Yamila Lebeque

Phytochemical screening and effects on cell-mediated immune response of Pleurotus fruiting bodies powder

This study examined the phytochemical profile and the effects of Pleurotus fruiting bodies powder on cell-mediated immune response in both in vivo and in vitro assays. Although carbohydrates (55%, w/w) appear to be the most important immunomodulatory compound, secondary metabolites (terpenoids, phenols and flavonoids) would also enhance immunity. Pleurotus powder was administered orally during 7 days to Balb/c mice (1000 mg/kg) and cyclophosphamide (CY; 100 mg/kg) was inoculated intraperitoneally at the beginning of the experiment. The delayed-type hypersensitivity reaction measured at 48 and 72 h after antigen challenge was similar to that of control mice and it was associated with an increase in the mass index of popliteal lymph nodes (p< 0.05). An in vitro lymphoproliferative-stimulating response was also demonstrated with aqueous and ethanolic extracts obtained from Pleurotus powder. These effects suggest that Pleurotus supplement could potentiate the cellular immune response and should be promising for further immunotherapy studies.

Oral Administration of an Enzymatic Protein Hydrolysate from the Green Microalga Chlorella vulgaris Enhances the Nutritional Recovery of Malnourished Mice

This study examined the effects of oral administration of an enzymatic protein hydrolysate from green microalga Chlorella vulgaris (Cv-PH) on the nutritional recovery of malnourished Balb/c mice after a 3-day fasting period. Mice were refed with commercial diet supplemented or not supplemented with Cv-PH (500 mg/kg) for 8 days. Regardless of the diet used during refeeding, animal body weights and serum protein concentrations did not differ between groups. Mice given Cv-PH had a significant increase in hemoglobin concentrations. Most serum amino acid levels were similar in the control and Cv-PH animals. Starved mice refed with Cv-PH showed normal liver functions, as judged by liver weight, protein concentration, and the enzymatic activities of cholinesterase and arginase. Cv-PH increased DNA, protein content, and gut-mucosal weight. In addition, brush-border oligosaccharidase activities were also higher in the Cv-PH group. These findings suggest that Chlorella protein hydrolysate can be used to develop specific formulations suitable for pharmacologic nutrition.

Effect of starvation and refeeding on biochemical and immunological status of Balb/c mice: an experimental model of malnutrition.

Context: Although new methods for the induction of malnutrition disorders in laboratory animals have been developed, the bulk of the models described in the literature are essentially based on dietary restriction/starvation principle. In this context, little data are available about the metabolic and the immune system parameters of Balb/c mice under starvation/refeeding. Objective: This study examined the effects of starvation and refeeding on the biochemical and immunological status of undernourished Balb/c mice. Methods: Female Balb/c mice, weighing 20 g, were starved for 3 days and then refed with commercial pelleted diet for 8 days. The variables considered were as follows: body weight; serum protein and amino acid concentrations; liver protein content, and cholinesterase and arginase activities; jejunal protein and DNA contents as well as oligosaccharidase levels; hematological parameters (bone marrow and peripheral blood cellularity); peritoneal macrophage activation; and humoral and cell-mediated immune functions. Results: Profound alterations in both biochemical and immunological conditions appeared after the starvation period. Refeeding resulted in the normalization of serum albumin levels, the intestinal DNA content and the gut-mucosal associated enzymatic activities, the blood lymphocyte counts, and the number of peritoneal macrophages. The markers of liver metabolic function (cholinesterase and arginase activities), and those of bone marrow hemopoiesis and the adaptive immune response (T-dependent antibody titres and delayed-type hypersensitivity response) remained altered after refeeding compared with control mice. Conclusion: These findings suggest that fasted mice can be used as an animal model of acute starvation that might prove useful in evaluating the effectiveness of nutritional and immunopharmacological interventions.

A note on the in vitro macrophage-stimulating activity of water-soluble extracts from mycelium of Pleurotus spp.

Abstract Since macrophages have been suggested to play important roles in immunological surveillance, the purpose of this study was to assess the in vitro effects on macrophage activation of five water-soluble fractions (F-I to F-V) extracted from mycelium of the edible mushroom Pleurotus spp., strain P-184 (P. ostreatus× P. pulmonarius hybrid). After incubation of murine peritoneal macrophages (1×105 cells/well) with mushroom fractions (50 µg/culture) or lipopolysaccharide (LPS) (10 and 100 µg/culture) used as a positive control for 48 h, the glucose consumption of the macrophages significantly increased to 1.8–2.9 times that of the control without samples. The lysosomal enzyme (acid phosphatase) activity, determined in cell lysate by the amount of nitrophenol released per 60 min, was also enhanced positively to 133–184%, compared to saline control group. The results suggest that Pleurotus fractions possessed the ability to activate macrophages in vitro and these effects may have importance in the immunopotentiating activity.

Haematopoiesis radioprotection in Balb/c mice by an aqueous mycelium extract from the Basidiomycete Pleurotus ostreatus mushroom

The study examined the radioprotective activity of an aqueous extract from Pleurotus ostreatus mycelium administered to Balb/c mice. Male mice were whole-body irradiated on day 0 (60Co, at 0.43 Gy/min) and divided into two groups. The extract was administered intraperitoneally to one group (100 mg/kg) on days − 10 to − 6 and − 2 to +1 with respect to the irradiation. The irradiated-control group was injected with saline solution; non-irradiated mice were used as negative controls. The radioprotective effect was evident by increases in bone marrow cellularity (5.1 × 106/femur vs. 1.1 × 106/femur in saline-control mice, p < 0.05), leucocyte counts (10.5 × 109/L vs. 4.5 × 109/L, p < 0.05), and spleen cellularity (11.2 × 107/spleen vs. 6.2 × 107/spleen, p < 0.05). The extract stimulated macrophage phagocytic activity as judged by a faster rate of carbon clearance in terms of absorbance ratios (1.62 vs. 2.01, p < 0.05). Therefore, this extract may be a candidate therapeutic agent with radioprotective activity for haematopoiesis damage, particularly to cells involved in immune function.

Oral administration of an aqueous extract from the oyster mushroom Pleurotus ostreatus enhances the immunonutritional recovery of malnourished mice

Mushroom nutriceutical components have lately attracted interest for developing immunonutritional support. However, there is relatively little information pertaining to the use of mushroom preparations for modulating the metabolic and immunological disorders associated to malnutrition. This study was aimed to evaluate the effects of oral administration of an aqueous extract (CW-P) from Pleurotus ostreatus on the recovery of biochemical and immunological functions of malnourished mice. 8-week old female BALB/c mice were starved for 3days and then refed with commercial diet supplemented with or without CW-P (100mg/kg) for 8days. Regardless of the diet used during refeeding, animal body weights and serum protein concentrations did not differ between groups. Oral treatment with CW-P normalized haemoglobin levels, liver arginase and gut mucosal weight. CW-P increased total liver proteins and also DNA and protein contents in gut mucosa. Pleurotus extract provided benefits in terms of macrophages activation as well as in haemopoiesis, as judged by the recovery of bone marrow cells and leukocyte counts. Moreover, CW-P stimulated humoral immunity (T-dependent and T non-dependent antibodies responses) compared to non-supplemented mice. CW-P extract from the oyster mushroom can be used to develop specific food or nutritional supplement formulations with potential clinical applications in the immunotherapy.