Tehranolide inhibits cell proliferation via calmodulin inhibition, PDE, and PKA activation

Advances in targeting Phosphodiesterase 1: From mechanisms to potential therapeutics

Phosphodiesterase 1 (PDE1) is an enzyme entrusted with the hydrolysis of the second messengers cAMP and cGMP, thereby governing a plethora of metabolic processes, encompassing ion channel modulation and cellular apoptosis. Recent advancements in the realm of small molecule structural variations have greatly facilitated the exploration of innovative applications for PDE1. Remarkably, a recent series of PDE1 inhibitors (PDE1i) have been meticulously formulated and devised, showcasing enhanced selectivity and potency. Among them, ITI-214 has entered Phase II clinical trials, holding promise for the treatment of Parkinson's disease and heart failure. Nevertheless, the majority of current PDE1 inhibitors have encountered substantial side effects in clinical trials attributable to their limited selectivity, this predicament presents a formidable obstacle in the development of specific small molecule inhibitors targeting PDE1. This Perspective endeavors to illuminate the potential design approaches, structure-activity relationships, and biological activities of current PDE1i, aiming to offer support and insights for clinical practice and the development of novel PDE1i.

Structure-Based Profiling of Potential Phytomolecules with AKT1 a Key Cancer Drug Target

Identifying cancer biomarkers is imperative, as upregulated genes offer a better microenvironment for the tumor; hence, targeted inhibition is preferred. The theme of our study is to predict molecular interactions between cancer biomarker proteins and selected natural compounds. We identified an overexpressed potential molecular target (AKT1) and computationally evaluated its inhibition by four dietary ligands (isoliquiritigenin, shogaol, tehranolide, and theophylline). The three-dimensional structures of protein and phytochemicals were retrieved from the RCSB PDB database (4EKL) and NCBI’s PubChem, respectively. Rational structure-based docking studies were performed using AutoDock. Results were analyzed based primarily on the estimated free binding energy (kcal/mol), hydrogen bonds, and inhibition constant, Ki, to identify the most effective anti-cancer phytomolecule. Toxicity and drug-likeliness prediction were performed using OSIRIS and SwissADME. Amongst the four phytocompounds, tehranolide has better potential to suppress the expression of AKT1 and could be used for anti-cancer drug development, as inhibition of AKT1 is directly associated with the inhibition of growth, progression, and metastasis of the tumor. Docking analyses reveal that tehranolide has the most efficiency in inhibiting AKT1 and has the potential to be used for the therapeutic management of cancer. Natural compounds targeting cancer biomarkers offer less rejection, minimal toxicity, and fewer side effects.

Co-treatment of Naringenin and Ketoprofen-RGD Suppresses Cell Proliferation via Calmodulin/PDE/cAMP/PKA Axis Pathway in Leukemia and Ovarian Cancer Cells

Background

Naringenin (Nar) has anti-inflammatory and anticarcinogenic properties. Arginine-glycine- aspartate (RGD) is a tripeptidic sequence used as an integrin ligand and targeting system for delivering chemotherapeutic agents to cancer cells.

Objectives

In this study, the inhibitory effects of Nar and ketoprofen-RGD on leukemia and ovarian cancer cells (K562 and SKOV3) were explored for the first time, focusing on their proliferation activity and their anti-inflammatory capacity.

Methods

Analyses were conducted on the calmodulin (CaM)-dependent phosphodiesterase 1 (PDE1) activation by ketoprofen-RGD, Nar, and their combination. These drugs' effects on protein kinase A (PKA) activation, intracellular cyclic adenosine monophosphate (cAMP) level, and PDE1 inhibition were identified. Later, it was also evaluated if ketoprofen-RGD alone or in combination with Nar had anti-inflammatory effects.

Results

Nar improved the antagonizing consequences of ketoprofen-RGD on the CaM protein, which hinders PDE1, improving PKA activity and cAMP levels. A mixture of ketoprofen-RGD and Nar and ketoprofen-RGD alone diminished K562 and SKOV3 cell viability through the cAMP/PKA pathway by inhibiting PDE1 and CaM. These two compounds showed anti-inflammatory effects on both cell lines.

