Chemotherapeutic properties and side-effects associated with the clinical practice of terpene alkaloids: paclitaxel, docetaxel, and cabazitaxel

Exploring the Biomedical Potential of Terpenoid Alkaloids: Sources, Structures, and Activities

Terpenoid alkaloids are recognized as a class of compounds with limited numbers but potent biological activities, primarily derived from plants, with a minor proportion originating from animals and microorganisms. These alkaloids are synthesized from the same prenyl unit that forms the terpene skeleton, with the nitrogen atom introduced through β-aminoethanol, ethylamine, or methylamine, leading to a range of complex and diverse structures. Based on their skeleton type, they can be categorized into monoterpenes, sesquiterpenes, diterpenes, and triterpene alkaloids. To date, 289 natural terpenoid alkaloids, excluding triterpene alkaloids, have been identified in studies published between 2019 and 2024. These compounds demonstrate a spectrum of biological activities, including anti-inflammatory, antitumor, antibacterial, analgesic, and cardioprotective effects, making them promising candidates for further development. This review provides an overview of the sources, chemical structures, and biological activities of natural terpenoid alkaloids, serving as a reference for future research and applications in this area.

Dual pH/redox-responsive hyperbranched polymeric nanocarriers with TME-trigger size shrinkage and charge reversible ability for amplified chemotherapy of breast cancer

A novel pH/redox-responsive hyperbranched MeO-PEG-b-(NIPAAm-co-PBAE) nanoparticles (NPs) were designed with size shrinkage and charge-reversible potential for targeted delivery of docetaxel (DTX) to MDA-MB-231 cell lines. In the tumor microenvironment (TME), amine protonation induces charge reversal and disulfide bond cleavage under high TME GSH concentration causing size shrinkage, improved deep tumor penetration, and active targeting of the therapeutic agents. These nano drug delivery systems (NDDSs) significantly promoted cancer cell uptake (~ 100% at 0.5 h), facilitating site-specific delivery and deep tumor penetration. The MTT assay revealed significantly higher cytotoxicity (P value < 0.0001) for DTX-loaded NPs compared to free DTX. Cell cycle analysis revealed G2/M (58.3 ± 2.1%) and S (21.5 ± 1.3%) arrest for DTX-loaded NPs, while free DTX caused G2/M (67.9 ± 1.1%) and sub-G1 (10.3 ± 0.8%) arrest. DTX-loaded NPs induced higher apoptosis (P value < 0.001) in MDA-MB-231 cells (71.5 ± 2.8%) compared to free DTX (42.3 ± 3.1%). Western blotting and RT-PCR assays confirmed significant up-regulation of protein levels and apoptotic genes by DTX-loaded NPs compared to free DTX. In conclusion, TME-responsive charge reversal and size-shrinkable smart NDDSs designed based on low pH, and high glutathione (GSH), offer more effective site-specific delivery of therapeutic agents to tumors.

Piperlongumine and its derivatives against cancer: A recent update and future prospective

Piperlongumine, or piplartine (PL), is a bioactive alkaloid isolated from Piper longum L. and a potent phytoconstituent in Indian Ayurveda and traditional Chinese medicine with a lot of therapeutic benefits. Apart from all of its biological activities, it demonstrates multimodal anticancer activity by targeting various cancer-associated pathways and being less toxic to normal cells. According to their structure-activity relationship (SAR), the trimethylphenyl ring (cinnamoyl core) and 5,6-dihydropyridin-2-(1H)-one (piperdine core) are responsible for the potent anticancer activity. However, it has poor intrinsic properties (low aqueous solubility, poor bioavailability, etc.). As a result, pharmaceutical researchers have been trying to optimise or modify the structure of PL to improve the drug-likeness profiles. The present review selected 26 eligible research articles on PL derivatives published between 2012 and 2023, followed by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) format. We have thoroughly summarised the anticancer potency, mode of action, SAR and drug chemistry of the proposed PL-derivatives against different cancer cells. Overall, SAR analyses with respect to anticancer potency and drug-ability revealed that substitution of methoxy to hydroxyl, attachment of ligustrazine and 4-hydroxycoumarin heterocyclic rings in place of phenyl rings, and attachment of heterocyclic rings like indole at the C7-C8 olefin position in native PL can help to improve anticancer activity, aqueous solubility, cell permeability, and bioavailability, making them potential leads. Hopefully, the large-scale collection and critical drug-chemistry analyses will be helpful to pharmaceutical and academic researchers in developing potential, less-toxic and cost-effective PL-derivatives that can be used against different cancers.

