Palmatine, a Bioactive Protoberberine Alkaloid Isolated from Berberis cretica, Inhibits the Growth of Human Estrogen Receptor-Positive Breast Cancer Cells and Acts Synergistically and Additively with Doxorubicin

The anti-aromatase and anti-estrogenic activity of plant products in the treatment of estrogen receptor-positive breast cancer

Despite being the focal point of decades of research, female breast cancer (BC) continues to be one of the most lethal cancers in the world. Given that 80% of all diagnosed BC cases are estrogen receptor-positive (ER+) with carcinogenesis driven by estrogen-ERα signalling, current standard of care (SOC) hormone therapies are geared towards modulating the function and expression levels of estrogen and its receptors, ERα and ERβ. Currently, aromatase inhibitors (AIs), selective ER modulators (SERMs) and selective ER degraders (SERDs) are clinically prescribed for the management and treatment of ER+ BC, with the anti-aromatase activity of AIs abrogating estrogen biosynthesis, while the anti-estrogenic SERMs and SERDs antagonise and degrade the ER, respectively. The use of SOC hormone therapies is, however, significantly hampered by the onset of severe side-effects and the development of resistance. Given that numerous studies have reported on the beneficial effects of plant compounds and/or extracts and the multiple pathways through which they target ER+ breast carcinogenesis, recent research has focused on the use of dietary chemopreventive agents for BC management. When combined with SOC treatments, several of these plant components and/or extracts have demonstrated improved efficacy and/or synergistic impact. Moreover, despite a lack of in vivo investigations, plant products are generally reported to have a lower side-effect profile than SOC therapies and are therefore thought to be a safer therapeutic choice. Thus, the current review summarizes the findings from the last five years regarding the anti-aromatase and anti-estrogenic activity of plant products, as well as their synergistic anti-ER+ BC effects in combination with SOC therapies.

Phytometabolites as modulators of breast cancer: a comprehensive review of mechanistic insights

Breast cancer (BC) is a highly debilitating malignancy affecting females globally and imposing a substantial burden on healthcare systems in both developed and developing nations. Despite the application of conventional therapeutic modalities such as chemotherapy, radiation therapy, and hormonal intervention, BC frequently exhibits resistance, necessitating the urgent development of novel, cost-effective, and accessible treatment strategies. In this context, there is a growing scientific interest in exploring the pharmacological potential of chemical compounds derived from botanical sources, which often exhibit notable biological activity. Extensive in vitro and in vivo investigations have revealed the capacity of these compounds, referred to as phytochemicals, to attenuate the metastatic cascade and reduce the risk of cancer dissemination. These phytochemicals exert their effects through modulation of key molecular and metabolic processes, including regulation of the cell cycle, induction of apoptotic cell death, inhibition of angiogenesis, and suppression of metastatic progression. To shed light on the latest advancements in this field, a comprehensive review of the scientific literature has been conducted, focusing on secondary metabolite agents that have recently been investigated and have demonstrated promising anticancer properties. This review aims to delineate their underlying mechanisms of action and elucidate the associated signaling pathways, thereby contributing to a deeper understanding of their therapeutic potential in the context of BC management.

Computational investigation of four isoquinoline alkaloids against polycystic ovarian syndrome

Hyperandrogenism, insulin resistance, and estrogen dominance are the prime defining traits of women with polycystic ovarian syndrome which disrupts hormonal, adrenal, or ovarian functions resulting in impaired folliculogenesis and excess androgen production. The purpose of this study is to identify an appropriate bioactive antagonistic ligand from isoquinoline alkaloids [palmatine (PAL), jatrorrhizine (JAT), magnoflorine (MAG) and berberine (BBR)] from stems of Tinospora cordifolia. Phytocomponents inhibit/prevent androgenic, estrogenic, and steroidogenic receptors, insulin binding, and resultant hyperandrogenism. Intending to develop new inhibitors for human androgen receptor (1E3G), insulin receptor (3EKK), estrogen receptor beta (1U3S), and human steroidogenic cytochromeP450 17A1 (6WR0), here we report the docking studies by employing a flexible ligand docking approach using AutodockVina 4.2.6. ADMET screened swissADME and toxicological predictions to identify novel and potent inhibitors against PCOS. Binding affinity was obtained using Schrodinger. Two ligands, mainly BER (-8.23) and PAL (-6.71) showed the best docking score against androgen receptors. A molecular docking study reveals that compounds BBR and PAL were found to be tight binder at the active site of IE3G. Molecular dynamics results suggest that BBR and PAL showed good binding stability of active site residues. The present study corroborates the molecular dynamics of the compound BBR and PAL, potent Inhibitors of IE3G, having therapeutic potential for PCOS. We project that this study's findings will be helpful in drug development efforts targeting PCOS. Hence isoquinoline alkaloids (BER& PAL) have potential roles against androgen receptors, and in specific PCOS, scientific evaluation has been put forth based on virtual screening.Communicated by Ramaswamy H. Sarma.

