Synthesis and Biological Evaluation of Novel Olean-28,13β-lactams as Potential Antiprostate Cancer Agents

Therapeutic potential of oleanolic acid in liver diseases

Liver-associated diseases affect millions of individuals worldwide. In developed countries, the incidence of viral hepatitis is reducing due to advancements in disease prevention, diagnosis, and treatment. However, with improvements in living standards, the prevalence of metabolic liver diseases, such as non-alcoholic fatty liver disease and alcohol-related liver disease, is expected to increase; notably, this rise in the prevalence of metabolic liver disease can lead to the development of more severe liver diseases, including liver failure, cirrhosis, and liver cancer. The growing demand for natural alternative therapies for chronic diseases has highlighted the importance of studying the pharmacology of bioactive compounds in plants. One such compound is oleanolic acid (OA), a pentacyclic triterpenoid known for its antioxidant, anti-inflammatory, anti-ulcer, antibacterial, antiviral, antihypertensive, anti-obesity, anticancer, anti-diabetic, cardioprotective, hepatoprotective, and anti-neurodegenerative properties. Recent studies have demonstrated that OA treatment can reduce the risk of pathological liver damage, ultimately alleviating liver dysregulation and restoring overall liver function. This review aims to explore the latest research on the biological effects of OA and its derivatives. Notably, it explores the mechanisms of action of these compounds in both in vitro and in vivo research models and, ultimately, highlights OA as a promising candidate for alternative therapies in the treatment and management of chronic liver disease.

Recent advances in medicinal chemistry of oleanolic acid derivatives

Oleanolic acid (OA), a ubiquitous pentacyclic oleanane-type triterpene isolated from edible and medicinal plants, exhibits a wide spectrum of pharmacological activities and tremendous therapeutic potential. However, the undesirable pharmacokinetic properties limit its application and development. Numerous researches on structural modifications of OA have been carried out to overcome this limitation and improve its pharmacokinetic and therapeutic properties. This review aims to compile and summarize the recent progresses in the medicinal chemistry of OA derivatives, especially on structure-activity relationship in the last few years (2010-2021). It gives insights into the rational design of bioactive derivatives from OA scaffold as promising therapeutic agents.

A synthesized olean-28,13β-lactam targets YTHDF1-GLS1 axis to induce ROS-dependent metabolic crisis and cell death in pancreatic adenocarcinoma

Background

Pancreatic adenocarcinoma (PAAD) is a severe malignant with a 5-year survival rate of approximately 9%. Oleanolic acid is a well-known natural triterpenoid which exhibits pharmacological activities. We previously synthesized a series of oleanolic acid derivatives and evaluated the tumor-suppressive activity of olean-28,13β-lactam (B28) in prostate cancer. However, the detailed mechanism remains to be understood.

Methods

The anti-tumor activity of B28 in PAAD was confirmed by RTCA, colony formation assay and flow cytometry. GO and KEGG enrichment analyses were performed to analyze the differentially expressed genes (DEGs) obtained by RNA sequencing. The effects of B28 on cell bioenergetics were evaluated by seahorse analyzer. Lenti-virus packaged plasmids were performed to knockdown or overexpress target genes. Alteration of mitochondrial membrane potential, ROS and GSH/GSSG were measured by corresponding detection kits according to the manufacturer's protocol.

Results

We evaluated and confirmed the promising anti-tumor activity of B28 in vitro. RNA-seq profile indicated that multiple metabolic pathways were interrupted in B28 treated PAAD cells. Next, we demonstrated that B28 induces cellular bioenergetics crisis to inhibit PAAD cells growth and induce cell death. We further validated that cell cycle arrest, inhibition of cell growth, cell apoptosis and cell bioenergetics disruption were functionally rescued by ROS scavenger NAC. Mechanistically, we found glutamine metabolism was inhibited due to B28 administration. Moreover, we validated that down-regulation of GLS1 contributes to ROS generation and bioenergetics interruption induced by B28. Furthermore, we elucidated that YTHDF1-GLS1 axis is the potential downstream target of B28 to induce PAAD cell metabolic crisis and cell death. Finally, we also confirmed the anti-tumor activity of B28 in vivo.

