Antitubercular constituents from Premna odorata Blanco

Four diterpenes identified in silico were isolated from Hyptidinae and demonstrated in vitro activity against Mycobacterium tuberculosis

Plants of Hyptidinae subtribe (Lamiaceae - family), as Mesosphaerum sidifolium, are a source of bioactive molecules. In the search for new drug candidates, we perform chemical characterization of diterpenes isolated from the aerial parts of M. sidifolium was carried out with uni- and bidimensional NMR spectral data, and evaluate in silico through the construction of a predictive model followed by in vitro testing Mycobacterium tuberculosis and Mycobacterium smegmatis. Resulted in the isolation of four components: Pomiferin D (1), Salviol (2), Pomiferin E (3) and 2α-hydroxysugiol (4), as well as two phenolic compounds, rosmarinic and caffeic acids. In silico model identified 48 diterpenes likely to have biological activity against M. tuberculosis. The diterpenes isolated were tested in vitro against M. tuberculosis demonstrating MIC = 125 µM for 4 and 1, while 2 and 3 -MIC = 250 µM. These compounds did not show biological activity at these concentrations for M. smegmatis.

Antimicrobial Secondary Metabolites from the Mangrove Plants of Asia and the Pacific

Microbes such as the White Spot Syndrome Virus account for severe losses in the shrimp farming industry globally. This review examines the literature on the mangrove plants of Asia and the Pacific with antibacterial, antifungal, or antiviral activities. All of the available data published on this subject were collected from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and a library search from 1968 to 2022. Out of about 286 plant species, 119 exhibited antimicrobial effects, and a total of 114 antimicrobial natural products have been identified including 12 with MIC values below 1 µg/mL. Most of these plants are medicinal. The mangrove plants of Asia and the Pacific yield secondary metabolites with the potential to mitigate infectious diseases in shrimp aquaculture.

Diosmetin inhibits apoptosis and activates AMPK-induced autophagy in myocardial damage under hypoxia environment

Inhibition of hypoxia-induced cardiomyocyte apoptosis is considered as an important treatment method for ischemic heart diseases, but related drugs are still insufficient. The present study aims to explore the protective function and mechanism of the key Chinese medicine monomer diosmetin (DIOS) on the injury of cardiomyocytes induced by hypoxia. Here, AC16 and HCM-a cells were treated with 40 μM of DIOS under hypoxic environment and a hypoxic rat model was built to study the role of DIOS. The viability and autophagy of cardiomyocytes were increased, but the apoptosis of cells was suppressed by 40 μM DIOS, under hypoxic environment. Intriguingly, 10 mM 3-methyladenine, an inhibitor of autophagy, reversed the effect of DIOS on autophagy and apoptosis of the cardiomyocytes under hypoxia. Furthermore, DIOS induced AMP-activated protein kinase (AMPK) activation and Compound C (5 μM), an AMPK inhibitor, attenuated the inhibition of DIOS on the apoptosis of cardiomyocytes under hypoxia environment. In isoprenaline-induced hypoxic rats, it was verified that DIOS inhibited apoptosis, accelerated autophagy, and activated AMPKα pathway in vivo. Our findings indicated that DIOS alleviated hypoxia-induced myocardial apoptosis via inducing the activation of AMPK-induced autophagy. In summary, the study suggested that DIOS inhibited the apoptosis and induced the autophagy of hypoxia-induced cardiomyocytes through AMPK activation.

Traditional Medicinal Plants as a Source of Antituberculosis Drugs: A System Review

Medicinal plants are the chief components in the different oriental formulations in different traditional medical systems worldwide. As a thriving source of medicine, the medicinal plants with antituberculosis (TB) properties inspire the pharmacists to develop new drugs based on their active components or semimetabolites. In the present review, the anti-TB medicinal plants were screened from the scientific literatures, based on the botanical classification and the anti-TB activity. The obtained anti-TB medicinal plants were categorized into three different categories, viz., 159 plants critically examined with a total 335 isolated compounds, 131 plants with their crude extracts showing anti-TB activity, and 27 plants in literature with the prescribed formula by the traditional healers. Our systemic analysis on the medicinal plants can assist the discovery of novel and more efficacious anti-TB drugs.