New trends in the practical use of isoquinoline alkaloids as potential drugs applicated in infectious and non-infectious diseases

In the last years, traditional natural products have been the center of attention for the scientific community and exploration of their therapeutic abilities is proceeding permanently. Isoquinoline alkaloids have always attracted scientific interest due to either their positive or negative effects on human organism. The present review describes research on isoquinoline alkaloids isolated from different plant species. Alkaloids are one of the most important classes of plant derived compounds among these isoquinoline alkaloids possess varied biological activities such as anticancer, antineurodegenerative diseases, antidiabetic, antiinflammatory, antimicrobial, and many others. The use of plants against different disorders is entrenched in traditional medicine around the globe. Recent progress in modern therapeutics has stimulated the use of natural products worldwide for various ailments and diseases. The review provides a collection of information on the capabilities of some isoquinoline alkaloids, its potential for the treatment of various diseases and is designed to be a guide for future research on different biologically active isoquinoline alkaloids and plant species containing them. The authors are aware that they were not able to cover the whole area of the topic related to biological activity of isoquinoline alkaloids. This review is intended to suggest directions for further research and can also help other researchers in future studies.

Bracteatinine and isogroenlandicine, two new isoquinoline alkaloids isolated from Corydalis bracteata and their effect on platelet function

Two previously undescribed isoquinoline alkaloids, bracteatinine (1) and isogroenlandicine (2), together with four known alkaloids - coptisine (3), dehydrocorydaline (4), palmatine (5) and jatrorrhizine (6) were isolated from the aerial parts of Corydalis bracteata (Steph. Ex. Willd.) Pers. The structures of the compounds were elucidated using 1D and 2D NMR data along with HRESI-MS. The isolated new compounds bracteatinine and isogroenlandicine are close structural derivatives and isomers of corgoine and groenlandicine, respectively. Bracteatinine is also notable, being a representative of the rare 2-benzylisoquinoline alkaloids. Many natural products isolated from different plants are used as adjuvants, in addition to standard chemotherapy, in treatment of different cancers. Cancer-associated thrombosis remains a common complication and leading cause of mortality for cancer patients. Because platelets play the key role in thrombotic complications, we investigated effects of the isolated alkaloids 1-6 on platelet reactivity and showed that they did not significantly affect platelet function.

Anti-cancer effect of palmatine through inhibition of the PI3K/AKT pathway in canine mammary gland tumor CMT-U27 cells

Canine mammary gland tumors (CMTs) are the most common and lethal cancers in female dogs. Dysregulated phosphoinositide 3-kinases (PI3K)/AKT pathway reportedly was involved in the growth and metastasis of CMTs. However, there are few studies on therapeutic strategies for targeting the PI3K pathway in CMTs. In this study, we aimed to determine whether palmatine, a natural isoquinoline alkaloid with anti-cancer properties, could inhibit the growth of CMTs and whether the inhibitory effect was mediated through the PI3K/AKT pathway. Our in vitro experiments on CMT-U27, a CMT cell line, showed that palmatine reduced cell proliferation and induced cell death. Western blotting results revealed that palmatine decreased the protein expression of PI3K, PTEN, AKT, and mechanistic target of rapamycin in the PI3K/AKT pathway, which was supported by the results of immunocytochemistry. Additionally, palmatine suppressed the migration and tube formation of canine aortic endothelial cells as well as the migration of CMT U27 cells. Our in vivo results showed that palmatine inhibited tumor growth in a CMT-U27 mouse xenograft model. We observed a decreased expression of proteins in the PI3K/AKT pathway in tumor tissues, similar to the in vitro results. Furthermore, palmatine significantly disrupted the tumor vasculature and inhibited metastasis to adjacent lymph nodes. In conclusion, our findings demonstrate that palmatine exerts anti-cancer effects against CMTs by inhibiting PI3K/AKT signaling pathway, suggesting that palmatine has potential as a canine-specific PI3K inhibitor for the treatment of CMTs.

