The synthesis and antitumor activity of lithocholic acid and its derivatives

Advancements in steroidal Pt(II) & Pt(IV) derivatives for targeted chemotherapy (2000-2023)

One of the key strategies in chemotherapy involves crosslinking the DNA strands of cancer cells to impede their replication, with platinum (Pt) coordination compounds being a prominent class and cisplatin being its major representative. Steroidal ligands tethered to DNA interactive Pt core act as drug carriers for targeted therapy. While crosslinking of nuclear or mitochondrial DNA strands using coordination complexes has been studied for years, there remains a lack of comprehensive reviews addressing the advancements made in steroidal-Pt derivatives. This review specifically focuses on advancements made in steroid-tethered structural derivatives of Pt(II) or prodrug Pt(IV) for targeted chemotherapy, synthesized between 2000 and 2023. This period was deliberately chosen due to the widespread use of computational techniques for more accurate structure-based drug-design in last two decades. This review discusses the strategy behind tethering steroidal ligands such as testosterone, estrogen, bile acids, and cholesterol to the central DNA interactive Pt core through specific linker groups. The steroidal ligands function as drug delivery vehicles of DNA interactive Pt core and bind with their respective target receptors or proteins that are often overexpressed in cancer cells, thus enabling targeted delivery of Pt moiety to interact with DNA. We discussed structural features such as the location of the linker group on the steroid, the mono, bi, and tridentate configuration of the chelating arm in coordination with Pt, and the rigidity and flexibility of the linker group. The comparative in vitro, in vivo activities, and relative binding affinities of the designed compounds against standard Pt drugs are also discussed. We also provided a critique of observed trends and shortcomings. Our review will provide insights into future molecular designing of targeted DNA crosslinkers and their structural optimization to achieve desired drug properties. From this analysis, we proposed further research directions leading to the future of targeted chemotherapy.

Research status of indole-modified natural products

Indole is a heterocyclic compound formed by the fusion of a benzene ring and pyrrole ring, which has rich biological activity. Many indole-containing compounds have been sold on the market due to their excellent pharmacological activity. For example, vincristine and reserpine have been widely used in clinical practice. The diverse structures and biological activities of natural products provide abundant resources for the development of new drugs. Therefore, this review classifies natural products by structure, and summarizes the research progress of indole-containing natural product derivatives, their biological activities, structure-activity relationship and research mechanism which has been studied in the past 13 years, so as to provide a basis for the development of new drug development.

Optimization and Impurity Control Strategy for Lithocholic Acid Production Using Commercially Plant-Sourced Bisnoralcohol

In this study, lithocholic acid (LCA) was prepared using commercially available plant-sourced bisnoralcohol (BA), and the overall yield of the product was 70.6% for five steps. To prevent process-related impurities, the isomerizations of catalytic hydrogenation in the C4-C5 double bond and reduction of the 3-keto group were optimized. The double bond reduction isomerization was improved (5β-H:5α-H = 97:3) using palladium-copper nanowires (Pd-Cu NWs) instead of Pd/C. The reduction of the 3-keto group was 100% converted to a 3α-OH product by 3α-hydroxysteroid dehydrogenase/carbonyl reductase catalysis. Moreover, the impurities during the optimization process were comprehensively studied. Compared with the reported synthesis methods, our developed method significantly improved the isomer ratio and overall yield, affording ICH-grade quality of LCA, and it is more cost-effective and suitable for large-scale production of LCA.

Combined treatment of disulfiram with PARP inhibitors suppresses ovarian cancer

Introduction

Due to the difficulty of early diagnosis, nearly 70% of ovarian cancer patients are first diagnosed at an advanced stage. Thus, improving current treatment strategies is of great significance for ovarian cancer patients. Fast-developing poly (ADP-ribose) polymerases inhibitors (PARPis) have been beneficial in the treatment of ovarian cancer at different stages of the disease, but PARPis have serious side effects and can result in drug resistance. Using PARPis in combination with other drug therapies could improve the efficacy of PRAPis.In this study, we identified Disulfiram as a potential therapeutic candidate through drug screening and tested its use in combination with PARPis.

Methods

Cytotoxicity tests and colony formation experiments showed that the combination of Disulfiram and PARPis decreased the viability of ovarian cancer cells.

