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Oral biofilms comprise extracellular polysaccharides and polymicrobial microorganisms. The objectives of the study were to characterize the deer velvet antler (DVA) compounds and their effect on Candida species biofilm formation with the hypothesis that DVA inhibits the biofilm of Candida spp. Liquid Chromatography-Quadrupole Time of Flight-Mass Spectrometry (LC-QTOF-MS) was conducted to characterize the DVA compounds. To study the effect of DVA on biofilm, Candida albicans ATCC MYA-4901 (ALT5), AIDS isolate (ALC2), oral cancer isolate (ALC3), C. dubliniensis ATCC MYA-2975, C. glabrata ATCC 90030 , C. krusei 14   243 , C. lusitaniae ATCC 34449 , C. parapsilosis ATCC 22019, and C. tropicalis ATCC 13803 were inoculated with DVA in separate wells of a 96-well plate containing RPMI-1640 followed by 72 h incubation. A total of 45 compounds were detected in the DVA extract. C. lusitaniae exhibited a higher percentage of biofilm biomass reduction when treated with DVA extract (66.10% ± 5.33), followed by ALC3 (44.12% ± 6.24). However, C. glabrata, C. krusei , and C. parapsilosis showed no reduction in biofilm biomass after being treated with DVA extract. Most Candida strains also exhibited decreased total cell count when treated with DVA extract, except for ALC3 and C. krusei. ALT5 had the lowest total cell count (0.17 × 105 cells/ml) when cultured with DVA extract. In conclusion, DVA extract inhibits Candida spp. biofilm formation except for C. glabrata, C. krusei , and C. parapsilosis. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma is associated with many known risk factors including tobacco smoking, chronic alcoholism, poor oral hygiene, unhealthy dietary habits and microbial infection. Previous studies have highlighted Candida albicans host tissue infection as a risk factor in the initiation and progression of oral cancer. C albicans invasion induces several cancerous hallmarks, such as activation of proto-oncogenes, induction of DNA damage and overexpression of inflammatory signalling pathways. However, the molecular mechanisms behind these responses remain unclear. A recently discovered fungal toxin peptide, candidalysin, has been reported as an essential molecule in epithelial damage and host recognition of C albicans infection. Candidalysin has a clear role in inflammasome activation and induction of cell damage. Several inflammatory molecules such as IL-6, IL-17, NLRP3 and GM-CSF have been linked to carcinogenesis. Candidalysin is encoded by the ECE1 gene, which has been linked to virulence factors of C albicans such as adhesion, biofilm formation and filamentation properties. This review discusses the recent epidemiological burden of oral cancer and highlights the significance of the ECE1 gene and the ECE1 protein breakdown product, candidalysin in oral malignancy. The immunological and molecular mechanisms behind oral malignancy induced by inflammation and the role of the toxic fungal peptide candidalysin in oral carcinogenesis are explored. With increasing evidence associating C albicans with oral carcinoma, identifying the possible fungal pathogenicity factors including the role of candidalysin can assist in efforts to understand the link between C albicans infection and carcinogenesis, and pave the way for research into therapeutic potentials. [ABSTRACT FROM AUTHOR]

It is estimated that 48% of children globally and over 70% of those in Malaysia suffer from early childhood caries (ECC). This review aimed to systematically gather studies on ECC and determine key factors associated with it using bibliometric analysis. The "early childhood caries" keyword was searched in the Scopus database. A total of 1,984 articles were selected based on the selection criteria. Author, country, document and keyword analysis was done using VOSviewer 1.6.19. The United States is the leading country in ECC research. The bibliometric analysis of keywords showed seven clusters and the keywords were further ranked according to the risk factors. Dental care was the main key factor of ECC, followed by microbiome, diet and socioeconomic. This insight highlights the emphasis on understanding and addressing issues related to dental care practices in the context of preventing and managing ECC. It is a disease of multifactorial aetiology. Hence, prevention might still be the best way forward. [ABSTRACT FROM AUTHOR]

