BACKGROUND AND OBJECTIVE

The emergence of antimicrobial resistance (AMR) poses a significant global health threat, with developing countries such as the Philippines facing particularly severe impacts due to resource limitations. The most affected by AMR is Healthcare Acquired Infections (HAIs), including Catheter-Related Bloodstream Infections (CRBSIs). These are commonly associated with biofilm-forming bacteria like Staphylococcus epidermidis, which complicates treatment due to antibiotic resistance. The Philippine variety of Psidium guajava, a folklorically used medicinal plant, has shown potential antimicrobial properties that could offer a new avenue for combating resistant pathogens.

This study evaluated the antibacterial and antibiofilm efficacy of crude Psidium guajava ethanolic leaf extracts (PGELE) against biofilm-forming S. epidermidis (ATCC 12228). PGELE was tested at five concentrations (ranging from 312.5 µg/mL to 10,000 µg/mL) using two-fold serial dilution to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) using agar dilution count method. For the Minimum Biofilm Inhibitory Concentration (MBIC) and Minimum Biofilm Eradication Concentration (MBEC), crude PGELE was tested at 0.25 x MIC, 0.5 x MIC, MIC, 2 x MIC and 4 x MIC.

The MIC for PGELE against S. epidermidis was determined to be 2500 µg/mL, and the MBC was 5000 µg/mL, indicating that PGELE exhibits bactericidal activity. In biofilm assays, PGELE demonstrated strong antibiofilm activity at concentrations as low as 625 µg/ mL, inhibiting biofilm formation by more than 50%. However, PGELE did not eradicate preformed biofilms, as indicated by the MBEC results at concentrations ranging from 625 µg/mL to 10,000 µg/mL.

Psidium guajava ethanolic leaf extracts exhibit antibacterial and antibiofilm activities against S. epidermidis, particularly in preventing biofilm formation. These findings suggest that PGELE could be developed as an effective natural antimicrobial agent for use in healthcare settings to prevent CRBSIs and other infections caused by biofilm-forming pathogens. Further research and development are warranted to explore the potential of PGELE for antimicrobial drug development.

Background: Medicinal plants are widely used for healthcare needs, including oral health. In the Philippines, garlic, guava, tsaang-gubat, and hierba buena, although primarily recognized as plants used for the treatment of systemic diseases, are indicated as analgesics for dental pain, treatment of gingival inflammation, and oral health maintenance. Despite studies focusing on the effectiveness of these plants for oral health, there is little to no research on the populace’s knowledge, attitude, and practices on these medicinal plants. Objectives: The study aimed to determine the knowledge, attitude, and practices of Oral Medicine patients from a dental college in Manila on four medicinal plants (garlic, guava, tsaang-gubat, and hierba buena) for oral health. Methods: A descriptive study design was used. Oral Medicine patients (694) were invited to participate in the study through daily text messages containing brief research details. The link to the three-part online questionnaire (Google Forms) was sent via text and Facebook messages, and was answerable within 15-20 minutes. Results: Two hundred fourteen (214) Oral Medicine patients participated, with 147 (68.69%) having knowledge on using medicinal plants for oral health which they mostly knew through friends and acquaintances. Most participants had a generally positive attitude toward medicinal plants for oral health and believed they were beneficial (177, 82.71%), safe, effective, and cheaper than conventional medicine (175, 81.78%), and accessible (171, 79.91%). Only 64 (29.91%) personally used medicinal plants to address their oral health conditions. Garlic (144, 97.96%) was the most widely known and used, followed by guava (52, 35.37%), hierba buena (12, 8.16%), and tsaang-gubat (4, 2.72%). Conclusion Most participants were knowledgeable with a generally positive attitude toward the four medicinal plants for oral health but did not use these to address their oral health problems.
Garlic ; Psidium ; Mentha ; Plants, Medicinal ; Oral Health

BACKGROUND

Medicinal plants are widely used for healthcare needs, including oral health. In the Philippines, garlic, guava, tsaang-gubat, and hierba buena, although primarily recognized as plants used for the treatment of systemic diseases, are indicated as analgesics for dental pain, treatment of gingival inflammation, and oral health maintenance. Despite studies focusing on the effectiveness of these plants for oral health, there is little to no research on the populace’s knowledge, attitude, and practices on these medicinal plants.

The study aimed to determine the knowledge, attitude, and practices of Oral Medicine patients from a dental college in Manila on four medicinal plants (garlic, guava, tsaang-gubat, and hierba buena) for oral health.

A descriptive study design was used. Oral Medicine patients (694) were invited to participate in the study through daily text messages containing brief research details. The link to the three-part online questionnaire (Google Forms) was sent via text and Facebook messages, and was answerable within 15-20 minutes.

Two hundred fourteen (214) Oral Medicine patients participated, with 147 (68.69%) having knowledge on using medicinal plants for oral health which they mostly knew through friends and acquaintances. Most participants had a generally positive attitude toward medicinal plants for oral health and believed they were beneficial (177, 82.71%), safe, effective, and cheaper than conventional medicine (175, 81.78%), and accessible (171, 79.91%). Only 64 (29.91%) personally used medicinal plants to address their oral health conditions. Garlic (144, 97.96%) was the most widely known and used, followed by guava (52, 35.37%), hierba buena (12, 8.16%), and tsaang-gubat (4, 2.72%).

