The value of natural products to future pharmaceutical discovery

Synthesis and Biological Activity of Tetracyclic Dispiro Core Derivatives of Natural Products Dispirocochlearoids A-C

Natural products dispirocochlearoids A-C, which are meroterpenoids derived from Ganoderma fungi, feature a 6/6/5/6/6/6 ring system and exhibit selective COX-2 inhibitory activity. Herein, the concise total synthesis of the tetracyclic core structure of dispirocochlearoids A-C was achieved through an aldol reaction/cyclization/deprotection/cyclization cascade sequence. A series of simplified tetracyclic analogues was successfully constructed and their anti-inflammatory activity was further explored, with several tetracyclic analogues (such as compound 8ab) exhibiting strong inhibitory activity against IL-1β expression in lipopolysaccharide-stimulated bone marrow-derived macrophage cells (IC50 = 2.8 μM).

Design strategy and preliminary antiproliferative investigation of a modified lignan skeleton derived from aryne and statin

The biological activities of natural products (NPs) provided precious resources for the development of new drugs. Numerous studies have shown that statins exhibit cytotoxic potential, which is now an extensive focus of investigation. Herein, a remarkably efficient method for modification of statins using hexadehydro-Diels-Alder (HDDA) arynes has been described. Notably, lactone, as the biologically active group of statins, was removed during the reaction and a novel modified lignan skeleton was generated via the Alder-ene process. Unexpectedly, these statin-derived novel chemical scaffolds exhibited moderate inhibition effects on the proliferation of cancer cells as determined by CCK-8 assays, and the IC50 values were in the micromolar range.

Synthesis of a collection of nootkatone analogues with diverse skeletons

A collection of ring distorted analogue of Nootkatone including 6 CTD (Complex to Diversity) compounds and 9 SAR (Structure Activity Relationship) compounds were synthesized utilizing the carbonyl group as a starting reaction point.

Cheminformatics-based analysis identified (Z)-2-(2,5-dimethoxy benzylidene)-6-(2-(4-methoxyphenyl)-2-oxoethoxy) benzofuran-3(2H)-one as an inhibitor of Marburg replication by interacting with NP

The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family, a non-segmented negative-strand RNA virus. This article represents the computer-aided drug design (CADD) approach for identifying drug-like compounds that prevent the MARV virus disease by inhibiting nucleoprotein, which is responsible for their replication. This study used a wide range of in silico drug design techniques to identify potential drugs. Out of 368 natural compounds, 202 compounds passed ADMET, and molecular docking identified the top two molecules (CID: 1804018 and 5280520) with a high binding affinity of -6.77 and -6.672 kcal/mol, respectively. Both compounds showed interactions with the common amino acid residues SER_216, ARG_215, TYR_135, CYS_195, and ILE_108, which indicates that lead compounds and control ligands interact in the common active site/catalytic site of the protein. The negative binding free energies of CID: 1804018 and 5280520 were -66.01 and -31.29 kcal/mol, respectively. Two lead compounds were re-evaluated using MD modeling techniques, which confirmed CID: 1804018 as the most stable when complexed with the target protein. PC3 of the (Z)-2-(2,5-dimethoxybenzylidene)-6-(2-(4-methoxyphenyl)-2-oxoethoxy) benzofuran-3(2H)-one (CID: 1804018) was 8.74 %, whereas PC3 of the 2'-Hydroxydaidzein (CID: 5280520) was 11.25 %. In this study, (Z)-2-(2,5-dimethoxybenzylidene)-6-(2-(4-methoxyphenyl)-2-oxoethoxy) benzofuran-3(2H)-one (CID: 1804018) unveiled the significant stability of the proteins' binding site in ADMET, Molecular docking, MM-GBSA and MD simulation analysis studies, which also showed a high negative binding free energy value, confirming as the best drug candidate which is found in Angelica archangelica which may potentially inhibit the replication of MARV nucleoprotein.

Chromatographic fingerprinting of epiphytic fungal strains isolated from Withania somnifera and biological evaluation of isolated okaramine H

Medicinal plants are "goldmines" of natural products, and continue to provide key scaffolds for drug development. They have immense therapeutic potential, encapsulating a plethora of metabolites within them, which have yet to be explored. Withania somnifera (L.) Dunal is one such medicinal plant known since time immemorial for its therapeutic activity in the Ayurveda system of medicine. Studies have revealed Nature's marvel of these medicinal plants harbouring endophytic and epiphytic microorganisms from phyllosphere to rhizosphere. Chromatographic fingerprinting was carried out using HPTLC and HPLC on five epiphytic strains isolated from the leaves, stem and fruits of Withania somnifera. Out of five filamentous fungi, one fungus identified as Aspergillus aculeatus S20 was well explored. An indole alkaloid, okaramine H, was isolated using systematic chromatographic investigation at a retention time of 26.278 min showing λmax at 206, 236, 284 and 370 nm. Confirmation was achieved using NMR and mass spectrometry (MS) as analytical techniques. Structure elucidation was done by studying the fragmentation pattern using MS/MS and an accurate mass was determined using HR-ESI-QTOF-MS showing m/z of 521.2546 [M + H]+. The percentage purity of isolated okaramine H was found to be >90. Well known for its insecticidal activity, okaramine H was explored for its antileishmanial activity against the Leishmania donovani parasite for the first time. Under in vitro conditions, the compound showed an inhibitory effect on Leishmania donovani promastigotes with an IC50 of 147 μg mL-1.

Isolation and comparative genotoxicity screening of trichokonins VI and VIII on CHO-K1 cells

Peptaibols are fungal peptides that exhibit efficacy against pathogen microorganisms. Trichokonin VI (TK-VI) and trichokonin VIII (TK-VIII) are known peptaibols isolated from the endolichenic fungi Hypocrea sp. Previous investigations reported that trichokonin VI presents antiproliferative effects on tumor cells. This study is pioneering in elucidating the genotoxic effects of TK-VI and TK-VIII, contributing to the thorough assessment of their safety as potential therapeutic agents. The present investigation aimed to evaluate the genotoxicity of TK-VI and TK-VIII on CHO-K1 cells. Cytotoxicity was evaluated using the XTT assay and clonogenic survival assays, followed by evaluation of DNA damage using the comet assay and micronucleus test conducted in vitro. The XTT assay results indicated IC50 values of 10.30 µM and 9.89 µM for TK-VI and TK-VIII, respectively. The clonogenic survival assay indicated that concentrations of 10 µM or higher completely inhibited the cell colony formation. In the comet assay, both TK-VI and TK-VIII increased the DNA damage score and the frequency of comet nuclei in all tested concentrations. In the micronucleus assay, TK-VI and TK-VIII at 10 µM increased the frequency of MN in CHO-K1 cells. Both TK-VI and TK-VIII exhibited genotoxic effects. Our findings underscore the importance of considering the genotoxicological safety of peptaibols, particularly when assessing their potential for other biological activities.

Cucurbitacin B Inhibits the Proliferation of WPMY-1 Cells and HPRF Cells via the p53/MDM2 Axis

Modern research has shown that Cucurbitacin B (Cu B) possesses various biological activities such as liver protection, anti-inflammatory, and anti-tumor effects. However, the majority of research has primarily concentrated on its hepatoprotective effects, with limited attention devoted to exploring its potential impact on the prostate. Our research indicates that Cu B effectively inhibits the proliferation of human prostate stromal cells (WPMY-1) and fibroblasts (HPRF), while triggering apoptosis in prostate cells. When treated with 100 nM Cu B, the apoptosis rates of WPMY-1 and HPRF cells reached 51.73 ± 5.38% and 26.83 ± 0.40%, respectively. In addition, the cell cycle assay showed that Cu B had a G2/M phase cycle arrest effect on WPMY-1 cells. Based on RNA-sequencing analysis, Cu B might inhibit prostate cell proliferation via the p53 signaling pathway. Subsequently, the related gene and protein expression levels were measured using quantitative real-time PCR (RT-qPCR), immunocytochemistry (ICC), and enzyme-linked immunosorbent assays (ELISA). Our results mirrored the regulation of tumor protein p53 (TP53), mouse double minute-2 (MDM2), cyclin D1 (CCND1), and thrombospondin 1 (THBS1) in Cu B-induced prostate cell apoptosis. Altogether, Cu B may inhibit prostate cell proliferation and correlate to the modulation of the p53/MDM2 signaling cascade.

