Drug discovery inspired by bioactive small molecules from nature

Heterocyclic phytometabolites formononetin and arbutin prevent in vitro oxidative and alkylation-induced mutagenicity

Phenolic phytometabolites are promising bioactive compounds for management of genomic instability related diseases. Formononetin (FMN) and arbutin (ARB) are found in several plant sources. Our goal was to investigate the safety and efficacy of FMN and ARB using in vitro both standardized and alternative toxicogenetic methods. FMN and ARB were evaluated through the OECD'S guidelines No. 471 (Bacterial Reverse Mutation Test -Salmonella/microsome) and No. 487 (In vitro Mammalian Micronucleus Test - CBMN assay), accordingly to the mentioned recommendations. Also, antimutagenicity of FMN and ARB was assessed in S. Typhimurium strains TA98, TA100 and TA1535, following pre-, co- and post- treatment protocols. Liver human lineages HepG2 and F C3H were assayed for cytotoxicity after exposure to FMN and ARB (24, 48 and 72 h) using in vitro WST-1 test. ARB showed no mutagenicity in the Salmonella/microsome test under both metabolic conditions (in presence or absence of 4 % S9 mix), but FMN was cytotoxic to the TA97 and TA100 strains after metabolic activation. Under this same condition, FMN induced an increase in the mutagenic index of strain TA1535 at two of the highest tested concentrations. Even so, ARB and FMN exhibited protection against the induced alkylation of DNA in multiple action modes. In the antimutagenicity assay, FMN reached the maximum of 80 % of oxidative-provoked mutagenicity reduction in TA98 strain in co-treatment with known mutagen, besides 69 % of reduction in TA100 in the same exposure condition. ARB showed up to reduce induced mutagenicity in strains TA100 and TA1535, reaching percentages from 55 % to 100 % of antimutagenicity in all of the tested exposure models against alkylating agent. In the CBMN assay, no increase in micronuclei formation was observed. The results suggest that FMN and ARB prevent DNA from mutation using multi-targeted antimutagenic roles. Finally, our data suggests that FMN and ARB are not genotoxic and presented encouraging antimutagenicity action in vitro, being promising compounds for use in genomic instability-related diseases therapeutics.

Doping In Vivo Alkylation in E. coli by Introducing the Direct Sulfurylation Pathway of S. cerevisiae

Methylation and alkylation are important techniques used for the synthesis and derivatisation of small molecules and natural products. Application of S-adenosylmethionine (SAM)-dependent methyltransferases (MTs) in biotechnological hosts such as Escherichia coli lowers the environmental impact of alkylation compared to chemical synthesis and facilitates regio- and chemoselective alkyl chain transfer. Here, we address the limiting factor for SAM synthesis, methionine supply, to accelerate in vivo methylation activity. Introduction of the direct sulfurylation pathway, consisting of O-acetylhomoserine sulfhydrolase (ScOAHS) and O-acetyltransferase (ScMET2), from S. cerevisiae into E. coli and supplementation with methanethiol or the corresponding disulfide improves atom-economic methylation activity in three different MT reactions. Up to 17-fold increase of conversion compared to the sole expression of the MT and incorporation of up to 79 % of the thiol compound added were achieved. Promiscuity of ScOAHS allowed in vivo production of methionine analogues from organic thiols. Further co-overproduction of a methionine adenosyltransferase yielded SAM analogues which were further transferred by MTs onto different substrates. For methylation of non-physiological substrates, conversion rates up to 73 % were achieved, with an isolated yield of 41 % for N-methyl-2,5-aminonitrophenol. The here described technique enables E. coli to become a biotechnological host for improved methylation and selective alkylation reactions.

Phosphatidylserine improves aging sepsis survival, modulates gut microbiome, and prevents sepsis-associated encephalopathy

Aged adults are prone to both short- and long-term complications following sepsis due to ineffective therapy. Phosphatidylserine (PS) is a membrane nutrient supplement known to enhance cognition and brain function, but its potential effects in treating sepsis are not well-documented. Our study aimed to explore the potential of PS in improving outcomes in sepsis and sepsis-associated encephalopathy (SAE). Middle-aged mice were administered PS for two months following induction of sepsis by lipopolysaccharides. The results indicated a significant increase in the survival rate of mice treated with PS after sepsis. Surviving mice underwent open field and shuttle box tests 45 days post-sepsis, revealing potential alleviation of neurobehavioral impairments due to PS pretreatment. Analysis at 60 days post-sepsis euthanasia showed reduced cleaved-caspase 3 in neurons and glial cell markers in the PS-treated group compared to the untreated sepsis group. Furthermore, PS administration effectively reduced proinflammatory cytokine gene expression in the hippocampus of mice with SAE, potentially inhibiting the TBK1/NLRP3/ASC signaling pathway. In the gut, PS pretreatment modulated β-diversity while maintaining jejunal morphology and colon ZO-1 expression, without significantly affecting α-diversity indices. Our findings suggest that PS administration improves survival rates, modulates the gut microbiome, preserves gut integrity, and ameliorates brain pathology in survived mice after sepsis. Importantly, these findings have significant implications for sepsis treatment and cognitive function preservation in aging individuals, providing new insights and sparking further interest and investigation into the potential of PS in sepsis treatment.

