reproductive organs was found to be more conserved than in leaves across 13 populations from the Central Balkans. The results suggest that N. nuda plants most likely invest more in constitutive than inducible biosynthesis of functional metabolites in flowers, since they are of essential importance for both pollination and defense against herbivores and pathogens. Conversely, specialized metabolism of leaves is found to be more susceptible to reprograming in response to differential growth conditions. The defense strategy of leaves, primarily functioning in CO2 fixation during photosynthesis, more likely relies on the induction of metabolite levels following plant-environment interplay. Organ-specific biosynthesis of iridoids in N. nuda is found to be tightly regulated at the transcriptional level, and high constitutive levels of these compounds in inflorescences most likely result from the up-regulated expression of several key genes (NnG8H, NnNEPS1, NnNEPS2, and NnNEPS3) determining the metabolic flux through the pathway. The organ-specific content of rosmarinic acid and co-expression patterns of the corresponding biosynthetic genes were much less correlated, which suggests independent organ-specific transcriptional regulation of the iridoid and phenolic pathways. Knowledge gathered within the present study can assist growers to select productive genotypes and manipulate phenology of N. nuda towards maximizing yields and facilitating its integration into pest management systems and other applications related to human health.

Patterns of Genetic Variation of Nepeta nuda L. from the Central Balkans: Understanding Drivers of Chemical Diversity

Nepeta nuda L., a notable medicinal species in the tradition of the Balkan region, is a rich source of bioactive iridoids and phenolics previously described as high-resolution taxonomical classifiers for the genus Nepeta. However, their potential in investigating intra-species differentiation is here described for the first time. The aim was to recognize the sources of natural chemical diversity and their association with the genetic variability both within and among N. nuda populations in the Central Balkans. Chemical diversity was assessed from methanol extracts and essential oils through untargeted and targeted metabolomics using state-of-the-art analytical tools, covering a broad spectrum of compounds that represent the N. nuda metabolome. We found that chemodiversity primarily resides within populations of N. nuda, and similar results were obtained at the DNA level using microsatellite markers. The low genetic and chemical differentiation of the studied N. nuda populations implies that their metabolomic profiles may be less influenced by geographic distance and variable environmental conditions within the Central Balkans, as they are under the pivotal control of their genetic backgrounds. Screening the distribution of the major bioactive compounds belonging to phenolics (phenolic acids and flavonoids) and iridoids (both aglycones and glycosylated forms), within and among N. nuda populations, is able to guarantee mass spectrometry-based tools for the selection of elite representative genotypes with practical importance. The knowledge acquired will allow us to delve deeper into the molecular background of N. nuda chemical diversity, which is the course of our further work.

Chemical composition, antimicrobial activity, and antioxidant capacity of Micromeria flagellaris Baker and M. madagascariensis Baker: Two endemic species from Madagascar as sources of essential oils

Background

The aerial parts of Micromeria madagascariensis Baker and M. flagellaris Baker are used by the population of the Vakinankaratra and Itasy regions (Madagascar) to treat breathing difficulty, fever and/or headache, wounds, and sores.

Purpose

This work aimed to characterise plant materials from M. madagascariensis and M. flagellaris to report i) chemical composition, ii) antimicrobial properties, and iii) antioxidant capacity of the essential oils extracted from the aerial parts of these species.

Materials and methods

The essential oils from M. madagascariensis (MMO) and M. flagellaris (MFO) were obtained by hydrodistillation. Their chemical composition was quantified using gas chromatography coupled with mass spectrometry (GC-MS). MMO and MFO were also tested against 7 microbial strains using the disk diffusion method and their antioxidant capacity was assessed using the DPPH scavenging assay.

Results

Hydrodistillation yielded 0.26% MMO and 0.29% MFO (w/w) in relation to the fresh weight. Twenty-seven compounds were identified by GC-MS in MMO extract against 36 in MFO one. The main compounds in MMO were pulegone (24.67%), trans-menthone (24.67%), eucalyptol (8.12%), β-caryophyllene (4.98%), α-guanene (4.47), iso-menthone (3.85%), iso-pulegone (3.34%), azulene (3.28%) and 2-isopropyl-5-methylcyclohexenone (2.82%). The main compounds in the MFO were eudesma-4,11-dien-2-ol (13.88%), δ-guanene (6.62%), pulegone (6.40%), cyperone (5.56%), 4-epi-dehydrobietinol acetate (5.39%), eucalyptol (5.12%), trans-menthone (4.67%), limonene (3.77%) and sabinene (2.29%). Regarding the chemotaxonomy, M. flagellaris was very different from M. madagascariensis and both species also differed from the other Micromeria species, as confirmed by multivariate statistical analysis. Both MMO and MFO exerted activities against a large microbial spectrum; the antimicrobial activity of MMO was higher than MFO one against S. pneumoniae and C. albicans due to the presence of pulegone as the main component. MFO showed an excellent scavenging capacity with an SC50 value of 2.17 ± 0.03 μg/mL.