Incarvine C and its analogues inhibit the formation of cell cytoskeleton by targeting Rac1

Ras-related C3 botulinum toxin substrate 1 (Rac1) has emerged as a key regulator in the treatment of cancer metastasis because of its involvement in the formation of cell plate pseudopods and effects on cell migration. In this study, we found that incarvine C, a natural product isolated from Incarvillea sinensis, and its seven analogues exhibited antitumour activity by inhibiting cell cytoskeleton formation, with moderate cytotoxicity. Accordingly, these compounds inhibited the cytoskeleton-mediated migration and invasion of MDA-MB-231 cells, with inhibition rates ranging from 37.30 % to 69.72 % and 51.27 % to 70.90 % in vitro, respectively. Moreover, they induced G2/M phase cell cycle arrest in MDA-MB-231 cells. A pull-down assay revealed that the interaction between Rac1 and its downstream effector protein PAK1 was inhibited by these compounds and that the compound Ano-6 exhibited substantial activity, with an inhibition rate of more than 90 %. Molecular docking showed that incarvine C and its analogues could bind to the nucleotide-binding pocket of Rac1, maintaining high levels of inactivated Rac1. As Ano-6 exhibited significant activity in vitro, its anti-cancer activity was tested in vivo. Four weeks of oral treatment with Ano-6 was well-tolerated in mice, and it induced a potential anti-tumour response in xenografts of MDA-MB-231 cells. Further studies demonstrated that Ano-6 was enriched in tumour tissues after 2 h of administration and induced an increase in the number of dead tumour cells. In summary, these findings not only reveal the mechanism of incarvine C but also provide a new molecular template for Rac1 inhibitors and identify a promising candidate for breast cancer treatment.

Ethnobotanical insights on the management of plant pests and diseases by smallholder farmers in Mpumalanga Province of South Africa

BACKGROUND

Pests and diseases are a major contributor to yield losses in sub-Saharan Africa, prompting smallholder farmers to seek cost-effective, accessible and ecologically friendly alternatives for crop protection. This study explored the management of pests and diseases affecting crops across eight selected villages in Ehlanzeni District, Mpumalanga Province, South Africa.

METHODS

A total of 120 smallholder farmers were purposefully selected utilising the snowball technique. Information on the management of plant pests and diseases was collected through interviews and focus group discussions using semi-structured interview schedules. Ethnobotanical indices, including relative frequency of citation (RFC), use-value (UV) and informant consensus factor (Fic), were used to quantify and rank the plants used for crop protection in the study area.

RESULTS

Twenty-three plant species (16 naturalised exotics and seven indigenous plants) belonging to 16 families were used for managing pests (vertebrates and invertebrates) and diseases (fungal and bacterial related) affecting crops in the study area. The dominant (100%) crops cultivated by the participants were Allium cepa L., Mangifera indica L., Solanum lycopersicum L. and Zea mays L. The RFC value ranged from 0.08 to 0.83 and the three most popular plants for crop protection were Capsium annuum L. (0.83), A. cepa (0.63) and Dichrostachys cinerea (L.) Wight & Arn. (0.43). In terms of the UV, the five most promising plants used as biocontrol were Tulbaghia violacea (0.13), A. cepa (0.12), C. annuum L. (0.09), Solanum campylacanthum Hochst. Ex A.Rich.(0.09) and Pinus pinaster (0.08). Based on the Fic, four categories were established and dominated by fungal diseases (0.64). Furthermore, T. violacea and A. cepa were the most often mentioned plants used against fungal conditions. Other categories cited were bacterial diseases (0.3), invertebrate pests (0.11) and vertebrate pests (0.14), an indication that smallholder farmers had limited agreement or common knowledge about the plants used for their management. The preparation methods included maceration (38%), decoction (38%) and burning (24%). Foliar application (67%) and soil drenching (33%) were used for administering plant extracts during the management of crop pests and diseases.

CONCLUSION

The study highlights the importance of botanicals and associated indigenous knowledge among smallholder farmers in Mpumalanga Province, South Africa. It is pertinent to explore the valorisation of these botanicals by generating empirical data on their biological efficacies and phytochemical profiles.

Phytochemical Analysis of Centaurea calcitrapa L. Aerial Flowering Parts Serial Solvent Extracts and Its Antibacterial and Antioxidant Activities

To evaluate the phytochemical composition, antibacterial, and antioxidant activity of successive extracts of Centaurea calcitrapa L. (C. calcitrapa) aerial flowering parts, they were assessed in vitro. Using a spectrophotometer, the sample absorbance at 517 nm was used to quantify the scavenging activity. The negative control was DPPH. In the current study, the diffusion using agar wells technique was adapted to measure antimicrobial activity. Phytochemical analysis was performed using the recommended standard procedures. The methanol extract of C. calcitrapa exhibited high levels of total phenolic acids expressed as gallic acid (GA), measured as (97.25 ± 0.73 mg GAE/g) content compared to the chloroform, acetyl acetate, and aqueous extracts (27.42 ± 0.29, 64.25 ± 0.96, and 17.25 ± 0.73 mg GAE/g), respectively. Additionally, the methanol extract had a higher total tannin (27.52 ± 0.53 mg TAE/g) content compared to the chloroform, ethyl acetate, and aqueous extracts (12.02 ± 0.55, 26.01 ± 0.81, and 7.35 ± 0.56 mg TAE/g), respectively, while the aqueous extract contains a lower percentage of flavonoids (141.10 ± 1.31 mg RTE/g) compared to the higher content achieved by the methanol extract (425.93 ± 1.27 mg RTE/g). The hydroxyl groups of the flavonoid and the phenolic compounds found in C. calcitrapa are essentially scavenging free radicals. Radical scavenging activity was highest in the methanol extract (IC50 = 2.82 μg/mL), aqueous extract (IC50 = 8.03 μg/mL), ethyl acetate extract (IC50 = 4.79 μg/mL), and chloroform extract (IC50 = 6.33 μg/mL), as compared to the standard scavenging activity (IC50 = 2.52 μg/mL). The antibacterial properties of C. calcitrapa against Gram-negative bacterial strains Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Acinetobacter baumanii, in addition to Gram-positive strains Staphylococcus haemolyticus, Enterococcus faecalis, and Staphylococcus aureus, revealed inhibition zone diameter. The findings of this investigation establish that the aerial flowering parts of C. calcitrapa have substantial antibacterial action against human infections, and the plant can serve as a significant antioxidant that can be employed to prevent and treat severe degenerative diseases brought on by oxidative stress. qPCR showed that C. calcitrapa extracts elevate both SOD1 and SOD2 (cellular oxidation markers) with remarkable folds (1.8-fold for SOD1 and SOD2) with ethyl acetate plant extract against ascorbic acid as a control. This result reflects that C. calcitrapa extracts have remarkable antioxidant activity.

Acoustic droplet ejection facilitates cell-based high-throughput screenings using natural products

Natural Products (NPs) are one of the main sources for drug discovery. Many clinical drugs are NPs or NP-inspired compounds, and recently discovered New Chemical Entities (NCEs) of NPs are emerging as promising new drugs. High-Throughput Screening (HTS) of large sample sets or libraries has grown to be vital for the drug discovery field. Industrial-scale HTS of NP libraries can be limited due to the difficulties entailed in working with tiny extract volumes and the variability in viscosity of NP extracts. For these reasons, the implementation of new technologies to miniaturize different reagent volumes grows to be fundamental. Since Acoustic Droplet Ejection (ADE) emerged as a helpful tool in HTS campaigns for the transference of compound libraries. The aim of this work was to test the effectiveness of ADE for the dispensation of NP extract libraries in cell-based HTS assays.