Identifying synergistic combinations of Doxorubicin-Loaded polyquercetin nanoparticles and natural Products: Implications for breast cancer therapy

Combining chemotherapeutic agents with bioactive natural products is an attractive cancer treatment modality to reduce the dose and side effects of chemotherapy. Combination treatments with drugs having different mechanisms of action can also be beneficial in combatting the development of drug resistance by cancer cells. Nanoparticle (NP)-mediated drug delivery can further improve the therapeutic index of cytotoxic agents by enabling passive and/or active targeting to tumor tissues in vivo. Using doxorubicin (DOX) as a model chemotherapeutic agent, we developed three NP formulations based on polyquercetin (pQCT), an emerging nanocarrier platform. The NPs were co-assembled with DOX, pQCT, and either Pluronic P123, methoxy poly(ethylene glycol)-amine, or D-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS). Physicochemical characterization of the NPs revealed them to have a spherical morphology with high monodispersity, excellent drug loading capacity, and sustained drug release. Then, the NPs were evaluated in vitro to determine their potential synergism when combined with the bioactive natural products curcumin (CUR), tannic acid (TA), and thymoquinone (TQ) against breast cancer cells (MCF-7 and MDA-MB-231). Surprisingly, most of the combinations were found to be antagonistic. However, combinations containing CUR exhibited greater pro-apoptotic effects compared to the single agents, with polymer-modified pQCT NPs presenting as a promising nanoplatform for enhancing DOX's ability to promote cancer cell apoptosis. Our findings provide insights into the potential application of pQCT in nanomedicine, as well as the use of bioactive natural products in combination with DOX as a free agent and as an NP formulation in the treatment of breast cancer.

Therapeutic Role of Alkaloids and Alkaloid Derivatives in Cancer Management

Cancer is a neoplastic disease that remains a global challenge with a reported prevalence that is increasing annually. Though existing drugs can be applied as single or combined therapies for managing this pathology, their concomitant adverse effects in human applications have led to the need to continually screen natural products for effective and alternative anticancer bioactive principles. Alkaloids are chemical molecules that, due to their structural diversity, constitute a reserve for the discovery of lead compounds with interesting pharmacological activities. Several in vitro studies and a few in vivo findings have documented various cytotoxic and antiproliferative properties of alkaloids. This review describes chaetocochin J, neopapillarine, coclaurine, reflexin A, 3,10-dibromofascaplysin and neferine, which belong to different alkaloid classes with antineoplastic properties and have been identified recently from plants. Despite their low solubility and bioavailability, plant-derived alkaloids have viable prospects as sources of viable lead antitumor agents. This potential can be achieved if more research on these chemical compounds is directed toward investigating ways of improving their delivery in an active form close to target cells, preferably with no effect on neighboring normal tissues.

Daphnetin, a Coumarin with Anticancer Potential against Human Melanoma: In Vitro Study of Its Effective Combination with Selected Cytostatic Drugs

(1) The treatment of metastatic or drug-resistant melanoma is still a significant therapeutic problem. The aim of this study was to evaluate the anticancer potential of daphnetin (7,8-dihydroxycoumarin) and its combinations with five different cytostatic drugs (mitoxantrone, docetaxel, vemurafenib, epirubicin and cisplatin). (2) The viability, proliferation and cytotoxicity of daphnetin against four human malignant melanoma cell lines were evaluated. The interactions were assessed using isobolographic analysis for the combinations of daphnetin with each of the five cytostatic drugs. (3) Daphnetin showed anticancer activity against malignant melanoma, with IC₅₀ values ranging from 40.48 ± 10.90 µM to 183.97 ± 18.82 µM, depending on the cell line. The combination of daphnetin with either vemurafenib or epirubicin showed an antagonistic interaction. Moreover, additive interactions were observed for the combinations of daphnetin with cisplatin and docetaxel. The most desirable synergistic interactions for human melanoma metastatic cell lines were observed for the combination of daphnetin with mitoxantrone. (4) The obtained results suggest that daphnetin should not be combined with vemurafenib or epirubicin in the treatment of malignant melanoma due to the abolition of their anticancer effects. The combination of daphnetin with mitoxantrone is beneficial in the treatment of metastatic melanoma due to their synergistic interaction.