PROTAC derivatization of natural products for target identification and drug discovery: Design of evodiamine-based PROTACs as novel REXO4 degraders

INTRODUCTION

Natural products (NPs) play a crucial role in the development of therapeutic drugs. However, it is still highly challenging to identify the targets of NPs. Besides, NPs usually exert their pharmacological activities via acting on multiple targets or pathways, which also poses great difficulties for the target identification of NPs.

OBJECTIVES

Inspired by our continuous efforts in designing drug-like protein degraders, this study introduced a successful example for the target identification and drug discovery of natural products evodiamine by employing PROTAC technology.

METHODS

Taking advantages of proteolysis targeting chimera (PROTAC), herein an integrated strategy combining PROTAC derivatization, quantitative proteomic analysis and binding affinity validation was developed for target identification and drug discovery of antitumor NP evodiamine.

RESULTS

In this study, both highly potent PROTACs and negative controls were designed for quantitative proteomic analysis. Furthermore, REXO4 was confirmed as a direct target of 3-fluoro-10-hydroxylevodiamine, which induced cell death through ROS. In addition, the PROTAC 13c effectively degraded REXO4 both in vitro and in vivo, leading to potent antitumor activities and reduced toxic side effects.

CONCLUSION

In summary, we developed an integrated strategy for the target identification and drug discovery of NPs, which was successfully applied to the PROTAC derivatization and target characterization of evodiamine. This proof-of-concept study highlighted the superiority of PROTAC technology in target identification of NPs and accelerated the process of NPs-based drug discovery, exhibiting broad application in NP-based drug development.

Topical and transdermal botanical formulations of the Chinese pharmacopoeia-A review

In pharmaceutics, ingredients are classified as active ingredients and excipients. In topical/transdermal phytomedicines, an ingredient may serve both functions. Published information on these dual-purpose ingredients and their pharmacological relevance is limited. An intriguing scenario arises in traditional Chinese medicine (TCM) formulations, where active ingredients and excipients are undifferentiated. This study analyzes ingredients in TCM topical/transdermal formulations, aiming at harmonization of understanding of TCMs. The most commonly recorded ingredients from such formulations in the Chinese pharmacopoeia 2020 (ChP 2020) are reviewed, aiming at developing innovative topical/transdermal phytomedicines. Current editions of Chinese historical documents were reviewed to explore the principles underlying the use of these ingredients. TCM formulations containing botanical drugs for topical/transdermal application were selected from the ChP 2020. The use of botanical materials in TCM formulations is guided by the "Jun-Chen-Zuo-Shi" principle rooted in Yin-Yang and the five elements' theories. In the ChP 2020, 155 botanical drugs, along with 40 excipients (from the "procedure" section, focusing on processing and technical parameters), were identified from 34 botanical formulations intended for topical/transdermal application. Pungent and aromatic botanical materials were the most frequently recorded. Adhesive plasters were the most commonly recorded TCM dosage form, employing specific matrix blends. This new perspective of study reveals the prevalence of pungent and aromatic botanical materials, the common use of adhesive plasters, multifunctional properties of botanical oils, and formulation adaptability in TCM topical/transdermal products. These insights should inform novel formulation designs for both pharmaceutical and phytopharmacological research.