Identification and characterization of a marine bacterium extract from Mameliella sp. M20D2D8 with antiviral effects against influenza A and B viruses

Despite significant improvements in vaccines and chemotherapeutic drugs, pathogenic RNA viruses continue to have a profound impact on the global economy and pose a serious threat to animal and human health through emerging and re-emerging outbreaks of diseases. To overcome the challenge of viral adaptation and evolution, increased vigilance is required. Particularly, antiviral drugs derived from new, natural sources provide an attractive strategy for controlling problematic viral diseases. In this antiviral study, we discovered a previously unknown bacterium, Mameliella sp. M20D2D8, by conducting an antiviral screening of marine microorganisms. An extract from M20D2D8 exhibited antiviral activity with low cytotoxicity and was found to be effective in vitro against multiple influenza virus strains: A/PR8 (IC50 = 2.93 µg/mL, SI = 294.85), A/Phil82 (IC50 = 1.42 µg/mL, SI = 608.38), and B/Yamagata (IC50 = 1.59 µg/mL, SI = 543.33). The antiviral action was found to occur in the post-entry stages of viral replication and to suppress viral replication by inducing apoptosis in infected cells. Moreover, it efficiently suppressed viral genome replication, protein synthesis, and infectivity in MDCK and A549 cells. Our findings highlight the antiviral capabilities of a novel marine bacterium, which could potentially be useful in the development of drugs for controlling viral diseases.

Divergent synthesis of fractionated Cannabis sativa extract led to multiple cannabinoids C-&O-glycosides with anti-proliferative/anti-metastatic properties

Here, we present an interesting, previously unreported method for fractionating a particular class of cannabinoids from the crude leaf extract of Cannabis sativa using HP-20 resins. In this study, we report a novel method of divergent synthesis of fractionated Cannabis sativa extract, which allows the generation of multiple cannabinoids C- and O-glycosides which react with the glycosyl donor 2,3,4,6-tetra-O-acetyl-d-mannosyl trichloroacetimidate (TAMTA) to create eight C- and O-β-d-cannabinoids glycosides (COCG), which are separated by HPLC and whose structures are characterized by 1D, 2D NMR, and mass spectrometry. These glycosides exhibit improved anti-proliferative and anti-metastatic effects against numerous cancer cell lines in vitro and are more water-soluble and stable than their parent cannabinoids. The in vitro testing of the pure cannabinoids (1-4) and their C- & O-glycosides (1a-4a) and 1b-4b exhibited anti-proliferative and anti-metastatic activities against a panel of eight human cancer cell lines in contrast to their respective parent molecules. Different cancer cell lines' IC50 values varied significantly when their cell viability was compared. In addition to the others, compounds 2a, 3a, 4a, and 2b, 3b were highly potent, with IC50values ranging from 0.74 µM (3a) to 51.40 µM (4a).Although2a(1.42 µM) and3a(0.74 µM) exhibited lower IC50values in the MiaPaca-2 cell line than4a(2.58 µM). But, in addition to the comparable anti-clonogenic activity of4ain MiaPaca-2 and Panc-1 cells, it manifested remarkable anti-invasive activity than either 2a or 3a.In contrast to 2a, 2b, 3a, and 3b and their respective parent compounds,4ahad substantial anti-invasive/anti-metastatic capabilities and possessed anti-proliferative activity.The effects of 4a treatment on MiaPaca-2 and Panc-1 cells include a dose-dependent increase in the expression of E-cadherin and a significant decrease in the expression of Zeb-1, Vimentin, and Snail1. Our results demonstrate that divergent synthesis of fractionated Cannabis sativa extract is a feasible and efficient strategy to produce a library of novel cannabinoid glycosides with improved pharmacological properties and potential anticancer benefits.

The role of tryptophan derivatives as anti-kinetoplastid agents

Kinetoplastids are the causative agents for a spectrum of vector-borne diseases including Leishmaniasis, Chagas disease and Trypanosomiasis that affect millions of people worldwide. In the absence of safe and effective vaccines, chemotherapy, in conjunction with vector control, remain the most significant control approach for kinetoplastid diseases. However, commercially available treatment for these neglected tropical diseases frequently ends up with toxic side effects and increasing resistance. To meet the rising need for innovative medications, alternative chemotherapeutic agents are required. Moreover, insights into target-based mode of action of chemotherapeutic agents are required if novel drugs that may outwit resistance to commercially available drugs are to be developed. Tryptophan has been implicated in a variety of diseases and disorders due to its fundamental role as a precursor to several bioactive metabolites, as well as its importance in the improvement of health and nutrition, diagnostics, and therapeutics. The regulation of tryptophan metabolism plays a fundamental role in the growth of kinetoplastids. Moreover, the levels of tryptophan may serve as a biomarker to distinguish between the stages of kinetoplastids making it an important amino acid to explore for drug targets. The main aim of this review is thus to provide a comprehensive literature synthesis of tryptophan derivatives to explore as potential anti-kinetoplastids. Here we highlight the role of tryptophan derivatives as chemotherapeutic agents against kinetoplastids. The reviewed compounds provide insights into potential new drug interventions that may combat the increasing problem of anti-kinetoplastid resistance.

The Antiproliferative and Proapoptotic Effects of Cucurbitacin B on BPH-1 Cells via the p53/MDM2 Axis

Cucurbitacin B (Cu B), a triterpenoid compound, has anti-inflammatory and antioxidant activities. Most studies only focus on the hepatoprotective activity of Cu B, and little effort has been geared toward exploring the effect of Cu B on the prostate. Our study identified that Cu B inhibited the proliferation of the benign prostatic hyperplasia epithelial cell line (BPH-1). At the molecular level, Cu B upregulated MDM2 and thrombospondin 1 (THBS1) mRNA levels. Immunocytochemistry results revealed that the protein expressions of p53 and MDM2 were upregulated in BPH-1 cells. Furthermore, Cu B upregulated THBS1 expression and downregulated COX-2 expression in the BPH-1 cell supernatant. Altogether, Cu B may inhibit prostate cell proliferation by activating the p53/MDM2 signaling cascade and downregulating the COX-2 expression.

Dimeric N-Acetyldopamine Derivatives Featuring a Seco-Benzene System from the Insects Aspongopus chinensis and Periostracum cicadae

Aspongamide F (1), a novel N-acetyldopamine (NADA) dimer possessing a 6/6/6 ring system, and (±)-aspongamides G (2) and H (3), rare NADA derivatives with fragmented benzene rings, were isolated from Aspongopus chinensis. (±)-Cicadamides C (4) and D (5), the first 1,4-Benzodioxane NADA dimers featuring a seco-benzene system, and (±)-cicadamides E (6) and F (7), the NADA dimers derivatives, were isolated from Periostracum cicadae. The structures of all compounds were elucidated by spectroscopic analyses and computational methods. A plausible biosynthetic pathway for compounds 1-5 was proposed. The biological assay revealed that (+)-4 and (-)-4 exhibit renal protection in a dose-dependent manner.

