Brazilian natural dietary components (annatto, propolis and mushrooms) protecting against mutation and cancer

Effect of date palm coproducts and annatto extract on lipid oxidation and microbial quality in a pork liver pâté

Dates are an interesting source of bioactive compounds, and coproducts from the date industry are of potential use in the manufacturing of meat products. In the present research, spreadable pork liver pâtés were made using fresh date coproducts (2.5% and 7.5%) as a potential functional ingredient and an ethanolic annatto extract (128 mg/kg) as colorant. The effect of these 2 ingredients on the lipid oxidation and microbial quality of the pâtés was assessed during 21 d of storage. The pâtés containing 7.5% date paste were seen to have the highest content of phenolic compounds during storage. The combination of 2.5% date paste and annatto protected pâtés against lipid oxidation throughout the 21 d of storage, thiobarbituric acid-reactive substances values being 0.47 mg MDA/kg at the end of this period, while other combinations increased oxidation compared to the control pâté. The control and those made with 2.5% date paste alone showed the highest counts of mesophilic aerobic bacteria, while the addition of annatto and/or 7.5% date paste reduced this count. The results suggest that a combination of both ingredients is necessary to reduce oxidation and microbial growth, but whereas the concentration of 2.5% is more appropriate to reduce oxidation, the combination with 7.5% date paste reduces the microbial counts. Both ingredients could have an opportunity of valorization in the meat industry for improving the quality.

Propolis decreases lipopolysaccharide-induced inflammatory mediators in pulp cells and osteoclasts

BACKGROUND

Intracanal medicaments are used to disinfect the root canal system, reduce interappointment pain and inflammation, and prevent resorption. Bacterial components such as lipopolysaccharide (LPS) are implicated in the development of pulpal and periapical inflammation and inducing osteoclastogenesis. Propolis is a natural, non-toxic substance collected from bee's wax that has been used for many years in folk medicine. Propolis has been demonstrated to have antibacterial and anti-inflammatory properties. Our previous studies have shown that propolis inhibits osteoclast maturation. However, the effect of propolis on the inflammatory response of pulp cells and osteoclasts has not been explored.

AIM

The purpose of this study was to evaluate whether propolis alters the inflammatory response of three endodontically relevant cell lines: mouse odontoblast-like cells (MDPC-23), macrophages (RAW264.7), and osteoclasts.

MATERIAL AND METHODS

Cells were exposed to 0-20 ug ml(-1) LPS to induce an inflammatory response, in the presence of propolis or vehicle control. Culture supernatants were collected after 6 and 24 h, and expression of multiple soluble mediators was determined using Luminex(®) multiplex technology.

RESULTS

Propolis was effective in reducing secretion of the LPS-induced inflammatory cyto/chemokines: IL-1α, IL-6, IL-12(p70), IL-15, G-CSF, TNF-α, MIP-1α, MCP-1, and IP-10.

CONCLUSION

Our results demonstrate that propolis suppresses the LPS-induced inflammatory response of key cells within the root canal system.

Effects of Brazilian green propolis on double-stranded RNA-mediated induction of interferon-inducible gene and inhibition of recruitment of polymorphonuclear cells

BACKGROUND

Propolis is a bee product with various biological properties, including an antiviral activity when taken orally. However, its mechanisms at the cellular and molecular level are not well understood.

RESULTS

We investigated the effect of propolis on antiviral signaling in A549 cells transfected with double-stranded RNA (dsRNA), a model for viral infection. Pretreatment of the cells with propolis inhibited poly I:C (synthetic dsRNA)-induced interferon (IFN)-β expression. Propolis had no effect on the dsRNA-induced expression of RIG-I-like receptors (RLRs), which are known as intracellular viral RNA sensors. As to the effect on antiviral executor genes, propolis enhanced myxovirus resistance 1 (MX1) expression, whereas interferon-inducible gene 6-16 (G1P3) and 2'-5'-oligoadenylate synthetase (OAS) were unaffected. All of these genes belong to the IFN-inducible genes, suggesting that the effect of propolis on antiviral signaling is not necessarily mediated by the autocrine regulation by IFN-β. Propolis pretreatment inhibited dsRNA-induced interleukin-8 (IL8) and CCL5 expression, and consequently lowered polymorphonuclear leukocyte (PMN) chemotactic activity in the cell-conditioned medium.

CONCLUSION

Taken together, these results suggest that propolis may suppress excess inflammatory responses without affecting the innate immunity during viral infection.

Electron microscopy studies of basidiosporogenesis in Agaricus brasiliensis

The objective of this work was to study the basidiosporogenesis and the intraspecific variation in the number of basidiospores produced per basidium in Agaricus brasiliensis with transmission (TEM) and scanning electron microscopy (SEM). A. brasiliensis produces predominantly tetrasporic basidia, but this trait may vary depending on the strain. For certain strains, such as CS2 and CS7, the frequency of bisporic and trisporic basidia was similar to, or greater than, that of tetrasporic strains. These results suggest that some strains of A. brasiliensis may be amphithallic; however, this behavior is variable and strain dependent. The development of basidia and basidiospores occurs asynchronously during basidiocarp production. The basidiospore cell wall is composed of three distinct layers and presents variable thickness. The conspicuous presence of lipid bodies also was observed in the basidiospores, while nuclei, mitochondria, vacuoles and dolipore septa could be visualized only in the basidia. The basidiospores generally are produced free but also may be enveloped by an extracellular matrix with unknown chemical composition. The presence of connection hyphae linking the basidia was observed for the first time in A. brasiliensis. This characteristic, so far not reported for other fungi, may represent a specific strategy of A. brasiliensis for exchanging nuclei and other cell material between basidial cells during basidiosporogenesis.