Camellia sinensis L. alleviates OVA-induced allergic asthma through NF-κB and MMP-9 pathways

Allergic asthma, a type of chronic airway inflammation, is a global health concern because of its increasing incidence and recurrence rates. Camellia sinensis L. yields a variety type of teas, which are also used as medicinal plants in East Asia and are known to have antioxidant, anti-inflammatory, and immune-potentiating properties. Here, we examined the constituents of C. sinensis L. extract (CSE) and evaluated the protective effects of CSE on allergic asthma by elucidating the underlying mechanism. To induce allergic asthma, we injected the sensitization solution (mixture of ovalbumin (OVA) and aluminum hydroxide) into mice intraperitoneally on days 0 and 14. Then, the mice were exposed to 1% OVA by a nebulizer on days 21 to 23, while intragastric administration of CSE (30 and 100 mg/kg) was performed each day on days 18 to 23. We detected five compounds in CSE, including (-)-epigallocatechin, caffeine, (-)-epicatechin, (-)-epigallocatechin gallate, and (-)-epicatechin gallate. Treatment with CSE remarkably decreased the airway hyperresponsiveness, OVA-specific immunoglobulin E level, and inflammatory cell and cytokine levels of mice, with a decrease in inflammatory cell infiltration and mucus production in lung tissue. Treatment with CSE also decreased the phosphorylation of nuclear factor-κB (NF-κB) and the expression of matrix-metalloproteinase (MMP)-9 in asthmatic mice. Our results demonstrated that CSE reduced allergic airway inflammation caused by OVA through inhibition of phosphorylated NF-κB and MMP-9 expression.

Assessment of antimicrobial activity and GC-MS using culture filtrate of local marine Bacillus strains

Secondary metabolites produced by Bacillus species from marine sources encompass a variety of compounds such as lipopeptides, isocoumarins, polyketides, macrolactones, polypeptides and fatty acids. These bioactive substances exhibit various biological activities, including antibiotic, antifungal, antiviral, and antitumor properties. This study aimed to isolate and identify a particular species of Bacillus from marine water and organisms that can produce bioactive secondary metabolites. Among the 73 Bacillus isolates collected, only 5 exhibited antagonistic activity against various viral and bacterial pathogens. The active isolates were subjected to 16S rRNA sequencing to determine their taxonomical affiliation. Among them, Bacillus tequilensis CCASU-2024-66 strain no. 42, with the accession number ON 054302 in GenBank, exhibited the highest inhibitory potential. It displayed an inhibition zone of 21 mm against Bacillus cereus while showing a minimum zone of inhibition of 9 mm against Escherichia coli and gave different inhibition against pathogenic fungi, the highest inhibition zone 15 mm against Candida albicans but the lowest inhibition zone 10 mm was against Botrytis cinerea, Fusarium oxysporum. Furthermore, it demonstrated the highest percentage of virucidal effect against the Newcastle virus and influenza virus, with rates of 98.6% and 98.1%, respectively. Furthermore, GC-MS analysis was employed to examine the bioactive substance components, specifically focusing on volatile and polysaccharide compounds. Based on these results, Bacillus tequilensis strain 42 may have the potential to be employed as an antiviral agent in poultry cultures to combat Newcastle and influenza, two extremely destructive viruses, thus reducing economic losses in the poultry production sector. Bacteria can be harnessed for the purpose of preserving food and controlling pathogenic fungi in both human and plant environments. Molecular docking for the three highly active derivatives 2,3-Butanediol, 2TMS, D-Xylopyranose, 4TMS, and Glucofuranoside, methyl 2,3,5,6-tetrakis-O-(trimethylsilyl) was carried out against the active sites of Bacillus cereus, Listeria monocytogenes, Candida albicans, Newcastle virus and influenza virus. The data obtained from molecular docking is highly correlated with that obtained from biology. Moreover, these highly active compounds exhibited excellent proposed ADMET profile.

Meirols A-C: Bioactive Catecholic Compounds from the Marine-Derived Fungus Meira sp. 1210CH-42

Three new catecholic compounds, named meirols A-C (2-4), and one known analog, argovin (1), were isolated from the marine-derived fungus Meira sp. 1210CH-42. Their structures were determined by extensive analysis of 1D, 2D NMR, and HR-ESIMS spectroscopic data. Their absolute configurations were elucidated based on ECD calculations. All the compounds exhibited strong antioxidant capabilities with EC50 values ranging from 6.01 to 7.47 μM (ascorbic acid, EC50 = 7.81 μM), as demonstrated by DPPH radical scavenging activity assays. In the α-glucosidase inhibition assay, 1 and 2 showed potent in vitro inhibitory activity with IC50 values of 184.50 and 199.70 μM, respectively (acarbose, IC50 = 301.93 μM). Although none of the isolated compounds exhibited cytotoxicity against one normal and six solid cancer cell lines, 1 exhibited moderate cytotoxicity against the NALM6 and RPMI-8402 blood cancer cell lines with GI50 values of 9.48 and 21.00 μM, respectively. Compound 2 also demonstrated weak cytotoxicity against the NALM6 blood cancer cell line with a GI50 value of 29.40 μM.

