Antimicrobial resistance is now considered a global health problem because it reduces the effectiveness of antimicrobial drugs. According to the World Health Organization (WHO), the highest mortality rate is associated with infections caused by multidrug-resistant microorganisms, with approximately 700,000 deaths worldwide each year. The aim of this study was to determine the potential of C-10 massoia lactone to inhibit the growth of fungi and C. tropicalis biofilm, and molecular docking studies were performed to determine the nature of the inhibition. The study was conducted using the microdilution method for antifungal and antibiofilm testing and designed with a molecular docking approach. Furthermore, an analysis using the scanning electron microscope (SEM) was performed to evaluate the mechanism of effect. The results obtained showed that C-10 massoia lactone can inhibit the growth of fungi by 84.21 w/v. Meanwhile, the growth of C. tropicalis biofilm in the intermediate phase was 80.23 w/v and in the mature phase was 74.23 w/v. SEM results showed that C-10 massoia lactone damaged the EPS matrix of C. tropicalis so that hyphal formation was hindered due to damage to fungal cells, resulting in a decrease in attachment, density, and lysis of C. tropicalis fungal cells. Based on molecular docking tests, C-10 massoia lactone was able to inhibit biofilm formation without affecting microbial growth, while docking C-10 massoia lactone showed a significant binding and has the potential as an antifungal agent. In conclusion, the C-10 massoia lactone compound has the potential as an antibiofilm against C. tropicalis, so it can become a new antibiofilm agent.

Setiawati S, Nuryastuti T, Sholikhak EN, Lisdiyanti P, Pratiwi SUT, Sulistiyanti TR, Ratnakomala S, Jumina, Mustofa. 2021. The potency of actinomycetes extracts isolated from Pramuka Island, Jakarta, Indonesia as antimicrobial agents. Biodiversitas 22: 1104-1111. Actinomycetes are one of the Gram-positive bacteria which are widely distributed and produce many secondary metabolites including those known as antibiotics, antifungals, anticancer, and antimalarials agents. The secondary metabolites of actinomycetes are abundant, which include many active compounds that have been identified because of the large diversity in the actinomycetes phylum. This study aimed to identify and screen collected by Indonesian Culture Collection (InaCC) from Bojong Gede and Pramuka Island, Jakarta, Indonesia as antibacterial and antifungal agents. Primary screening was done on 16 actinomycetes isolates by well-agar diffusion method. Antimicrobial activity was tested by using micro broth dilution methods to determine minimum inhibitory concentration (MIC). Molecular identification into level genera and species was determined by 16S rRNA gene sequencing. Out of 16 actinomycetes isolates used, 4 isolates have activity against Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538, Bacillus subtilis BTCC B-612, and Escherichia coli BTCC B-614, specifically InaCC A758, InaCC A759, InaCC A760 and InaCC A765 isolates. InaCC A758 have highest antimicrobial activity against mentioned microbial with MIC value at 50 μg/mL, 6.25 μg/mL, 31.25 μg/mL and 3.125 μg/mL, respectively. Three genera were found from the samples: i.e. Streptomyces (80%), Microbispora (13%) and Nocardia (6%). Based on 16S rRNA gene identification, the active isolates of actinomycetes InaCC A758, InaCC A759, InaCC A760 and InaCC A765 were similar to Streptomyces badius, Streptomyces olivaceus, Streptomyces sanyensis, and Nocardia otitidiscaviarum, respectively. The secondary metabolites of actinomycetes extracts from Pramuka Island can be potentially developed as antifungal and antibacterial agents.

The essential oil of Massoia (Massoia aromatica Becc., Lauraceae) bark is a potential immunomodulator in vitro. This study evaluated the potential immunomodulatory effects of Massoia bark infusion on the nonspecific immune response (phagocytosis) of Wistar rats. For the in vitro assay, macrophages were treated with the freeze-dried infusion at the concentrations of 2.5, 5, 10, 20, or 40 µg/mL media. For the in vivo assay, two-month-old male Wistar rats were divided into five groups. The baseline group received distilled water at the dose of 1 mL/100 g body weight (BW), with the herbal product containing Phyllanthus niruri extract that was administered as the positive control at the dose of 0.54 mL/rat. The treatment groups received the infusion at a dose of 100, 300, or 500 mg/100 g BW. Treatments were given orally every day for 14 days. The ability of macrophage cells to phagocyte latex was determined as phagocytic index (PI), and it was observed under microscopy with 300 macrophages. The in vitro study revealed that the phagocytic activity of the infusion-treated macrophages significantly increased in comparison with that of the control macrophages in a concentration-dependent manner. Among all of the treatment concentrations, the concentration of 40 µg/mL provided the highest activity with a PI value of 70.51 ± 1.11%. The results of the in vivo assay confirmed those of the in vitro assay. The results of the present study indicate that Massoia bark can increase the phagocytic activity of rat macrophage cells.

