Comparative inhibitory effects of 4-allylpyrocatechol isolated from Piper betle on Streptococcus intermedius, Streptococcus mutans, and Candida albicans

Antioxidant, antiglycation, and antibacterial of copper oxide nanoparticles synthesized using Caesalpinia Sappan extract

Synthesis of metal nanoparticles using plant extracts is environmentally friendly and of increasing interest. However, not all plant extracts can meet successfully on the synthesis. Therefore, searching for the high potential extracts that can reduce the metal salt precursor in the synthesis reaction is essential. The present study explores the synthesis of copper oxide nanoparticles (CuONPs) using Caesalpinia sappan heartwood extract. Phytochemical analysis and determination of the total phenolic content of the extract were performed before use as a reducing agent. Under the suitable synthesized condition, a color change in the color of the solutions to brown confirmed the formation of CuONPs. The obtained CuONPs were confirmed using ultraviolet-visible spectroscopy, photon correlation spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, and Fourier transform infrared analysis. The synthesized CuONPs investigated for antioxidant, antiglycation, and antibacterial activities. CuONPs possessed antioxidant activities by quenching free radicals with an IC50 value of 63.35 µg/mL and reducing activity with an EC range of 3.19-10.27 mM/mg. CuONPs also inhibited the formation of advanced glycation end products in the bovine serum albumin/ribose model with an IC50 value of 17.05 µg/mL. In addition, CuONPs showed inhibition of human pathogens, including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, and prevention of biofilm formation and biofilm eradication, with maximum inhibition of approx. 75%. Our findings suggest that C. sappan extract can be used to obtain highly bioactive CuONPs for the development of certain medical devices and therapeutic agents.

Insights into the anti-Candida albicans properties of natural phytochemicals: An in vitro and in vivo investigation

Invasive candidiasis, attributed to Candida albicans, has long been a formidable threat to human health. Despite the advent of effective therapeutics in recent decades, the mortality rate in affected patient populations remains discouraging. This is exacerbated by the emergence of multidrug resistance, significantly limiting the utility of conventional antifungals. Consequently, researchers are compelled to continuously explore novel solutions. Natural phytochemicals present a potential adjunct to the existing arsenal of agents. Previous studies have substantiated the efficacy of phytochemicals against C. albicans. Emerging evidence also underscores the promising application of phytochemicals in the realm of antifungal treatment. This review systematically delineates the inhibitory activity of phytochemicals, both in monotherapy and combination therapy, against C. albicans in both in vivo and in vitro settings. Moreover, it elucidates the mechanisms underpinning the antifungal properties, encompassing (i) cell wall and plasma membrane damage, (ii) inhibition of efflux pumps, (iii) induction of mitochondrial dysfunction, and (iv) inhibition of virulence factors. Subsequently, the review introduces the substantial potential of nanotechnology and photodynamic technology in enhancing the bioavailability of phytochemicals. Lastly, it discusses current limitations and outlines future research priorities, emphasizing the need for high-quality research to comprehensively establish the clinical efficacy and safety of phytochemicals in treating fungal infections. This review aims to inspire further contemplation and recommendations for the effective integration of natural phytochemicals in the development of new medicines for patients afflicted with C. albicans.

Cyclic strain of poly (methyl methacrylate) surfaces triggered the pathogenicity of Candida albicans