Myrsinane-Type Diterpenes: A Comprehensive Review on Structural Diversity, Chemistry and Biological Activities

Euphorbia species are important sources of polycyclic and macrocyclic diterpenes, which have been the focus of natural-product-based drug research due to their relevant biological properties, including anticancer, multidrug resistance reversal, antiviral, and anti-inflammatory activities. Premyrsinane, cyclomyrsinane, and myrsinane diterpenes are generally and collectively designated as myrsinane-type diterpenes. These compounds are derived from the macrocyclic lathyrane structure and are characterized by having highly oxygenated rearranged polycyclic systems. This review aims to describe and summarize the distribution and diversity of 220 myrsinane-type diterpenes isolated in the last four decades from about 20 Euphorbia species. Some myrsinane diterpenes obtained from Jatropha curcas are also described. Discussion on their plausible biosynthetic pathways is presented, as well as isolation procedures and structural elucidation using nuclear magnetic resonance spectroscopy. Furthermore, the most important biological activities are highlighted, which include cytotoxic and immunomodulatory activities, the modulation of efflux pumps, the neuroprotective effects, and the inhibition of enzymes such as urease, HIV-1 reverse transcriptase, and prolyl endopeptidase, among other biological effects.

Micro-Executor of Natural Products in Metabolic Diseases

Obesity, diabetes, and cardiovascular diseases are the major chronic metabolic diseases that threaten human health. In order to combat these epidemics, there remains a desperate need for effective, safe, and easily available therapeutic strategies. Recently, the development of natural product research has provided new methods and options for these diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are key regulators of metabolic diseases, and natural products can improve lipid and glucose metabolism disorders and cardiovascular diseases by regulating the expression of miRNAs. In this review, we present the recent advances involving the associations between miRNAs and natural products and the current evidence showing the positive effects of miRNAs for natural product treatment in metabolic diseases. We also encourage further research to address the relationship between miRNAs and natural products under physiological and pathological conditions, thus leading to stronger support for drug development from natural products in the future.

Hirsutine, an Emerging Natural Product with Promising Therapeutic Benefits: A Systematic Review

Fruits and vegetables are used not only for nutritional purposes but also as therapeutics to treat various diseases and ailments. These food items are prominent sources of phytochemicals that exhibit chemopreventive and therapeutic effects against several diseases. Hirsutine (HSN) is a naturally occurring indole alkaloid found in various Uncaria species and has a multitude of therapeutic benefits. It is found in foodstuffs such as fish, seafood, meat, poultry, dairy, and some grain products among other things. In addition, it is present in fruits and vegetables including corn, cauliflower, mushrooms, potatoes, bamboo shoots, bananas, cantaloupe, and citrus fruits. The primary emphasis of this study is to summarize the pharmacological activities and the underlying mechanisms of HSN against different diseases, as well as the biopharmaceutical features. For this, data were collected (up to date as of 1 July 2023) from various reliable and authentic literature by searching different academic search engines, including PubMed, Springer Link, Scopus, Wiley Online, Web of Science, ScienceDirect, and Google Scholar. Findings indicated that HSN exerts several effects in various preclinical and pharmacological experimental systems. It exhibits anti-inflammatory, antiviral, anti-diabetic, and antioxidant activities with beneficial effects in neurological and cardiovascular diseases. Our findings also indicate that HSN exerts promising anticancer potentials via several molecular mechanisms, including apoptotic cell death, induction of oxidative stress, cytotoxic effect, anti-proliferative effect, genotoxic effect, and inhibition of cancer cell migration and invasion against various cancers such as lung, breast, and antitumor effects in human T-cell leukemia. Taken all together, findings from this study show that HSN can be a promising therapeutic agent to treat various diseases including cancer.

Investigation of targets and anticancer mechanisms of covalently acting natural products by functional proteomics

Eriocalyxin B (EB), 17-hydroxy-jolkinolide B (HJB), parthenolide (PN), xanthatin (XT) and andrographolide (AG) are terpenoid natural products with a variety of promising antitumor activities, which commonly bear electrophilic groups (α,β-unsaturated carbonyl groups and/or epoxides) capable of covalently modifying protein cysteine residues. However, their direct targets and underlying molecular mechanisms are still largely unclear, which limits the development of these compounds. In this study, we integrated activity-based protein profiling (ABPP) and quantitative proteomics approach to systematically characterize the covalent targets of these natural products and their involved cellular pathways. We first demonstrated the anti-proliferation activities of these five compounds in triple-negative breast cancer cell MDA-MB-231. Tandem mass tag (TMT)-based quantitative proteomics showed all five compounds commonly affected the ubiquitin mediated proteolysis pathways. ABPP platform identified the preferentially modified targets of EB and PN, two natural products with high anti-proliferation activity. Biochemical experiments showed that PN inhibited the cell proliferation through targeting ubiquitin carboxyl-terminal hydrolase 10 (USP10). Together, this study uncovered the covalently modified targets of these natural products and potential molecular mechanisms of their antitumor activities.

3D-QSAR-Based Molecular Design to Discover Ultrahigh Active N-Phenylpyrazoles as Insecticide Candidates

Three-dimensional quantitative structure-activity relationship (3D-QSAR) is one of the most important and effective tools to direct molecular design in new pesticide development. Chlorantraniliprole is an anthranilic diamide ryanodine receptor (RyR) agonist with ultrahigh activity, high selectivity, and mammalian safety. To continue our studies on new insecticide development, here, we designed new insecticidal N-phenylpyrazoles by using 3D-QSAR of chlorantraniliprole analogues as a guide. Most of the target compounds synthesized exhibited medium to excellent activity against Mythimna separata, Plutella xylostella, and Spodoptera frugiperda. Compounds III b and III y showed similar activity against M. separata as chlorantraniliprole (LC₅₀ values: 0.21, 0.25, and 0.16 μg mL^-1 respectively). Compounds III b exhibited a 3-fold higher potency against P. xylostella than chlorantraniliprole. For S. frugiperda, the potency of III a and III b was 2.9 and 2.0 times higher than that of the positive control, respectively. The mode of action of the title compounds was validated by calcium imaging experiments and molecular docking using their target RyRs. III b can dock well with mutated P. xylostella RyRs, implying a potentially lower cross-resistance risk as compared with commercial RyR agonists. Density functional theory calculations suggested the feasibility of higher potency with the structural modifications. Compound III b was found to be an ultrahigh active insecticidal candidate with a broad spectrum for integrated pest management.

Virtual screening and structure-activity relationship study of novel BTK inhibitors in Traditional Chinese Medicine for the treatment of rheumatoid arthritis

Bruton tyrosine kinase (BTK) is a known drug target for the treatment of autoimmune diseases, including rheumatoid arthritis (RA). In this study, a series of 1-amino-1H-imidazole-5-carboxamide derivatives with good inhibitory activity against BTK were selected to explore the structure-activity relationships of these BTK inhibitors (BTKIs). Furthermore, we concentrated on 182 prescriptions of Traditional Chinese Medicine with therapeutic effects on RA. 54 herbs with a frequency of ≥10 were counted to establish a database containing 4027 ingredients for virtual screening. Five compounds with relatively higher docking scores and better absorption, distribution, metabolism, elimination and toxicity (ADMET) parameters were then selected for higher precision docking. The results demonstrated that the potentially active molecules form hydrogen bond interactions with the hinge region residues Met477, Glu475, glycine-rich P-loop residue Val416, Lys430 and DFG motif Asp539. In particular, they also interact with the key residues Thr474 and Cys481 of BTK. The molecular dynamics (MD) results demonstrated that all five compounds above could bind with BTK stably as its cognate ligand in dynamic conditions. This work identified several potential BTKIs using a computer-aided drug design approach and may provide crucial information for developing novel BTKIs.Communicated by Ramaswamy H. Sarma.

6-Gingerol-derived semisynthetic analogs mitigate oxidative stress, and reverse acrylamide induced neurotoxicity in zebrafish

A semisynthetic strategy has been developed for the synthesis of novel 6-gingerol based analogs using simple and robust chemistries.

