Formulation and Development of Bioadhesive Oral Films Containing Usnea barbata (L.) F.H.Wigg Dry Ethanol Extract (F-UBE-HPC) with Antimicrobial and Anticancer Properties for Potential Use in Oral Cancer Complementary Therapy

Molecular Targets of Plant-Derived Bioactive Compounds in Oral Squamous Cell Carcinoma

BACKGROUND

With a significant increase in both incidence and mortality, oral cancer-particularly oral squamous cell carcinoma (OSCC)-is one of the main causes of death in developing countries. Even though there is evidence of advances in surgery, chemotherapy, and radiotherapy, the overall survival rate for patients with OSCC has improved, but by a small percentage. This may be due, on the one hand, to the fact that the disease is diagnosed when it is at a too-advanced stage, when metastases are already present.

METHODS

This review explores the therapeutic potential of natural herbal products and their use as adjuvant therapies in the treatment of oral cancer from online sources in databases (PubMed, Web of Science, Google Scholar, Research Gate, Scopus, Elsevier).

RESULTS

Even if classic therapies are known to be effective, they often produce many serious side effects and can create resistance. Certain natural plant compounds may offer a complementary approach by inducing apoptosis, suppressing tumor growth, and improving chemotherapy effectiveness. The integration of these compounds with conventional treatments to obtain remarkable synergistic effects represents a major point of interest to many authors. This review highlights the study of molecular mechanisms and their efficiency in in vitro and in vivo models, as well as the strategic ways in which drugs can be administered to optimize their use in real contexts.

CONCLUSIONS

This review may have a significant impact on the oncology community, creating new inspirations for the development of more effective, safer cancer therapies with less toxic potential.

Cell death and DNA damage via ROS mechanisms after applied antibiotics and antioxidants doses in prostate hyperplasia primary cell cultures

Tumor heterogeneity results in aggressive cancer phenotypes with acquired resistance. However, combining chemical treatment with adjuvant therapies that cause cellular structure and function perturbations may diminish the ability of cancer cells to resist at chemical treatment and lead to a less aggressive cancer phenotype. Applied treatments on prostate hyperplasia primary cell cultures exerted their antitumor activities through mechanisms including cell cycle blockage, oxidative stress, and cell death induction by flow cytometry methods. A 5.37 mM Chloramphenicol dose acts on prostate hyperplasia cells by increasing the pro-oxidant status, inducing apoptosis, autophagy, and DNA damage, but without ROS changes. Adding 6.30 mM vitamin C or 622 µM vitamin E as a supplement to 859.33 µM Chloramphenicol dose in prostate hyperplasia cells determines a significant increase of ROS level for a part of cells. However, other cells remain refractory to initial ROS, with significant changes in apoptosis, autophagy, and cell cycle arrest in G0/G1 or G2/M. When the dose of Chloramphenicol was increased to 5.37 mM for 6.30 mM of vitamin C, prostate hyperplasia cells reacted by ROS level drastically decreased, cell cycle arrest in G2/M, active apoptosis, and autophagy. The pro-oxidant action of 1.51 mM Erythromycin dose in prostate hyperplasia cell cultures induces changes in the apoptosis mechanisms and cell cycle arrest in G0/G1. Addition of 6.30 mM vitamin C to 1.51 mM Erythromycin dose in hyperplasia cell cultures, the pro-oxidant status determines diminished caspase 3/7 mechanism activation, but ROS level presents similar changes as Chloramphenicol dose and cell cycle arrest in G2/M. Flow cytometric analysis of cell death, oxidative stress, and cell cycle are recommended as laboratory techniques in therapeutic and diagnostic fields.

Porphyrin Photosensitizers into Polysaccharide-Based Biopolymer Hydrogels for Topical Photodynamic Therapy: Physicochemical and Pharmacotechnical Assessments