Results

The combination of PARPis with Disulfiram also significantly increased the expression of DNA damage index gH2AX and induced more PARP cleavage. In addition, Disulfiram inhibited the expression of genes associated with the DNA damage repair pathway, indicating that Disulfiram functions through the DNA repair pathway.

Discussion

Based on these findings, we propose that Disulfiram reinforces PARPis activity in ovarian cancer cells by improving drug sensitivity. The combined use of Disulfiram and PARPis provides a novel treatment strategy for patients with ovarian cancer.

Design and synthesis of bile acid derivatives and their activity against colon cancer

Bile acids (BAs) containing both hydrophilic hydroxyl and carboxyl groups and hydrophobic methyl and steroid nuclei can promote the absorption of fat and other substances in the intestine, and they are synthesized by cholesterol in the liver and then returned to the liver through enteric liver circulation. Because there are many BA receptors on the cell membrane of colon tissues, BAs can improve the specific delivery and transport of medicines to colon tissues. Moreover, BAs have a certain anticancer and inflammation activity by themselves. Based on this theory, a series of BA derivatives against colon cancer including cholic acid (CA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA) and lithocholic acid (LCA) were designed and synthesized, and their antitumor activity was evaluated. For in vitro anti-tumor tests, all the compounds displayed cell proliferative inhibition to nine human malignant tumor cell lines to some degree, and in particular they showed stronger inhibition to the colon cancer cells than the other cell lines. Among them, four compounds (4, 5, 6, and 7) showed stronger activity than the other compounds as well as the positive control 5-FU against HCT116 cells, and their IC50 was between 21.32 μmol L-1 and 28.90 μmol L-1; cell clone formation and migration tests showed that they not only effectively inhibited the formation of HCT116 cell colonies, but also inhibited the HCT116 cell migration and invasion; moreover, they induced apoptosis, arrested the mitotic process at the G2/M phase of the cell cycle, reduced the mitochondrial membrane potential, increased the intracellular ROS levels, and reduced the expression of Bcl-2 and p-STAT3 in HCT 116 cells. In addition, they also displayed intermediate anti-inflammatory activity by inhibiting inflammatory mediators NO and downregulating TNF-α expression, which also is one of the causes of colon cancer. This suggests that they deserve to be further investigated as candidates for colon cancer treatment drugs.

In vitro protoscolicidal effects of lithocholic acid on protoscoleces of Echinococcus granulosus and its mechanism

Surgery has been found to be the best choice of treatment for hydatidosis. However, leakage of cyst contents during surgery is the foremost reason for recurrence of hydatidosis. In this study, we investigated the in vitro efficacy of lithocholic acid (LCA) against Echinococcus granulosus protoscoleces. The protoscoleces were divided into a control group, an albendazole (ABZ) positive control group and LCA intervention groups at concentrations of 0.5, 1, 2, and 3 mmol/L and stained with 0.1% eosin for observation using an inverted microscope; the protoscolecal ultrastructure was examined with SEM and TEM; the activities of ROS, SOD, and caspase-3 were investigated using an ROS kit, SOD kit, and caspase-3 kit, respectively; the contents of HO-1 and NQO-1 were analyzed by enzyme-linked immunosorbent assay; and the expression level of cytochrome c (Ctyc) was analyzed by western blotting. Results: As the concentration of LCA increased, the survival rate of protoscoleces gradually decreased. The microstructure shows that the external shape and internal structure were gradually deformed and collapse. SOD, GSH, HO-1 and NQO-1 decreased more significantly in the 3 mmol/L LCA group. However, ROS levels gradually increased. LCA treatment for 3 days at all concentrations significantly increased caspase-3 activity and expression in a dose-dependent manner. LCA decreased the level of Ctyc protein in vitro. LCA demonstrated a parasiticidal effect on the protoscoleces of Echinococcus granulosus in vitro. LCA may induce apoptosis of E. granulosus protoscoleces by oxidative stress and mitochondrial pathways.