Conclusions

Current study demonstrates B28 disrupts YTDFH1-GLS1 axis to induce ROS-dependent cell bioenergetics crisis and cell death which finally suppress PAAD cell growth, indicating that this synthesized olean-28,13β-lactam maybe a potent agent for PAAD intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02562-6.

A Hepatocellular Carcinoma Targeting Nanostrategy with Hypoxia-Ameliorating and Photothermal Abilities that, Combined with Immunotherapy, Inhibits Metastasis and Recurrence

Hepatocellular carcinoma (HCC) is a common and highly malignant tumor that is prone to recurrence and metastasis and has no effective treatment. Unsurprisingly, its prognosis is quite poor; early detection methods and effective low-toxicity treatments are urgently needed. To achieve these goals, we designed a multifunctional, U.S. Food and Drug Administration-approved Prussian blue (PB) nanoparticle (NP) with a porous metal organic frame loaded with sorafenib (SF), conjugated with HCC-specific targeting peptide SP94 and the near-infrared dye cyanine (Cy)5.5. These NPs are amenable to multimodal imaging for dynamic monitoring of their biodistribution and tumor-targeting effects. The SP94-PB-SF-Cy5.5 NPs achieved targeted delivery and controlled SF release and exhibited good photothermal effects. In this strategy, photothermal therapy and SF treatment complement each other, reducing the side effects of SF and achieving a therapeutic effect without local tumor recurrence. In addition, the catalase-like ability of the NPs alleviates tumor hypoxia, and their photothermal effects induce immunogenic cell death, leading to the release of tumor-associated antigens. These effects combine to trigger an antitumor immune response; the NPs also displayed promising inhibitory effects on tumor metastasis and recurrence and produced an abscopal effect and long-term immunological memory when combined with antiprogrammed death-ligand 1 (PD-L1) immunotherapy. These safe, multifunctional NPs represent a valuable treatment option for HCC. In addition, this next-generation treatment model may provide some ideas for the management of HCC and other cancers.

Prophylactic and therapeutic roles of oleanolic acid and its derivatives in several diseases

Oleanolic acid (OA) and its derivatives are widely found in diverse plants and are naturally effective pentacyclic triterpenoid compounds with broad prophylactic and therapeutic roles in various diseases such as ulcerative colitis, multiple sclerosis, metabolic disorders, diabetes, hepatitis and different cancers. This review assembles and presents the latest in vivo reports on the impacts of OA and OA derivatives from various plant sources and the biological mechanisms of OA activities. Thus, this review presents sufficient data proposing that OA and its derivatives are potential alternative and complementary therapies for the treatment and management of several diseases.

Direct Transformation of N-Protected α,β-Unsaturated γ-Amino Amides into γ-Lactams through a Base-Mediated Molecular Rearrangement

Here, we are reporting a single-step transformation of N-protected α,β-unsaturated γ-amino amides into 5,5-disubstituted γ-lactams through a base-mediated new molecular rearrangement. In contrast to the known N- to C(O) cyclization of saturated γ-amino acids into corresponding γ-lactams, the new rearrangement involves the cyclization between N-terminal C^γ- to C-terminal amide N. The cyclization process was initiated by the migration of double bond from α,β → β,γ position. The enamine-imine tautomerization of the new β,γ-double bond and subsequent 5-exo-trig cyclization of terminal amide leads to the formation of N-protected 5,5-disubstituted γ-lactam. The structures of various γ-lactams obtained from the rearrangement were studied in single crystals. Overall, the results reported here demonstrate the facile and single-step transformation of N-protected α,β-unsaturated γ-amino amides into γ-lactams and provided an excellent opportunity to construct small-molecule peptidomimetics.