Oxypalmatine regulates proliferation and apoptosis of breast cancer cells by inhibiting PI3K/AKT signaling and its efficacy against breast cancer organoids

BACKGROUND

Breast cancer (BC) is known as the most common cancer in women. Discovering novel and effective drugs is a priority for the treatment of BC. Oxypalmatine (OPT) is a natural protoberberine-type alkaloid isolated from Phellodendron amurense Rupr. (Rutaceae) with potential anti-cancer activity.

PURPOSE

This investigation aimed to elucidate the biological role and potential mechanisms of OPT in BC cells, and intended to assess the therapeutic potential of OPT in BC patient-derived organoid models.

METHODS

CCK-8 and EdU assays, and flow cytometry were used to test the activity of OPT against BC cells. In addition, patient-derived organoid models were constructed to assess the therapeutic efficiency of OPT in BC. Besides, network pharmacological analysis and RNA sequencing analysis were performed to predict the underlying anti-BC mechanism of OPT. Moreover, Western blot analysis was applied to test the expression of genes modulated by OPT.

RESULTS

OPT attenuated the proliferation and DNA replication, and induced apoptosis in multiple BC cells. Interestingly, OPT also exerted a cytotoxic effect on BC organoids characterized as luminal A, HER2-overexpressing, and triple-negative subtypes, indicating that OPT was a potential broad-spectrum anticancer drug. Network pharmacological analysis suggested that OPT might affect signals contributing to BC progression, including PI3K/AKT, MAPK, and VEGFA-VEGFR2 signaling pathways. Moreover, bioinformatics analysis of data from our RNA sequencing suggested that PI3K/AKT was a downstream pathway of OPT in BC. Finally, OPT was shown to inactivate PI3K/AKT signaling pathway in BC cells by Western blot analysis.

CONCLUSIONS

Collectively, our study demonstrated that OPT suppressed proliferation and induced apoptosis through mitigating the PI3K/AKT signaling pathway in BC cells. Moreover, our work first adopted BC organoid models to confirm OPT as an effective and promising drug, laying a foundation for the potential use of OPT in BC treatment.

Synergy, Additivity and Antagonism between Esculetin and Six Commonly Used Chemotherapeutics in Various Malignant Melanoma Cell Lines-An Isobolographic Analysis

(1) Malignant melanomas are dangerous skin cancers, and the treatment of melanomas with various cytostatic drugs often causes side effects and after their prolonged use resistance to these drugs appears. The aim of this study was to evaluate the anticancer effects of esculetin (a simple coumarin) and to assess pharmacodynamic interactions between esculetin and six commonly used cytostatic drugs (cisplatin, epirubicin, docetaxel, paclitaxel, mitoxantrone and vemurafenib) using an isobolographic analysis. (2) The experiments were carried out on four human malignant melanoma cell lines (FM55P, A375, FM55M2 and SK-MEL28). The effects of esculetin on viability, cell proliferation and cytotoxicity were verified in the range of concentrations of 2-200 μM. (3) Esculetin inhibited, in a dose-dependent manner, malignant melanoma cell viability and proliferation. The IC₅₀ for esculetin ranged from 18.20 ± 2.93 to 120.64 ± 30.39 μM depending on the melanoma cell lines used. The combinations of esculetin with epirubicin and vemurafenib showed antagonistic interactions, the combinations of esculetin with cisplatin, docetaxel and paclitaxel showed additive interactions. For the combinations of esculetin with mitoxantrone, the isobolographic analysis displayed synergy. (4) In the treatment of malignant melanoma, esculetin should not be combined with epirubicin or vemurafenib, due to the reduction of their anticancer effects, while the synergistic interactions (esculetin + mitoxantrone) deserve a preclinical recommendation as a beneficial combination during anticancer therapy.

