Antifungal Potential of Secondary Metabolites Derived from Arcangelisia flava (L.) Merr.: An Analysis of In Silico Enzymatic Inhibition and In Vitro Efficacy against Candida Species.

Considering the escalating resistance to conventional antifungal medications, it is critical to identify novel compounds that can efficiently counteract this challenge. The purpose of this research was to elucidate the fungicidal properties of secondary metabolites derived from Arcangelisia flava, with a specific focus on their efficacy against Candida species. This study utilized a combination approach comprising laboratory simulations and experiments to discern and evaluate the biologically active constituents present in the dichloromethane extract of A. flava. The in vitro experiments demonstrated that compounds 1 (palmatine) and 2 (fibraurin) exhibited antifungal properties. The compounds exhibited minimum inhibitory concentrations (MICs) ranging from 15.62 to 62.5 µg/mL against Candida sp. Moreover, compound 1 demonstrated a minimum fungicidal concentration (MFC) of 62.5 µg/mL against Candida glabrata and C. krusei. In contrast, compound 2 exhibited an MFC of 125 µg/mL against both Candida species. Based on a molecular docking study, it was shown that compounds 1 and 2 have a binding free energy of -6.6377 and -6.7075 kcal/mol, respectively, which indicates a strong affinity and specificity for fungal enzymatic targets. This study utilized pharmacophore modeling and Density Functional Theory (DFT) simulations to better understand the interaction dynamics and structural properties crucial for antifungal activity. The findings underscore the potential of secondary metabolites derived from A. flava to act as a foundation for creating novel and highly efficient antifungal treatments, specifically targeting fungal diseases resistant to existing treatment methods. Thus, the results regarding these compounds can provide references for the next stage in antifungal drug design. Further investigation is necessary to thoroughly evaluate these natural substances' clinical feasibility and safety characteristics, which show great potential as antifungal agents.

α-glucosidase and α-amylase inhibitory activity of flavonols from Stenochlaena palustris (Burm.f.) Bedd.

Stenochlaena palustris (Burm.f.) Bedd., a fern species native to India, Southeast Asia, Polynesia, and Australia, has a long history of medical including as a diabetic therapy. This study aimed to isolate bioactive compounds from S. palustris ethyl acetate extract and assess their in vitro and in silico inhibitory activities against α-glucosidase and α-amylase. The successful separation of five flavonols, namely stenopalustroside A (1), tiliroside (2), kaempferol (3), quercetin (4), and rutin (5), was achieved through phytochemical analysis. The compounds exhibited a range of inhibitory activities against α-glucosidase and α-amylase, with IC50 values ranging from 40 to 250 µg/mL. Notably, the biological activities of compound 1 have been reported for the first time. Compound 4 was the most effective inhibitor of both enzymes among the isolated compounds. Studies performed in silico reveal that the interactions between amino acids in compounds 4 and 5 are remarkably comparable to those observed in the positive control. These compounds share this commonality, and as a result, they both have the potential to be active agents.

Free Radical Scavenging, Anti-Infectious, and Toxicity Activities from Stenochlaena palustris (Burm.f.) Bedd. Extracts.

Stenochlaena palustris (Burm.f.) Bedd. (Blechnaceae) or Kelakai is a traditional medicinal plant found in the Indonesian islands of Borneo and Sumatra. It has been used to treat wound healing, infection, and diabetes. This study looked into the free radical scavenging activity, antiplasmodial activity, toxicity, and antibacterial activity against pathogenic bacteria. The species' aerial part was extracted with methanol, followed by a liquid-liquid extraction against (n-hexane, dichloromethane, and ethyl acetate). The extracts' free radical scavenging activities were determined using DPPH and NO radicals. The antiplasmodial and toxicity assays were conducted using two Plasmodium falciparum strains (3D7 and W2) and the brine shrimp lethality test. In addition, antibacterial activity was determined using the well diffusion method. The results revealed that ethyl acetate depicted potential activities toward the assay. The ethyl acetate showed potential free radical scavenging activities with an IC50 value of 51.63 ± 0.46 µg/mL (DPPH) and 60.03 ± 0.65 µg/mL (NO). The antiplasmodial activities showed that the ethyl acetate had potential activities among the extracts with an IC50 value of 11.06 ± 0.45 µg/mL. However, all the extracts demonstrated nontoxic toward Artemia salina with LC50 > 1000 µg/mL. Furthermore, the ethyl acetate demonstrated intermediate susceptibility against B. cereus ATCC 10876, V. parahaemolyticus ATCC 17802, L. monocytogenes ATCC 7644, and S. Typhimurium ATCC 14028 at a concentration of 500 µg/disc. According to these findings, the ethyl acetate extract of S. palustris (Burm.f.) Bedd is a promising source of natural antioxidants and antiplasmodial agents.