The role of key gut microbial metabolites in the development and treatment of cancer

In recent years, the role of gut microbial metabolites on the inhibition and progression of cancer has gained significant interest in anticancer research. It has been established that the gut microbiome plays a pivotal role in the development, treatment and prognosis of different cancer types which is often mediated through the gut microbial metabolites. For instance, gut microbial metabolites including bacteriocins, short-chain fatty acids and phenylpropanoid-derived metabolites have displayed direct and indirect anticancer activities through different molecular mechanisms. Despite the reported anticancer activity, some gut microbial metabolites including secondary bile acids have exhibited pro-carcinogenic properties. This review draws a critical summary and assessment of the current studies demonstrating the carcinogenic and anticancer activity of gut microbial metabolites and emphasises the need to further investigate the interactions of these metabolites with the immune system as well as the tumour microenvironment in molecular mechanistic and clinical studies.

Investigation of the potential of bile acid methyl esters as inhibitors of aldo-keto reductase 1C2: insight from molecular docking, virtual screening, experimental assays and molecular dynamics

Human aldo-keto reductase 1C isoforms catalyze reduction of endogenous and exogenous compounds, including therapeutic drugs, and are associated with chemotherapy resistance. AKR1C2 is involved in metastatic processes and is a target for the treatment of various cancers. Here we used molecular docking to explore a series of bile acid methyl esters as AKR1C2 inhibitors. Autodock 4.2 ranked 10 of 11 test compounds above decoys based on ursodeoxycholate, an AKR1C2 inhibitor, while 5 ranked above 94% of decoys in Autodock Vina. Seven inactives reported not to inhibit AKR1C2 ranked below the decoy threshold. Virtual screen of a natural product library in Autodock Vina using the same parameters, identified steroidal derivatives, bile acids, and other AKR1C ligands in the top 5%. In experiments, 6 out of 11 tested bile acid methyl esters inhibited >50% of AKR1C2 activity, while 2 compounds were AKR1C3 inhibitors. The top ranking compound showed dose-dependent inhibition of AKR1C2 (IC50 ~3.6 µM). Molecular dynamics was used to explore interactions between a bile acid methyl ester and the AKR1C2 active site. Our molecular docking results identify AKR1C2 as a target for bile acid methyl esters, which combined with virtual screening results provides new directions for the synthesis of AKR1C inhibitors.

Polyphenol Oxidase as a Promising Alternative Therapeutic Agent for Cancer Therapy

Cancers have always been the most difficult to fight, the treatment of cancer is still not considered. Thus, exploring new anticancer drugs is still imminent. Traditional Chinese medicine has played an important role in the treatment of cancer. Polyphenol oxidase (PPO) extracted from Edible mushroom has many related reports on its characteristics, but its role in cancer treatment is still unclear. This study aims to investigate the effects of PPO extracted from Edible mushroom on the proliferation, migration, invasion, and apoptosis of cancer cells in vitro and explore the therapeutic effects of PPO on tumors in vivo. A cell counting kit-8 (CCK8) assay was used to detect the effect of PPO on the proliferation of cancer cells. The effect of PPO on cancer cell migration ability was detected by scratch test. The effect of PPO on the invasion ability of cancer cells was detected by a transwell assay. The effect of PPO on the apoptosis of cancer cells was detected by flow cytometry. Female BALB/c mice (18-25 g, 6-8 weeks) were used for in vivo experiments. The experiments were divided into control group, model group, low-dose group (25 mg/kg), and high-dose group (50 mg/kg). In vitro, PPO extracted from Edible mushroom significantly inhibited the proliferation, migration, and invasion capability of breast cancer cell 4T1, lung cancer cell A549, and prostate cancer cell C4-2, and significantly promoted the apoptosis of 4T1, A549, and C4-2. In vivo experiments showed PPO inhibitory effect on tumor growth. Collectively, the edible fungus extract PPO could play an effective role in treating various cancers, and it may potentially be a promising agent for treating cancers.

Iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabled aldehyde C-H methylation

A practical and general iron-catalyzed domino decarboxylation-oxidation of α,β-unsaturated carboxylic acids enabling aldehyde C-H methylation for the synthesis of methyl ketones has been developed. This mild, operationally simple method uses ambient air as the sole oxidant and tolerates sensitive functional groups for the late-stage functionalization of complex natural-product-derived and polyfunctionalized molecules.