Protective Effects of Glatiramer Acetate Against Paclitaxel-Induced Peripheral Neuropathy in Rats: A Role for Inflammatory Cytokines and Oxidative Stress

Chemotherapy-induced peripheral neuropathy (CIPN) is a major challenge for cancer patients who undergo chemotherapy with paclitaxel. Therefore, finding effective therapies for CIPN is crucial. Glatiramer acetate is used to treat multiple sclerosis that exerts neuroprotective properties in various studies. We hypothesized that glatiramer acetate could also improve the paclitaxel-induced peripheral neuropathy. We used a rat model of paclitaxel (2 mg/kg/every other day for 7 doses)-induced peripheral neuropathy. Rats were treated with either different doses of glatiramer acetate (1, 2, 4 mg/kg/day) or its vehicle for 14 days in separate groups. The mechanical and thermal sensitivity of the rats by using the Von Frey test and the Hot Plate test, respectively, were assessed during the study. The levels of oxidative stress (malondialdehyde and superoxide dismutase), inflammatory markers (TNF-α, IL-10, NF-kB), and nerve damage (H&E and S100B staining) in the sciatic nerves of the rats were also measured at the end of study. Glatiramer acetate (2 and 4 mg/kg) exerted beneficial effects on thermal and mechanical allodynia tests. It also modulated the inflammatory response by reducing TNF-α and NF-κB levels, enhancing IL-10 production, and improving the oxidative stress status by lowering malondialdehyde and increasing superoxide dismutase activity in the sciatic nerve of the rats. Furthermore, glatiramer acetate enhanced nerve conduction velocity in all treatment groups. Histological analysis revealed that glatiramer acetate (2 and 4 mg/kg) prevented paclitaxel-induced damage to the nerve structure. These results suggest that glatiramer acetate can alleviate the peripheral neuropathy induced by paclitaxel.

TRF2 as novel marker of tumor response to taxane-based therapy: from mechanistic insight to clinical implication

BACKGROUND

Breast Cancer (BC) can be classified, due to its heterogeneity, into multiple subtypes that differ for prognosis and clinical management. Notably, triple negative breast cancer (TNBC) - the most aggressive BC form - is refractory to endocrine and most of the target therapies. In this view, taxane-based therapy still represents the elective strategy for the treatment of this tumor. However, due variability in patients' response, management of TNBC still represents an unmet medical need. Telomeric Binding Factor 2 (TRF2), a key regulator of telomere integrity that is over-expressed in several tumors, including TNBC, has been recently found to plays a role in regulating autophagy, a degradative process that is involved in drug detoxification. Based on these considerations, we pointed, here, at investigating if TRF2, regulating autophagy, can affect tumor sensitivity to therapy.

METHODS

Human TNBC cell lines, over-expressing or not TRF2, were subjected to treatment with different taxanes and drug efficacy was tested in terms of autophagic response and cell proliferation. Autophagy was evaluated first biochemically, by measuring the levels of LC3, and then by immunofluorescence analysis of LC3-puncta positive cells. Concerning the proliferation, cells were subjected to colony formation assays associated with western blot and FACS analyses. The obtained results were then confirmed also in mouse models. Finally, the clinical relevance of our findings was established by retrospective analysis on a cohort of TNBC patients subjected to taxane-based neoadjuvant chemotherapy.

RESULTS

This study demonstrated that TRF2, inhibiting autophagy, is able to increase the sensitivity of TNBC cells to taxanes. The data, first obtained in in vitro models, were then recapitulated in preclinical mouse models and in a cohort of TNBC patients, definitively demonstrating that TRF2 over-expression enhances the efficacy of taxane-based neoadjuvant therapy in reducing tumor growth and its recurrence upon surgical intervention.