Conclusions

This study indicated for the first time that combining ketoprofen-RGD and Nar can be a promising anti-inflammatory therapeutic regimen for treating leukemia and ovarian cancer.

Naringenin enhances anti-proliferation effect of 1-ferrocenyl-3-(4-methylsulfonylphenyl) propen-1-one on two different cells via targeting calmodulin signaling pathway

BACKGROUND

FMSP is a synthesized ferrocene derivative with anti-cancer characteristics on tumor cells. Naringenin is a polyphenolic flavonoid with anti-tumor ability.

METHODS

Cell viability and proliferation of two cancer cells and a normal cell line after treatment with these agents were determined with MTT assay. To predict the possible interaction between calmodulin (CaM) and FMSP and naringenin, docking studies were performed. By using fluorescence emission spectra, the effects of FMSP and naringenin on CaM structure and activity were studied. CaM-dependent activation of phosphodiesterase 1 (PDE1) by FMSP in relation to naringenin and their combination were compared. Effects of these compounds on PDE1 inhibition, cAMP accumulation, and cAMP-dependent protein kinase A (PKA) activation were assayed.

RESULTS

The combination of FMSP and naringenin had more inhibitory effects on CaM structure than FMSP and naringenin alone. Results of docking analyses also confirmed efficient interaction of the two compounds with a hydrophobic pocket of calmodulin active site. Kinetic analyses of these agents' interaction with CaM showed FMSP and naringenin both competitively inhibited PDE1 activation without changing the Vmax parameter. FMSP and naringenin synergistically increased Km values at a higher level compared to FMSP or naringenin alone. The combination of these two agents also had more cytotoxic effects on cancer cells than FMSP alone.

CONCLUSIONS

It was shown that mechanism of proliferation inhibition in both cancer cells by these compounds is based on CaM and consequent PDE inhibition followed by intracellular cAMP level elevation and increased PKA activity in a dose-dependent manner.

Artemisia scoparia promotes adipogenesis in the absence of adipogenic effectors

OBJECTIVE

Extracts of Artemisia scoparia (SCO) have antidiabetic properties in mice and enhance adipogenesis in vitro, but the underlying mechanisms are unknown. Thiazolidinediones, including rosiglitazone (ROSI), are pharmacological activators of peroxisome proliferator-activated receptor gamma that also promote adipogenesis. The aim of this study was to examine adipogenic pathways responsible for SCO-mediated adipogenesis and identify potential differences between SCO and ROSI in the ability to promote adipocyte development.

METHODS

The ability of SCO or ROSI to promote adipogenesis in 3T3-L1 cells following systematic omission of the common triad of adipogenic effectors dexamethasone, 1-methyl-3-isobutylxanthine (MIX), and insulin was examined. Adipogenesis was assessed by both neutral lipid quantitation and adipocyte marker gene expression.

RESULTS

The results demonstrate that SCO and ROSI promote adipogenesis and increase the expression of several peroxisome proliferator-activated receptor gamma target genes involved in lipid accumulation in the absence of MIX. However, ROSI can enhance adipogenesis in the absence of MIX and insulin and differentially regulates adipogenic and lipid metabolism genes as compared with SCO.

CONCLUSIONS

These data demonstrate the adipogenic capabilities of SCO are similar but not identical to ROSI, thereby warranting further research into SCO as a promising source of therapeutic compounds in the treatment of metabolic disease states.

