Enhancing the antischistosomal activity of carvacryl acetate using nanoemulsion

In Situ Preparation of Dehydrodieugenol-Loaded Silver Nanoparticles and their Antischistosomal Activity

Schistosomiasis is a major neglected disease that imposes a substantial worldwide health burden, affecting approximately 250 million people globally. As praziquantel is the only available drug to treat schistosomiasis, there is a critical need to identify new anthelmintic compounds, particularly from natural sources. To enhance the activity of different natural products, one potential avenue involves its combination with silver nanoparticles (AgNP). Based on this approach, a one-step green method for the in situ preparation of dehydrodieugenol (DHDG) by oxidation coupling reaction using silver and natural eugenol is presented. AgNP formation was confirmed by UV-Vis spectroscopy due to the appearance of the surface plasmon resonance (SPR) band at 430 nm which is characteristic of silver nanoparticles. The nanoparticles were spherical with sizes in the range of 40 to 50 nm. Bioassays demonstrated that the silver nanoparticles loaded with DHDG exhibited significant anthelmintic activity against Schistosoma mansoni adult worms without toxicity to mammalian cells and an in vivo animal model (Caenorhabditis elegans), contributing to the development of new prototypes based on natural products for the treatment of schistosomiasis.

Nanoemulsion Improves the Anti-Inflammatory Effect of Intraperitoneal and Oral Administration of Carvacryl Acetate

Carvacryl acetate (CA) is a monoterpene obtained from carvacrol, which exhibits anti-inflammatory activity. However, its low solubility in aqueous media limits its application and bioavailability. Herein, we aimed to develop a carvacryl acetate nanoemulsion (CANE) and assess its anti-inflammatory potential in preclinical trials. The optimized nanoemulsion was produced by ultrasound, and stability parameters were characterized for 90 days using dynamic light scattering after hydrophilic-lipophilic balance (HLB) assessment. To evaluate anti-inflammatory activity, a complete Freund's adjuvant-induced inflammation model was established. Paw edema was measured, and local interleukin (IL)-1β levels were quantified using ELISA. Toxicity was assessed based on behavioral changes and biochemical assays. The optimized nanoemulsion contained 3% CA, 9% surfactants (HLB 9), and 88% water and exhibited good stability over 90 days, with no signs of toxicity. The release study revealed that CANE followed zero-order kinetics. Dose-response curves for CA were generated for intraperitoneal and oral administration, demonstrating anti-inflammatory effects by both routes; however, efficacy was lower when administered orally. Furthermore, CANE showed improved anti-inflammatory activity when compared with free oil, particularly when administered orally. Moreover, daily treatment with CANE did not induce behavioral or biochemical alterations. Overall, these findings indicate that nanoemulsification can enhance the anti-inflammatory properties of CA by oral administration.

Targeting the Schistosoma mansoni nutritional mechanisms to design new antischistosomal compounds

The chemical classes of semicarbazones, thiosemicarbazones, and hydrazones are present in various compounds, each demonstrating diverse biological activities. Extensive studies have revealed their potential as schistosomicidal agents. Thiosemicarbazones, in particular, have shown inhibitory effects on Schistosoma mansoni's cathepsin B1 enzyme (SmCB1), which plays a crucial role in hemoglobin degradation within the worm's gut and its nutrition processes. Consequently, SmCB1 has emerged as a promising target for novel schistosomiasis therapies. Moreover, chloroquinoline exhibits characteristics in its aromatic structure that hold promise for developing SmCB1 inhibitors, along with its interaction with hemoglobin's heme group, potentially synergizing against the parasite's gut. In this context, we report the synthesis of 22 hybrid analogs combining hydrazones and quinolines, evaluated against S. mansoni. Five of these hybrids demonstrated schistosomicidal activity in vitro, with GPQF-8Q10 being the most effective, causing worm mortality within 24 h at a concentration of 25 µM. GPQF-8Q8 proved to be the most promising in vivo, significantly reducing egg presence in feces (by 52.8%) and immature eggs in intestines (by 45.8%). These compounds exhibited low cytotoxicity in Vero cells and an in in vivo animal model (Caenorhabditis elegans), indicating a favorable selectivity index. This suggests their potential for the development of new schistosomiasis therapies. Further studies are needed to uncover specific target mechanisms, but these findings offer a promising starting point.