Journey of the Probiotic Bacteria: Survival of the Fittest

This review aims to bring a more general view of the technological and biological challenges regarding production and use of probiotic bacteria in promoting human health. After a brief description of the current concepts, the challenges for the production at an industrial level are presented from the physiology of the central metabolism to the ability to face the main forms of stress in the industrial process. Once produced, these cells are processed to be commercialized in suspension or dried forms or added to food matrices. At this stage, the maintenance of cell viability and vitality is of paramount for the quality of the product. Powder products requires the development of strategies that ensure the integrity of components and cellular functions that allow complete recovery of cells at the time of consumption. Finally, once consumed, probiotic cells must face a very powerful set of physicochemical mechanisms within the body, which include enzymes, antibacterial molecules and sudden changes in pH. Understanding the action of these agents and the induction of cellular tolerance mechanisms is fundamental for the selection of increasingly efficient strains in order to survive from production to colonization of the intestinal tract and to promote the desired health benefits.

Drug discovery inspired by bioactive small molecules from nature

Natural products (NPs) have greatly contributed to the development of novel treatments for human diseases such as cancer, metabolic disorders, and infections. Compared to synthetic chemical compounds, primary and secondary metabolites from medicinal plants, fungi, microorganisms, and our bodies are promising resources with immense chemical diversity and favorable properties for drug development. In addition to the well-validated significance of secondary metabolites, endogenous small molecules derived from central metabolism and signaling events have shown great potential as drug candidates due to their unique metabolite-protein interactions. In this short review, we highlight the values of NPs, discuss recent scientific and technological advances including metabolomics tools, chemoproteomics approaches, and artificial intelligence-based computation platforms, and explore potential strategies to overcome the current challenges in NP-driven drug discovery.

Antrodia cinnamomea Suppress Dengue Virus Infection through Enhancing the Secretion of Interferon-Alpha

Dengue caused by dengue virus (DENV) is a mosquito-borne disease. Dengue exhibits a wide range of symptoms, ranging from asymptomatic to flu-like illness, and a few symptomatic cases may develop into severe dengue, leading to death. However, there are no effective and safe therapeutics for DENV infections. We have previously reported that cytokine expression, especially inflammatory cytokines, was altered in patients with different severities of dengue. Antrodia cinnamomea (A. cinnamomea) is a precious and endemic medical mushroom in Taiwan. It contains unique chemical components and exhibits biological activities, including suppressing effects on inflammation and viral infection-related diseases. According to previous studies, megakaryocytes can support DENV infection, and the number of megakaryocytes is positively correlated with the viral load in the serum of acute dengue patients. In the study, we investigated the anti-DENV effects of two ethanolic extracts (ACEs 1-2) and three isolated compounds (ACEs 3-5) from A. cinnamomea on DENV infection in Meg-01 cells. Our results not only demonstrated that ACE-3 and ACE-4 significantly suppressed DENV infection, but also reduced interleukin (IL)-6 and IL-8 levels. Moreover, the level of the antiviral cytokine interferon (IFN)-α was also increased by ACE-3 and ACE-4 in Meg-01 cells after DENV infection. Here, we provide new insights into the potential use of A. cinnamomea extracts as therapeutic agents against DENV infection. However, the detailed mechanisms underlying these processes require further investigation.

Agrimonia eupatoria L.: An integrative perspective on ethnomedicinal use, phenolic composition and pharmacological activity

ETHNOPHARMACOLOGICAL RELEVANCE

Agrimonia eupatoria L., a plant which belongs to the Rosaceae family, is widespread in temperate regions, particularly throughout the northern hemisphere. In folk medicine, this plant species has been used for its astringent, anti-inflammatory, analgesic and hypotensive properties as well as in gastrointestinal disorders. As these biological properties have been linked to its phenolic composition, this plant species could be an interesting source of bioactive compounds with therapeutic potential.

AIM OF THE STUDY

The aim of the present review is to provide a comprehensive overview of the scientific literature on A. eupatoria, particularly in regard to its ethnobotanics and ethnomedicinal uses, phenolic composition and biological and pharmacological activities.

MATERIAL AND METHODS

Literature was retrieved from several bibliographic sources, namely PubMed, ScienceDirect and Google Scholar, since the first report on A. eupatoria in 1993.

RESULTS

Regarding the phytochemical composition, A. eupatoria is rich in phenolic acids, flavonoids and tannins. The most commonly reported compounds are astragalin, cynaroside, hyperoside, isoquercitrin, isovitexin, rutin, catechin, procyanidin B3 and agrimoniin. In terms of bioactivity, extracts or fractions obtained from this plant species have shown antioxidant, antimicrobial, antidiabetic, antinociceptive and anti-inflammatory properties, among others. So far, two clinical studies with the infusion of A. eupatoria have shown hepatoprotective properties as well as a protective role in cardiovascular disease, metabolic disorders and diabetes.

CONCLUSIONS

In this review, an integrative perspective on ethnomedicinal use, phenolic composition and pharmacological activity of A. eupatoria has been provided. As can be seen, this plant species exhibits several potential applications, including those beyond its traditional ethnomedicinal uses, as the safety of its consumption has been shown clinically. There still is limited pharmacological evidence that corroborates the ethnomedicinal uses of this plant species as well as regarding the specific bioactive compounds.

Evaluation of antimicrobial, antiquorum sensing, and cytotoxic activities of new vanillin 1,2,3-triazole derivatives

Vanillin (1), the main constituent of vanilla species, was used as a starting natural scaffold for the synthesis of five new (2-6) and one known (7) triazole derivatives via click chemistry using the copper (I)-catalyzed azide-alkyne cycloaddition method. Vanillin and its new derivatives; 4-{1-[2-Hydroxymethyl-5-(5 methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-tetrahydro-furan-3-yl]-1H[1,2,3]triazol-4-ylmethoxy}-3-methoxy-benzaldehyde (2); [4-(4-Formyl-2methoxy-phenoxymethyl)-[1,2,3]triazol-1-yl]-acetic acid methyl ester (3); 4-[1-(4-Acetyl-phenyl)-1H-[1,2,3]triazol-4-ylmethoxy]-3-methoxy-benzaldehyde (4); 4-[4-(1-Benzyl-1H-[1,2,3]triazol-4-ylmethoxy)-3-methoxy-phenyl]-but-3-en-2-one (5); and 4-[4-(1-Benzyl-1H-[1,2,3]triazol-4-ylmethoxy)-3-methoxy-phenyl]-4-hydroxy-butan-2-one (6), as well as the previously known derivative (7) were subjected to antimicrobial, antiquorum-sensing and cytotoxic evaluation. Compounds 4-7 possessed the most notable enhancement in the anti-bacterial activity against Bacillus cereus, Pseudomonas aeruginosa and antifungal activity against Candida albicans. However, compounds 1 and 2 exhibited high antiquorum-sensing activity against Chromobacterium violaceum using catechin as a positive control. Compounds 4-7 demonstrated selective cytotoxicity against MCF-7 and HepG2 cancer cells compared to normal lung fibroblast cells (WI-38). These findings proved the usefulness of synthesis bioactive derivatives from vanillin through chemical modifications.

A High-Throughput Continuous Spectroscopic Assay to Measure the Activity of Natural Product Methyltransferases

Natural product methyltransferases (NPMTs) represent an emerging class of enzymes that can be of great use for the structural and functional diversification of bioactive compounds, such as the strategic modification of C-, N-, O- and S-moieties. To assess the activity and the substrate scope of the ever-expanding repertoire of NPMTs, a simple, fast, and robust assay is needed. Here, we report a continuous spectroscopic assay, in which S-adenosyl-L-methionine-dependent methylation is linked to NADH oxidation through the coupled activities of S-adenosyl-L-homocysteine (SAH) deaminase and glutamate dehydrogenase. The assay is highly suitable for a high-throughput evaluation of small molecule methylation and for determining the catalytic parameters of NPMTs under conditions that remove the potent inhibition by SAH. Through the modular design, the assay can be extended to match the needs of different aspects of methyltransferase cascade reactions and respective applications.