Morphology, Anatomy and Secondary Metabolites Investigations of Premna odorata Blanco and Evaluation of Its Anti-Tuberculosis Activity Using In Vitro and In Silico Studies

In-depth botanical characterization was performed on Premna odorata Blanco (Lamiaceae) different organs for the first time. The leaves are opposite, hairy and green in color. Flowers possess fragrant aromatic odors and exist in inflorescences of 4-15 cm long corymbose cyme-type. In-depth morphological and anatomical characterization revealed the great resemblance to plants of the genus Premna and of the family Lamiaceae, such as the presence of glandular peltate trichomes and diacytic stomata. Additionally, most examined organs are characterized by non-glandular multicellular covering trichomes, acicular, and rhombic calcium oxalate crystals. P. odorata leaves n-hexane fraction revealed substantial anti-tuberculous potential versus Mycobacterium tuberculosis, showing a minimum inhibition concentration (MIC) of 100 μg/mL. Metabolic profiling of the n-hexane fraction using gas-chromatography coupled to mass spectrometry (GC/MS) analysis revealed 10 major compounds accounting for 93.01%, with trans-phytol constituting the major compound (24.06%). The virtual screening revealed that trans-phytol highly inhibited MTB C171Q receptor as M. tuberculosis KasA (β-ketoacyl synthases) with a high fitting score (∆G = -15.57 kcal/mol) approaching that of isoniazid and exceeding that of thiolactomycin, the co-crystallized ligand. Absorption, distribution, metabolism, excretion and toxicity predictions (ADME/TOPKAT) revealed that trans-phytol shows lower solubility and absorption levels when compared to thiolactomycin and isoniazid. Still, it is safer, causing no mutagenic or carcinogenic effects with higher lethal dose, which causes the death of 50% (LD50). Thus, it can be concluded that P. odorata can act as a source of lead entities to treat tuberculosis.

Antibacterial Components of Levisticum officinale Koch against Multidrug-resistant Mycobacterium tuberculosis

Background: A bioassay-guided fractionation technique was used to evaluate the active constituents of the perennial plant L. officinale W.D.J. Koch (Apiaceae) against multidrug resistant (MDR) Mycobacterium tuberculosis. Methods: Column chromatography was used to isolation of compounds from L. officinale and spectroscopic methods including 1D and 2D NMR (Nuclear magnetic resonance) and HRMS (high resolution mass spectrometry) were used to identification of the isolated compounds. Also, to evaluate antibacterial activity, minimum inhibitory concentration (MIC) was carried out by broth micro-dilution method. Finally, molecular docking (MD) was performed using the Schrödinger package to evaluate interactions between the active compounds and InhA protein. Results: Phytochemical analysis of the ethyl acetate extract of the plant roots led to isolation of bergapten (1), isogosferol (2), oxypeucedanin (3), oxypeucedanin hydrate (4), imperatorin (5), ferulic acid (6) and falcarindiol (7). Falcarindiol and oxypeucedanin indicated a moderate activity on MDR M. tuberculosis with MIC values of = 32 and 64 μg/mL, respectively. Antibacterial activity of falcarindiol was also observed against S. aureus and methicillin-resistant S. aureus strains with the MIC values of 7.8 and 15.6 μg/mL, respectively. The results of docking analysis showed a good affinity of oxypeucedanin (3) and falcarindiol (7) to InhA enzyme with docking score values of -7.764 and -7.703 kcal/mol, respectively. Conclusion: Finally, 7 compounds were isolated from L. officinale that compounds 2-6 report for the first time from this plant. On the basis of the molecular docking (MD) study, oxypeucedanin (3) and falcarindiol (7) as active compounds against M. tuberculosis may be proposed as potential inhibitors of 2-trans-enoyl-ACP reductase (InhA), a key enzyme involved in the biosynthesis of the mycobacterial cell wall. Moreover, antibacterial activity of falcarindiol against methicillin-resistant S. aureus (MRSA) was remarkable.

A review of medicinal plant of Middle East and North Africa (MENA) region as source in tuberculosis drug discovery