Synthesis and biological evaluation of 3-nitro-4-chromanone derivatives as potential antiproliferative agents for castration-resistant prostate cancer

A series of novel 3-nitro-4-chromanones were synthesized and their in vitro cytotoxicity was evaluated on castration-resistant prostate cancer cell (CRPC) lines using the sulforhodamine B (SRB) assay. The amide derivatives showed more potent antitumor activity than their corresponding ester derivatives. Most of the tested compounds showed less toxicity towards human fibroblasts (HAF) compared with the tumor cell lines. The optimal compound 36 possessed much more potent antiproliferative activity than the positive compound cisplatin. The colony formation, cell cycle distribution, apoptosis, transwell migration and wound healing assays of 36 were performed on CRPC cell lines.

Antitumorigenic and antiangiogenic efficacy of apatinib in liver cancer evaluated by multimodality molecular imaging

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related mortality worldwide. Sorafenib is the standard first-line treatment for advanced HCC, but its efficacy is limited. Apatinib is a small-molecule tyrosine kinase inhibitor that has shown promising antitumor effects in gastric and non-small cell lung cancers in clinical trials, but there have been only a few studies reporting its anti-HCC effects in vitro and in HCC xenograft models. Hence, our present study systemically investigated and compared the antitumorigenic and antiangiogenic efficacy of apatinib and sorafenib in HCC in vitro and in vivo using multimodality molecular imaging, including bioluminescence imaging (BLI), bioluminescence tomography (BLT), fluorescence molecular imaging (FMI), and computed tomography angiography (CTA). Moreover, the safety and side effects of the two drugs were systemically evaluated. We found that apatinib showed a comparable therapeutic efficacy to sorafenib for the inhibition of HCC. The drug safety evaluation revealed that both of these drugs caused hypertension and mild liver and kidney damage. Sorafenib caused diarrhea, rash, and weight loss in mice, but these effects were not observed in mice treated with apatinib. In conclusion, apatinib has similar antitumorigenic and antiangiogenic efficacy as sorafenib in HCC with less toxicity. These findings may provide preclinical evidence supporting the potential application of apatinib for the treatment of HCC patients.

Researchers have combined different sophisticated imaging techniques to assess the safety and efficacy of liver cancer therapy in animal models. Many hepatocellular carcinoma (HCC) patients respond to sorafenib, but this drug is expensive and may cause severe side-effects. Qian Liang at China’s Institute of Automation, Beijing, and colleagues have employed cutting-edge imaging technologies to study an alternative drug, apatinib, which has shown promise for stomach and lung cancer and has an excellent safety profile. Using bioluminescence imaging, the researchers could directly visualize apatanib-mediated inhibition of tumor growth in live mice much earlier than would be possible with other methods. The researchers subsequently used additional imaging techniques to demonstrate that apatanib inhibits tumor blood vessel growth. These findings reveal a promising alternative treatment for HCC, as well as a powerful strategy for drug testing in animals.

Novel hybrids derived from aspirin and chalcones potently suppress colorectal cancer in vitro and in vivo

Colorectal cancer (CRC) remains the fourth leading cause of cancer deaths around the world despite the availability of many approved small molecules for treatment. The issues lie in the potency, selectivity and targeting of these compounds. Therefore, new strategies and targets are needed to optimize and develop novel treatments for CRC. Here, a group of novel hybrids derived from aspirin and chalcones were designed and synthesized based on recent reports of their individual benefits to CRC targeting and selectivity. The most active compound 7h inhibited proliferation of CRC cell lines with better potency compared to 5-fluorouracil, a currently used therapeutic agent for CRC. Importantly, 7h had 8-fold less inhibitory activity against non-cancer CCD841 cells. In addition, 7h inhibited CRC growth via the inhibition of the cell cycle in the G1 phase. Furthermore, 7h induced apoptosis by activating caspase 3 and PARP cleavage, as well as increasing ROS in CRC cells. Finally, 7h significantly retarded the CRC cell growth in a mouse xenograft model. These findings suggest that 7h may have potential to treat CRC.

