Background: Leishmaniasis is a vector-borne disease that is endemic in the tropical and sub-tropical areas of the world. Low efficacy and high cytotoxicity of the current treatment regimens for leishmaniasis is one of the most important health problems. In this experimental study, anti-leishmanial effects of different concentrations of resveratrol and resveratrol nano-emulsion (RNE) were assessed. Methods: RNE was prepared using the probe ultra-sonication method. The cytotoxicity was evaluated using the MTT technique on the L929 cell line. The anti-leishmanial activities on promastigotes of leishmania were assessed using vital staining and infected BALB/c mice were used to assess the in vivo anti-leishmanial effects. Results: In vitro and in vivo assays revealed that all concentrations of resveratrol and RNE had valuable inhibitory effects against Leishmania major in comparison to the control group (P < 0.05). The half maximal inhibitory concentration (IC₅₀) values were calculated as 16.23 and 35.71 µg/mL for resveratrol and RNE, respectively. Resveratrol and RNE showed no cytotoxicity against the L929 cell line. Conclusions: According to the potent in vitro and in vivo anti-leishmanial activity of RNE at low concentration against L. major, we suggest that it could be a promising anti-leishmanial therapeutic against L. major in the future.

Toxoplasma gondii is an obligatory intracellular parasite that infects a wide range of warm-blooded animals and humans. Considering the severity of toxoplasmosis, side effects of current treatments, and the contribution of the ethnopharmacological knowledge for the treatment of parasitic infections, the aim of the present study was to investigate the efficacy of methanolic extracts from the fruits and leaves of Sambucus nigra against tachyzoite of T. gondii. For this, fruits and leaves of S. nigra were collected from Mazandaran province, Iran, were dried under the shade, and powdered using a commercial electrical blender. For extractions, methanol was used as solvent. Virulent RH strain of T. gondii was maintained in mice and macrophages containing tachyzoites were aspirated from the peritoneal cavity. Four concentrations (5, 10, 25 and 50mg/mL) of S. nigra extract were incubated with infected macrophages for 30, 60, 120 and 180 minutes and the viability of the tachyzoites were evaluated by trypan blue staining. Results showed that S. nigra fruit extracts at the concentrations of 5 and 10mg/mL killed 100% of T. gondii tachyzoites after 60 and 120 minutes, respectively; and concentrations of 25 and 50mg/mL killed 100% of the tachyzoites after 30 minutes. Additionally, extract of S. nigra leaves, at the concentrations of 5, 10 and 25mg/mLafter 180 minutes, and concentration of 50mg/mLafter 60 minutes, resulted with the highest efficacy. Our results showed that S. nigra has acceptable efficacy in vitro and the parasiticidal effect of fruit extract was significantly better than leaf extract. However, in vivo efficacy of this extract needs further investigation.

Cutaneous leishmaniasis (CL), classified as a neglected tropical disease (NTD), is a significant public health concern caused by Leishmania protozoa. It is transmitted through the bites of infected female sandflies and manifests in various forms, ranging from localized skin ulcers to social stigma due to scarring. Numerous reports highlight the life-threatening side effects of glucantim, the first-line treatment for this disease, indicating a pressing need foralternative drugs. This experimental study aims to assess the anti-leishmanial effects of chitosan and chitosan- amphotericin B against Leishmania major (L. major) in vitro and in vivo. Chitosan and amphotricine B were purchased, and different concentrations were prepared. L. major promastigotes were cultured in RPMI-1640 medium. In vitro anti-leishmanial activity was assessed against the promastigotes of L. major using vital staining. For the in vivo assessment, lesion sizes were measured before and after ointment treatments in Bagg Albino mice (BALB/c). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT) assay was utilized to evaluate the cytotoxic effects of chitosan and chitosan–amphotericin B at varying concentrations on the L929 cell line. Additionally, the in vitro hemolytic activity was measured using a spectrophotometric method. The in vitro and in vivo experiments demonstrated that chitosan–amphotericin B exhibited superior inhibitory effects against L. major compared to either chitosan or amphotericin B alone, and even against the positive control, particularly at higher concentrations (P < 0.05). Furthermore, cytotoxicity tests indicated that both chitosan and amphotericin, whether used separately or in combination, had no cytotoxic effects on the L929 cell line or human blood samples in vitro and did not impact liver enzymes in vivo (P < 0.05). The findings from this in vitro and in vivo study highlighted the impressive anti-leishmanial effects of chitosan, which were further enhanced with the addition of amphotericin B.

Background: Diarrheal disease is one of the most common problems that affected deployed military personnel during operations and maneuvers. Giardia (G.) lamblia is one of the causes of parasitic diarrhea in humans. There are very few therapeutics agents with unpleasant adverse effects available for treating giardiasis. Stachys lavandulifolia with polyphenolic structure is considered as an antimicrobial agent. In this study we evaluated the in vitro inhibitory activity of Stachys lavandulifolia leaves on cysts of G. lamblia. Methods: G. lamblia cysts were isolated by the sucrose method. Various concentrations of the watery and n-hexane extracts (2.5, 5, 10, 25, 50 mg/mL respectively) were used for giardiacidal activity in 6 different times (1, 5, and 30 minutes, as well as 1, 3, and 6 hours). Results: The watery and n-hexane extract revealed great activity when compared to the control group (P < 0.05). The watery extract at the concentration of 100 mg/mL killed 93% of cysts after 6 hours. The n-hexane extract at the concentration of 100 mg/mL killed 100% of cysts after 6 hours. Both extracts showed dose dependent antigiardial activity and the n-hexane extract was better than the watery extract. When the doses of the extracts and contact times are increased, a gradual increase in antiprotozoal activity was observed. Conclusions: Stachys lavandulifolia leaves, as a safe herbal medicine could be confirmed for anti giardial activity. Keywords: Herbal Medicines; In Vitro; Giardia Lamblia; Stachys Lavandulifolia