Tuberculosis (TB) is a disease that affects one-third of the world's population. Although currently available TB drugs have many side effects, such as nausea, headache and gastrointestinal discomfort, no new anti-TB drugs have been produced in the past 30 years. Therefore, the discovery of a new anti-TB agent with minimal or no side effects is urgently needed. Many previous works have reported the effects of medicinal plants against Mycobacterium tuberculosis (MTB). However, none have focused on medicinal plants from the Middle Eastern and North African (MENA) region. This review highlights the effects of medicinal plants from the MENA region on TB. Medicinal plants from the MENA region have been successfully used as traditional medicine and first aid against TB related problems. A total of 184 plants species representing 73 families were studied. Amongst these species, 93 species contained more active compounds with strong anti-MTB activity (crude extracts and/or bioactive compounds with activities of 0-100 µg/ml). The extract of Inula helenium, Khaya senegalensis, Premna odorata and Rosmarinus officinalis presented the strongest anti-MTB activity. In addition, Boswellia papyrifera (Del) Hochst olibanum, Eucalyptus camaldulensis Dehnh leaves (river red gum), Nigella sativa (black cumin) seeds and genus Cymbopogon exhibited anti-TB activity. The most potent bioactive compounds included alantolactone, octyl acetate, 1,8-cineole, thymoquinone, piperitone, α- verbenol, citral b and α-pinene. These compounds affect the permeability of microbial plasma membranes, thus kill the mycobacterium spp. As a conclusion, plant species collected from the MENA region are potential sources of novel drugs against TB.

Hassan H. Anti-Inflammatory and Antioxidant Activities of Terpene- and Polyphenol-Rich Premna odorata Leaves on Alcohol-Inflamed Female Wistar Albino Rat Liver

Premna odorata Blanco (Lamiaceae) is an ethnomedicinal plant native to different tropical regions. Although some reports addressed their anti-inflammatory, cytotoxic, and antituberculotic effects, their hepatoprotective potential is yet to be discovered. Accordingly, this study investigated the crude extract and different fractions of the plant leaves; metabolic profiling using liquid chromatography/high-resolution electrospray ionization mass spectroscopy (LC–HRESIMS) analysis, in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties for the dereplicated metabolite via online PreADMET program, ROS scavenger activity on the Hep G2 human liver cancer cell line, and the possible hepatic cellular treatment effects in alcohol-inflamed liver female Wistar albino rats. Metabolic profiling dereplicated a total of 28 metabolites from the crude extract and its various fractions. In silico ADMET and ROS scavenger activity screening suggested plant metabolites are of potential bioactivity. In vivo hepatic treatment with crude, defatted crude, and n-hexane leave extracts suggested all extracts significantly improved liver damage, which was indicated by the reduction of elevated serum levels of bilirubin, AST, ALT, ALP, CRP, TNF-α, ICAM-1, VCAM-1, and MDA. The reduced levels of GSH and TAC were normalized during the study. Histological examinations of liver tissue showed collagen fiber distribution nearly back to its normal pattern. The anti-inflammatory and antioxidant potentials of Premna odorata extracts could be partly related to the combined effects of these phytochemicals or their synergistic interactions.

Metabolomic Profiling and Cytotoxic Tetrahydrofurofuran Lignans Investigations from Premna odorata Blanco

Metabolomic profiling of different Premna odorata Blanco (Lamiaceae) organs, bark, wood, young stems, flowers, and fruits dereplicated 20, 20, 10, 20, and 20 compounds, respectively, using LC-HRESIMS. The identified metabolites (1-34) belonged to different chemical classes, including iridoids, flavones, phenyl ethanoids, and lignans. A phytochemical investigation of P. odorata bark afforded one new tetrahydrofurofuran lignan, 4β-hydroxyasarinin 35, along with fourteen known compounds. The structure of the new compound was confirmed using extensive 1D and 2D NMR, and HRESIMS analyses. A cytotoxic investigation of compounds 35-38 against the HL-60, HT-29, and MCF-7 cancer cell lines, using the MTT assay showed that compound 35 had cytotoxic effects against HL-60 and MCF-7 with IC50 values of 2.7 and 4.2 µg/mL, respectively. A pharmacophore map of compounds 35 showed two hydrogen bond acceptor (HBA) aligning the phenoxy oxygen atoms of benzodioxole moieties, two aromatic ring features vectored on the two phenyl rings, one hydrogen bond donor (HBD) feature aligning the central hydroxyl group and thirteen exclusion spheres which limit the boundaries of sterically inaccessible regions of the target's active site.

Antimicrobial activity of nanoemulsion on drug-resistant bacterial pathogens

The appearance of drug-resistant (DR) bacteria in the community is a crucial development, and is associated with increased morbidity, mortality, healthcare costs, and antibiotic use. Natural oil nanoemulsions (NEs) have potential for antimicrobial applications. In the present study, we determined the antimicrobial activity of an NE against DR bacterial pathogens in vitro. The NE comprised Cleome viscosa essential oil, Tween 80 nonionic surfactant, and water. We found that an NE with a droplet size of 7 nm and an oil:surfactant (v/v) ratio of 1:3 was effective against methicillin-resistant Staphylococcus aureus (MRSA), DR Streptococcus pyogenes, and DR extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Fourier-transform infrared (FTIR) spectroscopy revealed that NE treatment modified the functional groups of lipids, proteins, and nucleic acids in DR bacterial cells. Scanning electron microscopy (SEM) showed damage to the cell membranes and walls of NE-treated DR bacteria. These alterations were caused by bioactive compounds with wide-spectrum enzyme-inhibiting activity in the NE, such as β-sitosterol, demecolcine, campesterol, and heneicosyl formate. The results suggest that the nanoemulsion is effective against DR bacteria, and acts by inhibiting the drug efflux mechanism of DR strains.

