جستجوی مقالات مرتبط با کلیدواژه "proteolytic enzymes" در نشریات گروه "پزشکی"

Introduction and purpose: Leishmaniasis are neglected diseases that are endemic in more than half of the provinces of Iran. The causative agent of this disease is Leishmania protozoa and its transmission to human is through the bites of phlebotomine sand flies. This study reviews the growth and development of Leishmania in the body of sand flies at the molecular level. In this study a narrative review was carried out. The corpus was collected by searching the keywords of Leishmania, sand fly, phlebotomus, lutzomyia in the databases of PubMed, Scopus, SID, Web of Science, Ovid Medline, and Google Scholar search engine. The studied articles were those which has been published on the interaction between the sand fly vectors and Leishmania parasite until 2018. The parasites grow when they encounter natural barriers in the body of the sand flies, including proteolytic enzymes, peritrophic membrane, excretion of the digestive system, and immune system in sand fly vectors. Attachment of Leishmania to sand fly digestive tract determines the ability of sand fly to support the development of parasite, which leads to the transmission of leishmaniasis. Studies on the development and life cycle of Leishmania within the body of sand flies are of utmost importance due to the spread of leishmaniasis in Iran and the world, difficulty in their control, and lack of effective vaccine products against leishmaniasis. The findings of the current study aimed at identifying and enhancing the natural barriers to the development of Leishmania in sand fly vectors and introducing new strategies for the control of leishmaniasis.

The delivery of protein pharmaceuticals to the systemic circulation through oral administration is the goal of many research groups. This route of administration is hindered by numerous barriers. New drug delivery systems such as vesicles can overcome this barriers. Different niosomal formulations composed of sorbitan monoesters (Spans®)/ polyoxyethylen sorbitan esters (Tweens®)/cholesterol were prepared for encapsulation of insulin with or without aprotinin. In vitro characterization of vesicles were carried out including size distribution analysis, microscopic observation, insulin release measurement and SDS-gel electerophoresis.The protection of protein against three enzymes was evaluated. Span/Tween 80 did not form niosomes, but the other surfactant combinations formed stable niosomal suspensions. Insulin was protected from proteolytic effects of enzymes efficiently (p<0.05). the mean volum diameter of prepared lipid vesicles was related directly to hydrophilicity of surfactants indicated by hydrophilicic-lipophilic balance (HLB) of the used amphiphiles. The maximum encapsulation of insulin 48.9±13.08, was seen in Span/Tween 60 formulations. The release profile of insulin was tow-phasic in both simulated gastric and intestinal fluids. Aprotinin had no significant effect on the protection of insulin (p<0.05). these results indicated that niosomes could be developed as oral dosage forms for delivery of proteins such as insulin.