Microbial infection has been shown to involve in oral carcinogenesis; however, the underlying mechanisms remain poorly understood. The present study aimed to characterize the growth of oral microorganisms as both monospecies and polymicrobial biofilms and determine the effects of their products on oral keratinocytes. Candida albicans (ALC3), Actinomyces naeslundii (AN) and Streptococcus mutans (SM) biofilms or a combination of these (TRI) were grown in flow-cell system for 24 h. The biofilms were subjected to fluorescent in situ hybridization using species-specific probes and analysed using confocal laser scanning microscopy. The effluent derived from each biofilm was collected and incubated with malignant (H357) and normal (OKF6) oral keratinocytes to assess extracellular matrix adhesion, epithelial–mesenchymal transition (EMT) and cytokines expression. Incubation of OKF6 with ALC3 and TRI effluent significantly decreased adhesion of the oral keratinocyte to collagen I, whereas incubation of H357 with similar effluent increased adhesion of the oral keratinocyte to laminin I, significantly when compared with incubation with artificial saliva containing serum-free medium (NE; P < 0.05). In OKF6, changes in E-cadherin and vimentin expression were not consistent with EMT although there was evidence of a mesenchymal to epithelial transition in malignant oral keratinocytes incubated with AN and SM effluent. A significant increase of pro-inflammatory cytokines expression, particularly interleukin (IL)-6 and IL-8, was observed when H357 was incubated with all biofilm effluents after 2- and 24-h incubation when compared with NE (P < 0.05). In conclusion, C.albicans, A.naeslundii and S.mutans form polymicrobial biofilms which differentially modulate malignant phenotype of oral keratinocytes. [ABSTRACT FROM AUTHOR]

Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganismswas prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P < .01). In conclusion, biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent. [ABSTRACT FROM AUTHOR]

Microbial interactions are necessarily associated with the development of polymicrobial oral biofilms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and artificial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 106, 107 and 108 cells mL-1 respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm (ΔAbs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean ΔAbs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent. [ABSTRACT FROM AUTHOR]

Individuals with a history of coronavirus disease 2019 (COVID-19) exhibit memory immunity acquired during natural infection. However, a decline in immunity after infection renders these individuals vulnerable to re-infection, in addition to a higher risk of infection with new variants. This systematic review examined related studies to elucidate the antibody response in these infected individuals after messenger ribonucleic acid (mRNA) vaccination. Hence, the focus of this review was to ascertain differences in the concentration of binding and neutralising antibodies of previously infected individuals in comparison to those of infection-naïve individuals after administration of two doses of mRNA vaccination through available case-control and cohort studies. Positive reverse transcriptase-polymerase chain reaction (RT-PCR) test or detectable anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies at the baseline in included studies showed categorisation of infected and uninfected individuals. This review utilised three online databases: PubMed, Scopus and Cochrane with the following keywords: (COVID-19 OR 'Coronavirus Disease 2019' OR SARS-CoV-2) AND Immun* AND (Pfizer OR BioNTech OR BNT162b2 OR Comirnaty OR Moderna OR mRNA-1273) from January 2019 to July 2021. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) 2020 guidelines and assessment based on the Crowe Critical Appraisal Tool (CCAT), we included 13 related qualified papers of observational studies discerning the binding and neutralising antibody concentrations of infected and uninfected individuals after administration of mRNA vaccines, such as the BNT162b2 and mRNA-1273 vaccine. The mRNA vaccines induced robust binding and neutralising antibody responses in both groups. However, infected individuals showed induction of higher antibody responses in a shorter time compared to uninfected individuals. Hence, a single dose of mRNA vaccination for infected individuals may be sufficient to reach the same level of antibody concentration as that observed in uninfected individuals after receiving two doses of vaccination. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has had a significant impact globally. Healthcare workers (HCWs) were forced to work with uncertainties about the virus, extended working hours, and increasing cases. It is known that stress causes immunosuppression, and salivary IgA (sIgA) is the immune marker most strongly related to work stress. However, the relationship between stress level, COVID-19 fear, and immunosuppression was unknown. The study investigated the relationship between COVID-19-related fear and stress of the sIgA level. A cross-sectional study was conducted among 109 staff nurses in SASMEC, Kuantan, Pahang. Stratified randomised sampling was done for selection of participants. The PSS-10 and FCV -19S-M Questionnaires were administered to objectively assess stress and fear, followed by non-invasive saliva sample collection. Quantitative measurement of IgA level was done using an Enzyme- linked Immunosorbent Assay Kit (ELISA) for sIgA. Pearson correlation test and coefficient of determination (R2) were applied. 86% of participants were female, 83% were aged between 26-45 years old, 75% were married, 95% had worked for more than 1 year, and 68% worked in high-risk stations. The majority of the participants scored moderate severity in terms of perceived stress (84%) and fear level (61%), and the mean sIgA level was 3.96ng/mL. Further analysis showed no linear correlation between stress and fear with salivary IgA levels. Conclusion: HCWs are inevitably exposed to high stress, especially during the pandemic, not just work-related stress and COVID exposure but also other demographic and situational factors. Though the current study revealed moderate stress and fear levels among the staff nurses with no significant association between salivary IgA and stress and fear, further study should examine other factors such as coping skills, working environment, and protective factors that may modify perceived stress and, subsequently, immunological response. [ABSTRACT FROM AUTHOR]