Crystal Structures and Physicochemical Properties of 3-Chloro-4-hydroxyphenylacetic Acid Salts with Amines

3-chloro-4-hydroxyphenylacetic acid (CHPAA) is a fungal metabolite. It is a small molecule that is useful in crystal engineering studies due to the functional groups present. Six amines were selected to form salts with CHPAA. Linear derivatives included diethylamine (DEA) and di-N-butylamine (DBM). The aromatic compounds chosen were 2-aminopyridine (A2MP), 2-amino-4-methylpyridine (A24MP), 2-amino-6-methylpyridine (A26MP) and 4-dimethylaminopyridine (DMAP). The salts were characterised using single-crystal X-ray diffraction, thermal analysis, FTIR spectroscopy and Hirshfeld surface analysis. For all the crystal structures, N-H···O and C-H···Cl contacts were present. O-H···O contacts were found in all the crystal structures except for (CHPAA2-)2DEA+, which was also the only structure that displayed a Cl···Cl contact. Furthermore, C-H···O contacts were found in all the crystal structures except for (CHPAA-)(DBM+). The thermal stability trend showed that the DBM salt was more stable than the DEA salt. For the aromatic co-formers, the thermal stability trend showed the following: CHPAA-(DMAP+) > (CHPAA-)(A2MP+)>2CHPAA-2A26MP+>(CHPAA-)(A24MP+).

Spexin-based galanin receptor 2 agonist improves renal injury in mice with type 2 diabetes

The spexin-based GALR2 agonist (NS200) is a novel drug, which has shown antidepressant and anxiolytic action in a recent experimental study. In this study, we investigated the effects of NS200 on renal injury in an animal model of type 2 diabetes. Eight-week-old diabetic db/db mice were administered NS200 for 12 weeks. NS200 was intraperitoneally administered at a dose of 1.0 mg/kg/day. Metabolic parameters and structural and molecular changes in the kidneys were compared among the three groups: non-diabetic db/m control, db/db mice, and NS200-treated db/db mice. In db/db mice, NS200 administration did not impact the body weight, food and water intake, urinary volume, fasting blood glucose level, or HbA1c levels. Insulin and glucose tolerance were also unaffected by NS200 treatment. However, NS200 improved urinary albumin excretion and glomerulosclerosis in diabetic kidneys. Activation of TGFβ1 and insulin signaling pathways, such as PI3 K /AKT/ERK, were inhibited by NS200. In conclusion, a spexin-based GALR2 agonist attenuated diabetic nephropathy by alleviating renal fibrosis in mice with type 2 diabetes. Spexin-based GALR2 agonists have considerable potential as novel treatment agents in diabetic nephropathy.

The Anticancer Effect of Napabucasin (BBI608), a Natural Naphthoquinone

Napabucasin (also known as BBI608) is a natural naphthoquinone originally identified as a cancer cell stemness inhibitor. Accumulated in vitro and in vivo evidence demonstrated that napabucasin showed significant anticancer effects in various types of cancers. Napabucasin inhibits cancer cell proliferation, induces apoptosis and cell cycle arrest, and suppresses metastasis and relapse. Such anticancer activities of napabucasin mainly rely on the inhibition of cancer stemness by targeting signal transducer and activator of transcription 3 (STAT3) and its related gene inhibition. However, several novel molecular targets for napabucasin, such as NAD(P)H:quinone oxidoreductase 1 (NQO1) and thioredoxin reductase 1 (TrxR1), have been reported. Napabucasin represents a promising anticancer lead for multiple cancers. In this mini review, the anticancer potential and the molecular mechanism of napabucasin will be briefly highlighted.

Effective derivation of ventricular cardiomyocytes from hPSCs using ascorbic acid-containing maturation medium

Cardiomyocytes derived from human pluripotent stem cells (hPSCs) can be used in various applications including disease modeling, drug safety screening, and novel cell-based cardiac therapies. Here, we report an optimized selection and maturation method to induce maturation of cardiomyocytes into a specific subtype after differentiation driven by the regulation of Wnt signaling. The medium used to optimize selection and maturation was in a glucose starvation conditions, supplemented with either a nutrition complex or ascorbic acid. Following optimized selection and maturation, more cardiac Troponin T (cTnT)-positive cardiomyocytes were detected using albumin and ascorbic acid than B27. In addition, ascorbic acid enriched maturation of ventricular cardiomyocytes. We compared cardiomyocyte-specific gene expression patterns under different selection and maturation conditions by next-generation sequencing (NGS) analysis. Our optimized conditions will enable simple and efficient maturation and specification of the desired cardiomyocyte subtype, facilitating both biomedical research and clinical applications.