Immunosuppressive effects of protein derivatives from Mucuna pruriens on a streptozotocin-induced type 1 diabetes murine model.

Type 1 diabetes is an autoimmune disease induced by abnormal insulin secretions from ß-cells in pancreas. The present study aimed to investigate the immunosuppressive effects from protein derivatives of Mucuna pruriens on a murine model of Type 1 diabetes. Hydrolyzate and five peptide fractions with different molecular weight were administered orally by 14 days, followed T1D murine model was built by intraperitoneal injection of streptozotocin over 5 days. The mice weight, blood glucose levels, anti-insulin, and anti-pancreatic islet ß-cells antibodies, pro-inflammatory cytokines as tumor necrosis factor alpha and interleukin-6 were determined in four times (0, 15, 30, and 45 day). Mice were sacrificed and pancreatic tissues samples were obtained and staining with hematoxylin and eosin to determine the degree of damage. The study demonstrated immunosuppressive activity in four of the six treatment groups: (a) T1D PPH, (b) T1D F 5-10 kDa, (c) T1D F 3-5 kDa, and (d) T1D F 1-3 kDa. PRACTICAL APPLICATIONS: Due to the high content of native protein in seeds of Mucuna pruriens, studies have reported potential in the elaboration of hydrolysates and peptides with biological activity. These protein derivatives could help in the treatment of immunological disorders that are observed in several chronic non-communicable disease and inflammatory diseases, such as T1D. Activated macrophages and lymphoplasmacytic infiltrate plays a crucial role in the initiation and maintenance of T1D; therefore, several studies has focused to reduce the effector functions of this cells for diminishing the clinical manifestations in inmmunocompromised patients. Thus, this study indicates the potential application of hydrolyzate and peptide fractions of M. pruriens in functional foods and dietary supplements could be developed for the treatment of inflammatory and chronic non-communicable diseases.

Anti-inflammatory and diuretic effects of the diterpene ent-dihydrotucumanoic acid.

Gymnosperma glutinosum (Spreng) Less (Asteraceae) is a shrub used in traditional medicine for the treatment of inflammatory and renal diseases. The ent-dihydrotucumanoic acid (DTA) is a diterpene obtained from G. glutinosum. This study evaluated the antioxidant, genotoxic, and diuretic properties of DTA, as well as its in vitro and in vivo anti-inflammatory actions. The antioxidant actions of DTA were assessed with the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assays, the genotoxic action was assessed with the comet assay, and the diuretic effects of DTA were assessed using metabolic cages. The anti-inflammatory actions were evaluated using primary murine peritoneal macrophages stimulated with LPS and the λ-carrageenan-induced hind paw edema test. DTA lacked antioxidant (IC50 > 25,000 µg/mL) activity in the ABTS, FRAP, and DPPH assays. DTA at 500-1,000 µg/mL showed moderate genotoxicity. In LPS-stimulated macrophages, DTA showed IC50 values of 74.85 µg/mL (TNF-α) and 58.12 µg/mL (NO), whereas the maximum inhibition of IL-6 (24%) and IL-1ß (36%) was recorded at 200 µg/mL. DTA induced in vivo anti-inflammatory effects with ED50 = 124.3 mg/kg. The in vitro anti-inflammatory activity of DTA seems to be associated with the decrease in the release of TNF-α and NO. DTA promoted the excretion of urine (ED50 = 86.9 mg/kg), Na+ (ED50 = 66.7 mg/kg), and K+ (ED50 = 8.6 mg/kg). The coadministration of DTA with L-NAME decreased the urinary excretion shown by DTA alone. Therefore, the diuretic activity is probably associated with the participation of nitric oxide synthase. In conclusion, DTA exerted anti-inflammatory and diuretic effects, but lacked antioxidant effects.

IMMUNOSUPPRESIVE EFFECTS OF THE METHANOLIC EXTRACT OF CHRYSOPHYLLUM CAINITO LEAVES ON MACROPHAGE FUNCTIONS.

BACKGROUND: The aim of this work was to evaluate the immunomodulatory effect of the methanol extract (MeOH) from Chrysophyllum cainito leaves on the MΦs functions. MATERIAL AND METHODS: Peritoneal murine MΦs isolated from Balb/c mice were treated with the MeOH extract and stimulated with LPS. The effect on the phagocytosis was evaluated by flow cytometry assay. The nitric oxide (NO) and hydrogen peroxide (H2O2) production was measured by the Griess reagent and phenol red reaction, respectively. Levels of IL-6 and TNF-α was measured using an ELISA kit. Viability of MΦs and Vero cells was determined by the MTT method. RESULTS: The MeOH extract of C. cainito leaves inhibited significantly the phagocytosis, and decreased IL-6 and TNF-α production as well as NO and H2O2 released by the MΦs, in a concentration-dependent manner. In addition, MeOH extract of C. cainito showed low cytotoxicity effect against the cells. CONCLUSION: These results suggest that MeOH extract of C. cainito leaves has an immunosuppressive effect on murine MΦs, without effects on cell viability. GC-MS chromatogram analysis of MeOH extract showed that lupeol acetate and alpha-amyrin acetate are the principal compounds.