New strategies in the treatment of diseases caused by Acanthamoeba based on nanoparticles: a systematic review.

BACKGROUND: Acanthamoeba is one of the opportunistic parasites with a global prevalence. Currently, due to the side effects and the emergence of drug resistance to this parasite, much research has been performed on the use of nano-drugs to treat Acanthamoeba-caused diseases. Therefore, this systematic review study aims to evaluate new strategies for treating diseases caused by Acanthamoeba based on nanoparticles (NPs). METHODS: We designed a systematic review based on the articles published in English between 2000 and 2022. Our search strategy was based on syntax and specific tags for each database, including ScienceDirect, PubMed, Scopus, Ovid, and Cochrane. From the articles, those that had inclusion criteria were selected, and their data were extracted and analyzed. RESULTS: In this study, 26 studies were selected. Metallic nanoparticles were mostly used against the Acanthamoeba species (80.7%). 19.2% of the studies used polymeric nanoparticles, and 3.8% used emulsion nanoparticles. Most studies (96.1%) were performed in vitro, and only one study (3.8%) was carried out in vivo. Silver NPs were the most used metallic nanoparticles in the studies. The best effect of the anti-Acanthamoeba compound was observed for green synthesized nanoparticles based on stabilization by plant gums, loaded with citrus fruits flavonoids hesperidin (HDN) and naringin (NRG) with a 100% growth inhibition at a concentration of 50 µg/mL. CONCLUSION: This study showed that chlorhexidine and other plant metabolites loaded with silver and gold nanoparticles increase the anti-Acanthambae activity of these nanoparticles. However, green synthesized nanoparticles based on stabilization by plant gums, loaded with citrus fruits flavonoids hesperidin (HDN) and naringin (NRG), showed the best anti-Acanthambae effect. Nevertheless, further studies should be performed to determine their safety for human use.

Antileishmanial and antibacterial activities of the hydroalcoholic extract of Rhus coriaria L.

Leishmaniosis is one of the most serious public health concern with a worldwide distribution. Since the current treatments of leishmaniosis are toxic and expensive, frequent studies have been conducted to investigate the benefits of new resources such as medicinal plants for treatment of this infectious disease. Recent studies revealed the antiparasitic potential of Rhus coriaria. Here we investigated the potential antileishmanial and antibacterial activities of the hydroalcoholic extract of R. coriaria fruits. The fruits were extracted using 80% methanol by maceration method. The concentrations of 312, 156, 78, and 37 µg/ml of the extract were added separately to the wells containing Leishmania major (L. major) promastigotes and amastigotes. Amphotericin B was considered as positive control. Finally, the death rate was determined for the extract-treated parasites as compared to the non-treated parasite. The antibacterial activity was evaluated by measurement of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against a set of Gram-positive and Gram-negative bacteria. The extract significantly inhibited the growth of both promastigotes (60,7%) and amastigotes (59%) at the concentration of 312 µg/ml with the IC50 values of 147 µg/ml and 233 µg/ml, respectively. The extract showed bactericidal effects against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Acinetobacter baumannii. Totally, Grampositive bacteria were more susceptible to the extract. Our findings show that the hydroalcoholic extract of R. coriaria fruits are rich in tannins and can be considered for further in vivo studies on the antileishmanial and antibacterial activities especially on dermal lesions caused by L. major.

Tropolone alkaloids from Colchicum kurdicum (Bornm.) Stef. (Colchicaceae) as the potent novel antileishmanial compounds; purification, structure elucidation, antileishmanial activities and molecular docking studies.

Natural compounds played an important role for prevention and treatment of the disease as well as are the important compounds for the design of the new bioactive compounds. In this study, eight tropolone alkaloids were isolated from Colchicum kurdicum including colchicoside, 2-demethyl colchicine, 3-demethyl colchicine, demecolcine, colchifoline, N-deacetyl-N-formyl colchicine, colchicine and cornigerine by column and preparative thin layer chromatography. The chemical structures were identified by 1H NMR and 13C NMR spectroscopy. Moreover, the antileishmanial activity on Leishmania major, anti-inflammatory activity, iron chelating activity and toxicity studies including hemolytic activity, brine shrimp toxicity, cytotoxicity and acute toxicity and docking study of all isolated bioactive compounds were evaluated. As result, colchicoside and colchicine had potent leishmanicidal effects and N-deacetyl-N-formyl colchicine and cornigerine had the highest anti-inflammatory effects. All compounds had the significant iron chelating activity. According to toxicity studies, isolated compounds showed the low hemolytic activity and cytotoxicity, high LC50, LC90 and LD50. In the molecular docking study, colchicoside had the high dockscore. According to the study, with future studies all isolated compounds could be used for design the novel antileishmanial drugs.

Investigating in vitro anti-leishmanial effects of silibinin and silymarin on Leishmania major

Cutaneous leishmaniosis is an important zoonotic disease caused by various Leishmania species. The aim of this study was to investigate the effects of silibinin and silymarin on the in vitro growth and proliferation of promastigotes and amastigotes of Leishmania major compared to glucantime-treated parasites. The promastigotes and amastigotes of this parasite were treated with the two drugs, silibinin and silymarin, in several concentrations (25­100 µM). The highest effect on promastigotes was for silymarin in concentration of 100 µM with 90% and 91% death rate at hours 48 and 72, respectively. Regarding amastigotes, the highest effect at 48 hours was for silibinin in concentration of 100 µM with 35% death rate. However, at 72 hours, silymarin showed the highest effect with 63% death rate in concentration of 100 µM. The highest observed maximal 50% lethal concentration (LC50) for promastigotes was for silymarin with 19.34 µM at 48 hours and 18.22 µM at 72 hours. Likewise, maximal LC50 for amastigotes was for silymarin with 191 µM at 48 hours and 24.27 µM at 72 hours. Our findings demonstrated that both medications have suitable effects like Glucantime® on the parasite in vitro. Therefore, clinical assessment of the anti-leishmanial activity of silibinin and silymarin for treating the dermal lesions caused by L. major is recommended.