CONCLUSIONS

Based on our finding it is possible to conclude that TRF2, already known for its role in promoting tumor formation and progression, might represents an Achilles' heel for cancer. In this view, TRF2 might be exploited as a putative biomarker to predict the response of TNBC patients to taxane-based neoadjuvant chemotherapy.

Clinicopathological Significance and Expression Pattern of Bcl2 in Breast Cancer: A Comprehensive in silico and in vitro Study

B-cell lymphoma/leukemia gene-2 (Bcl-2) is the primary proto-oncogene that has been shown to work by preventing apoptosis/programmed cell death. Bcl-2 combines a variety of cell-generated signals associated to the survival and death of cells. In glioma, lung, and breast cancer, Bcl-2 over-expression has been linked to an increase in invasion and migration. Many treatment regimens that target Bcl2 have been established and approved, and thus increasing the survival rates of the patients. The primary goal of this research was to recognize new therapeutic compounds that target Bcl2 and assess Bcl2 expression pattern in BC patients. We used various bioinformatic tools as well as several in vitro assays to look out the expression and inhibition of Bcl2 in BC. Our study depicted that Bcl2 had a strong connection with tumour stroma, notably with suppressor cells originating from myeloid tissues. Moreover, in vitro and in silico research identified Paclitaxel as a promising natural substance that targets Bcl2. Overall, this work shows that Bcl2 overexpression accelerates the development of BC, and that targeting Bcl2 in combination with other drugs will dramatically improve BC patient's response to treatment and prevent the emergence of drug resistance.

Chloroquine and Chemotherapeutic Compounds in Experimental Cancer Treatment

Chloroquine (CQ) and its derivate hydroxychloroquine (HCQ), the compounds with recognized ability to suppress autophagy, have been tested in experimental works and in clinical trials as adjuvant therapy for the treatment of tumors of different origin to increase the efficacy of cytotoxic agents. Such a strategy can be effective in overcoming the resistance of cancer cells to standard chemotherapy or anti-angiogenic therapy. This review presents the results of the combined application of CQ/HCQ with conventional chemotherapy drugs (doxorubicin, paclitaxel, platinum-based compounds, gemcitabine, tyrosine kinases and PI3K/Akt/mTOR inhibitors, and other agents) for the treatment of different malignancies obtained in experiments on cultured cancer cells, animal xenografts models, and in a few clinical trials. The effects of such an approach on the viability of cancer cells or tumor growth, as well as autophagy-dependent and -independent molecular mechanisms underlying cellular responses of cancer cells to CQ/HCQ, are summarized. Although the majority of experimental in vitro and in vivo studies have shown that CQ/HCQ can effectively sensitize cancer cells to cytotoxic agents and increase the potential of chemotherapy, the results of clinical trials are often inconsistent. Nevertheless, the pharmacological suppression of autophagy remains a promising tool for increasing the efficacy of standard chemotherapy, and the development of more specific inhibitors is required.

Durvalumab and taxane family combination therapy enhances the antitumoral effects for NSCLC: An in vitro study

Immunotherapy has lately become the most preferred cancer treatment method, and for non-small cell lung cancer (NSCLC) first-line treatment, there are many immunotherapy options. This study aimed to assess the effectiveness and toxicity of paclitaxel (PTX), docetaxel (DTX) chemotherapy, immune checkpoint inhibitor treatment (durvalumab; DVL), and their combination in NSCLC. A-549 cells were treated with DVL in combination with PTX and DTX (a quarter of the IC50 ) to investigate their anticancer effects on these cells. The MTT assay, wound healing tests, and double-staining with Annexin V/PI were used to assess the cell viability, apoptosis, and migration. The results showed that a combination of 0.35 mg/mL DVL with 6.5 μg/mL PTX and 1.75 μg/mL DTX produced a synergistic effect with CI values of 0.88, 0.37, and 0.81, respectively. Moreover, the PTX + DTX + DVL combination led to a significantly increased apoptotic rate up to 88.70 ± 3.39% in the A549 cell line compared to monotherapy (p < .001). In addition, we found that the combination therapy with these agents increased the expression level of Bax, Cas-3, p53, and Bax/Bcl-2 ratio in all experimental groups. In conclusion, the results suggest that combining anti-PD-L1 antibody therapy with chemotherapy may provide a promising approach to enhance treatment outcomes and be a potentially efficacious strategy for treating NSCLC patients. Further research and clinical investigations are needed to elucidate the underlying molecular mechanisms and validate the therapeutic potential of these compounds in vivo.