Most participants were knowledgeable with a generally positive attitude toward the four medicinal plants for oral health but did not use these to address their oral health problems.

Introduction: Breast cancer is the most common cancer among women in the Philippines and about 3 in every 100 Filipina will be diagnosed with breast cancer in their lifetime. There is a need to discover safe, yet inexpensive herbal extracts with potential cytotoxic properties as potential treatment modalities to treat breast cancer. Objectives: This study seeks to explore the cytotoxic and apoptotic properties of the ethyl acetate fraction of the defatted crude methanol leaf extract of Syzygium samarangense in MCF-7 breast cancer cell lines. Methods: Screening for flavonoids of the extracts was performed using TLC, total flavonoids, total phenols, FTIR and LC-MS spectroscopy. The hydrogen peroxide and ferric reducing anti-oxidant power were used as substrates to assess in vitro anti-oxidative properties of the extracts. The MTT dye viability assay was used to assess the cytotoxic properties of the extracts against MCF-7 cells. Apoptotic properties of the extracts in MCF-7 cells were determined by caspase-3 activation assay, DNA fragmentation patterns and fluorescence microscopy after annexin-V and propidium iodide staining. Results: The abundance of flavonoids in the ethyl acetate fraction of the crude methanol leaf extract was established by TLC, FTIR, LC-MS/MS, total flavonoid and total phenol analyses. The in vitro anti-oxidative properties of this extract was comparable to ascorbic acid. The median inhibitory concentration (IC50) of this extract in MCF-7 breast cancer cell lines was 7.2 mcg/mL while doxorubicin registered an IC50 of 1.2 mcg/mL. At this concentration, the extract was not cytotoxic to normally-dividing breast epithelial cells. Cytotoxicity of the extract was mediated via apoptosis as demonstrated by DNA fragmentation, caspase-3 activation and fluorescence microscopic analyses. Conclusion The study shows that the flavonoid-rich ethyl acetate fraction of the crude methanol leaf extract of S. samarangense possesses potent apoptotic and cytotoxic properties against MCF-7 breast cancer cell lines at low concentrations.
MCF-7 Cells ; Syzygium

Humans ; Child ; Myrtus ; Molluscum Contagiosum/drug therapy* ; Dermatitis, Atopic/drug therapy*

Over the past few decades, complementary and alternative treatments have become increasingly popular worldwide. The purported therapeutic characteristics of natural products have come under increased scrutiny both in vitro and in vivo as part of efforts to legitimize their usage. One such product is tea tree oil (TTO), a volatile essential oil primarily obtained from the native Australian plant, Melaleuca alternifolia, which has diverse traditional and industrial applications such as topical preparations for the treatment of skin infections. Its anti-inflammatory-linked immunomodulatory actions have also been reported. This systematic review focuses on the anti-inflammatory effects of TTO and its main components that have shown strong immunomodulatory potential. An extensive literature search was performed electronically for data curation on worldwide accepted scientific databases, such as Web of Science, Google Scholar, PubMed, ScienceDirect, Scopus, and esteemed publishers such as Elsevier, Springer, Frontiers, and Taylor & Francis. Considering that the majority of pharmacological studies were conducted on crude oils only, the extracted data were critically analyzed to gain further insight into the prospects of TTO being used as a neuroprotective agent by drug formulation or dietary supplement. In addition, the active constituents contributing to the activity of TTO have not been well justified, and the core mechanisms need to be unveiled especially for anti-inflammatory and immunomodulatory effects leading to neuroprotection. Therefore, this review attempts to correlate the anti-inflammatory and immunomodulatory activity of TTO with its neuroprotective mechanisms.
Tea Tree Oil/therapeutic use* ; Melaleuca ; Neuroprotection ; Drug Repositioning ; Neuroinflammatory Diseases ; Australia ; Oils, Volatile ; Anti-Inflammatory Agents/pharmacology*

Wax apple (Syzygium samarangense) has received growing research interest for its high nutritional and medicinal value due to its constituents such as polysaccharide, organic acids, flavonoids, minerals, and other substances. In this study, wax apple polysaccharide (WAP) was isolated from this plant and its protective effect against ethyl carbamate (EC)‍-induced oxidative damage was evaluated in human hepatocytes (L02 cells). Firstly, a series of analyses such as high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), gas chromatography/mass spectrometry (GC/MS), and ¹H and ¹³C nuclear magnetic resonance (NMR) were conducted to identify the structure of WAP. Thereafter, in vitro cell experiments were performed to verify the protective effects of WAP against EC-induced cytotoxicity, genotoxicity, and oxidative damage in L02 cells. Our results revealed that WAP is composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose in a molar ratio of 2.20:‍3.94:‍4.45:‍8.56:‍8.86:‍30.82:‍39.78:‍1.48. Using a combination of methylation and NMR spectroscopic analysis, the primary structure of WAP was identified as Araf-(1→, Glcp-(1→, →2)‍-Araf-(1→, →3)‍-Galp-(1→, →3)‍-Araf-‍(1→, and →6)‍-Galp-‍(1→. Cell experiments indicated that WAP exhibited significant protective effects on EC-treated L02 cells via suppressing cytotoxicity and genotoxicity, reducing reactive oxygen species (ROS) and O₂^•- formation, as well as improving mitochondrial membrane potential (MMP) and glutathione (GSH). In a nutshell, WAP has the potential as an important therapeutic agent or supplement for hepatic oxidative damage. Meanwhile, further studies are needed to prove the above effects in vivo at the biological and clinical levels.
Humans ; Syzygium/chemistry* ; Urethane/pharmacology* ; Spectroscopy, Fourier Transform Infrared ; Oxidative Stress ; Glutathione/pharmacology* ; Hepatocytes ; Polysaccharides/pharmacology*