Candida albicans is an opportunistic yeast and the primary etiological factor in oral candidiasis and denture stomatitis. The pathogenesis of C. albicans could be triggered by several variables, including environmental, nutritional, and biomaterial surface cues. Specifically, biomaterial interactions are driven by different surface properties, including wettability, stiffness, and roughness. Dental biomaterials experience repetitive (cyclic) stresses from chewing and biomechanical movements. Pathogenic biofilms are formed over these biomaterial surfaces under cyclic strain. This study investigated the effect of the cyclic strain (deformation) of biomaterial surfaces on the virulence of Candida albicans. Candida biofilms were grown over Poly (methyl methacrylate) (PMMA) surfaces subjected to static (no strain) and cyclic strain with different levels (ε˜x=0.1 and 0.2%). To evaluate the biomaterial-biofilm interactions, the biofilm characteristics, yeast-to-hyphae transition, and the expression of virulent genes were measured. Results showed the biofilm biomass and metabolic activity to be significantly higher when Candida adhered to surfaces subjected to cyclic strain compared to static surfaces. Examination of the yeast-to-hyphae transition showed pseudo-hyphae cells (pathogenic) in cyclically strained biomaterial surfaces, whereas static surfaces showed spherical yeast cells (commensal). RNA sequencing was used to determine and compare the transcriptome profiles of cyclically strained and static surfaces. Genes and transcription factors associated with cell adhesion (CSH1, PGA10, and RBT5), biofilm formation (EFG1), and secretion of extracellular matrix (ECM) (CRH1, ADH5, GCA1, and GCA2) were significantly upregulated in the cyclically strained biomaterial surfaces compared to static ones. Genes and transcription factors associated with virulence (UME6 and HGC1) and the secretion of extracellular enzymes (LIP, PLB, and SAP families) were also significantly upregulated in the cyclically strained biomaterial surfaces compared to static. For the first time, this study reveals a biomaterial surface factor triggering the pathogenesis of Candida albicans, which is essential for understanding, controlling, and preventing oral infections. STATEMENT OF SIGNIFICANCE: Fungal infections produced by Candida albicans are a significant contributor to various health conditions. Candida becomes pathogenic when certain environmental conditions change, including temperature, pH, nutrients, and CO2 levels. In addition, surface properties, including wettability, stiffness, and roughness, drive the interactions between Candida and biomaterials. Clinically, Candida adheres to biomaterials that are under repetitive deformation due to body movements. In this work, we revealed that when Candida adhered to biomaterial surfaces subjected to repetitive deformation, the microorganism becomes pathogenic by increasing the formation of biofilms and the expression of virulent factors related to hyphae formation and secretion of enzymes. Findings from this work could aid the development of new strategies for treating fungal infections in medical devices or implanted biomaterials.

Influence of Benincasa hispida Peel Extracts on Antioxidant and Anti-Aging Activities, including Molecular Docking Simulation

Benincasa hispida peel, a type of postconsumer waste, is considered a source of beneficial phytochemicals. Therefore, it was subjected to investigation for biological activities in this study. B. hispida peel was extracted using 95% v/v, 50% v/v ethanol and water. The obtained extracts were B95, B50 and BW. B95 had a high flavonoid content (212.88 ± 4.73 mg QE/g extract) and phenolic content (131.52 ± 0.38 mg GAE/g extract) and possessed high antioxidant activities as confirmed by DPPH, ABTS and lipid peroxidation inhibition assays. Moreover, B95 showed inhibitory effects against collagenase and hyaluronidase with values of 41.68 ± 0.92% and 29.17 ± 0.66%, which related to anti-aging activities. Via the HPLC analysis, one of the potential compounds found in B95 was rutin. Molecular docking has provided an understanding of the molecular mechanisms underlying the interaction of extracts with collagenase and hyaluronidase. All extracts were not toxic to fibroblast cells and did not irritate the hen's egg chorioallantoic membrane, which indicated its safe use. In conclusion, B. hispida peel extracts are promising potential candidates for further use as antioxidant and anti-aging agents in the food and cosmetic industries.

Targeting bone cancer with 4-Allylbenzene-1,2-diol purified from Piper betle L.: an in silico and cytotoxicity scrutiny

Piper betle L., a well-known medicinal plant with rich source of bioactive compounds, is widely used in several therapeutics. The present study was performed to scrutinize the anti-cancer potential of compounds P. betle petiole by means of in silico studies, purification of 4-Allylbenzene-1,2-diol from petioles and assessing its cytotoxicity on bone cancer metastasis. Subsequent to SwissADME screening, 4-Allylbenzene-1,2-diol and Alpha terpineol were chosen for molecular docking together with eighteen approved drugs against fifteen important bone cancer targets accompanied with molecular dynamics simulation studies. 4-Allylbenzene-1,2-diol was found to be multi-targeting, interacted effectively with all targets, particularly exhibited good stability with MMP9 and MMP2 during molecular dynamics simulations and Molecular Mechanics- Generalized Born and Surface Area (MM-GBSA) analysis using Schrodinger. Later, the compound was isolated, purified and the cytotoxicity studies on MG63 bone cancer cell lines confirmed the cytotoxicity nature (75.98% at 100 µg/ml concentration). The results demonstrated the compound as a matrix metalloproteinase inhibitor, and therefore 4-Allylbenzene-1,2-diol may possibly be prescribed in targeted therapy for alleviating the bone cancer metastasis upon further wet lab experimental validations.Communicated by Ramaswamy H. Sarma.