Photodynamic therapy (PDT) is an emerging treatment modality that utilizes light-sensitive compounds, known as photosensitizers, to produce reactive oxygen species (ROS) that can selectively destroy malignant or diseased tissues upon light activation. This study investigates the incorporation of two porphyrin structures, 5-(4-hydroxy-3-methoxyphenyl)-10,15,20-tris-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.2.) and 5,10,15,20-tetrakis-(4-acetoxy-3-methoxyphenyl) porphyrin (P2.1.), into hydroxypropyl cellulose (HPC) hydrogels for potential use in topical photodynamic therapy (PDT). The structural and compositional properties of the resulting hydrogels were characterized using advanced techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM), UV-Visible (UV-Vis) spectroscopy, and fluorescence spectroscopy. FTIR spectra revealed a slight shift of the main characteristic absorption bands corresponding to the porphyrins and their interactions with the HPC matrix, indicating successful incorporation and potential hydrogen bonding. XRD patterns revealed the presence of crystalline domains within the HPC matrix, indicating partial crystallization of the porphyrins dispersed within the amorphous polymer structure. TGA results indicated enhanced thermal stability of the HPC-porphyrin gels compared to 10% HPC gel, with additional weight loss stages corresponding to the thermal degradation of the porphyrins. Rheological analysis showed that the gels exhibited pseudoplastic behavior and thixotropic properties, with minimal impact on the flow properties of HPC by P2.1., but notable changes in viscosity and shear stress with P2.2. incorporation, indicating structural modifications. AFM imaging revealed a homogeneous distribution of porphyrins, and UV-Vis and fluorescence spectroscopy confirmed the retention of their photophysical properties. Pharmacotechnical evaluations showed that the hydrogels possessed suitable mechanical properties, optimal pH, high swelling ratios, and excellent spreadability, making them ideal for topical application. These findings suggest that the porphyrin-incorporated HPC hydrogels have significant potential as effective therapeutic agents for topical applications.

Comprehensive Analysis of Novel Synergistic Antioxidant Formulations: Insights into Pharmacotechnical, Physical, Chemical, and Antioxidant Properties

(1) Background: Oxidative stress plays a pivotal role in the pathogenesis of various diseases, including neurodegenerative disorders, cardiovascular diseases, cancer, and diabetes, highlighting the pressing need for effective antioxidant interventions. (2) Methods: In this study, we aimed to develop and characterise two novel antioxidant formulations, F3 and F4, as therapeutic interventions for oxidative stress-related conditions. (3) Results: The physicochemical characterisation, preformulation analysis, formulation, preparation of filling powders for capsules, capsule content evaluation, and antioxidant activity assessment of the two novel antioxidant formulations were assessed. These formulations comprise a combination of well-established antioxidants like quercetin, biotin, coenzyme Q10, and resveratrol. Through comprehensive testing, the formulations' antioxidant efficacy, stability, and potential synergistic interactions were evaluated. (4) Conclusions: The findings underscore the promising potential of these formulations as therapeutic interventions for oxidative stress-related disorders and highlight the significance of antioxidant interventions in mitigating their progression.

Preparation and Preliminary Analysis of Several Nanoformulations Based on Plant Extracts and Biodegradable Polymers as a Possible Application for Chronic Venous Disease Therapy

Nanotechnology is one of the newest directions for plant-based therapies. Chronic venous disease often predisposes to long-term and invasive treatment. This research focused on the inclusion of vegetal extracts from Sophorae flos (SE), Calendulae flos (CE), and Ginkgo bilobae folium (GE) in formulations with PHB and PLGA polymers and their physicochemical characterization as a preliminary stage for possible use in the development of a complex therapeutic product. The samples were prepared by an oil-water emulsification and solvent evaporation technique, resulting in suspensions with high spreadability and a pH of 5.5. ATR-FTIR analysis revealed bands for stretching vibrations (O-H, C=O, and C-H in symmetric and asymmetric methyl and methylene) in the same regions as the base components, but switched to high or low wavenumbers and absorbance, highlighting the formation of adducts/complexes between the extracts and polymers. The obtained formulations were in the amorphous phase, as confirmed by XRD analysis. AFM analysis emphasized the morphological peculiarities of the extract-polymer nanoformulations. It could be noticed that, in the case of SE-based formulations, the dominant characteristics for SE-PHB and SE-PLGA composition were the formation of random large (SE-PHB) and smaller uniform (SE-PLGA) particles; further on, these particles tended to aggregate in the case of SE-PHB-PLGA. For the CE- and GE-based formulations, the dominant surface morphology was their porosity, generally with small pores, but larger cavities were observed in some cases (CE- and GE-PHB). The highest roughness values at the (8 µm × 8 μm) scale were found for the following samples and succession: CE-PHB < SE-PLGA < SE-PHB-PLGA. In addition, by thermogravimetric analysis, impregnation in the matrix of compression stockings was evaluated, which varied in the following order: CE-polymer > SE-polymer > GE-polymer. In conclusion, nine vegetal extract-polymer nanoformulations were prepared and preliminarily characterized (by advanced physicochemical methods) as a starting point for further optimization, stability studies, and possible use in complex pharmaceutical products.