Protective effects of Chinese and Brazilian propolis treatment against hepatorenal lesion in diabetic rats

Diabetes mellitus promoted an overproduction of free radicals and an increased incidence of both diabetic nephropathy and liver disease. In this report, we evaluated the effects of Chinese and Brazilian propolis on streptozotocin-induced hepatorenal injury in rats. The results demonstrated that Chinese propolis-treated rats had a 7.4% reduction in the glycated hemoglobin (HbAlc) level compared with untreated diabetic rats. Additionally, Chinese propolis induced an increase in the serum superoxide dismutase (SOD) level significantly while Brazilian propolis raised serum SOD and reduced level of malonaldehyde (MDA) and nitric synthetase (NOS). Of the measurable decrease in serum alanine transaminase (ALT), aspartate transaminase (AST) and microalbuminuria demonstrated the propolis-mediated improvement of hepatorenal function, which was further confirmed by histological examination. We also observed that Chinese and Brazilian propolis increased hepatorenal glutathione peroxidase (GSH-px) level and inhibited MDA production significantly. These results suggested that propolis may prevent hepatorenal injury by inhibiting lipid peroxidation and enhancing the activities of antioxidant enzymes.

Propolis inhibits osteoclast maturation

Propolis, a natural product produced by the honey bee, has been successfully used in medicine as an anti-inflammatory and antimicrobial agent. Traumatic injuries to the teeth, especially avulsion injuries, present a challenging situation for the clinician because of post-treatment complications, such as inflammatory and/or replacement resorption. Agents that reduce osteoclast numbers and activity may be useful in the treatment of traumatic injuries to the teeth. In this study, we evaluated propolis as an anti-resorptive agent. Calcitriol-stimulated mouse marrow cultures, which contain both osteoclasts and osteoblasts, were exposed to the ethanol extracts of propolis or vehicle control and stained for tartrate-resistant acid phosphatase (TRAP)-activity to identify osteoclasts. A significant, dose-dependent reduction in multinuclear TRAP+ cells was demonstrated, although the propolis treatment accommodated cell growth and survival (P < 0.05). Propolis also reduced the formation of actin rings in pure cultures of RAW 264.7 osteoclast-like cells, suggesting that it exerts direct actions on osteoclast maturation. In summary, our data suggest that propolis inhibits late stages of osteoclast maturation including fusion of osteoclasts precursors to form giant cells and formation of actin rings. This supports the hypothesis that it may prove useful as a medicament to reduce resorption associated with traumatic injuries to the teeth.

Lack of chemoprevention of dietary Agaricus blazei against rat colonic aberrant crypt foci

The mushroom Agaricus blazei (Ab) has been widely used in folk medicine to treat various diseases including cancer. No information is available on its possible protective effects on the development of colon cancer. The potential blocking effect of Ab intake on the initiation stage of colon carcinogenesis was investigated in a short-term (4-week) bioassay using aberrant crypt foci (ACF) as biomarker. Male Wistar rats were given four subcutaneous injections of the carcinogen 1,2-dimethylhydrazine (DMH, 40 mg/kg bw, twice a week), during 2 weeks to induce ACF. The diet containing Ab at 5% was given 2 weeks before and during carcinogen treatment to investigate the potential beneficial effects of this edible mushroom on DMH-induced ACF. All groups were killed at the end of the fourth week. The colons were analyzed for ACF formation in 1% methylene blue whole-mount preparations and for cell proliferation in histological sections immunohistochemically stained for the proliferating cell nuclear antigen (PCNA). All DMH-treated rats developed ACF mainly in the middle and distal colon. Agaricus blazei intake at 5% did not alter the number of ACF induced by DMH or the PCNA indices in the colonic mucosa. Thus, the results of the present study did not confirm a chemopreventive activity of Ab on the initiation stage of rat colon carcinogenesis.

Evaluation of radioprotective effects of propolis and quercetin on human white blood cells in vitro

This in vitro study aimed at investigating the possible radioprotective effects of natural substances propolis and quercetin on gamma-irradiated human white blood cells. The levels of primary DNA damage were studied by the alkaline comet assay, while the cytogenetic damage was evaluated using the analysis of structural chromosome aberration and cytokinesis-block micronucleus assay. The results obtained by all endpoints indicate acceptable toxicity profiles of propolis and quercetin in vitro, and also confirmed their radioprotective abilities. Propolis was found to be more effective in diminishing the levels of primary and more complex cytogenetic DNA damage in gamma-irradiated white blood cells. Data gathered in present study support the use of propolis and quercetin as non-toxic protective substances. However, to clarify the underlying mechanisms of their cyto/radioprotective activities, additional studies are necessary at both in vitro and in vivo levels.

Effect of the water extracts of propolis on stimulation and inhibition of different cells

The water extracts of propolis (WEP) could inhibit growth of different cell lines namely McCoy, HeLa, SP2/0, HEp-2, and BHK21 and stimulate growth of normal cell named human lymphocyte, rat kidney, rat liver, and rat spleen. In these experiments 1 and 2 mg of WEP were added to 1 ml RPMI media with 5% FCS. Cell counts and cell viability of propolis-treated and propolis-free cells were assessed by Trypan blue dye exclusion test and MTT assay. The results showed that in case of McCoy, HeLa, SP20, HEp-2, and BHK21 cell lines, the water extracts of propolis could inhibit cell growth as well as reduction on size of the cells. In contrast the same amount of WEP could stimulate growth of normal cells up to 60% with the same concentration used for cell lines. Thus our study indicates that although WEP consists only of the soluble part of propolis, it enables to inhibit different cell lines and increase growth of normal cells. This indicates also that WEP contains the specific compounds with bioactivity against cell lines. Although propolis contain different number of compounds it is clear that WEP has enough biological compounds useful for the treatment of some diseases, medical and related applications.