Conclusion

The biological properties of the essential oils extracted from the selected species may explain their therapeutic value showing that Malagasy Micromeria species may be very important as new natural sources of bioactive compounds. This study may promote the effectiveness and quality of Malagasy Micromeria species, contributing to sustainable development and commercial valorisation of traditional preparations based on natural local resources.

Leaves micromorphology, chemical profile, and bioactivity of in vitro-propagated Nepeta cyrenaica (Lamiaceae)

INTRODUCTION

The endemic species Nepeta cyrenaica Quézel & Zaffran, native to northeastern Libya, is valued as an important honey-bearing plant.

OBJECTIVES

This study was aimed to examine the micromorphology, phytochemistry, and bioactivity of in vitro-propagated N. cyrenaica for the first time.

MATERIALS AND METHODS

The leaf indumentum was examined using light and scanning electron microscopy and further characterised for histochemistry. The chemical composition of essential oil (EO) was performed using GC-MS analysis, while dichloromethane (DCM), methanol (ME), ethanol (ET), and aqueous (AQ) extracts were analysed using qualitative and quantitative LC/MS analyses. The antioxidant activities of EO and extracts were assessed using three parallel assays, while enzyme-inhibiting effects were evaluated against four enzymes.

RESULTS

The leaves bear various types of glandular trichomes, with lipophilic secretion predominating. The main EO component of EO was 1,8-cineole. A considerable number of phenolics and iridoids were tentatively identified in the ME extract. Quantitative LC/MS analysis confirmed that ferulic acid, rosmarinic acid, and epigallocatechin gallate were present in the highest amount in the extracts, in which three iridoids were also quantified. Although the ME extract contained the highest amount of polyphenolics and iridoids, the DCM extract showed the best overall biological potential. Additionally, EO exerted the strongest acetylcholinesterase and tyrosinase inhibition.

CONCLUSION

This study demonstrated that the endemic N. cyrenaica can be efficiently grown under in vitro conditions, where it develops various glandular trichomes that are thought to secrete and/or accumulate bioactive compounds with valuable medicinal potential.

Screening for Chemical Characterization and Pharmacological Properties of Different Extracts from Nepeta italica

Plants from the Nepeta genus have been proved to possess different pharmacological properties, among which are antimicrobial, antioxidant, anti-inflammatory, analgesic, and cytotoxic effects. Nepeta italica is a medicinal plant traditionally used for its analgesic effects, and in the present study, the phytochemical composition and biological effects of hexane, dichloromethane (DCM), ethyl acetate (EA), ethanol, ethanol-water, and water extracts of the aerial parts were investigated for determining phenolic composition, antioxidant effects, and anti-inflammatory effects in isolated mouse colon specimens exposed to lipopolysaccharide (LPS). Polar extracts were the richest in terms of phenolic compounds, especially rosmarinic acid. In parallel, ethanol, ethanol-water, and water extracts were also the most effective as scavenging/reducing and enzyme inhibition agents, especially towards cholinesterases and α-glucosidase, and in inhibiting the LPS-induced cyclooxygenase-2 (COX-2) and tumor necrosis factor α (TNFα) gene expression in mouse colon. This poses the basis for future in vivo investigations for confirming the protective effects of polar extracts of N. italica against inflammatory bowel diseases.

Açaí (Euterpe oleracea Mart.) Seed Oil Exerts a Cytotoxic Role over Colorectal Cancer Cells: Insights of Annexin A2 Regulation and Molecular Modeling

Açaí, Euterpe oleracea Mart., is a native plant from the Amazonian and is rich in several phytochemicals with anti-tumor activities. The aim was to analyze the effects of açaí seed oil on colorectal adenocarcinoma (ADC) cells. In vitro analyses were performed on CACO-2, HCT-116, and HT-29 cell lines. The strains were treated with açaí seed oil for 24, 48, and 72 h, and cell viability, death, and morphology were analyzed. Molecular docking was performed to evaluate the interaction between the major compounds in açaí seed oil and Annexin A2. The viability assay showed the cytotoxic effect of the oil in colorectal adenocarcinoma cells. Acai seed oil induced increased apoptosis in CACO-2 and HCT-116 cells and interfered with the cell cycle. Western blotting showed an increased expression of LC3-B, suggestive of autophagy, and Annexin A2, an apoptosis regulatory protein. Molecular docking confirmed the interaction of major fatty acids with Annexin A2, suggesting a role of açaí seed oil in modulating Annexin A2 expression in these cancer cell lines. Our results suggest the anti-tumor potential of açaí seed oil in colorectal adenocarcinoma cells and contribute to the development of an active drug from a known natural product.