The Ternate Blue Pea, renowned for its antibacterial properties and native to the northern Maluku islands, has been a subject of scientific investigation. Despite previous studies on this plant, its potential antibiofilm activity against Staphylococcus aureus (SA) has remained unexplored. This research aimed to assess the efficacy of Ternate Blue Pea flower extract (TBPE) in inhibiting and eradicating SA biofilm activity. Antibiofilm activity was evaluated using the microtiter broth method, with the minimum biofilm inhibitory concentration (MBIC50) and minimum biofilm eradication concentration (MBEC50) values serving as determinants. The antibiofilm mechanism was elucidated through scanning electron microscopy (SEM). Statistical analysis was conducted using ANOVA (p<0.05). Results revealed that TBPE inhibited SA growth by 85.20% ± 0.01, slightly lower than the control activity of Vancomycin at 88.00% ± 0.01. In the antibiofilm test, TBPE exhibited significant efficacy in inhibiting biofilm during the mid-phase (81.40% ± 0.01) and preventing biofilm formation in the maturation phase (78.14% ± 0.01) of biofilm, whereas Vancomycin demonstrated slightly higher inhibitory activity in both the mid-phase (85.40% ± 0.01) and maturation phase (82.00% ± 0.01) of biofilm. TBPE disrupted the SA biofilm formation by 74.44% ± 0.01, while Vancomycin was marginally more effective with the disruption value of 77.00% ± 0.01. SEM analysis confirmed that TBPE could inhibit and breakdown SA biofilm by damaged the extracellular polymer (EPS) matrix in biofilms. In conclusion, TBPE exhibits promising antibiofilm activity against SA.Keywords: Antibacterial,

Indonesia is rich in the biodiversity of medicinal plants used traditionally for healing several ailments. Melastoma malabathricum L. is one of the traditional herbs used to treat many diseases. A TLC-densitometric method was developed for determining secondary metabolites such as phenolic compounds and their related compounds, M. malabathricum leaves from Riau, Indonesia. This study investigated the secondary metabolites of M. malabathricum extract by spraying reagent: FeCl3, p-anisaldehyde, and cerium (IV) sulfate and followed by antibacterial assay through broth macro dilution method. Densitometric qualitative analysis of phenolic compounds and their related compounds was employed to examine peaks of the M. malabathricum extract through winCATS software. After spraying with particular reagents, the three extracts showed various spots/bands with several colors and exhibited peaks in TLC densitogram profiles. Three extracts were tested for antibacterial activity against Staphylococcus aureus and Escherichia coli. The result showed that ethyl acetate extract revealed excellent antibacterial activity against S. aureus and E. coli with MIC values of 3.125±0.6 mg/mL and 6.25±0.5 mg/mL, respectively. Owing to the presence of a wide variety of secondary metabolites, the leaf extract of M. malabathricum is expected to exhibit and help develop as a therapeutic agent.

Context: One strategy to address the emergence of infectious diseases supported by the increasing cases of microbial antibiotic resistance is the development of anti-pathogenic drugs, a quorum quenching compound(s) capable of inhibiting microbial communication (quorum sensing inhibitor). Pseudomonas aeruginosa is one of the most common source of chronic opportunistic infections, which demonstrates the most consistent resistance to antimicrobial agents. Quorum sensing (QS) controls secretion of virulence factors in P. aeruginosa. Aim: This study aims to discover quorum sensing inhibitors (QSI) from some Indonesian medicinal plants ethanol extract to analyze their inhibitory activities against QS-mediated virulence factors in P. aeruginosa. Settings and Design: In-vitro experimental study-laboratory setting Materials and Methods: Indonesian medicinal plant ethanolic extracts were tested for their capability to inhibit P. aeruginosa motility, biofilm formation using microtiter plate method, pyocyanin and LasA production using LasA staphylolytic assay. Statistical analysis used: Statistical significance of the data were determined using one way ANOVA, followed by Dunnett's test. Differences were considered significant with P values of 0.05 or less. Results: Ethanolic extract of T. catappa leaves and A. alitilis flower capable to inhibit P. aeruginosa motility as well as pyocyanin production and biofilm formation. Both extracts also showed capability in reducing LasA protease production. Conclusion: T. catappa and A. alitilis are an interesting sources of innovative plant derived quorum quenching compound(s), thus can be used in the development of new antipathogenic drug.