Cytotoxicity Analysis and In Silico Studies of Three Plant Extracts with Potential Application in Treatment of Endothelial Dysfunction

Endothelial dysfunction is the basis of the physiopathological mechanisms of vascular diseases. In addition to the therapeutic activity of plant extracts, cytotoxicity is significant. This research evaluates the cytotoxicity of three vegetal extracts (Calendulae flos extract-CE, Ginkgo bilobae folium extract-GE, and Sophorae flos extract-SE). In vitro evaluation was performed using an endothelial cell line model (Human Pulmonary Artery Endothelial Cells-HPAEC) when a dose-dependent cytotoxic activity was observed after 72 h. The IC50 values were calculated for all extracts: Calendulae flos extract (IC50 = 91.36 μg/mL), Sophorae flos extract (IC50 = 68.61 μg/mL), and Ginkgo bilobae folium extract (IC50 = 13.08 μg/mL). Therefore, at the level of HPAEC cells, the cytotoxicity of the extracts follows the order GE > SE > CE. The apoptotic mechanism implied in cell death was predicted for several phytocompounds using the PASS algorithm and molecular docking simulations, highlighting potential interactions with caspases-3 and -8. In vivo analysis was performed through brine shrimp lethality assay (BSLA) when lethal, behavioral, and cytological effects were evaluated on Artemia salina larvae. The viability examined after 24 h (assessment of lethal effects) follows the same sequence: CE > SE > GE. In addition, the predicted cell permeability was observed mainly for GE constituents through in silico studies. However, the extracts can be considered nontoxic according to Clarckson's criteria because no BSL% was registered at 1200 µg/mL. The obtained data reveal that all three extracts are safe for human use and suitable for incorporation in further pharmaceutical formulations.

Antibacterial and Antibiofilm Effects of Different Samples of Five Commercially Available Essential Oils

Essential oils (EOs) have gained economic importance due to their biological activities, and increasing amounts are demanded everywhere. However, substantial differences between the same essential oil samples from different suppliers are reported-concerning their chemical composition and bioactivities-due to numerous companies involved in EOs production and the continuous development of online sales. The present study investigates the antibacterial and antibiofilm activities of two to four samples of five commercially available essential oils (Oregano, Eucalyptus, Rosemary, Clove, and Peppermint oils) produced by autochthonous companies. The manufacturers provided all EOs' chemical compositions determined through GC-MS. The EOs' bioactivities were investigated in vitro against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The antibacterial and antibiofilm effects (ABE% and, respectively, ABfE%) were evaluated spectrophotometrically at 562 and 570 nm using microplate cultivation techniques. The essential oils' calculated parameters were compared with those of three standard broad-spectrum antibiotics: Amoxicillin/Clavulanic acid, Gentamycin, and Streptomycin. The results showed that at the first dilution (D1 = 25 mg/mL), all EOs exhibited antibacterial and antibiofilm activity against all Gram-positive and Gram-negative bacteria tested, and MIC value > 25 mg/mL. Generally, both effects progressively decreased from D1 to D3. Only EOs with a considerable content of highly active metabolites revealed insignificant differences. E. coli showed the lowest susceptibility to all commercially available essential oils-15 EO samples had undetected antibacterial and antibiofilm effects at D2 and D3. Peppermint and Clove oils recorded the most significant differences regarding chemical composition and antibacterial/antibiofilm activities. All registered differences could be due to different places for harvesting the raw plant material, various technological processes through which these essential oils were obtained, the preservation conditions, and complex interactions between constituents.

High-Content Aloe vera Based Hydrogels: Physicochemical and Pharmaceutical Properties

The present research focuses on the physicochemical and pharmacotechnical properties of new hydrogels obtained using allantoin, xanthan gum, salicylic acid and different concentrations of Aloe vera (5, 10, 20% w/v in solution; 38, 56, 71 wt% in dry gels). The thermal behavior of Aloe vera composite hydrogels was studied using DSC and TG/DTG analyses. The chemical structure was investigated using different characterization methods (XRD, FTIR and Raman spectroscopies) and the morphology of the hydrogels was studied SEM and AFM microscopy. Pharmacotechnical evaluation on tensile strength and elongation, moisture content, swelling and spreadability was also completed. Physical evaluation confirmed that the appearance of the prepared Aloe vera based hydrogels was homogeneous and the color varied from pale beige to deep opaque beige with increasing Aloe vera concentration. All other evaluation parameters, e.g., pH, viscosity, spreadability and consistency were found to be adequate in all hydrogel formulations. SEM and AFM images show that the structure of the hydrogels condensed into homogeneous polymeric solids with the addition of Aloe vera, in accordance with the decrease in peak intensities observed via XRD analysis. These results suggest interactions between the hydrogel matrix and Aloe vera as observed via FTIR and TG/DTG and DSC analyses. Considering that Aloe vera content higher than 10% (w/v) did not stimulate further interactions, this formulation (FA-10) can be used for further biomedical applications.