Cytotoxicity against A549 Human Lung Cancer Cell Line via the Mitochondrial Membrane Potential and Nuclear Condensation Effects of Nepeta paulsenii Briq., a Perennial Herb

The genus Nepeta belongs to the largest Lamiaceae family, with 300 species, which are distributed throughout the various regions of Africa, Asia, India, and America. Along with other plant families distinguished by their medicinal and therapeutic values, the Nepeta genus of Lameaceae remains relatively valuable. Hence, the phytochemicals of N. paulsenii Briq. were extracted using different plant parts, i.e., leaves, stem, roots, flowers, and the whole plant by using various solvents (ethanol, water, and ethyl acetate), obtaining 15 fractions. Each extract of dried plant material was analyzed by FT-IR and GC-MS to identify the chemical constituents. The cytotoxicity of each fraction was analyzed by MTT assay and mitochondrial membrane potential and nuclear condensation assays against lung cancer cells. Among the ethyl acetate and ethanolic extracts, the flowers showed the best results, with IC₅₀ values of 51.57 μg/mL and 50.58 μg/mL, respectively. In contrast, among the water extracts of the various plant segments, the stem showed the best results, with an IC₅₀ value of 123.80 μg/mL. 5-flourouracil was used as the standard drug, providing an IC₅₀ value of 83.62 μg/mL. The Hoechst 33342 stain results indicated apoptotic features, i.e., chromatin dissolution and broken down, fragmented, and crescent-shaped nuclei. The ethanolic extracts of the flowers showed more pronounced apoptotic effects on the cells. The mitochondrial membrane potential indicated that rhodamine 123 fluorescence signals suppressed mitochondrial potential due to the treatment with the extracts. Again, the apoptotic index of the ethanolic extract of the flowers remained the highest. Hence it can be concluded that the flower part of N. paulsenii Briq. was found to be the most active against the A459 human lung cancer cell line.

Cytotoxic Activities and Fingerprint Analysis of Triterpenes by HPTLC Technique for Distinguishing Ganoderma Species from Vietnam and other Asian Countries

Ganoderma lucidum (Fr.) P. Karst. (Ganodermataceae), commonly called Linhzhi, is traditionally employed in the treatment of human diseases, including hepatitis, liver disorders, hypercholesterolemia, arthritis, bronchitis, and tumorigenic diseases. In this study, the fingerprint profiles of five different strains of G. lucidum originated from Japan, Korea, China, and Vietnam, five samples of G. lucidum growing on Erythrophloeum fordii Oliv. in Vietnam, and five related Linhzhi species (Ganoderma applanatum, Ganoderma australe, Ganoderma clossum, Ganoderma subresinosu, and Ganoderma sp.) were investigated for triterpene derivatives using high-pressure, thin-layer chromatography (HPTLC). The HPTLC fingerprint profiles demonstrated significant differences between G. lucidum and other related Linhzhi species in the presence of triterpene derivatives. Evaluation for the cytotoxicity of these samples against four cancer cell lines, including A549, MCF7, PC3, and HepG2, displayed various levels of cytotoxic effects, with IC50 values of: 15.6-46.3 µg/mL on the A549 cancer cell line, of 18.4-43.6 µg/mL on the MCF7 cancer cell line, of 10.0-32.1 µg/mL on the PC3 cancer cell line, and of 10.6-27.6 µg/mL on the HepG2 cancer cell line. Conclusively, these data contributed to the literature on the cytotoxic activities and fingerprint analysis of triterpenes by the HPTLC technique for distinguishing Ganoderma species from Vietnam and other Asian countries.