Development, method validation and simultaneous quantification of eleven bioactive natural products from high altitude medicinal plant by high performance liquid chromatography

Herein, a novel, rapid, reliable, simple method validation and simultaneous quantification of eleven bioactive compounds mostly xanthones have been described. ICH guidelines were used for the analytical method validation. Good linearity, repeatability, intra-day and inter-day precision, accuracy and reliability is well illuminated in the method validation procedure. The calibration curves showed a good linear relationship (r>0.999) within test range. Precision was evaluated by intra- and inter-day tests with RSDs <2.79%, accuracy validation recovery 74.16-91.84%. On quantification study, validated method described the high content of bioactive xanthone derivative including 1-hydroxy-3, 5-dimethoxyxanthone (7), 2-(allyloxy)-8-hydroxy-1, 6-dimethoxyxanthone (6) 1, 7, 8-trihydroxy-3-methoxyxanthone (9) and Coxanthone E (5) in the C. ovata which is advantageous due to numerous pharmacological and biological effects associated with these compounds mostly anti-cancers, antioxidant, anti-inflammatory, anti-mutagenic and anti-obesity activity. The bulk abundance of these compounds can also be used for the further modification to produce better lead molecules for drug discovery with low toxicity and high potency. The proposed method makes it possible to determine simultaneously all bioactive compounds in one run and can be extended for marker based standardization of herbal formulations in medicinal and pharmaceutical industries.

Research Progress in the Field of Gambogic Acid and Its Derivatives as Antineoplastic Drugs

Gambogic acid (GA) is a natural product with a wide range of pharmacological properties. It plays an important role in inhibiting tumor growth. A large number of GA derivatives have been designed and prepared to improve its shortcomings, such as poor water solubility, low bioavailability, poor stability, and adverse drug effects. So far, GA has been utilized to develop a variety of active derivatives with improved water solubility and bioavailability through structural modification. This article summarized the progress in pharmaceutical chemistry of GA derivatives to provide a reference and basis for further study on structural modifications of GA and expansion of its clinical applications.

Set of Cytochrome P450s Cooperatively Catalyzes the Synthesis of a Highly Oxidized and Rearranged Diterpene-Class Sordarinane Architecture

Cytochrome P450s are one of the most versatile oxidases that catalyze significant and unique chemical transformations for the construction of complex structural frameworks during natural product biosynthesis. Here, we discovered a set of P450s, including SdnB, SdnH, SdnF, and SdnE, that cooperatively catalyzes the reshaping of the inert cycloaraneosene framework to form a highly oxidized and rearranged sordarinane architecture. Among them, SdnB is confirmed to be the first P450 (or oxidase) that cleaves the C-C bond of the epoxy residue to yield formyl groups in pairs. SdnF selectively oxidizes one generated formyl group to a carboxyl group and accelerates the final Diels-Alder cyclization to furnish the sordarinane architecture. Our work greatly enriches the enzyme functions of the P450 superfamily, supplies the missing skills of the P450 synthetic toolbox, and supports them as biocatalysts in further applications toward the synthesis of new chemical entities.

Herbal nanomedicines: Recent advancements, challenges, opportunities and regulatory overview

BACKGROUND

Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs.

PURPOSE

This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent.

METHODS

The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science.

RESULTS

In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index.

CONCLUSION

A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.

Natural Products in Modulating Methamphetamine-Induced Neuronal Apoptosis

Methamphetamine (METH), an amphetamine-type psychostimulant, is highly abused worldwide. Chronic abuse of METH causes neurodegenerative changes in central dopaminergic neurons with numerous neuropsychiatric consequences. Neuronal apoptosis plays a critical role in METH-induced neurotoxicity and may provide promising pharmacological targets for preventing and treating METH addiction. In recent years, accumulating evidence has revealed that natural products may possess significant potentials to inhibit METH-evoked neuronal apoptosis. In this review, we summarized and analyzed the improvement effect of natural products on METH-induced neuronal apoptosis and their potential molecular mechanisms on modulating dopamine release, oxidative stress, mitochondrial-dependent apoptotic pathway, endoplasmic reticulum stress-mediated apoptotic pathway, and neuroinflammation. Hopefully, this review may highlight the potential value of natural products in modulating METH-caused neuronal apoptosis and provide useful information for future research and developments of novel and efficacious pharmacotherapies in this field.

Mono-/Bis-Alkenoic Acid Derivatives From an Endophytic Fungus Scopulariopsis candelabrum and Their Antifungal Activity

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.

UPLC-ESI-MS/MS profiling of the underground parts of common Iris species in relation to their anti-virulence activities against Staphylococcusaureus

ETHNOPHARMACOLOGICAL RELEVANCE

The use of plant extracts and their phytochemicals as candidates for targeting the microbial resistance inhibition is increasingly focused in last decades. In Mongolian traditional medicine, Irises were long used for the treatment of bacterial infections. Irises have been used since the Ancient Egyptians.

AIM OF THE STUDY

Chemical composition and virulence inhibition potential of both polar (PF) and non-polar fractions (NPF) of three common Iris species (I. confusa, I. pseudacorus and I. germanica) were explored.

MATERIAL AND METHODS

Secondary metabolites profiling was characterized by the UPLC-HRMS/MS technique. Multi-variate data analysis was performed using Metaboanalyst 3.0. Anti-virulence inhibitory activity was evaluated via anti-haemolytic assay and Quantitative biofilm inhibition assay.

RESULTS

I. pseudacorus PF exhibited the most potent effect against S. aureus haemolytic activity. All the tested fractions from all species, except I. pseudacorus NPF, have no significant inhibition on the biofilm formation of methicillin resistant and sensitive (MRSA and MSSA) S. aureus. I. pseudacorus NPF showed potent biofilm inhibitory potential of 71.4 and 85.8% against biofilm formation of MRSA and MSSA, respectively. Metabolite profiling of the investigated species revealed ninety and forty-five metabolites detected in the PFs and NPFs, respectively. Nigricin-type, tectorigenin-type isoflavonids and xanthones allowed the discrimination of I. pseudacorus PF from the other species, highlighting the importance of those metabolites in exerting its promising activity. On the other hand, triterpene acids, iridals, triacylglycerols and ceramides represented the metabolites detected in highest abundance in I. pseudacorus NPF.

CONCLUSIONS

This is the sole map represents the secondary metabolites profiling of the PFs and NPFs of common Iris species correlating them with the potent explored Staphylococcus aureus anti-virulence activity.

A novel regulatory mechanism of geniposide for improving glucose homeostasis mediated by circulating RBP4

BACKGROUND

Systemic insulin signal transduction is influenced by the inter-tissue crosstalk, which might be the potential therapeutic strategy for T2DM. Although anti-diabetic function of geniposide has been previously reported, the underlying mechanism was not completely clear in light of the complex pathogenesis of T2DM.

PURPOSE

The present experiment is devoted to investigate the potential effects of geniposide on systemic insulin sensitivity mediated by hepatokine-RBP4 in high fat diet (HFD)-fed mice.

METHODS

The HFD-fed wild type mice were administered with geniposide (25 or 50 mg/kg/d) by intraperitoneal injection, and the normal saline and Metformin were used as negative control group and positive control group, respectively. After administration for 4 weeks, the food intake, body weight, glucose tolerance tests, insulin tolerance tests and serum biochemical indices were examined, along with insulin signaling pathway-associated proteins and hepatic histomorphological analysis. The liver, gastrocnemius and mouse primary hepatocytes were also harvested for molecular mechanism study.

RESULTS

After geniposide treatment for 4 weeks, the blood glucose level was reduced in HFD-fed mice. Furthermore, geniposide treatment improved insulin sensitivity both in the liver and gastrocnemius (GAS). In terms of mechanism, geniposide disturbed circulating RBP4 level including its synthesis, secretion and homeostasis. Moreover, geniposide modified fuel selection and promoted glucose uptake in skeletal muscle and reduced glycogen storage, which were closely related to impaired circulating RBP4 homeostasis, leading to ameliorative systemic insulin sensitivity.

