Autophagy as a targeted therapeutic approach for skin cancer: Evaluating natural and synthetic molecular interventions

Autophagy in disease management: Exploring the potential of natural products as targeted therapies

Autophagy is a vital cellular process that degrades and recycles intracellular components via lysosomes, playing a key role in maintaining cellular homeostasis. Alteration of this mechanism has been implicated in the occurrence and progression of numerous diseases, including cancer, neurodegenerative disorders, cardiovascular conditions, and microbial and viral infections. Recent studies have identified several mutations affecting autophagy-related genes and elucidated how defective degradation of specific substrates contributes to disease mechanisms. Natural products are gaining attention for their ability to modulate autophagy through several molecular targets. Herin, we highlight the complicated role of autophagy in disease pathogenesis. We also illustrate how natural products may offer therapeutic value by targeting autophagy in different pathological contexts.

Therapeutic Efficacy Studies on the Monoterpenoid Hinokitiol in the Treatment of Different Types of Cancer

Hinokitiol (HK), a monoterpenoid that naturally occurs in plants belonging to the Cupressaceae family, possesses important biological activities, including an anticancer effect. This review summarizes its anticancer potential and draws possible molecular interventions. In addition, it evaluates the biopharmaceutical, toxicological properties, and clinical application of HK to establish its viability for future advancement as a dependable anticancer medication. The assessment is based on the most recent information available from various databases. Findings demonstrate that HK possesses substantial therapeutic advantages against diverse types of cancer (colon, cervical, breast, bone, endometrial, liver, prostate, oral, and skin) through various molecular mechanisms. HK induces oxidative stress, cytotoxicity, apoptosis, cell-cycle arrest at the G and S phases, and autophagy through modulation of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), p38/ERK/MAPK, nuclear factor kappa B, and c-Jun N-terminal kinase signaling pathways. Furthermore, this compound exhibits good oral bioavailability with excellent plasma clearance. Clinical uses of HK demonstrate therapeutic advantages without any significant negative effects. A thorough study of the pertinent data suggests that HK may serve as a viable candidate for developing novel cancer therapies. Consequently, more extensive studies are necessary to evaluate its cancer treatment efficacy, safety, and possible long-term hazards.

GC-MS Analysis, Neuropharmacological, and Antidiarrheal Activities of the Acetone Extract of Najas gracillima Seaweed: In Vivo and In Silico Study

Najas gracillima, a marine seaweed found in North America and Asia, was investigated for its neuropharmacological and antidiarrheal properties. Acetone extracts of N. gracillima (ANG) were analyzed using both in vivo and in silico methods. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to identify bioactive compounds present in the extract. In vivo assessments, including the elevated plus maze, light-dark box, and hole board tests, showed that ANG at doses of 200 and 400 mg/kg exhibited significant (p < 0.001) anxiolytic effects. Both doses also demonstrated antidepressant effects in the forced swimming and tail suspension tests by significantly (p < 0.001) reducing immobility time, with the 200 mg/kg dose showing more pronounced effects. Sedative activity was confirmed through open field and hole cross tests, where both doses exhibited significant (p < 0.001) sedative effects. ANG also demonstrated significant antidiarrheal effects at 400 mg/kg in castor oil-induced diarrhea (p < 0.05) and gastrointestinal motility tests (p < 0.01). Molecular docking simulations revealed that compounds from ANG had strong binding affinities to critical drug targets involved in anxiety, depression, sleep disorders, and diarrhea. These findings suggest that N. gracillima holds potential for therapeutic use in treating neuropharmacological disorders and diarrhea, warranting further investigation.

Computational identification of potential natural terpenoid inhibitors of MDM2 for breast cancer therapy: molecular docking, molecular dynamics simulation, and ADMET analysis

Background

Breast cancer (BC) remains a leading cause of cancer-related mortality in women. The oncoprotein MDM2 negatively regulates the tumor suppressor p53, and its overexpression in BC promotes tumor progression and resistance to therapy. Targeting the MDM2-p53 interaction represents a promising therapeutic approach. However, many existing MDM2 inhibitors suffer from poor pharmacokinetics and off-target toxicity, necessitating the discovery of novel, more selective alternatives. This study aims to identify natural terpenoid compounds with potent MDM2 inhibitory potential through computational approaches.