ROS-Induced DNA-Damage and Autophagy in Oral Squamous Cell Carcinoma by Usnea barbata Oil Extract-An In Vitro Study

Oxidative stress is associated with aging, cancers, and numerous metabolic and chronic disorders, and phenolic compounds are well known for their health-promoting role due to their free-radical scavenging activity. These phytochemicals could also exhibit pro-oxidant effects. Due to its bioactive phenolic secondary metabolites, Usnea barbata (L.) Weber ex. F.H. Wigg (U. barbata) displays anticancer and antioxidant activities and has been used as a phytomedicine for thousands of years. The present work aims to analyze the properties of U. barbata extract in canola oil (UBO). The UBO cytotoxicity on oral squamous cell carcinoma (OSCC) CLS-354 cell line and blood cell cultures was explored through complex flow cytometry analyses regarding apoptosis, reactive oxygen species (ROS) levels, the enzymatic activity of caspase 3/7, cell cycle, nuclear shrinkage (NS), autophagy (A), and synthesis of deoxyribonucleic acid (DNA). All these studies were concomitantly performed on canola oil (CNO) to evidence the interaction of lichen metabolites with the constituents of this green solvent used for extraction. The obtained data evidenced that UBO inhibited CLS-354 oral cancer cell proliferation through ROS generation (316.67 × 10⁴), determining higher levels of nuclear shrinkage (40.12%), cell cycle arrest in G0/G1 (92.51%; G0 is the differentiation phase, while during G1 phase occurs preparation for cell division), DNA fragmentation (2.97%), and autophagy (62.98%) than in blood cells. At a substantially higher ROS level in blood cells (5250.00 × 10⁴), the processes that lead to cell death-NS (30.05%), cell cycle arrest in G0/G1 (86.30%), DNA fragmentation (0.72%), and autophagy (39.37%)-are considerably lower than in CLS-354 oral cancer cells. Our work reveals the ROS-mediated anticancer potential of UBO through DNA damage and autophagy. Moreover, the present study suggests that UBO pharmacological potential could result from the synergism between lichen secondary metabolites and canola oil phytoconstituents.

Design, Characterization, and Anticancer and Antimicrobial Activities of Mucoadhesive Oral Patches Loaded with Usnea barbata (L.) F. H. Wigg Ethanol Extract F-UBE-HPMC

The oral cavity's common pathologies are tooth decay, periodontal disease, and oral cancer; oral squamous cell carcinoma (OSCC) is the most frequent oral malignancy, with a high mortality rate. Our study aims to formulate, develop, characterize, and pharmacologically investigate the oral mucoadhesive patches (F-UBE-HPMC) loaded with Usnea barbata (L.) F.H. Wigg dry ethanol extract (UBE), using HPMC K100 as a film-forming polymer. Each patch contains 312 µg UBE, with a total phenolic content (TPC) of 178.849 µg and 33.924 µg usnic acid. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were performed for their morphological characterization, followed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Pharmacotechnical evaluation involved the measurement of the specific parameters for mucoadhesive oral patches as follows: weight uniformity, thickness, folding endurance, tensile strength, elongation, moisture content, pH, disintegration time, swelling rate, and ex vivo mucoadhesion time. Thus, each F-UBE-HPMC has 104 ± 4.31 mg, a pH = 7.05 ± 0.04, a disintegration time of 130 ± 4.14 s, a swelling ratio of 272 ± 6.31% after 6 h, and a mucoadhesion time of 102 ± 3.22 min. Then, F-UBE-HPMCs pharmacological effects were investigated using brine shrimp lethality assay (BSL assay) as a cytotoxicity prescreening test, followed by complex flow cytometry analyses on blood cell cultures and oral epithelial squamous cell carcinoma CLS-354 cell line. The results revealed significant anticancer effects by considerably increasing oxidative stress and blocking DNA synthesis in CLS-354 cancer cells. The antimicrobial potential against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27353, Candida albicans ATCC 10231, and Candida parapsilosis ATCC 22019 was assessed by a Resazurin-based 96-well plate microdilution method. The patches moderately inhibited both bacteria strains growing and displayed a significant antifungal effect, higher on C. albicans than on C. parapsilosis. All these properties lead to considering F-UBE-HPMC suitable for oral disease prevention and therapy.