The synergistic effects of hydroxychavicol and amphotericin B towards yeast-hyphae transition and the germination of Candida albicans

Objectives

Dimorphic transformation from yeast cells to hyphae is considered one of the major virulence factors of candidal species. The development of antifungal resistance against several candida diseases has led researchers to find plant derived alternatives. We aimed to determine the effect of hydroxychavicol (HC), Amphotericin B (AMB), and their combination (HC + AMB) on the transition and germination of oral Candida species.

Methods

The antifungal susceptibility of hydroxychavicol (HC) and Amphotericin B (AMB) separately and in a mixture (HC + AMB) against Candida albicans ATCC 14053, Candida parapsilosis ATCC 22019, Candida tropicalis ATCC 13803, and Candida dubliniensis ATCC MYA-2975 was determined by broth microdilution technique. Minimal Inhibitory Concentration was calculated based on the CLSI protocols. The MIC₅₀, fractional inhibitory concentration (FIC) index, and IC₅₀ were also determined. The IC₅₀ values were used as the treatment concentration of HC, AMB, and HC + AMB to study the effect of antifungal inhibition on yeast hypha transition (gemination). The germ tube formation percentage of candida species was calculated at several intervals using a colorimetric assay.

Results

The MIC₅₀ range of HC alone against Candida species was between 120-240 µg per mL while that of AMB was between 2-8 µg per mL, respectively. The combination of HC + AMB at 1:1 and 2:1 demonstrated the strongest synergistic activity against C. albicans with an FIC index of 0.07. Moreover, within the first hour of treatment, the total percentage of germinating cells was significantly reduced by 79% (p < 0.05).

Conclusion

The combination of HC + AMB displayed synergism and inhibited C. albicans hyphal growth. HC + AMB combination slowed the germination process and exhibited consistent prolonged effect up to 3 h post-treatment. The results of this study will pave the way for potential in vivo studies.

Antimicrobial activity of jambu mawar [Syzygium jambos (L.) Alston] leaf extract against foodborne pathogens and spoilage microorganisms

The present work evaluated the antimicrobial potential of the ethanolic extract of jambu mawar [Syzygium jambos (L.) Alston] leaves against various foodborne pathogens and spoilage microorganisms via the disc diffusion assay (DDS) and the time-kill curve assay. These microorganisms included bacteria (Klebsiella pneumoniae ATCC13773, Listeria monocytogenes ATCC19112, Proteus mirabilis ATCC21100, Pseudomonas aeruginosa ATCC9027, Staphylococcus aureus ATCC29737, and Vibrio parahaemolyticus ATCC17802), yeasts (Candida albicans ATCC10231, C. krusei ATCC32196, C. glabrata ATCC2001, and C. parapsilosis ATCC22019), and moulds (Aspergillus fumigatus ATCC26430, A. niger ATCC9029, Rhizopus oligosporus ATCC22959, and R. oryzae ATCC22580). The inhibition zone of DDA ranged from 7.00 ± 0.23 to 10.25 ± 0.29 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal (MBC/MFC) of the ethanolic leaf extract were obtained at the concentrations of 0.01 to 2.50 and 0.01 to 5.00 mg/mL, respectively. The time-kill curve assay showed that except for P. mirabilis, other microorganisms were completely killed at MIC concentrations ranging from 0.5 to 4× MIC. In comparison, P. mirabilis showed a growth reduction of > 3 log10 CFU/mL for 4 h. Meanwhile, the conidial germination of A. fumigatus was fully inhibited at 0.5× MIC. Though not fully inhibited, the ethanolic leaf extract significantly reduced the conidial germination of A. niger, R. oryzae, and R. oligosporus to 7.0, 7.0, and 11.0%, respectively. Overall, the ethanolic leaf extract of S. jambos exhibited antimicrobial activity against foodborne pathogens and spoilage microorganisms.