The Sources of Essential Fatty Acids for Allergic and Cancer Patients; a Connection with Insight into Mammalian Target of Rapamycin: A Narrative Review

Background:

Disturbance in essential fatty acids (EFA) metabolism plays a key role in autoimmune diseases, but EFA supplementation with sources of borage, evening primrose, hemp seed and fish oils was not effective in atopic and cancer diseases, as that seen in the case of multiple sclerosis. It seems that two complexes of the mammalian target of rapamycin (mTOR) signaling, mTORC1 and mTORC2, are congruent with the two bases of the Traditional Iranian Medicine (TIM) therapy, Cold and Hot nature, which are essential for the efficacy of functional oils for controlling immune responses in autoimmune diseases.

Methods:

We searched PubMed database, Web of Science (WOS), Google Scholar, Scopus and selected studies by predefined eligibility criteria. We then assessed their quality and extracted data.

Results:

The oils controlled by Cold or Hot nature may be helpful in maintaining homeostasis and preventing autoimmune diseases. In summary, studies of randomized controlled trials for allergy and cancer patients found no improvement in the signs or response to tests, despite a remarkable change in EFA fractions in the blood by supplementation with sources of borage, evening primrose, hemp seed and fish oils. In contrast, portulaca oleracea oil exhibited protective effects by anti-inflammatory properties via the PI3K/Akt/mTORC2 pathway with a deviation immune response to Th1 to treat atopic diseases and cancer.

Conclusions:

According to the concept of Traditional Iranian Medicine therapy, in contrast to Cold-nature oils, EFA supplementation with the sources of Hot-nature oilsis not suitable for the treatment of atopic and cancerous diseases.

Synthesis and evaluation of 2-cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide as a potent anti-inflammatory agent for intervention of LPS-induced acute lung injury

The present study was designed to synthesize 2-Cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide (1), a lactone derivative of oleanolic acid (OA) and evaluate its anti-inflammatory activity. Compound 1 significantly diminished nitric oxide (NO) production and down-regulated the mRNA expression of iNOS, COX-2, IL-6, IL-1β, and TNF-α in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Further in vivo studies in murine model of LPS-induced acute lung injury (ALI) showed that 1 possessed more potent protective effects than the well-known anti-inflammatory drug dexamethasone by inhibiting myeloperoxidase (MPO) activity, reducing total cells and neutrophils, and suppressing inflammatory cytokines expression, and thus ameliorating the histopathological conditions of the injured lung tissue. In conclusion, compound 1 could be developed as a promising anti-inflammatory agent for intervention of LPS-induced ALI.

Anti-hepatocarcinoma effect of cordycepin against NDEA-induced hepatocellular carcinomas via the PI3K/Akt/mTOR and Nrf2/HO-1/NF-κB pathway in mice

The purpose of the present study was to evaluate the effects of cordycepin (CA) on N-nitrosodiethylamine (NDEA)-induced hepatocellular carcinomas (HCC) and explore its potential mechanisms. Mice were randomly assigned to four groups: control group, NDEA group, NDEA+CA (20mg/kg) group, NDEA+CA (40mg/kg) group. The animal of each group were given NDEA (100ppm) in drinking water. One hour later, CA, which was dissolved in PBS, were intragastrically administered for continuous seven days. The results showed that CA reduced the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in liver and serum. CA also reduced the levels of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), methane dicarboxylic aldehyde (MDA), and stored the activity of superoxygen dehydrogenises (SOD) in serum. CA could obviously attenuate the hepatic pathological alteration. Furthermore, CA effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase(PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR). In conclusion, our research suggested that CA exhibited protective effects on NDEA-induced hepatocellular carcinomas via the PI3K/Akt/mTOR pathway.

