Larrea divaricata Cav (Jarilla): production of superoxide anion, hydrogen peroxide and expression of zymosan receptors

Expression of toll-like receptors 2 and 3 on esophageal epithelial cell lines and on eosinophils during esophagitis

BACKGROUND

The chronic disease eosinophilic esophagitis may be mediated by the innate immune system. Activation of toll-like receptors (TLRs) in other tissues is known to initiate eosinophil infiltration, thus TLRs may be a potential mediator of esophageal eosinophilia. Little is known about TLRs in the esophagus.

AIMS

The purpose of this study was to identify the presence and activation of TLR2 and TLR3 on esophageal epithelial cell lines, primary epithelial cells and mucosal esophageal biopsies.

METHODS

TLR2 and TLR3 were identified by immunocytochemistry and immunoblot. PCR assessed alterations to gene expression by activation of TLR2 and TLR3. Immunohistochemistry co-localized eosinophils and TLR2/TLR3 on esophageal biopsies.

RESULTS

TLR2 and TLR3 were expressed on the esophageal adenocarcinoma cell lines TE-1 and TE-7, but only TLR3 was present on the esophageal epithelial cell line HET-1A. Thymic stromal lymphopoietin gene expression was altered in response to ligands zymosan and polyI:C, demonstrating activation. Primary esophageal epithelial cells did not express TLR2 or TLR3. In esophageal biopsies, TLR2 and TLR3 expression was limited to eosinophils and other immune cells during esophagitis.

CONCLUSIONS

TLR2 and TLR3 expression on cultured esophageal epithelial cells differs from TLR2 and TLR3 expression in esophageal biopsies, which is limited to immune cells during esophagitis.

In vivo effect of three fractions of Larrea divaricata Cav. (jarilla) on the innate immune system: macrophage response against Candida albicans

Larrea divaricata Cav. (jarilla) is a plant with well-documented applications in folk medicine in Argentina. In this study, we aimed to evaluate functional parameters of peritoneal macrophages isolated from mice injected with three fractions (F1, F2 and F3) of L. divaricata. The response of macrophages against Candida albicans was evaluated. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, apoptosis was evaluated using Giemsa, acridine orange/ethidium bromide and ladder assay, oxidative burst was assayed using nitroblue tetrazolium test and nitrite production using Griess assay. Cell stimulation and their ability to kill C. albicans in vitro were measured. The number and cell viability were similar to controls. However, we found that F1 induces pre-activation of macrophages, and this pre-activation is enhanced by C. albicans. The effects exerted by F1 make it more important than F2 and F3 for the treatment of disseminated candidiasis in patients with immunodeficiency diseases such as AIDS and chronic granulomatous disease, among others.

In vitro immunomodulatory effects of fractions obtained from aqueous extracts of Larrea divaricata Cav (Jarilla) on mouse peritoneal macrophages

BACKGROUND AND AIM

Larrea divaricata Cav. (Zygophyllaceae) is a plant widely used in Argentina.

MATERIAL AND METHODS

We isolated different fractions of L. divaricata aqueous extract containing minor amounts of NDGA, and we analyzed these fractions on mouse macrophages.

RESULTS

We showed that a fraction without NDGA was capableof activating macrophages, principally through the production of mitochondrial anion superoxide and H(2)O(2). This could be important in the defense of infections. Moreover, this fraction decreased NO level suggesting an anti-inflammatory action.

CONCLUSION

These results indicate that NDGA was not the compound responsible for the immunomodulatory action exerted by the aqueous extract from L. divaricata.

"In vivo" murine macrophages activation by a dichloromethane extract of Tilia x viridis

Macrophages are involved in the host defense against infectious pathogens and tumors. Tilia species have been used in folk medicine for the treatment of infectious diseases, previously it was demonstrated that a dichloromethane (DM) extract possess antiproliferative action "in vitro" on a lymphoma cell line. The aim of this work was to study the "in vivo" effect of DM extract upon mice peritoneal macrophages. DM extract-activated macrophages phagocytosis through hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) production (phagocytosis (%): basal 16.93 +/- 0.18, DM extract 25.93 +/- 2.8; H(2)O(2) (M): basal 0.0022 +/- 0.00016, DM extract 0.0036 +/- 0.0005; NO (mM): basal 0.0052 +/- 0.0007, DM extract 0.0099 +/- 0.0004). These actions were mediated by cell superoxide dismutase activation. On the other hand, DM extract decreased tumor necrosis factor alpha but increased interleukin-10 in serum. These results suggest that the modulation activity exerted by the extract on immune system cells could be an important mechanism to acquire resistance to tumors and infectious diseases.