Isolation, identification and bioactivities of abietane diterpenoids from Premna szemaoensis

Investigation of the leaves and stems of Premna szemaoensis resulted in the isolation of twelve new abietane diterpenoids, szemaoenoids A–L (1–12), together with four known abietane diterpenoids (13–16). The structures involved two rearranged-abietane skeletons: 17(15 → 16)-abeo-abietane (7, 10–12, 14 and 15) and 17(15 → 16),18(4 → 3)-diabeo-abietane (1–6, 13 and 16). The structures of the new compounds were established mainly by analyzing NMR and HRESIMS data. The absolute configurations of 1, 3 and 10 were confirmed by single crystal X-ray diffraction analysis. In bioactivity assays, compounds 11, 12, 14 and 15 were active against two human colon cancer cell lines (HCT-116 and HT-29) with IC₅₀ values ranging from 8.8 to 34.3 μM, and compounds 10, 13 and 14 exhibited effective free radical scavenging activity with IC₅₀ values ranging from 35.6 to 41.5 μM by DPPH experiment.

Active abietane diterpenoids with two rearranged-abietane skeletons: 17(15 → 16)-abeo-abietane and 17(15 → 16),18(4 → 3)-diabeo-abietane were isolated from Premna szemaoensis.

Ethnomedicinal uses, phytochemistry and pharmacological aspects of the genus Premna: a review

CONTEXT

The genus Premna (Lamiaceae), distributed throughout tropical and subtropical Asia, Africa, Australia and the Pacific Islands, is used in folk medicine primarily to treat inflammation, immune-related diseases, stomach disorders, wound healing, and skin diseases.

OBJECTIVES

This review exhaustively gathers available information on ethnopharmacological uses, phytochemistry, and bioactivity studies on more than 20 species of Premna and critically analyzes the reports to provide the perspectives and directions for future research for the plants as potential source of drug leads and pharmaceutical agents.

METHODS

A literature search was performed on Premna species based on books of herbal medicine, major scientific databases including Chemical Abstract, Pubmed, SciFinder, Springerlink, Science Direct, Scopus, the Web of Science, Google Scholar, and ethnobotanical databases.

RESULTS

More than 250 compounds have been isolated and identified from Premna species, comprising of diterpenoids, iridoid glycosides, and flavonoids as the most common secondary metabolites, followed by sesquiterpenes, lignans, phenylethanoids, megastigmanes, glyceroglycolipids, and ceramides. Many in vitro and in vivo studies have been conducted to evaluate the biological and pharmacological properties of the extracts, and isolated compounds of Premna species with antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antihyperglycaemia, and cytotoxic activities.

CONCLUSION

The bioactive compounds responsible for the bioactivities of most plants have not been well identified as the reported in vivo pharmacological studies were mostly carried out on the crude extracts. The isolated bioactive components should also be further subjected to more preclinical studies and elaborate toxicity study before clinical trials can be pursued.

Acylated Iridoids and Rhamnopyranoses from Premna odorata (Lamiaceae) as Novel Mesenchymal-Epithelial Transition Factor Receptor Inhibitors for the Control of Breast Cancer

Phytochemical investigation of Premna odorata Blanco, Lamiaceae, leaves afforded three new acylated iridoid glycosides 1-3 and two new acylated rhamnopyranoses 9 and 10, in addition to ten known compounds. The structures of the new compounds were confirmed using extensive 1D and 2D NMR analysis. Molecular modeling study suggested the potential of the acylated rhamnopyranoses to bind at the c-Met kinase domain. Cell-free Z'-LYTE™ assay testing revealed the good c-Met phosphorylation inhibitory activity of 9, followed by 8, and 10, with IC₅₀ values of 2.5, 6.9, and 12.7 μM, respectively. The (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assay testing against the human c-Met expressing highly invasive MDA-MB-231 suggested compound 9 as the most active with IC₅₀ value of 13.3 μM. Testing of compound 9 against multiple phenotypic breast cancer cell lines including MCF-7, BT-474 cells, and MDA-MB-468 proved enhanced activity against the highly c-Met expressing triple-negative breast cancer cell lines. Acylated rhamnopyranoses are potential novel c-Met inhibitors appropriate for future optimizations to control c-Met-dependent breast malignancies. Copyright © 2017 John Wiley & Sons, Ltd.

