Efecto hipoglucemiante y nefroprotector de Olea europea, Moringa oleifera y Chicorium intibus var en un modelo experimental de diabetes mellitus

La diabetes mellitus tiene una prevalencia del 14% en la República Mexicana, y la población sigue empleando en su tratamiento plantas medicinales, de las cuales se deben corroborar sus propiedades terapéuticas. Por lo que se estudiaron las propiedades hipoglucemiantes y nefroprotectoras de las hojas frescas de Olea europea, Moringa oleífera, y Chicorium intibus var, en un modelo de diabetes mellitus en ratas. Se trabajó con ratas machos, raza Wistar, a las que se les indujo diabetes mellitus por tratamiento con estreptozotocina 55 mg/kg, vía intraperitoneal. A partir del cuarto día se les administraron a ratas diabéticas los extractos etanólicos de las hojas frescas de las plantas (100 y 200 mg/kg, vía oral) durante 2 semanas. Por HPLC se determinaron flavonoides, ácidos fenólicos y terpenoides en los extractos. Se evaluaron la glucemia, la proteinuria y la hipertrofia renal. Los extractos de O. europea, M. oleífera, y C. intibus var mostraron efectos hipoglucemiantes y renoprotectores en las ratas diabéticas.Diabetes mellitus has a prevalence of 14% in the Mexican Republic, and the population continues to use medicinal plants in their treatment, of which their therapeutic properties must be corroborated. To study the hypoglycemic and nephroprotective properties of fresh leaves of Olea europea, Moringa oleifera, and Chicorium intibus var. in a model of diabetes mellitus in rats. Diabetes mellitus was induced in rats by treatment with streptozotocin 55 mg/kg, intraperitoneally. From the fourth day, ethanolic extracts from fresh leaves of plants (100 and 200 mg/kg, orally) were given to diabetic rats for 2 weeks. Flavonoids, phenolic acids, and terpenoids were determined by HPLC in extracts. Blood glucose, proteinuria and renal hypertrophy were evaluated. Extracts of O. europea, M. oleifera, and C. intibus var showed hypoglycaemic and renoprotective effects in diabetic rats

Efecto de las vitaminas antioxidantes C y E sobre la hipertrofia renal en ratas diabéticas

La estimulación de las enzimas antioxidantes en el riñón puede disminuir las complicaciones renales en la diabetes mellitus (DM). En este trabajo se estudió el efecto de las vitaminas C y E como antioxidantes en el daño renal producido por la DM. La DM se indujo con estreptozotocina 65 mg/kg, vía intraperitoneal. A las ratas DM se les administraron las vitaminas E y C en dosis de 250 y 500 mg/kg, vía oral, durante 2 semanas. Las vitaminas C y E restablecieron la función renal en ratas diabéticas: aumentaron la depuración de creatinina y disminuyeron la proteinuria; se observó una disminución del peso del riñón, del área celular tubular proximal y del coeficiente proteínas/DNA, aumentaron la actividad de las enzimas catalasa, superóxido dismutasa y glutatión peroxidasa. Así, las vitaminas E y C restauran las enzimas antioxidantes y retardan el desarrollo de la hipertrofia renal diabéticaStimulation of antioxidant enzymes in the kidney can decrease kidney complications in diabetes mellitus (DM). This paper studied the effect of vitamins C and E as antioxidants on kidney damage caused by DM. DM was induced with streptozotocin 65 mg/kg, intraperitoneally. DM rats were given vitamins E and C in doses of 250 and 500 mg/kg orally for 2 weeks. Vitamins C and E restored renal function in diabetic rats: they increased creatinine purification and decreased proteinuria; a decrease in kidney weight, proximal tubular cell area and protein/DNA coefficient were observed, increased the activity of the enzymes catalase, superoxide dismutase and glutathione peroxidase. Thus, vitamins E and C restore antioxidant enzymes and slow the development of diabetic renal hypertrophy

