OBJECTIVE: This review was aimed to critically overview the literature and summarizes the antibacterial, antiprotozoal, and antifungal trends of E. longifolia and its medicinally active components.
RESULTS: Besides its well-documented safety, efficacy, and tolerability, a plethora of in vitro, in vivo, and human clinical studies has evidenced the antimicrobial efficacy of E. longifolia and its bioactive constituents. Phytochemical screening of various types of extracts (methanolic, ethyl acetate, and nbutanolic) from different parts (roots, stem, and leaves) of E. longifolia displayed a dose-dependent antibacterial, antiprotozoal, and antifungal responses. Comparative analysis revealed that the root extract of E. longifolia exhibited the highest antimicrobial efficacy compared to other parts of the plant. Bioactivity-guided fractionation identified that among all of the medicinal compounds isolated/ extracted from different parts of E. longifolia, eurycomanone displayed the strongest antibacterial, antiprotozoal and antifungal activities.
CONCLUSION: Based on the critical analysis of the literature, we identified that E. longifolia exhibits promising antibacterial, antiprotozoal, and antifungal efficacies against various pathogenic microbes and thus can be considered as a potential complementary and alternative antimicrobial therapy.
METHODS: In this study, we characterized niosomes, PEG-b-PCL, and their combination loaded with KRe and tested the effect of these NPs on Acanthamoeba triangularis stages. KRe-loaded PEG-b-PCL, KRe-loaded niosome, and KRe-loaded PEG-b-PCL plus niosome were synthesized and characterized regarding particle size and charge, yield, encapsulation efficiency (EE), and drug loading content (DLC). The effect of these KRe-loaded NPs on trophozoite and cystic forms of A. triangularis was assessed through assays of minimal inhibitory concentration (MIC), using trypan blue exclusion to determine the viability. The effect of KRe-loaded NPs was also determined on A. triangularis trophozoite for 24-72 h. Additionally, the anti-adhesion activity of the KRe-loaded niosome on trophozoites was also performed on a 96-well plate. Cytotoxicity activity of KRe-loaded NPs was assessed on VERO and HaCaT cells using MTT assay.
RESULTS: KRe-loaded niosome demonstrated a higher yielded (87.93 ± 6.03%) at 286 nm UV-Vis detection and exhibited a larger size (199.3 ± 29.98 nm) and DLC (19.63 ± 1.84%) compared to KRe-loaded PEG-b-PCL (45.2 ± 10.07 nm and 2.15 ± 0.25%). The EE (%) of KRe-loaded niosome was 63.67 ± 4.04, which was significantly lower than that of the combination of PEG-b-PCL and niosome (79.67 ± 2.08). However, the particle charge of these NPs was similar (-28.2 ± 3.68 mV and -28.5 ± 4.88, respectively). Additionally, KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exhibited a lower MIC at 24 h (0.25 mg/mL), inhibiting 90-100% of Acanthamoeba trophozoites which lasted 72 h. KRe-loaded niosome affected adherence by around 40-60% at 0.125-0.25 mg/mL and removed Acanthamoeba adhesion on the surface by about 90% at 0.5 mg/mL. Cell viability of VERO and HaCaT cells treated with 0.125 mg/mL of KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exceeded 80%.
CONCLUSION: Indeed, niosome and niosome plus PEG-b-PCL were suitable nanocarrier-loaded KRe, and they had a greater nanoparticle property to test with high activities against A. triangularis on the reduction of adherence ability and demonstration of its low toxicity to VERO and HaCaT cells.
OBJECTIVE: To study the antiamoebic effects of four novel synthetic dihydropyridine (DHP) compounds against Acanthamoeba castellanii belonging to the T4 genotype. Furthermore, to evaluate their activity against amoeba-mediated host cells cytopathogenicity as well as their cytotoxicity against human cells.
METHODS: Dihydropyridines were synthesized by cyclic dimerization of alkylidene malononitrile derivatives. Four analogues of functionally diverse DHPs were tested against Acanthamoeba castellanii by using amoebicidal, encystation and excystation assays. Moreover, Lactate dehydrogenase assays were carried out to study cytopathogenicity and cytotoxicity against human cells.
RESULTS: These compounds showed significant amoebicidal and cysticidal effects at 50 μM concentration, whereas, two of the DHP derivatives also significantly reduced Acanthamoebamediated host cell cytotoxicity. Moreover, these DHPs were found to have low cytotoxicity against human cells suggesting a good safety profile.
CONCLUSION: The results suggest that DHPs have potential against Acanthamoeba especially against the more resistant cyst stage and can be assessed further for drug development.