In silico Molecular Docking for assessing Anti-fungal Competency of Hydroxychavicol, a Phenolic Compound of Betel Leaf (Piper betle L.) against COVID-19 Associated Maiming Mycotic Infections

Objective: To investigate the inhibitory nature of hydroxychavicol against the Covid-19 associated mycotic infections, the present in silico study was performed in hydroxychavicol with the target Lanosterol 14 alpha demethylase and its competency was compared with four approved anti-fungal drugs. Significance: The corona virus pandemic has drawn stark lines between rich nations and poor, and the occurrence of COVID-19 associated mycotic infections, mucormycosis epidemic stands as the latest manifestation. The increase in resistance in known fungal pathogens to the available anti-fungal drugs and side effects are the important demands that forced to search anti-fungal compounds from medicinal plants as therapeutic alternatives. During the fishing expedition, Piper betle L., gets tremendous attention for its rich source of medicinally important compounds. Among them, hydroxychavicol has the enormous supportive records against microbial growth. Methods: Hydroxychavicol and the chosen drugs were retrieved from the Pubchem database and subjected to ADME analysis. The structure of the target of the chosen COVID-19 associated fungal pathogens was retrieved from PDB and unavailable protein structures were modeled using Swiss Model and validated. Virtual screening (PyRx version 0.8) was performed and the interactions were visualized using BIOVIA Discovery Studio. Results: ADME screening of hydroxychavicol was found to have clear reciprocity with the drug-likeliness nature and the subsequent molecular docking study revealed its good binding affinity towards the target protein suggesting its inhibitory nature. Conclusion: This study offers the possibility of making use of the suppressive nature of hydroxychavicol in the treatment of mycotic infections either exclusively/in synergistic approach.

Antibiofilm Potential of Medicinal Plants against Candida spp. Oral Biofilms: A Review

The use of natural products to promote health is as old as human civilization. In recent years, the perception of natural products derived from plants as abundant sources of biologically active compounds has driven their exploitation towards the search for new chemical products that can lead to further pharmaceutical formulations. Candida fungi, being opportunistic pathogens, increase their virulence by acquiring resistance to conventional antimicrobials, triggering diseases, especially in immunosuppressed hosts. They are also pointed to as the main pathogens responsible for most fungal infections of the oral cavity. This increased resistance to conventional synthetic antimicrobials has driven the search for new molecules present in plant extracts, which have been widely explored as alternative agents in the prevention and treatment of infections. This review aims to provide a critical view and scope of the in vitro antimicrobial and antibiofilm activity of several medicinal plants, revealing species with inhibition/reduction effects on the biofilm formed by Candida spp. in the oral cavity. The most promising plant extracts in fighting oral biofilm, given their high capacity to reduce it to low concentrations were the essential oils extracted from Allium sativum L., Cinnamomum zeylanicum Blume. and Cymbopogon citratus (DC) Stapf.

Mixed biofilms of pathogenic Candida-bacteria: regulation mechanisms and treatment strategies

Mixed-species biofilm is one of the most frequently recorded clinical problems. Mixed biofilms develop as a result of interactions between microorganisms of a single or multiple species (e.g. bacteria and fungi). Candida spp., particularly Candida albicans, are known to associate with various bacterial species to form a multi-species biofilm. Mixed biofilms of Candida spp. have been previously detected in vivo and on the surfaces of many biomedical instruments. Treating infectious diseases caused by mixed biofilms of Candida and bacterial species has been challenging due to their increased resistance to antimicrobial drugs. Here, we review and discuss the clinical significance of mixed Candida-bacteria biofilms as well as the signalling mechanisms involved in Candida-bacteria interactions. We also describe possible approaches for combating infections associated with mixed biofilms, such as the use of natural or synthetic drugs and combination therapy. The review presented here is expected to contribute to the advances in the biomedical field on the understanding of underlying interaction mechanisms of pathogens in mixed biofilm, and alternative approaches to treating the related infections.

Piper betle (L): Recent Review of Antibacterial and Antifungal Properties, Safety Profiles, and Commercial Applications

Piper betle (L) is a popular medicinal plant in Asia. Plant leaves have been used as a traditional medicine to treat various health conditions. It is highly abundant and inexpensive, therefore promoting further research and industrialization development, including in the food and pharmaceutical industries. Articles published from 2010 to 2020 were reviewed in detail to show recent updates on the antibacterial and antifungal properties of betel leaves. This current review showed that betel leaves extract, essential oil, preparations, and isolates could inhibit microbial growth and kill various Gram-negative and Gram-positive bacteria as well as fungal species, including those that are multidrug-resistant and cause serious infectious diseases. P. betle leaves displayed high efficiency on Gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa, Gram-positive bacteria such as Staphylococcus aureus, and Candida albicans. The ratio of MBC/MIC indicated bactericidal and bacteriostatic effects of P. betle leaves, while MFC/MIC values showed fungicidal and fungistatic effects. This review also provides a list of phytochemical compounds in betel leaves extracts and essential oils, safety profiles, and value-added products of betel leaves. Some studies also showed that the combination of betel leaves extract and essential oil with antibiotics (streptomycin, chloramphenicol and gentamicin) could provide potentiating antibacterial properties. Moreover, this review delivers a scientific resume for researchers in respected areas and manufacturers who want to develop betel leaves-based products.