Why Did I Consult My Pharmacist about Herbal and Dietary Supplements? An Online Survey Amid the COVID-19 Pandemic in Malaysia

Herbal and dietary supplements (HDSs) are frequently obtained from community pharmacies, but community pharmacists (CPs) have been underutilized for information regarding them. This study aimed to determine the prevalence of, factors behind, and reasons for consultation with CPs among HDS consumers in Malaysia. A cross-sectional study using an online survey was conducted among conveniently sampled individuals in Malaysia. Reasons for consultation or non-consultation with CPs about HDSs were sought from the respondents. A logistic regression analysis was conducted to determine the predictors of consultation with CPs. Overall, 40.3% (239/593) of participants consulted CPs about the HDSs that they purchased. The participants were predominantly unmarried (362/588, 61.6%) and belonged to the 18-29 age group (332/593, 56%). The multivariate analysis showed that a suburban residential setting was the only significant predictor for consultation with CPs (adjusted odds ratio = 0.390, 95% CI = 0.260-0.583). Respondents who consulted CPs generally agreed that the CPs were the right people to consult on HDSs (mean = 4.37, SD = 0.73). However, their discussion with CPs regarding HDSs mostly revolved around the benefits and directions for use, but little on the potential risks. Meanwhile, most respondents who did not consult CPs agreed that they had never thought of consulting CPs about their HDS use (mean = 3.45, SD = 1.02). The majority of them referred to the Internet (61.3%, 217/354) and social media (59.9%, 212/354) for information about HDSs. The findings from this study show that more efforts are warranted in encouraging consumers to consult CPs about their HDS use and to enhance their awareness of the roles of CPs in ensuring the safe use of HDSs.

Natural Antioxidants as Additional Weapons in the Fight against Malarial Parasite

BACKGROUND

All currently available antimalarial drugs are developed from natural product lineages that may be traced back to herbal medicines, including quinine, lapachol, and artemisinin. Natural products that primarily target free radicals or reactive oxygen species, play an important role in treating malaria.

OBJECTIVES

This review analyses the role of antioxidative therapy in treating malaria by scavenging or countering free radicals and reviews the importance of natural plant extracts as antioxidants in oxidative therapy of malaria treatment.

METHODS

The search for natural antioxidants was conducted using the following databases: ResearchGate, ScienceDirect, Google Scholar, and Bentham Science with the keywords malaria, reactive oxygen species, natural antioxidants, and antiplasmodial.

CONCLUSION

This study reviewed various literature sources related to natural products employed in antimalarial therapy directly or indirectly by countering/scavenging reactive oxygen species published between 2016 till date. The literature survey made it possible to summarize the natural products used in treating malaria, emphasizing botanical extracts as a single component and in association with other botanical extracts. Natural antioxidants like polyphenols, flavonoids, and alkaloids, have a broad range of biological effects against malaria. This review is pivoted around natural antioxidants obtained from food and medicinal plants and explores their application in restraining reactive oxygen species (ROS). We anticipate this article will provide information for future research on the role of antioxidant therapy in malaria infection.

Seven Compounds from Turmeric Essential Oil Inhibit Three Key Proteins Involved in SARS-CoV-2 Cell Entry and Replication in silico

Introduction: Turmeric rhizome (Cucurma longa L.) has showed great potential as a traditional drug in folk medicine of several countries. In light of the prominent use of turmeric rhizome in treating both respiratory and viral diseases, we aimed to dock major compounds from the essential oil of turmeric against three key proteins involved in COVID-19 cell entry and replication. Methods: The essential oil of turmeric rhizome was obtained using a hydrodistillation technique, and the chemical characterization of the oil was investigated using GC-MS/GC-FID. Then, main compounds were docked with the key proteins of COVID-19. Results: A total of 26 components were identified in the essential oil extracted from the rhizomes via GC-MS/GC-FID. Seven dominant compounds (turmerone (31.4%), ar-turmerone (16.1%), turmerol (14.6%), terpinolene (11.0%), [Formula: see text]-zingiberene (5.2%), [Formula: see text]-sesquiphellandrene (4.8%), and [Formula: see text]-caryophyllene (3.5%)) were docked against COVID-19 main protease, papain-like protease (PLpro), spike protein and 3C-like protease (3CLpro), and the best inhibitor was picked according to the calculated binding affinity and non-bonding interactions with the protein active site. [Formula: see text]-sesquiphellandrene and [Formula: see text]-zingiberene showed highest besides the same binding affinity towards COVID-19 virus ([Formula: see text] and [Formula: see text][Formula: see text]kcal/mol, respectively). [Formula: see text]-zingiberene was found to bind at the active site of the COVID-19 protein and interacted with different non-bonding interactions, while turmerol showed the highest affinity ([Formula: see text][Formula: see text]kcal/mol) against CLpro enzyme by binding with Met165, Leu141, Met49, Ser144, Cys145, and Glu166 residues. Conclusion: The essential oil of turmeric harbors a blend of potentially bioactive compounds that may be considered as a good target against COVID-19 virus and warrants further experimental studies.