Gongolarones as antiamoeboid chemical scaffold

Free Living Amoeba (FLA) infections caused by Acanthamoeba genus include chronic nervous system diseases such as Granulomatous Amoebic Encephalitis (GAE), or a severe eye infection known as Acanthamoeba keratitis (AK). Current studies focused on therapy against these diseases are aiming to find novel compounds with amoebicidal activity and low toxicity to human tissues. Brown algae, such as Gongolaria abies-marina (previously known as Cystoseira abies-marina, S.G. Gmelin), presents bioactive molecules of interest, including some with antiprotozoal activity. In this study, six meroterpenoids were isolated and purified from the species Gongolaria abies-marina. Gongolarones A (1), B (2) and C (3) were identified as new compounds. Additionally, cystomexicone B (4), 1′-methoxyamentadione (5) and 6Z-1′-methoxyamentadione (6) were isolated. All compounds exhibited amoebicidal activity against Acanthamoeba castellanii Neff, A. polyphaga and A. griffini strains. Gongolarones A (1) and C (3) showed the lowest IC50 values against the two stages of these amoebae (trophozoite and cyst). Structure-activity relationship revealed that the cyclization by ether formation from C-12 to C-15 of 1, and the isomerization Δ2 t to Δ3 t of 3, increased the antiamoeboid activity of both compounds. Furthermore, gongolarones A (1) and C (3) triggered chromatin condensation, mitochondrial malfunction, oxidative stress, and disorganization of the tubulin-actin cytoskeleton in treated trophozoites. Moreover, transmission electron microscopy (TEM) images analysis revealed that compounds 1 and 3 induced autophagy process and inhibited the encystation process. All those results suggest that both compounds could induce programmed cell death (PCD) in Acanthamoeba.This study was supported funded by projects PID2019-109476RB-C21 (BIOALGRI) (Spanish Ministry of Science), Madrid, Spain; Fundación CajaCanarias–Fundación Bancaria “La Caixa” (2019SP52). Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), Spain (project no. RD16/0027/0001 of the programe of Redes Temáticas de Investigación Cooperativa, FIS). Consorcio Centro de Investigación Biomédica en Red (CIBER), Área de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029, Madrid, Spain (CB21/13/00100). Project No. 21/0587 funded by the Cabildo de Tenerife, Tenerife innova, Marco Estratégico de Desarrollo Insular (MEDI) and Fondo de Desarrollo de Canarias (FDCAN). Project number ProID2021010118 funded by Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI). RLRE was funded by a grant from ACIISI cofunded by Fondo Social Europeo (FSE) and FEDER, (TESIS2020010117). MOM was supported by the Programa de Apoyos para la Superación del Personal Académico de la UNAM (PASPA 2021) for carrying out the research stay between the Universidad de La Laguna and la Facultad de Estudios Superiores Iztacala.Peer reviewe

Induction of Morphological and Electrophysiological Changes in Hamster Cornea after In Vitro Interaction with Trophozoites of Acanthamoeba spp.

Acanthamoeba castellani and Acanthamoeba polyphaga are free-living amebae that cause keratitis and granulomatous encephalitis in humans. We have analyzed the early morphological and electrophysiological changes occurring during the in vitro interaction of cultured amebae with intact or physically damaged corneas obtained from hamsters. Both species of Acanthamoeba produced similar cytopathic changes, as seen by light microscopy and scanning electron microscopy. After adhesion to the epithelial surface, trophozoites formed clumps and migrated toward the cell borders, causing the separation of adjacent cells at 1 h of coculture. At later stages (2 to 4 h), some amebae were found under desquamating epithelial cells whereas others were seen associated with damaged cells or forming amebostome-like structures to ingest detached epithelial cells. Control corneas incubated in culture medium conditioned with amebae showed a cytoplasmic vacuolization and blurring of the epithelial-stromal junction. The early stages of corneal epithelial damage caused by amebae were also analyzed by measuring the transepithelial resistance changes in corneas mounted in Ussing chambers. Both species of Acanthamoeba caused a rapid decrease in electrical resistance. The present observations demonstrate that under in vitro conditions, Acanthamoeba trophozoites rapidly cause significant damage to the corneal epithelium. Furthermore, in our experimental model, previous physical damage to the corneas was not a prerequisite for the development of amebic corneal ulcerations

Schwann Cell Autophagy and Necrosis as Mechanisms of Cell Death by Acanthamoeba

Amoebae of the genus Acanthamoeba are etiological agents of granulomatous amoebic encephalitis (GAE). Recently, through an in vivo GAE model, Acanthamoeba trophozoites were immunolocalized in contact with the peripheral nervous system (PNS) cells—Schwann cells (SC). In this study, we analyzed in greater detail the in vitro early morphological events (1, 2, 3, and 4 h) during the interaction of A. culbertsoni trophozoites (ATCC 30171) with SC from Rattus norvegicus (ATCC CRL-2941). Samples were processed for scanning and transmission electron microscopy as well as confocal microscopy. After 1 h of interaction, amoebae were observed to be adhered to the SC cultures, emitting sucker-like structures associated with micro-phagocytic channels. In addition, evidence of necrosis was identified since edematous organelles as well as multivesicular and multilamellar bodies characteristics of autophagy were detected. At 2 h, trophozoites migrated beneath the SC culture in which necrosis and autophagy persisted. By 3 and 4 h, extensive lytic zones were observed. SC necrosis was confirmed by confocal microscopy. We reported for the first time the induction of autophagic and necrotic processes in PNS cells, associated in part with the contact-dependent pathogenic mechanisms of A. culbertsoni trophozoites