CONCLUSION

Our current study proposes a novel regulatory mechanism of geniposide for improving glucose homeostasis through regulating circulating RBP4 level, which also provides new strategies for the prevention and treatment of T2DM.

Artemisia santolinifolia-Mediated Chemosensitization via Activation of Distinct Cell Death Modes and Suppression of STAT3/Survivin-Signaling Pathways in NSCLC

Conventional chemotherapy remains an integral part of lung cancer therapy, regardless of its toxicity and drug resistance. Consequently, the discovery of an alternative to conventional chemotherapy is critical. Artemisia santolinifolia ethanol extract (AS) was assessed for its chemosensitizer ability when combined with the conventional anticancer drug, docetaxel (DTX), against non-small cell lung cancer (NSCLC). SRB assay was used to determine cell viability for A549 and H23 cell lines. The potential for this combination was examined by the combination index (CI). Further cell death, analyses with Annexin V/7AAD double staining, and corresponding protein expressions were analyzed. Surprisingly, AS synergistically enhanced the cytotoxic effect of DTX by inducing apoptosis in H23 cells through the caspase-dependent pathway, whereas selectively increased necrotic cell population in A549 cells, following the decline in GPX4 level and reactive oxygen species (ROS) activation with the highest rate in the combination treatment group. Furthermore, our results highlight the chemosensitization ability of AS when combined with DTX. It was closely associated with synergistic inhibition of oncogenesis signaling molecule STAT3 in both cell lines and concurrently downregulating prosurvival protein Survivin. Conclusively, AS could enhance DTX-induced cancer cells apoptosis by abrogating substantial prosurvival proteins' expressions and triggering two distinct cell death pathways. Our data also highlight that AS might serve as an adjunctive therapeutic option along with a conventional chemotherapeutic agent in the management of NSCLC patients.

Dereplication Based Strategy for Rapid Identification and Isolation of a Novel Anti-inflammatory Flavonoid by LCMS/MS from Colebrookea oppositifolia

Colebrookea oppositifolia is a folkloric medicinal plant, well known for its tremendous medicinal properties such as curing epilepsy, ulcers, and urinary problems. The aim of the present study was to apply the dereplication strategy on the ethanol extract of C. oppositifolia with potent anti-inflammatory activity for the rapid identification and isolation of novel bioactive molecules to aid the drug discovery process. An integrated approach using liquid chromatography-mass spectrometry (LCMS) followed by preparative high-performance liquid chromatography (HPLC) was used for the isolation of potent molecules from the anti-inflammatory extract of C. oppositifolia . Purity of the compounds (>98.5%) was established by HPLC, and identification was carried out by NMR and ESI-MS. 5,6,7-Trihydroxyflavone-3-O-glucuronide methyl ester (compound III) isolated from C. oppositifolia was extensively studied for anti-inflammatory potential in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the mice model. Compound III significantly repressed various proinflammatory mediators and upregulated the release of anti-inflammatory cytokine IL-10. Compound III reduced inflammation when studied for parameters such as the phagocytic index, carrageenan-induced paw edema in mice, and effect on organ weight. It reduced inflammation in a dose-dependent manner both in vitro and in vivo. Further molecular insights into the study revealed that compound III blocks the phosphorylation of I kappa b kinase α/β (IKKα/β), IκBα, and nuclear factor kB p65 (NF-κBp65) which is a key controller of inflammation, thereby showing anti-inflammatory potential. Hence, this study permits further investigation to develop compound III as an anti-inflammatory drug.

Bacterial Natural Product Drug Discovery for New Antibiotics: Strategies for Tackling the Problem of Antibiotic Resistance by Efficient Bioprospecting

The problem of antibiotic resistance has become a challenge for our public health and society; it has allowed infectious diseases to re-emerge as a risk to human health. New antibiotics that are introduced to the market face the rise of resistant pathogens after a certain period of use. The relatively fast development of resistance against some antibiotics seems to be closely linked to their microbial origin and function in nature. Antibiotics in clinical use are merely products of microorganisms or derivatives of microbial products. The evolution of these antimicrobial compounds has progressed with the evolution of the respective resistance mechanisms in microbes for billions of years. Thus, antimicrobial resistance genes are present within the environment and can be taken up by pathogens through horizontal gene transfer. Natural products from bacteria are an important source of leads for drug development, and microbial natural products have contributed the most antibiotics in current clinical use. Bioprospecting for new antibiotics is a labor-intensive task as obstacles such as redetection of known compounds and low compound yields consume significant resources. The number of bacterial isolates one can theoretically investigate for new secondary metabolites is, on the other hand, immense. Therefore, the available capacity for biodiscovery should be focused on the most promising sources for chemical novelty and bioactivity, employing the appropriate scientific tools. This can be done by first looking into under- or unexplored environments for bacterial isolates and by focusing on the promising candidates to reduce the number of subjects.

Andrographis-mediated chemosensitization through activation of ferroptosis and suppression of β-catenin/Wnt-signaling pathways in colorectal cancer

Colorectal cancer (CRC) remains one of the leading causes of cancer-related mortality in the USA. As much as 50-60% of CRC patients develop resistance to 5-fluorouracil (5FU)-based chemotherapeutic regimens, attributing the increased overall morbidity and mortality. In view of the growing evidence that active principles in various naturally occurring botanicals can facilitate chemosensitization in cancer cells, herein, we undertook a comprehensive effort in interrogating the activity of one such botanical-andrographis-by analyzing its activity in CRC cell lines [both sensitive and 5FU resistant (5FUR)], a xenograft animal model and patient-derived tumor organoids. We observed that combined treatment with andrographis was synergistic and resulted in a significant and dose-dependent increase in the efficacy of 5FU in HCT116 and SW480 5FUR cells (P < 0.05), reduced clonogenic formation (P < 0.01) and increased rates of caspase-9-mediated apoptosis (P < 0.05). The genomewide expression analysis in cell lines led us to uncover that activation of ferroptosis and suppression of β-catenin/Wnt-signaling pathways were the key mediators for the anti-cancer and chemosensitizing effects of andrographis. Subsequently, we validated our findings in a xenograft animal model, as well as two independent CRC patient-derived organoids-which confirmed that combined treatment with andrographis was significantly more effective than 5FU and andrographis alone and that these effects were in part orchestrated through dysregulated expression of key genes (including HMOX1, GCLC, GCLM and TCF7L2) within the ferroptosis and Wnt-signaling pathways. Collectively, our data highlight that andrographis might offer a safe and inexpensive adjunctive therapeutic option in the management of CRC patients.

Essential Oils of Seven Lamiaceae Plants and Their Antioxidant Capacity

Oxidative stress has been reported as a cause of many diseases like Parkinson's, Alzheimer's, cardiovascular disease, and diabetes. Oxidative stress can also lead to cancer formation by promoting tumor development and progression. Antioxidants derived from Lamiaceae plants play an important role in natural medicine, pharmacology, cosmetology, and aromatherapy. Herein, we examine the antioxidative capacity of essential oils from seven aromatic Lamiaceae plants against the synthetic radicals DPPH and ABTS. Among the essential oils analyzed, the most robust scavenging capacities were found in mixtures of volatile compounds from thyme and savory. The scavenging activity of tested EOs against the ABTS radical was clearly higher than activity towards DPPH. Analysis of essential oils with weaker antioxidant activity has shown that volatile compounds from marjoram, sage, and hyssop were more active than EOs from lavender and mint. It can be suggested that the potent antioxidant capacity of thyme (Thymus vulgaris) and savory (Satyreja hortensis) are related to a high level of phenolic constituents, such as thymol and carvacrol. On the other hand, the elevated antioxidative power of marjoram, sage, and hyssop essential oils may also be due to their terpinene, o-cymene, terpinolene, and terpinen-4-ol constituents. Although non-phenolic components are less active than thymol or carvacrol, they may affect antioxidant capacity synergistically.