Synthesis and Anticancer Activity of Hybrid Molecules Based on Lithocholic and (5Z,9Z)-Tetradeca-5,9-dienedioic Acids Linked via Mono(di,tri,tetra)ethylene Glycol and α,ω-Diaminoalkane Units

For the first time, hybrid molecules were synthesized on the basis of lithocholic and (5Z,9Z)-1,14-tetradeca-5,9-dienedicarboxylic acids, obtained in two stages using the homo-cyclomagnesiation reaction of 2-(hepta-5,6-diene-1-yloxy)tetrahydro-2H-pyran at the key stage. The resulting hybrid molecules containing 5Z,9Z-dienoic acids are of interest as novel synthetic biologically active precursors to create modern drugs for the treatment of human oncological diseases. The synthesized hybrid molecules were found to exhibit extremely high in vitro inhibitory activity against human topoisomerase I, which is 2-4 times higher than that of camptothecin, a known topoisomerase I inhibitor. Using flow cytometry and fluorescence microscopy, it was first shown that these new molecules are efficient apoptosis inducers in HeLa, U937, Jurkat, K562, and Hek293 cell cultures. In addition, the results of investigations into the effect of the synthesized acids on mitochondria and studies of possible DNA damage in Jurkat tumor cells are also presented.

Hydrocortisone Suppresses Early Paraneoplastic Inflammation And Angiogenesis To Attenuate Early Hepatocellular Carcinoma Progression In Rats

Background

Inflammation is implicated in both hepatic cirrhosis development and hepatocellular carcinogenesis, and treatment with long-acting glucocorticoid dexamethasone prevented liver carcinogenesis in mice. However, it is unclear whether glucocorticoids have anti-inflammatory effect on hepatocellular carcinoma (HCC) and if short-acting glucocorticoids (with fewer adverse effects) inhibit paraneoplastic inflammation and HCC progression.

Methods

To investigate whether different types of anti-inflammatory agents attenuate HCC progression, the current study compared effects of treatments with hydrocortisone (a short-acting glucocorticoid) or aspirin on HCC progression. HCC was induced in diethylnitrosamine-treated rats which were randomly divided into 4 groups (n=8), respectively receiving orally once daily vehicle, glucuronolactone, glucuronolactone+hydrocortisone, and glucuronolactone+aspirin. Diethylnitrosamine (DEN) was given to rats in drinking water (100mg/L) to induce HCC. At weeks 12 and 16 post-induction, effects were compared on HCC nodule formation, microvessel density, and macrophage infiltration, and levels of paraneoplastic protein expression of tumor necrosis factor (TNF)-α, p38 mitogen-activated protein kinase (p38), phosphorylated p38 (p-p38), nuclear factor (NF)-κB, interleukin (IL)-10, hepatocyte growth factor (HGF), transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF).

Results

Compared to the model and glucuronolactone alone groups, HCC nodule number and microvessel density in the glucuronolactone+hydrocortisone group were significantly lower at week 12. At week 12 but not week 16, significantly lower levels of macrophages, TNF-α, p-p38, NF-κB, IL-10, HGF, TGF-β1 and VEGF were observed in the paraneoplastic tissue of the glucuronolactone+hydrocortisone group when compared with the control and glucuronolactone groups.

Conclusion

The results suggest that hydrocortisone treatment reduces macrophage polarization, expression of inflammatory and anti-inflammatory cytokines, and angiogenesis in paraneoplastic tissue, and attenuates early HCC progression. Although hydrocortisone did not have attenuation effect on advanced solid tumor, the current study shows the potential benefits and supports potential clinical use of hydrocortisone in attenuating early progression of HCC, which is through suppressing paraneoplastic inflammation and angiogenesis.

A facile synthesis of ursodeoxycholic acid and obeticholic acid from cholic acid

A novel synthetic route of producing ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) was developed through multiple reactions from cheap and readily-available cholic acid. The reaction conditions of the key elimination reaction of mesylate ester group were also investigated and optimized, including solvent, base and reaction temperature. In the straightforward synthetic route for preparation of UDCA and OCA, most of the reaction steps have high conversions with average yields of 94% and 92%, and overall yield up to 65% (7 steps) and 36% (11 steps) from cholic acid, respectively. This promising route offers economical and efficient strategies for potential large-scale production of UDCA and OCA.