Novel Derivative of Bardoxolone Methyl Improves Safety for the Treatment of Diabetic Nephropathy

Currently, no effective and safe medicines are available to treat diabetic nephropathy (DN). Bardoxolone methyl (CDDO-Me) has displayed promising anti-DN activity as well as serious side effects in clinical trials, probably because the highly reactive α-cyano-α,β-unsaturated ketone (CUK) in ring A of CDDO-Me can covalently bind to thiol functionalities in many biomacromolecules. In this study, we designed and synthesized a γ-glutamyl transpeptidase (GGT)-based and CUK-modified derivative of CDDO-Me (2) to address this issue. 2 can be specifically cleaved by GGT, which is highly expressed in the kidney, to liberate CDDO-Me in situ. It should be noted that 2 exhibited anti-DN efficacy comparable to that of CDDO-Me with much less toxicity in cells and db/db mice, suggesting that its safety is better than CDDO-Me. Our findings not only reveal the therapeutic potential of 2 but also provide a strategy to optimize other synthetic molecules or natural products bearing a pharmacophore like CUK to achieve safer pharmaceutical drugs.

Antihepatocarcinoma Effect of Portulaca oleracea L. in Mice by PI3K/Akt/mTOR and Nrf2/HO-1/NF-κB Pathway

The purpose of the present study was to evaluate the pharmacological effects of Portulaca oleracea L. (Purslane) (PL) on N-nitrosodiethylamine- (NDEA-) induced hepatocellular carcinomas (HCC) and explore its potential mechanism. Mice were randomly assigned to four groups: control group, NDEA group, NDEA + Purslane (100 mg/kg) group, and NDEA + Purslane (200 mg/kg) group. The animal of each group was given NDEA (100 ppm) in drinking water. 1 h later, Purslane dissolved in PBS was intragastrically administered for continuous seven days. The results showed that Purslane reduced the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in liver and serum. Purslane also reduced the contents of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and methane dicarboxylic aldehyde (MDA) and restored the activity of superoxygen dehydrogenises (SOD) in serum. Purslane could obviously attenuate the hepatic pathological alteration. Furthermore, treatment with Purslane effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), nuclear factor-kappa B (NF-κB), and inhibitor of NF-κBα (IκBα) and upregulated the expressions of NF-E2-related factor 2 (Nrf2) and heme oxygenase- (HO-) 1. In conclusion, our research suggested that Purslane exhibited protective effects on NDEA-induced hepatocellular carcinomas by anti-inflammatory and antioxidative properties via the PI3K/Akt/mTOR and Nrf2/HO-1/NF-κB pathway.

Potent Inhibition of Nitric Oxide-Releasing Bifendate Derivatives against Drug-Resistant K562/A02 Cells in Vitro and in Vivo

Multidrug resistance is a major obstacle to successful chemotherapy for leukemia. In this study, a series of nitric oxide (NO)-releasing bifendate derivatives (7a-n) were synthesized. Biological evaluation indicated that the most active compound (7a) produced relatively high levels of NO and significantly inhibited the proliferation of drug-resistant K562/A02 cells in vitro and in vivo. In addition, 7a induced the mitochondrial tyrosine nitration and the intracellular accumulation of rhodamine 123 by inhibiting P-gp activity in K562/A02 cells. Furthermore, 7a remarkably down-regulated AKT, NF-κB, and ERK activation and HIF-1α expression in K562/A02 cells, which are associated with the tumor cell proliferation and drug resistance. Notably, the antitumor effects were dramatically attenuated by an NO scavenger or elimination of the NO-releasing capability of 7a, indicating that NO produced by 7a contributed to, at least partly, its cytotoxicity against drug-resistant K562/A02 cells. Overall, 7a may be a potential agent against drug-resistant myelogenous leukemia.

Highly efficient asymmetric hydrogenation of cyano-substituted acrylate esters for synthesis of chiral γ-lactams and amino acids

A highly efficient Rh-catalyzed asymmetric hydrogenation of 3-cyano acrylate esters is reported for the first time, which provides straightforward access to chiral cyano compounds with excellent enantioselectivities (up to 98% ee) and high turnover numbers (TON up to 10 000).