Evaluation of cytotoxicity of areca nut and its commercial products on normal human gingival fibroblast and oral squamous cell carcinoma cell lines

Development of monoclonal antibodies against P. gingivalis Mfa1 and their protective capacity in an experimental periodontitis model

Porphyromonas gingivalis (P. gingivalis), a gram-negative, black-pigmented anaerobe, is a major etiological agent and a leading cause of periodontitis. Fimbriae protein Mfa1 is a key virulence factor of P. gingivalis and plays a crucial role in bacterial adhesion, colonization, biofilm formation, and persistent inflammation, making it a promising therapeutic target. However, the role of anti-Mfa1 antibodies and the underlying protective mechanisms remain largely unexplored. Here, we developed and characterized the monoclonal antibodies (mAbs) targeting the Mfa1 protein of P. gingivalis. Function analysis showed that anti-Mfa1 mAbs mediated bacterial agglutination and inhibited P. gingivalis adhesion to saliva-coated hydroxyapatite and host cells. Notably, anti-Mfa1 mAbs significantly reduced bacterial burden and alveolar bone loss in a P. gingivalis-induced experimental periodontitis model. These results show that anti-Mfa1 mAbs can be beneficial in alleviating P. gingivalis infections, and provide important insights for the development of adequate adjuvant treatment regimens for Mfa1-targeted therapeutics.

IMPORTANCE

Fimbriae (pili) play an important role in bacterial adhesion, invasion of host cells and tissues, and formation of biofilms. Studies have shown that two types of fimbriae of Porphyromonas gingivalis, FimA and Mfa1, are important for colonization and infection through their binding to host tissues and other bacteria. While anti-FimA antibodies have been shown to improve periodontitis, the effect of anti-Mfa1 antibodies on P. gingivalis infection and periodontitis was previously unknown. In this study, we report for the first time that anti-Mfa1 monoclonal antibodies can reduce P. gingivalis infection and improve periodontitis. These findings suggest that Mfa1 represents a promising therapeutic target, and the development of anti-Mfa1 mAbs holds a potential as essential diagnostic and adjunctive therapeutic tools for managing P. gingivalis-related diseases.

Advances in nanotechnology-based approaches for the treatment of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), one of the most common types of cancers occurring in the head and neck region, is often associated with high mortality rates due to its invasiveness and morbidity. The mainstream treatment methods in clinical settings, including surgery, chemotherapy, and radiotherapy, may cause poor overall survival rate and prognosis, with issues such as drug resistance, damage to adjacent healthy tissues, and potential recurrences. Other treatment approaches such as immunotherapy, photodynamic therapy (PDT), and photothermal therapy (PPT) also suffer from inefficient tumor targeting and suboptimal therapeutic outcomes. Early detection is vital for HNSCC patients, but it is always limited by insensitivity and confusing clinical manifestations. Hence, it is highly desirable to develop optimized therapeutic and diagnostic strategies. With the boom in nanomaterials, nanotechnology-conducted HNSCC therapy has attracted widespread attention. Nanoparticles (NPs) are distinguished by their unique morphology and superior physicochemical property, and some can exhibit direct antitumor activity, while others serve as promising candidates for drug delivery. In addition, NPs offer the potential for structural modification for drug delivery and tumor targeting, enabling specific delivery to tumor cells through conjugation with biomarker ligands and improving cargo biocompatibility. This work reviews current therapies and diagnosis methods for HNSCC, highlights the characteristics of the major NPs, surveys their uses and advantages in the treatment of HNSCC, and discusses the obstacles and prospects in clinical applications, aiming to enlighten future research directions for nanotechnology-based therapy for HNSCC.

Potential Role of Host Microbiome in Areca Nut-Associated Carcinogenesis and Addiction

Areca nut (AN) is widely consumed all over the world, bringing great harm to human health and economy. Individuals with AN chewing are at high risk of cardiovascular disease and impaired immune system and metabolic system. Despite a growing number of studies having reported on the adverse effects brought by AN chewing, the exact mechanism of it is limited and the need for additional exploration remains. In recent years, the interaction between microorganisms, especially intestinal microorganism and host, has been extensively studied. AN chewing might disrupt the oral and intestinal microbiota communities through direct connect with the microbes it contains, altering PH, oxygen of oral and intestinal microenvironment, and disturbing the immune homeostasis. These mechanisms provide insights into the interplay between areca nut and host microbiota. Emerging studies have proposed that bidirectional interaction between polyphenols and intestinal microbes might play a potential role in the divergence of polyphenol, extracted from AN, among individuals with or without AN-induced cancer development and progression. Although some AN chewers have been aware of the harmful effects brought by AN, they cannot abolish this habit because of the addiction of AN. Increasing studies have tried to revealed that gut microbiota might influence the onset/development of addictive behaviors. Altogether, this review summarizes the possible reasons for the disturbance of host microbiota caused by areca nut chewing and clarifies the complex interaction between human microbiome and major constituents and the addiction and carcinogenicity of AN, tempting to provide novel insights into the development and utilization of it, and to control the adverse consequences caused by AN chewing.