Denture-Soaking Solution Containing Piper betle Extract-Loaded Polymeric Micelles; Inhibition of Candida albicans, Clinical Study, and Effects on Denture Base Resin

Candida albicans is a common overgrowth in people wearing dentures. Long-term use of antifungal chemicals carries a risk of toxic side effects. This study focused on the edible Piper betle extract because of its safety. The broth dilution method was applied for antifungal determination of the ethyl acetate fractionated extract (fEA) and fEA-loaded polymeric micelles (PMF). The PMF was prepared by thin-film hydration using poloxamer 407 as a polymer base. The results found that the weight ratio of fEA to polymer is the main factor to obtain PMF system as a clear solution, nanoparticle sizes, narrow size distribution, negative zeta potential, and high entrapment efficiency. The activity of PMF against C. albicans is significantly higher than fEA alone, with a minimum fungicidal concentration of 1.5 mg/mL. PMF from 1:3 ratio of fEA to polymer is used to develop a denture-soaking solution contained 1.5 mg fEA/mL (PMFS). A clinical study on dentures of 15 volunteers demonstrated an 86.1 ± 9.2% reduction of C. albicans after soaking the dentures in PMFS daily for 14 days. Interestingly, PMFS did not change the hardness and roughness of the denture base resins. The developed PMFS may serve as a potential natural denture-soaking solution against candidiasis in denture wearers.

Development of Self-Nanoemulsifying Drug Delivery Systems Containing 4-Allylpyrocatechol for Treatment of Oral Infections Caused by Candida albicans

Clinical use of 4-Allylpyrocatechol (APC), a potential antifungal agent from Piper betle, is limited because of its low water solubility. The current study explores the development of the self-nanoemulsifying drug delivery system (SNEDDS) containing APC (APC-SNEDDS) to enhance APC solubility. Results demonstrated that excipient type and concentration played an important role in the solubility of APC in the obtained SNEEDS. SNEDDS, comprising 20% Miglyol 812N, 30% Maisine 35-1, 40% Kolliphor RH40, and 10% absolute ethanol, provided the highest loading capacity and significantly increased water solubility of APC. Oil-in-water nanoemulsions (NE) with droplet sizes of less than 40 nm and a narrow size distribution were obtained after dispersing this APC-SNEDDS in water. The droplets had a negative zeta potential between -10 and -20 mV. The release kinetics of APC from APC-SNEDDS followed the Higuchi model. The NE containing 1.6 mg APC/mL had effective activity against Candida albicans with dose-dependent killing kinetics and was nontoxic to normal cells. The antifungal potential was similar to that of 1 mg nystatin/mL. These findings suggest that APC-SNEDDS are a useful system to enhance the apparent water solubility of APC and are a promising system for clinical treatment of oral infection caused by C. albicans.

A new sesquineolignan and four new neolignans isolated from the leaves of Piper betle, a traditional medicinal plant in Myanmar

One new sesquineolignan, piperneolignan A (1), four new neolignans, piperneolignans B-E (2-5), and eight known compounds were isolated from the leaves of Piper betle (Piperaceae) collected from Myanmar. These new structures were determined by analysis of MS and NMR data, and the absolute configuration of piperneolignan A was elucidated by electronic circular dichroism (ECD) calculations. Piperneolignan A (1), piperneolignan B (2), hydroxychavicol (6), p-hydroxycinnamaldehyde (10), and diallylcatechol (13) possessed anti-inflammatory activity against nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells with IC₅₀ values of 9.87, 45.94, 4.80, 26.40, and 40.45 μM, respectively, compared with the positive control NG-monomethyl-l-arginine (l-NMMA, IC₅₀ = 33.84 μM). The two hydroxy groups in the structure of hydroxychavicol are essential for activity, and dimerization or trimerization of hydroxychavicol decreases activity.