Meroterpenoids from <i>Gongolaria abies-marina</i> against Kinetoplastids: <i>In Vitro</i> Activity and Programmed Cell Death Study

Leishmaniasis and Chagas disease affect millions of people worldwide. The available treatments against these parasitic diseases are limited and display multiple undesired effects. The brown alga belonging to the genus Gongolaria has been previously reported as a source of compounds with different biological activities. In a recent study from our group, Gongolaria abies-marine was proven to present antiamebic activity. Hence, this brown alga could be a promising source of interesting molecules for the development of new antiprotozoal drugs. In this study, four meroterpenoids were isolated and purified from a dichloromethane/ethyl acetate crude extract through a bioguided fractionation process targeting kinetoplastids. Moreover, the in vitro activity and toxicity were evaluated, and the induction of programmed cell death was checked in the most active and less toxic compounds, namely gongolarone B (2), 6Z-1′-methoxyamentadione (3) and 1′-methoxyamentadione (4). These meroterpenoids triggered mitochondrial malfunction, oxidative stress, chromatin condensation and alterations of the tubulin network. Furthermore, a transmission electron microscopy (TEM) image analysis showed that meroterpenoids (2–4) induced the formation of autophagy vacuoles and ER and Golgi complex disorganization. The obtained results demonstrated that the mechanisms of action at the cellular level of these compounds were able to induce autophagy as well as an apoptosis-like process in the treated parasites

Extracellular Vesicles Secreted by <i>Acanthamoeba culbertsoni</i> Have COX and Proteolytic Activity and Induce Hemolysis

Several species of Acanthamoeba genus are potential pathogens and etiological agents of several diseases. The pathogenic mechanisms carried out by these amoebae in different target tissues have been documented, evidencing the relevant role of contact-dependent mechanisms. With the purpose of describing the pathogenic processes carried out by these protozoans more precisely, we considered it important to determine the emission of extracellular vesicles (EVs) as part of the contact-independent pathogenicity mechanisms of A. culbertsoni, a highly pathogenic strain. Through transmission electronic microscopy (TEM) and nanoparticle tracking analysis (NTA), EVs were characterized. EVs showed lipid membrane and a size between 60 and 855 nm. The secretion of large vesicles was corroborated by confocal and TEM microscopy. The SDS-PAGE of EVs showed proteins of 45 to 200 kDa. Antigenic recognition was determined by Western Blot, and the internalization of EVs by trophozoites was observed through Dil-labeled EVs. In addition, some EVs biological characteristics were determined, such as proteolytic, hemolytic and COX activity. Furthermore, we highlighted the presence of leishmanolysin in trophozites and EVs. These results suggest that EVs are part of a contact-independent mechanism, which, together with contact-dependent ones, allow for a better understanding of the pathogenicity carried out by Acanthamoeba culbertsoni

Morphological Description of the Early Events during the Invasion of Acanthamoeba castellanii Trophozoites in a Murine Model of Skin Irradiated under UV-B Light

Skin infections have been associated with Acanthamoeba, nevertheless the events during skin invasion and UV-B light effects on it are unknown. The early morphological events of Acanthamoeba castellanii skin invasion are shown in SKH-1 mice that were chronically UV-B light irradiated. Mice that developed skin lesions (group 1) were topical and intradermally inoculated with A. castellanii trophozoites and sacrificed 48 h or 18 days later. Mice that showed no skin lesions (group 2) were intradermally inoculated and sacrificed 24, 48 or 72 h later. Mice ventral areas were considered controls with and without trophozoites intradermally inoculated. Skin samples were processed by histological and immunohistochemistry techniques. In group 1, trophozoites were immunolocalized in dermal areas, hair cysts, sebaceous glands, and blood vessels, and collagen degradation was observed. One of these mice shown trophozoites in the spleen, liver, and brain. In group 2, few trophozoites nearby collagenolytic activity zones were observed. In control samples, nor histological damage and no trophozoites were observed. Adherence and collagenolytic activity by A. castellanii were corroborated in vitro. We can infer that UV-B light irradiated skin could favor A. castellanii invasiveness causing damage in sites as far away as the brain, confirming the invasive capacity and pathogenic potential of these amphizoic amoebae