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Background: Propolis is a natural resinous product from a variety of plants and combines it with beeswax and salivary enzymes to create bee glue. Its potentials have been employed in the treatment of many diseases and conditions for centuries. This study, therefore, aims to determine the anti-Acanthamoeba properties of the propolis extract, eye drops coupled to some mechanisms such as inhibition of encystation and excystation. Methods: The minimum inhibitory concentrations (MICs) of the most active propolis extract were assessed in trophozoites and cysts of Acanthamoeba triangularis (A. triangularis) at 0.256 and 1 mg/mL, respectively. Results: Active eye drops inhibited trophozoites and cysts with a MIC value of 100%. At concentrations lower than their MICs values (1/2--1/16 MIC), propolis and eye drops revealed inhibition of encystation. In addition, at 1/2 MIC, both the propolis extract and eye drops showed potential inhibition of excystation. In combined sets of propolis extract and eye drops, they showed slightly increasing inhibition of encystation and excystation. Surprisingly, the MIC of chlorhexidine decreased when combined with the propolis and eye drops. SEM and TEM images displayed morphological changes in A. triangularis treated with combined sets of propolis extract and eye drops. Conclusion: From this study, a new combined eye drop solution with propolis extract was found to be helpful in reducing encystation and excystation in A. triangularis. Therefore, this combination is an alternative for the treatment of eye diseases in early stages along with reducing the entry into the cyst stage of Acanthamoeba. The results of this study revealed new anti-Acanthamoeba inhibitors with promising combined alternative therapeutic potential for the treatment of Acanthamoeba keratitis. [ABSTRACT FROM AUTHOR]

The biosynthesis of nanoparticles using the green route is an effective strategy in nanotechnology that provides a cost-effective and environmentally friendly alternative to physical and chemical methods. This study aims to prepare an aqueous extract of Ocimum sanctum (O. sanctum)-based silver nanoparticles (AgNPs) through the green route and test their antibacterial activity. The biosynthesized silver nanoparticles were characterised by colour change, UV spectrometric analysis, FTIR, and particle shape and size morphology by SEM and TEM images. The nanoparticles are almost spherical to oval or rod-shaped with smooth surfaces and have a mean particle size in the range of 55 nm with a zeta potential of -2.7 mV. The antibacterial activities of AgNPs evaluated against clinically isolated multidrug-resistant Acinetobacter baumannii (A. baumannii) showed that the AgNPs from O. sanctum are effective in inhibiting A. baumannii growth with a zone of inhibition of 15 mm in the agar well diffusion method and MIC and MBC of 32 mg/mL and 64 mg/mL, respectively. The SEM images of A. baumannii treated with AgNPs revealed damage and rupture in bacterial cells. The time-killing assay by spectrophotometry revealed the time- and dose-dependent killing action of AgNPs against A. baumannii, and the assay at various concentrations and time intervals indicated a statistically significant result in comparison with the positive control colistin at 2 mg/mL (P <0:05). The cytotoxicity test using the MTT assay protocol showed that prepared nanoparticles of O. sanctum are less toxic against human cell A549. This study opens up a ray of hope to explore the further research in this area and to improve the antimicrobial activities against multidrug resistant bacteria. [ABSTRACT FROM AUTHOR]

Recent studies have revealed the essential role played by nerves in tumor progression. Nerves have been shown to infiltrate the tumor microenvironment and actively stimulate cancer cell growth and dissemination. This mechanism involves the release of neurotransmitters, such as catecholamines and acetylcholine, directly into the vicinity of cancer and stromal cells to activate corresponding membrane receptors. Conversely, the secretion of neurotrophic growth factors by cancer cells drives the outgrowth of nerves in solid tumors. This reciprocal interaction between nerves and cancer cells provides new insights into the cellular and molecular bases of tumorigenesis and points to the potential utility of antineurogenic therapies. This review will discuss our evolving understanding of the cross-talk between nerves and cancer cells. [ABSTRACT FROM AUTHOR]

Background: Acanthamoeba spp. is a waterborne, opportunistic protozoan that can cause amebic keratitis and granulomatous amebic encephalitis. Knema retusa is a native tree in Malaysia, and its extracts possess a broad range of biological activities. Niosomes are non-ionic surfactant-based vesicle formations and suggest a future targeted drug delivery system. Copolymer micelle (poly(ethylene glycol)-block-poly( ɛ -caprolactone); PEG- b -PCL) is also a key constituent of niosome and supports high stability and drug efficacy. To establish Knema retusa extract (KRe) loading in diverse nanocarriers via niosome, PEG- b -PCL micelle, and their combination and to study the effect of all types of nanoparticles (NPs) on Acanthamoeba viability, adherent ability, elimination of adherence, and cytotoxicity., 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., Competing Interests: Sónia MR Oliveira is an Academic Editor for PeerJ., (©2024 Chimplee et al.)