Methods

A library of 398 natural terpenoids was sourced from the NPACT database and filtered based on Lipinski's Rule of Five. A two-stage docking strategy was applied: 1) rigid protein-flexible ligand docking to screen for high-affinity binders, followed by 2) ensemble docking using multiple MDM2 conformations derived from molecular dynamics (MD) simulations. The top candidates were further evaluated for their pharmacokinetic and toxicity profiles using ADMET analysis. Finally, 150 ns MD simulations and binding free energy (MM-PBSA) calculations were performed to assess the stability and strength of protein-ligand interactions.

Results

Three terpenoid compounds, olean-12-en-3-beta-ol, cabralealactone, and 27-deoxyactein demonstrated strong binding affinities toward MDM2 in ensemble docking studies. ADMET analysis confirmed their favorable pharmacokinetic properties. Further MD simulations indicated that these compounds formed highly stable complexes with MDM2. Notably, 27-deoxyactein exhibited the lowest binding free energy (-154.514 kJ/mol), outperforming the reference inhibitor Nutlin-3a (-133.531 kJ/mol), suggesting superior binding stability and interaction strength.

Conclusion

Our findings highlight 27-deoxyactein as a promising MDM2 inhibitor with strong binding affinity, stability, and a favorable pharmacokinetic profile. This study provides a computational foundation for further experimental validation, supporting the potential of terpenoid-based MDM2 inhibitors in BC therapy.

Promising antifungal properties of the orally active autophagy inhibitor SBP-7455 against fluconazole-resistant Candida clinical isolates

Candida species, the single most common cause of fungal infections, are major opportunistic pathogens. Novel antifungal agents are needed to address the threat of Candida infections resistant to first-line antifungal agents and those that are multi-drug resistant, both being increasingly reported. Here, we explore the antifungal properties of the novel autophagy inhibitor SBP-7455, whose anticancer effects have been recently described. Using broth microdilution, SBP-7455 inhibited the fluconazole-resistant standard C. albicans strain with minimum inhibitory concentration (MIC) values of 43.91 and 21.95 µM in the presence and absence of d-glucose, respectively. SBP-7455 inhibited the growth of six fluconazole-resistant Candida clinical isolates (MIC range 5.48-87.82 µM). Using the checkerboard assay, the fluconazole-resistant standard strain (MIC > 250 µg/ml) was rendered sensitive (MIC = 3.9 µg/ml) to fluconazole when combined with SBP-7455, but combining SBP-7455 with chloroquine was antagonistic. Compared with control, SBP-7455 treated cell membranes showed disrupted integrity and bulging on SEM images. Treatment with SBP-7455 significantly (P < 0.01) increased reduced glutathione levels with no significant change in nitric oxide levels, possibly adapting to oxidative stress induced by autophagy inhibition. Taken together, our results report for the first time the promising antifungal effects of the dual autophagy inhibitor SBP-7455 against fluconazole-resistant Candida, worthy of further investigation.