Role of phosphodiesterase 1 in the pathophysiology of diseases and potential therapeutic opportunities

Cyclic nucleotide phosphodiesterases (PDEs) are superfamily of enzymes that regulate the spatial and temporal relationship of second messenger signaling in the cellular system. Among the 11 different families of PDEs, phosphodiesterase 1 (PDE1) sub-family of enzymes hydrolyze both 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) in a mutually competitive manner. The catalytic activity of PDE1 is stimulated by their binding to Ca²⁺/calmodulin (CaM), resulting in the integration of Ca²⁺ and cyclic nucleotide-mediated signaling in various diseases. The PDE1 family includes three subtypes, PDE1A, PDE1B and PDE1C, which differ for their relative affinities for cAMP and cGMP. These isoforms are differentially expressed throughout the body, including the cardiovascular, central nervous system and other organs. Thus, PDE1 enzymes play a critical role in the pathophysiology of diseases through the fundamental regulation of cAMP and cGMP signaling. This comprehensive review provides the current research on PDE1 and its potential utility as a therapeutic target in diseases including the cardiovascular, pulmonary, metabolic, neurocognitive, renal, cancers and possibly others.

Research Advances on Health Effects of Edible Artemisia Species and Some Sesquiterpene Lactones Constituents

The genus Artemisia, often known collectively as "wormwood", has aroused great interest in the scientific community, pharmaceutical and food industries, generating many studies on the most varied aspects of these plants. In this review, the most recent evidence on health effects of edible Artemisia species and some of its constituents are presented and discussed, based on studies published until 2020, available in the Scopus, Web of Sciences and PubMed databases, related to food applications, nutritional and sesquiterpene lactones composition, and their therapeutic effects supported by in vivo and clinical studies. The analysis of more than 300 selected articles highlights the beneficial effect on health and the high clinical relevance of several Artemisia species besides some sesquiterpene lactones constituents and their derivatives. From an integrated perspective, as it includes therapeutic and nutritional properties, without ignoring some adverse effects described in the literature, this review shows the great potential of Artemisia plants and some of their constituents as dietary supplements, functional foods and as the source of new, more efficient, and safe medicines. Despite all the benefits demonstrated, some gaps need to be filled, mainly related to the use of raw Artemisia extracts, such as its standardization and clinical trials on adverse effects and its health care efficacy.

Bicyclo [6.3.0] Undecane Sesquiterpenoids: Structures, Biological Activities, and Syntheses

Sesquiterpenoids constitute a marvelously varied group of natural products that feature a vast array of molecular architectures. Among them, the unusual bicyclo [6.3.0] undecane sesquiterpenoids are one of the most representative. To date, only approximately 42 naturally occurring compounds with this unique scaffold, which can be classified into seven different groups, have been reported. As the first-found member of each type, dactylol, asteriscanolide, dumortenol, toxicodenane C, and capillosanane S are characteristic of the four methyl groups on the five-eight-membered ring system. Only 11-hydroxyjasionone and sinuketal decorate the core with an isopropyl group. These natural products exhibit a wide range of bioactivities, including antifouling, anti-inflammatory, immune suppression, cytotoxic, antimutagenic, antiplasmodial, and antiviral activities. It was noted that some total syntheses of precapnellane-sesquiterpenoids (dactylol, poitediol, precapnelladiene), asteriscanolide, and 11-hydroxyjasionone have been achieved, because their cyclooctanoid core represents an important target for the development of synthetic strategies to prepare eight-membered ring-containing compounds. This review focuses on these natural sesquiterpenoids and their biological activities and synthesis, and aims to provide a foundation for further research of these interesting compounds.

Synthesis of Ergosterol Peroxide Conjugates as Mitochondria Targeting Probes for Enhanced Anticancer Activity

Inspired by the significant bioactivity of ergosterol peroxide, we designed and synthesized four fluorescent coumarin and ergosterol peroxide conjugates 8a–d through the combination of ergosterol peroxide with 7-N,N-diethylamino coumarins fluorophore. The cytotoxicity of synthesized conjugates against three human cancer cells (HepG2, SK-Hep1, and MCF-7) was evaluated. The results of fluorescent imaging showed that the synthesized conjugates 8a–d localized and enriched mainly in mitochondria, leading to significantly enhanced cytotoxicity over ergosterol peroxide. Furthermore, the results of biological functions of 8d showed that it could suppress cell colony formation, invasion, and migration; induce G2/M phase arrest of HepG2 cells, and increase the intracellular ROS level.