High-throughput screening for natural compound-based autophagy modulators reveals novel chemotherapeutic mode of action for arzanol

Autophagy is an intracellular recycling pathway with implications for intracellular homeostasis and cell survival. Its pharmacological modulation can aid chemotherapy by sensitizing cancer cells toward approved drugs and overcoming chemoresistance. Recent translational data on autophagy modulators show promising results in reducing tumor growth and metastasis, but also reveal a need for more specific compounds and novel lead structures. Here, we searched for such autophagy-modulating compounds in a flow cytometry-based high-throughput screening of an in-house natural compound library. We successfully identified novel inducers and inhibitors of the autophagic pathway. Among these, we identified arzanol as an autophagy-modulating drug that causes the accumulation of ATG16L1-positive structures, while it also induces the accumulation of lipidated LC3. Surprisingly, we observed a reduction of the size of autophagosomes compared to the bafilomycin control and a pronounced accumulation of p62/SQSTM1 in response to arzanol treatment in HeLa cells. We, therefore, speculate that arzanol acts both as an inducer of early autophagosome biogenesis and as an inhibitor of later autophagy events. We further show that arzanol is able to sensitize RT-112 bladder cancer cells towards cisplatin (CDDP). Its anticancer activity was confirmed in monotherapy against both CDDP-sensitive and -resistant bladder cancer cells. We classified arzanol as a novel mitotoxin that induces the fragmentation of mitochondria, and we identified a series of targets for arzanol that involve proteins of the class of mitochondria-associated quinone-binding oxidoreductases. Collectively, our results suggest arzanol as a valuable tool for autophagy research and as a lead compound for drug development in cancer therapy.

Natural Compounds as Therapeutic Agents: The Case of Human Topoisomerase IB

Natural products are widely used as source for drugs development. An interesting example is represented by natural drugs developed against human topoisomerase IB, a ubiquitous enzyme involved in many cellular processes where several topological problems occur due the formation of supercoiled DNA. Human topoisomerase IB, involved in the solution of such problems relaxing the DNA cleaving and religating a single DNA strand, represents an important target in anticancer therapy. Several natural compounds inhibiting or poisoning this enzyme are under investigation as possible new drugs. This review summarizes the natural products that target human topoisomerase IB that may be used as the lead compounds to develop new anticancer drugs. Moreover, the natural compounds and their derivatives that are in clinical trial are also commented on.

Potential significance of medicinal plants in forensic analysis: A review

Medicinal plants are a two-edged sword that might be exploited as a treatment specific dosage, and as deadly poisonous substances to commit murder or suicide when administered in high doses. Forensic experts can collect traces and residual materials from these toxic medicinal plants at a crime scene as forensic evidence. Further, more investigations need to be deeply implemented to in the future to understand the significance of medicinal plants in forensic investigations to detect these criminal offenses. Additionally, to provides a deep understanding of chemical substances that can impact human life positively or negatively with different doses as well as identifying the optimal or overdose concentrations for either treatments or poisonous effects using recent biotechnological approaches. This review aims to illustrate different contributions and the significance of medicinal plants in the field and further employment in the context of forensic science, especially in the Kingdom of Saudi Arabia.

Expanding the Scope of Detectable Microbial Natural Products by Complementary Analytical Methods and Cultivation Systems

Recent advances in genome sequencing have unveiled a large discrepancy between the genome-encoded capacity of microorganisms to produce secondary metabolites and the number detected. In this work, a two-platform mass spectrometry analysis for the comprehensive secondary metabolomics characterization of nine myxobacterial strains, focusing on extending the range of detectable secondary metabolites by diversifying analytical methods and cultivation conditions, is presented. Direct infusion measurements of crude extracts on a Fourier transform ion cyclotron resonance mass spectrometer are compared to a time-of-flight device coupled to liquid chromatography measurements. Both methods are successful in detecting known metabolites, whereas statistical analysis of unknowns highlights their complementarity: Strikingly, 82-99% of molecular features detected with one setup were not detectable with the other. Metabolite profile differences from our set of strains grown in liquid culture versus their swarming colonies on agar plates were evaluated. The detection of up to 96% more molecular features when both liquid and plate cultures were analyzed translates into increased chances to identify new secondary metabolites. Discrimination between primary and secondary metabolism in combination with GNPS molecular networking revealed strain Mx3 as particularly promising for the isolation of novel secondary metabolites among the nine strains investigated in this study.

Complex natural product production methods and options

Natural products have had a major impact upon quality of life, with antibiotics as a classic example of having a transformative impact upon human health. In this contribution, we will highlight both historic and emerging methods of natural product bio-manufacturing. Traditional methods of natural product production relied upon native cellular host systems. In this context, pragmatic and effective methodologies were established to enable widespread access to natural products. In reviewing such strategies, we will also highlight the development of heterologous natural product biosynthesis, which relies instead on a surrogate host system theoretically capable of advanced production potential. In comparing native and heterologous systems, we will comment on the base organisms used for natural product biosynthesis and how the properties of such cellular hosts dictate scaled engineering practices to facilitate compound distribution. In concluding the article, we will examine novel efforts in production practices that entirely eliminate the constraints of cellular production hosts. That is, cell free production efforts will be introduced and reviewed for the purpose of complex natural product biosynthesis. Included in this final analysis will be research efforts made on our part to test the cell free biosynthesis of the complex polyketide antibiotic natural product erythromycin.

Pharmacoinformatic Investigation of Medicinal Plants from East Africa

Medicinal plants have widely been used in the traditional treatment of ailments and have been proven effective. Their contribution still holds an important place in modern drug discovery due to their chemical, and biological diversities. However, the poor documentation of traditional medicine, in developing African countries for instance, can lead to the loss of knowledge related to such practices. In this study, we present the Eastern Africa Natural Products Database (EANPDB) containing the structural and bioactivity information of 1870 unique molecules isolated from about 300 source species from the Eastern African region. This represents the largest collection of natural products (NPs) from this geographical region, covering literature data of the period from 1962 to 2019. The computed physicochemical properties and toxicity profiles of each compound have been included. A comparative analysis of some physico-chemical properties like molecular weight, H-bond donor/acceptor, logPo/w , etc. as well scaffold diversity analysis has been carried out with other published NP databases. EANPDB was combined with the previously published Northern African Natural Products Database (NANPDB), to form a merger African Natural Products Database (ANPDB), containing ∼6500 unique molecules isolated from about 1000 source species (freely available at http://african-compounds.org). As a case study, latrunculins A and B isolated from the sponge Negombata magnifica (Podospongiidae) with previously reported antitumour activities, were identified via substructure searching as molecules to be explored as putative binders of histone deacetylases (HDACs).

Hetiamacin E and F, New Amicoumacin Antibiotics from Bacillus subtilis PJS Using MS/MS-Based Molecular Networking

To combat escalating levels of antibiotic resistance, novel strategies are developed to address the everlasting demand for new antibiotics. This study aimed at investigating amicoumacin antibiotics from the desert-derived Bacillus subtilis PJS by using the modern MS/MS-based molecular networking approach. Two new amicoumacins, namely hetiamacin E (1) and hetiamacin F (2), were finally isolated. The planar structures were determined by analysis of extensive NMR spectroscopic and HR-ESI-MS data, and the absolute configurations were concluded by analysis of the CD spectrum. Hetiamacin E (1) showed strong antibacterial activities against methicillin-sensitive and resistant Staphylococcus epidermidis at 2-4 µg/mL, and methicillin-sensitive and resistant Staphylococcus aureus at 8-16 µg/mL. Hetiamacin F (2) exhibited moderate antibacterial activities against Staphylococcus sp. at 32 µg/mL. Both compounds were inhibitors of protein biosynthesis demonstrated by a double fluorescent protein reporter system.