Overview of skin cancer types and prevalence rates across continents

Skin cancer is one of the most prevalent cancers in the world, and its incidence and mortality rates are increasing continuously, mostly in regions with white-skinned inhabitants. The types of skin cancer vary in their origin and clinical appearances and also differ in their extensiveness. The continents of the world have different scenarios of skin cancer prevalence. This review aims to explore the different types of skin cancer, their clinical features, and their worldwide prevalence based on the literature. Literature from different electronic databases, including Google Scholar, ResearchGate, PubMed, Scopus, Web of Science, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Elsevier, and Springer, were collected through a literature search using specific keywords such as "skin cancer", "skin cancer types", "melanoma", "non-melanoma", "skin cancer continental prevalence" or similar keywords. The search included English publications from 2000 to 2024. Melanoma skin cancer (MSC) ranks 17th in global prevalence, with the highest incidence and deaths occurring in Europe, However, Australia and New Zealand record the highest incidence and mortality rates. Asia has a lower incidence rate of melanoma, but a higher mortality rate. Superficial spreading melanoma (SSM) is the most common type of MSC. Non-melanoma skin cancers (NMSCs) have the highest incidence in North America, with the highest number of deaths occurring in Asia, Australia and New Zealand have the highest incidence rates for basal cell carcinoma (BCC). BCC is the most commonly diagnosed skin cancer worldwide and the most prevalent form of NMSCs; however, squamous cell carcinoma is the most aggressive form of NMSCs, causing more deaths. NMSCs are the most prevalent cancers worldwide, causing most skin cancer-related deaths. The prevalence of skin cancer rising globally, with several continents experiencing higher incidence and mortality rates. The types and subtypes of skin cancer are becoming more common among clinically diagnosed cancers. This review comprehensively describes skin cancer types and their prevalence worldwide. However, the actual prevalence of skin cancer in these countries should be investigated. Further research on the prevalence of skin cancer across different continents is required to develop more effective cancer management strategies and control the spread of the disease.

The Olive Oil Monophenolic Secoiridoid Ligstroside Aglycone Suppresses Melanoma Progression by Targeting the BRAF Signaling Pathway

Melanoma is among the most abundant malignancies in the US and worldwide. Ligstroside aglycone (LA) is a rare extra-virgin olive oil-derived monophenolic secoiridoid with diverse bioactivities. LA dose-response screening at the NCI 60 cancer cells panel identified the high sensitivity of the Malme-3M cell line, which harbors a BRAF V600E mutation. Daily oral 10 mg/kg LA exhibited potent in vivo antitumor effects against Malme-3M cells xenograft in a nude mouse model by targeting the BRAF signaling pathway. A human Clariom S microarray analysis of the collected Malme- 3M tumors identified 571 dysregulated genes, with the downregulation of pathways critical for melanoma cells growth and survival. A Western blot analysis of the collected animal tumors further validated the downregulation of the mutated BRAF-MAPK axis, as well as the GPD1 and ELOVL6 expression levels. A histopathological analysis of Malme-3M tumor sections showed extensive focal tumor necrosis in treated mice. An immunofluorescence study of tumor sections showed notable reductions in proliferation marker ki67 and the vasculogenesis marker CD31 in treated tumors. These findings promote LA as a potential nutraceutical lead for the control of the BRAF V600E mutant melanoma.

Marine natural compounds as potential CBP bromodomain inhibitors for treating cancer: an in-silico approach using molecular docking, ADMET, molecular dynamics simulations and MM-PBSA binding free energy calculations

The cAMP-responsive element binding protein (CREB) binding protein (CBP), a bromodomain-containing protein, engages with multiple transcription factors and enhances the activation of many genes. CBP bromodomain acts as an epigenetic reader and plays an important role in the CBP-chromatin interaction which makes it an important drug target for treating many diseases. Though inhibiting CBP bromodomain was reported to have great potential in cancer therapeutics, approved CBP bromodomain inhibitor is yet to come. We utilized various in silico approaches like molecular docking, ADMET, molecular dynamics (MD) simulations, MM-PBSA calculations, and in silico PASS predictions to identify potential CBP bromodomain inhibitors from marine natural compounds as they have been identified as having distinctive chemical structures and greater anticancer activities. To develop a marine natural compound library for this investigation, Lipinski's rule of five was used. Sequential investigations utilizing molecular docking, ADMET studies, 100 ns MD simulations, and MM-PBSA calculations revealed that three marine compounds-ascididemin, neoamphimedine, and stelletin A-demonstrated superior binding affinity compared to the standard inhibitor, 69 A. These compounds also exhibited suitable drug-like properties, a favorable safety profile, and formed stable protein-ligand complexes. The in-silico PASS tool predicted that these compounds have significant potential for anticancer activity. Among them, ascididemin demonstrated the highest binding affinity in both molecular docking and MM-PBSA calculations, as well as a better stability profile in MD simulations. Hence, ascididemin can be a potential inhibitor of CBP bromodomain. However, in vitro and in vivo validation is required for further confirmation of these findings.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00258-5.