Southeast Asian Medicinal Plants as a Potential Source of Antituberculosis Agent

Despite all of the control strategies, tuberculosis (TB) is still a major cause of death globally and one-third of the world's population is infected with TB. The drugs used for TB treatment have drawbacks of causing adverse side effects and emergence of resistance strains. Plant-derived medicines have since been used in traditional medical system for the treatment of numerous ailments worldwide. There were nine major review publications on antimycobacteria from plants in the last 17 years. However, none is focused on Southeast Asian medicinal plants. Hence, this review is aimed at highlighting the medicinal plants of Southeast Asian origin evaluated for anti-TB. This review is based on literatures published in various electronic database. A total of 132 plants species representing 45 families and 107 genera were reviewed; 27 species representing 20.5% exhibited most significant in vitro anti-TB activity (crude extracts and/or bioactive compounds 0–<10 µg/ml). The findings may motivate various scientists to undertake the project that may result in the development of crude extract that will be consumed as complementary or alternative TB drug or as potential bioactive compounds for the development of novel anti-TB drug.

Tuberculosis and nature's pharmacy of putative anti-tuberculosis agents

Due to the growing problem of drug resistant Mycobacterium tuberculosis strains, coupled with the twinning of tuberculosis (TB) to human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), the burden of TB is now difficult to manage. Therefore, new antimycobacterial agents are being sought from natural sources. This review focuses on natural antimycobacterial agents from endophytes and medicinal plants of Africa, Europe, Asia, South America and Canada. In the countries mentioned in this review, numerous plant species display putative anti-TB activity. Several antimycobacterial chemical compounds have also been isolated, including: ellagitannin punicalagin, allicin, anthraquinone glycosides, iridoids, phenylpropanoids, beta-sitosterol, galanthimine, crinine, friedelin, gallic acid, ellagic acids, anthocyanidin, taraxerol, termilignan B, arjunic acid, glucopyranosides, 1-epicatechol, leucopelargonidol, hydroxybenzoic acids, benzophenanthridine alkaloids, neolignans, and decarine. These compounds may provide leads to novel and more efficacious drugs to lessen the global burden of TB and drug-resistant M. tuberculosis strains. If there is a long-term remedy for TB, it must lie in nature's pharmacy of putative antimycobacterial agents.

Anti-Vancomycin-resistant Enterococcus faecium and E. faecalis Activities of (-)-Gossypol and Derivatives from Thespesia garckeana

The root extract of Thespesia garckeana yielded three known oxidatively coupled sesquiterpenoids, namely (-)-gossypol (1) and two of its derivatives (-)-6-methoxygossypol (2) and (+)-6,6′-dimethoxygossypol (3), and the stem bark afforded ( E)-docosyl-3-(3,4-dihydroxyphenyl) acrylate (4), stigmasterol (5) and betulinic acid (6). The structures of the isolated compounds were determined on the basis of full spectral data (1D and 2D NMR and HRMS) and comparison with literature values. Compound 1 showed potent antibacterial activity against vancomycin-resistant Enterococcus faecium (VRE) with IC50/MIC/MBC values of 1.71/4.82/19.31 μM, respectively, whereas the reference standard vancomycin was found to be inactive. The mono- and di-methoxylated derivatives of this compound, (-)-6-methoxygossypol (2) and (+)-6,6′-dimethoxygossypol (3), were less active with respective IC50/MIC/MBC values of 2.73/4.70/9.40 μM and 6.14/18.32/18.32 μM against this microbe. Compound 2 was more potent than 1 against the low level VRE strain with IC50/MIC/MBC values of 4.34/9.40/9.40 μM ( vs 5.23/19.31/19.31μM for 1). This compound also showed interesting activities against Candida glabrata with an IC50 value of 2.97 μM, but was less active against methicillin-resistant S. aureus (MRSA) exhibiting an IC50 value of 17.33 μM. Compound 1 demonstrated modest activity against the other microbes tested including C. glabrata, S. aureus and MRSA with IC50 values of 0.73, 9.15 and 8.99 μM, respectively.