Palmatine ameliorates LPS-induced HT-22 cells and mouse models of depression by regulating apoptosis and oxidative stress

Depression is one of the most common neuropsychiatric disorders that is characterized by low mood, lack of motivation, slow thinking, and recurrent suicidal thoughts. The mechanism of action of palmatine in depression has been rarely reported and remains unclear. The present study examined the neuroprotective effects of palmatine on lipopolysaccharide (LPS)-induced oxidative stress, apoptosis, and depression-like behavior. In this study, cell apoptosis was evaluated by CCK-8, flow cytometry, and Hoechst 33258 staining in LPS-induced HT-22 cells. Meanwhile, reactive oxygen species (ROS) and mitochondrial membrane potential were detected in vitro. In vivo, we investigated depressive-like behaviors in mice by an open field test (OFT) and elevated plus-maze test (EPM). Additionally, the levels of superoxide dismutases (SOD), TNF-α, IL-1β, and IL-6 were detected by enzyme-linked immunosorbent assay. The hematoxylin-eosin staining and TUNEL staining were used to evaluate the pathology of the hippocampus. The expression of Nrf2/HO-1 and BAX/Bcl-2 pathways in the hippocampus were assessed by Western blot analysis. Palmatine could significantly reduce apoptosis and ROS levels, and improve mitochondrial damage. Moreover, palmatine significantly improves movement time and central square crossing time in OFT, and improves open arms and movement time in EMP. And the levels of SOD, TNF-α, IL-1β, and IL-6 were significantly decreased after palmatine treatment. More importantly, palmatine improved neuronal apoptosis in the hippocampus, and depression through BAX/Bcl-2 and Nrf2/HO-1 signaling pathways. We provide evidence that palmatine further alleviates the depressive-like behavior of LPS-induced by improving apoptosis and oxidative stress.

Fraxetin Interacts Additively with Cisplatin and Mitoxantrone, Antagonistically with Docetaxel in Various Human Melanoma Cell Lines-An Isobolographic Analysis

Malignant melanoma is a skin cancer characterized by rapid development, poor prognosis and high mortality. Due to the frequent drug resistance and/or early metastases in melanoma, new therapeutic methods are urgently needed. The study aimed at assessing the cytotoxic and antiproliferative effects of scoparone and fraxetin in vitro, when used alone and in combination with three cytostatics: cisplatin, mitoxantrone, and docetaxel in four human melanoma cell lines. Our experiments showed that scoparone in the concentration range tested up to 200 µM had no significant effect on the viability of human malignant melanoma (therefore, it was not possible to evaluate it in combination with other cytostatics), while fraxetin inhibited cell proliferation with IC₅₀ doses in the range of 32.42-73.16 µM, depending on the cell line. Isobolographic analysis allowed for the assessment of the interactions between the studied compounds. Importantly, fraxetin was not cytotoxic to normal keratinocytes (HaCaT) and melanocytes (HEMa-LP), although it slightly inhibited their viability at high concentrations. The combination of fraxetin with cisplatin and mitoxantrone showed the additive interaction, which seems to be a promising direction in melanoma therapy. Unfortunately, the combination of fraxetin with docetaxel may not be beneficial due to the antagonistic antiproliferative effect of both drugs used in the mixture.

Discovery of New Microbial Collagenase Inhibitors

Bacterial virulence factors are mediating bacterial pathogenesis and infectivity. Collagenases are virulence factors secreted by several bacterial stains, such as Clostridium, Bacillus, Vibrio and Pseudomonas. These enzymes are among the most efficient degraders of collagen, playing a crucial role in host colonization. Thus, they are an important target for developing new anti-infective agents because of their pivotal roles in the infection process. A primary screening using a fluorescence resonance energy-transfer assay was used to experimentally evaluate the inhibitory activity of 77 compounds on collagenase A. Based on their inhibitory activity and chemical diversity, a small number of compounds was selected to determine the corresponding half maximal inhibitory con-centration (IC50). Additionally, we used molecular docking to get a better understanding of the enzyme-compound interaction. Several natural compounds (capsaicin, 4',5-dihydroxyflavone, curcumin, dihydrorobinetin, palmatine chloride, biochanin A, 2'-hydroxychalcone, and juglone) were identified as promising candidates for further development into useful anti-infective agents against infections caused by multi-drug-resistant bacterial pathogens which include collagenase A in their enzymatic set.