Antitumor Research on Artemisinin and Its Bioactive Derivatives

Cancer is the leading cause of human death which seriously threatens human life. The antimalarial drug artemisinin and its derivatives have been discovered with considerable anticancer properties. Simultaneously, a variety of target-selective artemisinin-related compounds with high efficiency have been discovered. Many researches indicated that artemisinin-related compounds have cytotoxic effects against a variety of cancer cells through pleiotropic effects, including inhibiting the proliferation of tumor cells, promoting apoptosis, inducing cell cycle arrest, disrupting cancer invasion and metastasis, preventing angiogenesis, mediating the tumor-related signaling pathways, and regulating tumor microenvironment. More importantly, artemisinins demonstrated minor side effects to normal cells and manifested the ability to overcome multidrug-resistance which is widely observed in cancer patients. Therefore, we concentrated on the new advances and development of artemisinin and its derivatives as potential antitumor agents in recent 5 years. It is our hope that this review could be helpful for further exploration of novel artemisinin-related antitumor agents.

Inhibitors of phosphodiesterase as cancer therapeutics

Phosphodiesterases (PDEs) are a class of enzymes that hydrolyze cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) which is involved in many physiological processes including visual transduction, cell proliferation and differentiation, cell-cycle regulation, gene expression, inflammation, apoptosis, and metabolic function. PDEs are composed of 11 different families and each family contains different subtypes. The distribution, expression, regulation mode and sensitivity to inhibitors of each subtype are different, and they are involved in cancer, inflammation, asthma, depression, erectile dysfunction and other pathological processes of development. A large number of studies have shown that PDEs play an important role in the development of tumors by affecting the intracellular level of cAMP and/or cGMP and PDEs could become diagnostic markers or therapeutic targets. This review will give a brief overview of the expression and regulation of PDE families in the process of tumorigenesis and their anti-tumor inhibitors, which may guide the design of novel therapeutic drugs targeting PDEs for anticancer agent.

Synthesis of 5α,8α-Ergosterol Peroxide 3-Carbamate Derivatives and a Fluorescent Mitochondria-Targeting Conjugate for Enhanced Anticancer Activities

Inspired by the significant anticancer activity of our previously screened natural ergosterol peroxide (1), we synthesized and characterized a series of novel ergosterol peroxide 3-carbamate derivatives. The antiproliferative activities of the synthesized compounds against human hepatocellular carcinoma cells (HepG2, SK-Hep1) and human breast cancer cells (MCF-7, MDA-MB231) were investigated. 5α,8α-Epidioxyergosta-3-yl-(piperazine-1)carbamate (3 d) and 5α,8α-epidioxyergosta-3-yl-(piperidin-4-methylamine)carbamate (3 f) and their hydrochloride salts exhibited significant in vitro antiproliferative activities against the tested tumor cell lines, with IC₅₀ values ranging from 0.85 to 4.62 μm. Furthermore, fluorescent imaging showed that the designed coumarin-3 d conjugate (5) localized mainly in mitochondria, leading to enhanced anticancer activities over the parent structure 1. As a whole, it appeared that substituent changes at the C3 position could serve as a promising launch point for further design of this type of steroidal anticancer agent.

Calmodulin inhibitors from natural sources: an update

Calmodulin (CaM) plays a central role in regulating a myriad of cellular functions in physiological and pathophysiological processes, thus representing an important drug target. In previous reviews, our group has reported relevant information regarding natural anti-CaM compounds up to 2009. Natural sources continue to provide a diverse and unique reservoir of CaM inhibitors for drug and research tool discovery. This review provides an update of natural products with reported CaM inhibitory properties, which includes around 70 natural products and some synthetic analogues, belonging to different structural classes. Most of these natural inhibitors were isolated from fungi and plants and belong to the stilbenoid, polyketide, alkaloid, and peptide structural classes. These products were discovered mainly using a fluorescence-based method on rationally designed biosensors, which are highly specific, low-cost, and selective and have short reaction times. The effect of several antimitotic drugs on Ca(2+)-hCaM is also described.