Cytotoxicity and Antiplasmodial Properties of Different Hylocereus polyrhizus Peel Extracts.

BACKGROUND Dragon fruit (Hylocereus polyrhizus) is one of the most common fruits in tropical countries, including Indonesia. The unique deep purple-colored pulp of the fruit is eaten whole and consumed as juice. However, the inedible thick peel is wasted, causing environmental issues. In this study, the toxic, cytotoxic, and antiplasmodium activity from various extract of H. polyrhizus peels were examined. MATERIAL AND METHODS We evaluated the cytotoxicity and antiplasmodial properties of the various peel extracts by using different organic solvents.The extraction of the peels was conducted using maceration to obtain pigment, n-hexane, dichloromethane, and ethyl acetate extracts. The toxicity of the extract was assessed using the brine shrimp lethality test, followed by WST assay to test in vitro cytotoxic properties and in vitro antiplasmodial properties in 2 Plasmodium falciparum strains (3D7 and W2). RESULTS The n-hexane, dichloromethane, and ethyl acetate extracts depicted various levels of activity, whereas the pigment extract did not show any activities. However, dichloromethane demonstrated a high toxicity level with LC50 of 10.32±0.13 µg/mL and a weak cytotoxic level against SK-OV-3 cell lines (IC50 of 560.86±0.63 µg/mL). Moreover, the dichloromethane and n-hexane extracts showed high and promising antiplasmodial activity with IC50 2.13±0.42 and 6.51±0.49 µg/mL, respectively. CONCLUSIONS The dichloromethane extract demonstrated high antiplasmodial activity. Our observations have elucidated the cytotoxic and antiplasmodial activity of the peel of dragon fruits and can be used as a foundation for further research into the isolation and bioactivity of secondary metabolites.

Antibacterial activity in secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa.

Background: Disease causing bacteria such as Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa present a problem for fish farming. Treatment to remove them are generally carried out using antibiotics which have side effects on fish, the environment and humans. However, the use of antibacterial compounds derived from heterotrophic bacteria serve as a good alternative for antibiotics. Therefore, this study aimed to explore antibacterial activity in the secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. Methods: Heterotrophic bacteria namely Bacillus sp. JS04 MT102913.1, Bacillus toyonensis JS08 MT102920.1, Bacillus cereus JS10 MT102922.1, Bacillus sp. JS11 MT102923.1, Pseudoalteromonas sp. JS19 MT102924.1, Bacillus cereus JS22 MT102926.1, and Bacillus sp. strain JS25 MT102927.1 were used in this study. The sequences of these bacteria have been deposited and are available from NCBI GenBank. Each heterotrophic bacterium was cultured on 6L nutrient broth for 8 days, and extracts produced using ethyl acetate to obtain their secondary metabolites. These extracts were tested for their phytochemical contents using FT-IR and also tested for their inhibitory property in pathogenic bacteria by agar diffusion method. Results: Phytochemical test results showed that the seven heterotrophic bacterial isolates produced terpenoid compounds. Based on the inhibitory test, the secondary metabolite extracts from Bacillus sp strain JS04 had the highest inhibitory effect on the growth of pathogenic bacteria namely, V. alginolyticus (17.5 mm), A. hydrophila (16.8 mm), and P. aeruginosa (17.3 mm). Conclusion: It was concluded that the secondary metabolite extracts of heterotrophic bacteria inhibit the growth of V. alginolyticus, A. hydrophila, and P. aeruginosa.