Mechanisms through which lithocholic acid delays yeast chronological aging under caloric restriction conditions

All presently known geroprotective chemical compounds of plant and microbial origin are caloric restriction mimetics because they can mimic the beneficial lifespan- and healthspan-extending effects of caloric restriction diets without the need to limit calorie supply. We have discovered a geroprotective chemical compound of mammalian origin, a bile acid called lithocholic acid, which can delay chronological aging of the budding yeast Saccharomyces cerevisiae under caloric restriction conditions. Here, we investigated mechanisms through which lithocholic acid can delay chronological aging of yeast limited in calorie supply. We provide evidence that lithocholic acid causes a stepwise development and maintenance of an aging-delaying cellular pattern throughout the entire chronological lifespan of yeast cultured under caloric restriction conditions. We show that lithocholic acid stimulates the aging-delaying cellular pattern and preserves such pattern because it specifically modulates the spatiotemporal dynamics of a complex cellular network. We demonstrate that this cellular network integrates certain pathways of lipid and carbohydrate metabolism, some intercompartmental communications, mitochondrial morphology and functionality, and liponecrotic and apoptotic modes of aging-associated cell death. Our findings indicate that lithocholic acid prolongs longevity of chronologically aging yeast because it decreases the risk of aging-associated cell death, thus increasing the chance of elderly cells to survive.

The Apoptosis Effect on Liver Cancer Cells of Gold Nanoparticles Modified with Lithocholic Acid

Functionalized gold nanoparticles (AuNPs) have widely applied in many fields, due to their good biocompatibility, a long drug half-life, and their bioactivity is related to their size and the modified ligands on their surface. Here, we synthesized the AuNPs capped with ligands that possess polyethylene glycol (PEG) and lithocholic acid (LCA) linked by carboxyl groups (AuNP@MPA-PEG-LCA). Our cytotoxicity results indicated that AuNP@MPA-PEG-LCA have better cell selectivity; in other words, it could inhibit the growth of multiple liver cancer cells more effectively than other cancer cells and normal cells. Apoptosis plays a role in AuNP@MPA-PEG-LCA inhibition cell proliferation, which was convincingly proved by some apoptotic index experiments, such as nuclear staining, annexin V-FITC, mitochondrial membrane potential (MMP) analysis, and AO/EB staining experiments. The most potent AuNP@MPA-PEG-LCA were confirmed to efficiently induce apoptosis through a reactive oxygen species (ROS) mediating mitochondrial dysfunction. And AuNP@MPA-PEG-LCA could be more effective in promoting programmed cell death of liver cancer cells.

Protective effects of yangonin from an edible botanical Kava against lithocholic acid-induced cholestasis and hepatotoxicity

Accumulation of toxic bile acids in liver could cause cholestasis and liver injury. The purpose of the current study is to evaluate the hepatoprotective effect of yangonin, a product isolated from an edible botanical Kava against lithocholic acid (LCA)-induced cholestasis, and further to elucidate the involvement of farnesoid X receptor (FXR) in the anticholestatic effect using in vivo and in vitro experiments. The cholestatic liver injury model was established by intraperitoneal injections of LCA in C57BL/6 mice. Serum biomarkers and H&E staining were used to identify the amelioration of cholestasis after yangonin treatment. Mice hepatocytes culture, gene silencing experiment, real-time PCR and Western blot assay were used to elucidate the mechanisms underlying yangonin hepatoprotection. The results indicated that yangonin promoted bile acid efflux and reduced hepatic uptake via an induction in FXR-target genes Bsep, Mrp2 expression and an inhibition in Ntcp, all of which are responsible for bile acid transport. Furthermore, yangonin reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in gene expression of Sult2a1, which are involved in bile acid synthesis and metabolism. In addition, yangonin suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α and IL-1β. In vitro evidences showed that the changes in transporters and enzymes induced by yangonin were abrogated when FXR was silenced. In conclusions, yangonin produces protective effect against LCA-induced hepatotoxity and cholestasis due to FXR-mediated regulation. Yangonin may be an effective approach for the prevention against cholestatic liver diseases.