Design of carboxymethylcellulose-conjugated polymeric prodrug micelles for enhanced in vivo performance of docetaxel

Docetaxel (DTX) has become one of the most important cytotoxic drugs to treat cancer; nevertheless, its poor hydrophilicity and non-specific distribution of DTX lead to detrimental side effects. In this article, we devised carboxymethylcellulose (CMC)-conjugated polymeric prodrug micelles (mPEG-CMC-DTX PMs) for DTX delivery. The ester-bonded polymeric prodrug, mPEG-CMC-DTX, was synthesized and exhibited the capacity for self-assembling into polymeric micelles. The CMC is profusely substituted and acetylated to promote the coupling rate of DTX. Covalent binding of DTX and CMC through an ester bond can be hydrolyzed to dissociate the bond under the action of esterase in the tumor. The mPEG-CMC-DTX PMs displayed promoted drug loading (>50 %, wt), commendable stability, and sustained release behavior in vitro. The gradual release of the prodrug amplified the selectivity of cytotoxicity between normal cells and tumor cells, mitigating the systemic toxicity of mPEG-CMC-DTX PMs and enabling dose intensification. Notably, mPEG-CMC-DTX PMs demonstrated a superior antitumor efficacy and low systemic toxicity due to the elevated tolerance dosage (even at 40 mg/kg DTX). In summation, mPEG-CMC-DTX PMs harmonized the antitumor efficacy and toxicity of DTX. In essence, innovative perspectives for the rational design of CMC-conjugated polymeric prodrug micelles for the delivery of potently toxic drugs were proffered.

Identification of the therapeutic mechanism of the saffron crocus on glioma through network pharmacology and bioinformatics analysis

Saffron crocus is a herbal medicine of traditional Tibetan medicine (TTM). Saffron extract has been indicated to inhibit tumor cell growth and promote tumor cell apoptosis in a variety of cancers, including glioma, but the specific mechanism is not clear. To study the possible mechanism of saffron action on glioma, network pharmacology and bioinformatics analysis methods were used in this study. We used the online database to obtain the active ingredients of saffron and their targets. Glioma-related targets were also acquired from online database. We intersected drug targets with glioma-related targets and conducted PPI network analysis to obtain network core genes. Then, we obtained RNA-seq data from The Cancer Genome Atlas (TCGA) database for glioma patients. Through different expression analysis and lasso regression, further screening of core genes in the network was conducted, and a prognostic model was established. The sample was divided into two groups with high and low risk using this model. The RNA-seq data from the Chinese Glioma Genome Atlas (CGGA) database were used to further validate our prediction model. Then, we explored the difference in pathways enrichment between high-risk patients and low-risk patients and calculated the difference in immune microenvironment between the two groups. Finally, we used scRNA-seq data in the CGGA database to analyze the cell types in which the model gene is mainly enriched and predicted the cell types which saffron effected on.

Network pharmacology and experimental verification reveal the mechanism of safranal against glioblastoma (GBM)

Introduction

Safranal is an active component of the traditional Tibetan medicine (TTM) saffron, which has potential anticancer activity.

Methods and results

Here, we studied the therapeutic effect and mechanism of safranal on GBM. CCK-8, GBM-brain organoid coculture experiments and 3D tumour spheroid invasion assays showed that safranal inhibited GBM cell proliferation and invasion in vitro. Network pharmacology, RNA-seq, molecular docking analysis, western blotting, apoptosis, and cell cycle assays predicted and verified that safranal could promote GBM cell apoptosis and G2/M phase arrest and inhibit the PI3K/AKT/mTOR axis. In vivo experiments showed that safranal could inhibit GBM cell growth alone and in combination with TMZ.

Conclusion

This study revealed that safranal inhibits GBM cell growth in vivo and in vitro, promotes GBM cell apoptosis and G2/M phase arrest, inhibits the PI3K/AKT/mTOR axis and cooperate with TMZ.