Rapid green analytical methodology for simultaneous biomonitoring of five toxic areca nut alkaloids using UHPLC-MS/MS for predicting health hazardous risks

Areca nut (AN) is a fundamental component of betel quid (BQ), an addictive and carcinogenic mixture chewed by hundreds of millions of people in India-Asia-Pacific. Chewing of BQ is associated with oral cancers due to specific carcinogenic alkaloids (arecaidine, guvacine, guvacoline, arecoline, N-Nitrosoguvacoline) in AN. To predict the hazardous health risks of short and long-term chewing of BQ, it is crucial to identify five toxic AN alkaloids in saliva and urine of BQ chewers. This study reports a green analytical methodology comprising in-syringe assisted vortex-induced salt-enhanced liquid-liquid microextraction coupled with ultra-HPLC-MS/MS for simultaneous biomonitoring of five AN alkaloids in saliva and urine. The analytical method validation results exhibited good linearities between 0.05 and 1000 ng mL^-1 with r² > 0.9930. The detection and quantification limits were between 0.01 and 1.5 and 0.05-5 ng mL^-1. Relative recoveries ranged between 87.9% and 110.1% with RSD < 9.1% for saliva samples, 81.5-115.1% with RSD < 9.7% for urine samples. The results indicated the successful identification and real-time monitoring of concentrations of five target AN alkaloids in saliva and urine of BQ chewers and demonstrated the utility of this technique as an efficient analytical protocol for routine biomonitoring of levels of toxic AN alkaloids from BQ chewers and to predict the exposure level and its harmful health risk.

Comprehensive Analysis of the Effects of Genetic Ancestry and Genetic Characteristics on the Clinical Evolution of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC), a kind of malignant cancer, is associated with increasing morbidity and mortality. Patients with different genetic ancestries may respond differently to clinical treatment. The limited understanding of the influence of genetic ancestry and genetic characteristics on OSCC impedes the development of precision medicine. To provide a reference for clinical treatment, this study comprehensively analyzed multigenomic differences in OSCC patients with different genetic ancestries and their impact on prognosis. An analysis of data from OSCC patients with different genetic ancestries in The Cancer Genome Atlas (TCGA) showed that the overall survival (OS) of African (AFR) patients was lower than that of primarily European (EUR) patients, and differences were also observed in the tumor-stroma ratio (TSR) and tumor-infiltrating lymphocytes (TILs), which are associated with prognosis. FAT1 is a key mutant gene in OSCC, and it has inconsistent effects on clinical evolution for patients with diverse genetic characteristics. PIKfyve and CAPN9 showed a significant difference in mutation frequency between EUR and AFR; PIKfyve was related to Ki-67 expression, suggesting that it could promote tumor proliferation, and CAPN9 was related to the expression of Bcl-2, promoting tumor cell apoptosis. A variant methylation locus, cg20469139, was correlated with the levels of PD-L1 and Caspase-7 and modulated tumor cell apoptosis. A novel ceRNA model was constructed based on genetic ancestries, and it could accurately evaluate patient prognosis. More importantly, although T cell dysfunction scores could determine the potential of tumor immune escape, the efficacy was obviously affected by patients' genetic ancestries. To provide patients with more precise, personalized therapy and to further improve their quality of life and 5-year survival rate, the influence of genetic ancestry should be fully considered when selecting treatments.

Chemical Composition, Pharmacological, and Toxicological Effects of Betel Nut

Betel nut, the fruit of Areca catechu L, has a long medical history in Southeast Asia. It is native to Malaysia and is cultivated and processed extensively in subtropical regions, such as South China and India. Betel nut almost appears as a "snack" in various occasions in most parts of China. Clinically, betel nut can play a certain pharmacology role and was used in malaria, ascariasis, arthritis, enterozoic abdominalgia, stagnation of food, diarrhea, edema, and beriberi. The nervous excitement of betel nut chewing has made it gradually become popular. However, chewing betel nut can induce oral submucosal fibrosis (OSF) and oral cancer (OC). At the same time, long-term chewing of betel nut also causes inhaled asthma, sperm reducing, betel quid dependence (BQD), and uterine and esophageal cancers. The main components of processed betel nut are the goal of this review. This study will mainly start from the pharmacological activity and toxicology study of betel nut in recent years, aiming to seek its advantages and disadvantages. In the meantime, this study will analyze and emphasize that betel nut and arecoline are the high-risk factors for oral cancer, which should arouse attention and vigilance of the public.

Identification, Characterization and Antihypertensive Effect In Vivo of a Novel ACE-Inhibitory Heptapeptide from Defatted Areca Nut Kernel Globulin Hydrolysates

The areca (Areca catechu L.) nut kernel (ANK) is a good potential protein source for its high protein content of 9.89-14.62 g/100 g and a high yield of around 300,000 tons per year in China. However, utilization of the areca nut kernel is limited. To expand the usage of ANK in pharmaceutical or foods industries, areca nut kernel globulin was extracted and angiotensin-I converting enzyme (ACE) inhibition peptides were prepared and identified using gel chromatography, reversed phase HPLC separation, UPLC-ESI-MS/MS analysis and in silico screening. Finally, a novel ACE-inhibitory heptapeptide (Ala-Pro-Lys-Ile-Glu-Glu-Val) was identified and chemically synthesized. The combination pattern between APKIEEV and ACE, and the inhibition kinetics, antihypertensive effect and endothlein-1 inhibition activity of APKIEEV were studied. The results of the molecular docking demonstrated that APKIEEV could bind to four active sites (not the key active sites) of ACE via short hydrogen bonds and demonstrated high ACE-inhibitory activity (IC₅₀: 550.41 μmol/L). Moreover, APKIEEV exhibited a significantly lowering effect on both the systolic blood pressure and diastolic blood pressure of spontaneously hypertensive rats, and had considerable suppression ability on intracellular endothelin-1. These results highlight the potential usage of APKIEEV as ingredients of antihypertensive drugs or functional foods.