Isoquinoline Alkaloids from Coptis chinensis Franch: Focus on Coptisine as a Potential Therapeutic Candidate against Gastric Cancer Cells

Gastric cancer (GC) has high incidence rates and constitutes a common cause of cancer mortality. Despite advances in treatment, GC remains a challenge in cancer therapy which is why novel treatment strategies are needed. The interest in natural compounds has increased significantly in recent years because of their numerous biological activities, including anti-cancer action. The isolation of the bioactive compounds from Coptis chinensis Franch was carried out with the Centrifugal Partition Chromatography (CPC) technique, using a biphasic solvent system composed of chloroform (CHCl₃)—methanol (MeOH)—water (H₂O) (4:3:3, v/v) with an addition of hydrochloric acid and trietylamine. The identity of the isolated alkaloids was confirmed using a high resolution HPLC-MS chromatograph. The phytochemical constituents of Coptis chinensis such as berberine, jatrorrhizine, palmatine and coptisine significantly inhibited the viability and growth of gastric cancer cell lines ACC-201 and NCI-N87 in a dose-dependent manner, with coptisine showing the highest efficacy as revealed using MTT and BrdU assays, respectively. Flow cytometry analysis confirmed the coptisine-induced population of gastric cancer cells in sub-G1 phase and apoptosis. The combination of coptisine with cisplatin at the fixed-ratio of 1:1 exerted synergistic and additive interactions in ACC-201 and NCI-N87, respectively, as determined by means of isobolographic analysis. In in vivo assay, coptisine was safe for developing zebrafish at the dose equivalent to the highest dose active in vitro, but higher doses (greater than 10 times) caused morphological abnormalities in larvae. Our findings provide a theoretical foundation to further studies on more detailed mechanisms of the bioactive compounds from Coptis chinensis Franch anti-cancer action that inhibit GC cell survival in in vitro settings.

Additive Interactions between Betulinic Acid and Two Taxanes in In Vitro Tests against Four Human Malignant Melanoma Cell Lines

The incidence of melanoma is steadily increasing worldwide. Melanoma is the most lethal skin cancer, and new therapeutic methods are being sought. Our research aimed to investigate the cytotoxic and antiproliferative effects of betulinic acid in vitro, used alone and in combination with taxanes (paclitaxel, docetaxel) in four melanoma cell lines. Isobolographic analysis allowed us to assess the interactions between these compounds. Betulinic acid had no cytotoxic effect on normal human keratinocyte HaCaT cells; the amount of LDH released by them was significantly lower compared to melanoma cell lines. The present study shows that betulinic acid significantly inhibits the growth of melanoma cell lines in vitro. The IC50 values of betulinic acid ranged from 2.21 µM to 15.94 µM against the four melanoma lines. Co-treatment of betulinic acid with paclitaxel or docetaxel generated desirable drug–drug interactions, such as an additive and additive with a tendency to synergy interactions.

Anticancer Activity of Amantadine and Evaluation of Its Interactions with Selected Cytostatics in Relation to Human Melanoma Cells

Patients with Parkinson’s disease are prone to a higher incidence of melanoma. Amantadine (an anti-Parkinson drug) possesses the antiproliferative potential that can be favorable when combined with other chemotherapeutics. Cisplatin (CDDP) and mitoxantrone (MTO) are drugs used in melanoma chemotherapy, but they have many side effects. (1) Clinical observations revealed a high incidence of malignant melanoma in patients with Parkinson’s disease. Amantadine as an anti-Parkinson drug alleviates symptoms of Parkinson’s disease and theoretically, it should have anti-melanoma properties. (2) To characterize the interaction profile for combinations of amantadine with CDDP and MTO in four human melanoma cell lines (A375, SK-MEL 28, FM55P and FM55M2), type I isobolographic analysis was used in the MTT test. (3) Amantadine produces the anti-proliferative effects in various melanoma cell lines. Flow cytometry analysis indicated that amantadine induced apoptosis and G1/S phase cell cycle arrest. Western blotting analysis showed that amantadine markedly decreased cyclin-D1 protein levels and increased p21 levels. Additionally, amantadine significantly increased the Bax/Bcl-2 ratio. The combined application of amantadine with CDDP at the fixed-ratio of 1:1 exerted an additive interaction in the four studied cell lines in the MTT test. In contrast, the combination of amantadine with MTO (ratio of 1:1) produced synergistic interaction in the FM55M2 cell line in the MTT (* p < 0.05). The combination of amantadine with MTO was also additive in the remaining tested cell lines (A375, FM55P and SK-MEL28) in the MTT test. (4) Amantadine combined with MTO exerted the most desirable synergistic interaction, as assessed isobolographically. Additionally, the exposure of melanoma cell lines to amantadine in combination with CDDP or MTO augmented the induction of apoptosis mediated by amantadine alone.

Special Issue “Natural Plant Substances—Structural and Application Aspects: A Theme Issue in Honor of Professor Wieslaw Oleszek”

Dear Colleagues, [...]