Aims: Many plants and their derivatives are widely used in food manufacturing because of their biological activities. They play a significant role as food additives to control microbial growth and the occurrence of oxidation reactions. Syzygium malaccense L. is a well-known plant with biological activities such as antimicrobial and antioxidant activities. Thus, the aims of this study were to evaluate the toxicity of the ethanolic leaves extract of S. malaccense and to study its antibacterial mode of action. Methodology and results: The toxicity assessment of S. malaccense leaves extract was determined using the brine-shrimp larvae model. The action mechanisms against bacterial membrane were determined by studying the intracellular material leakage by means of nucleic acid (DNA and RNA) release, crystal violet dye uptake and cellular protein leakage. The present findings proved the extract's safety as indicated by a high dose of 7.402 mg/mL for lethal concentration (LC50) against brine-shrimp larvae. On the other hand, the ethanolic extract caused a severe membrane permeability towards all the tested bacteria as indicated by the increased intracellular material leakage in a concentration-dependent manner. Conclusion, significance and impact of study The current study provides valuable information regarding the safety and antibacterial action mechanism of S. malaccense ethanolic leaves extract, thus paving the way for its utilization as a natural preservative in a wide range of food products.
Syzygium--toxicity ; Anti-Bacterial Agents

Gut bacterial nitroreductases play an important role in reduction of various nitroaromatic compounds to the corresponding N-nitroso compounds, hydroxylamines or aromatic amines, most of which are carcinogenic and mutagenic agents. Inhibition of gut nitroreductases has been recognized as an attractive approach for reducing mutagen metabolites in the colon, so as to prevent colon diseases. In this study, the inhibitory effects of 55 herbal medicines against Escherichia coli(E. coli) nitroreductase (EcNfsA) were examined. Compared with other herbal extracts, Syzygium aromaticum extract showed superior inhibitory potency toward EcNfsA mediated nitrofurazone reduction. Then, the inhibitory effects of 22 major constituents in Syzygium aromaticum against EcNfsA were evaluted. Compared with other tested natural compounds, ellagic acid, corilagin, betulinic acid, oleanic acid, ursolic acid, urolithin M5 and isorhamnetin were found with strong to moderate inhibitory effect against EcNfsA, with IC₅₀ values ranging from 0.67 to 28.98 mol·L^-1. Furthermore, the inhibition kinetic analysis and docking simulation demonstrated that ellagic acid and betulinic acid potently inhibited EcNfsA (K_i < 2 μmol·L ^-1) in a competitively inhibitory manner, which created strong interactions with the catalytic triad of EcNfsA. In summary, our findings provide new scientific basis for explaining the anti-mutagenic activity of Syzygium aromaticum, where some newly identified EcNfsA inhibitors can be used for developing novel agents to reduce the toxicity induced by bacterial nitroreductase.
Ellagic Acid/pharmacology* ; Escherichia coli ; Kinetics ; Nitroreductases/pharmacology* ; Plant Extracts/pharmacology* ; Syzygium

Twenty-six compounds, including sixteen meroterpenoids(1-16), a triterpenoid(17), four terpenoid derivatives(18-21), and five aromatic compounds(22-26), were isolated from the leaves of Psidium guajava. Their structures were identified by spectroscopic analyses including NMR and MS. Compounds 21-26 were obtained from plants of Psidium for the first time. Based on the structure,(R)-2-ethylhexyl 2H-1,2,3-triazole-4-carboxylate(24 a), an α-glucosidase inhibitor recently isolated from Paramignya trimera, should be revised as compound 24. Meroterpenoids 1-16 were evaluated for their antitumor and antifungal activities. Meroterpenoids psiguajadial D(4), guapsidial A(5), 4,5-diepipsidial A(7), guadial A(14), and guadial B(15) showed cytotoxicities against five human tumor cell lines(HL-60, A-549, SMMC-7721, MCF-7, and SW-480), among which 5 was the most effective with an IC_(50) of 3.21-9.94 μmol·L~(-1).
Antifungal Agents/pharmacology* ; Humans ; Magnetic Resonance Spectroscopy ; Plant Extracts ; Plant Leaves ; Psidium ; Terpenes