Mitragyna speciosa Korth (kratom) is a tropical indigenous tree of Southeast Asia. It is commonly consumed by the people due to its various pharmacological properties. The leaves of this plant are traditionally used for the treatment of several diseases including pain, fever, cough, anxiety, depression, obesity, diarrhoea, wound healing, diabetes, hypertension as well as for the prevention of cancer and improvement of sexual performance. Phytochemical investigations have confirmed the presence of more than forty alkaloids along with the presence of other bioactive secondary metabolites. Among the alkaloids isolated, mitragynine and 7-hydroxymitragynine along with their derivatives have been widely evaluated and reported to possess various pharmacological effects. Hence, the aim of this review is to shed light on the traditional uses of kratom and the scientific studies to justify the folkloric claims and active principles responsible for the various medicinal effects associated with the leaves of this plant. This review highlights the potential benefits and toxicities associated with M. speciosa leaves along with the phytochemistry. Moreover, the existing gaps in the field of M. speciosa study have been identified along with the future directions to further avail the benefits of this plant species.

This study was designed to investigate the chemical composition of the essential oil of Syzygium variolosum (King) Chantar. & J.Parn. and their cytotoxicity, acetylcholinesterase, antityrosinase, and anti-inflammatory activities. In total, 32 chemical components were identified in the essential oil, which made up 98.9%. The essential oil is mainly composed of β -elemene (20.2%), bicyclogermacrene (13.5%), viridiflorol (11.1%), globulol (8.6%), and selin-11-en-4 α -ol (5.3%). Acetylcholinesterase, antityrosinase, and anti-inflammatory activities were evaluated with the Ellman method, mushroom tyrosinase, and lipoxygenase enzymes, respectively, while cytotoxicity was assessed using an MTT assay. The results showed that essential oil gave significant percentage inhibition (I%: acetylcholinesterase 35.2%, antityrosinase 42.5%, lipoxygenase 48.6%). Furthermore, the essential oil exhibited cytotoxicity against three cancer cell lines, HepG2, MCF7, and A549, with IC 50 values ranging from 90.2 to 95.2 μg/mL. The current study highlights the potential of the use of essential oils as an alternative to the development of pharmaceutical antichemopreventives or cosmetics.

The current study describes the chemical composition, antifungal, antibiofilm, antibacterial and molecular docking studies of Syzygium dyerianum growing in Malaysia. The essential oil was obtained through hydrodistillation and characterized using gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The antifungal and antibacterial activities were developed using the broth microdilution assay, whereas the effect on the microbial biofilms was determined using a semi-quantitative static biofilm assay. A total of 31 components were identified, which represent 99.5 % of the essential oil. The results revealed that the essential oil consisted mainly of β -pinene (15.6 %), α -terpineol (13.3 %), α -pinene (11.1 %), caryophyllene oxide (8.8 %), limonene (8.1 %), borneol (6.0 %) and viridiflorol (5.1 %). The results of the microdilution method showed that essential oil exhibited activity against Candida albicans and Streptococcus mutans with minimal inhibitory concentration values of 125 and 250 μg/mL, respectively. Furthermore, essential oil decreased the biofilm of C. albicans and S. mutans by 20.11 ± 0.27 % and 32.10 ± 4.81 % when treated with 250 μg/mL. The best docking energy was observed with viridiflorol (-29.7 kJ/mol). This study highlights that essential oil can potentially be a natural antifungal, antibacterial, and antibiofilm agent that could be applied in the pharmaceutical and food industries., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)