A partial agonist of PPARγ prevents paclitaxel-induced peripheral neuropathy in mice, by inhibiting neuroinflammation.

BACKGROUND AND PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of paclitaxel, affecting 30-50% of patients. Increased survival and concern with patients' quality of life have encouraged the search for new tools to prevent paclitaxel-induced neuropathy. This study presents the glitazone 4-[(Z)-(2,4-dioxo-1,3-thiazolidin-5-ylidene)methyl]-N-phenylbenzene-sulfonamide (TZD-A1) as a partial agonist of peroxisome proliferator-activated receptor γ (PPARγ), its toxicological profile and effects on paclitaxel-induced CIPN in mice. EXPERIMENTAL APPROACH: Interactions of TZD-A1 with PPARγ were analysed using in silico docking and in vitro reporter gene assays. Pharmacokinetics and toxicity were evaluated using in silico, in vitro and in vivo (C57Bl/6 mice) analyses. Effects of TZD-A1 on CIPN were investigated in paclitaxel-injected mice. Axonal and dorsal root ganglion damage, mitochondrial complex activity and cytokine levels, brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2) and PPARγ, were also measured. KEY RESULTS: Docking analysis predicted TZD-A1 interactions with PPARγ compatible with partial agonism, which were corroborated by in vitro reporter gene assays. Good oral bioavailability and safety profile of TZD-A1 were shown in silico, in vitro and in vivo. Paclitaxel-injected mice, concomitantly treated with TZD-A1 by i.p. or oral administration, exhibited decreased mechanical and thermal hypersensitivity, effects apparently mediated by inhibition of neuroinflammation and mitochondrial damage, through increasing Nrf2 and PPARγ levels, and up-regulating BDNF. CONCLUSION AND IMPLICATIONS: TZD-A1, a partial agonist of PPARγ, provided neuroprotection and reduced hypersensitivity induced by paclitaxel. Allied to its safety profile and good bioavailability, TZD-A1 is a promising drug candidate to prevent and treat CIPN in cancer patients.

Effect of the metanolic extract from the leaves of Garcinia humilis Vahl (Clusiaceae) on acute inflammation.

Garcinia humilis is popularly used to treat digestive, intestinal and inflammatory illness. We investigated the in vivo and in vitro effects of the methanol extract of G. humilis leaves (MEGh) on inflammatory cells behavior (migration and chemical mediators release) and hypersensitivity. Anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice treated orally with MEGh (0.1-30 mg/kg). Leucocyte migration, chemical mediators secretion (TNF, IL-1ß, IL-6 and CXCL1) and protein exudation were quantified in the exudate. The adhesion molecules expression (CD62L and CD18), chemical mediators and chemotaxis was evaluated using neutrophils or macrophages RAW.264.7 previously treated with the extract (1-100 µg/mL) and activated with LPS. The anti-inflammatory activity of the isolated compounds friedelin, canophyllol, amentoflavone and 3-desmethyl-2-geranyl-4-prenylbellidypholine xanthone (10 µM) was evaluated in macrophages nitric oxide (NO) and TNF release. MEGh, given orally (30 mg/kg), significantly reduced neutrophil migration and decreased TNF, IL-1ß and CXCL1 levels, without interfering with protein exudation and IL-6. In vitro, the extract significantly reduced IL-1ß and IL-6 levels but did not alter TNF and CXCL1. The MEGh also reduced the expression of CD62L and CD18 and consequently neutrophil chemotaxis. The compounds friedelin, amentoflavone and 3-demethyl-2-geranyl-4-prenylbellidypholine xanthone decreased the secretion of NO and TNF by RAW264.7. The MEGh effects were extended to the pain-like behaviour induced by carrageenan in the mice hindpaw. MEGh presented important anti-inflammatory effects probably due to its activity on neutrophil migration and on important chemical mediator release, scientifically reinforcing its use as medicinal plant.

Effects of passion fruit peel flour (Passiflora edulis f. flavicarpa O. Deg.) in cafeteria diet-induced metabolic disorders.

ETHNOPHARMACOLOGICAL RELEVANCE: Passiflora edulis f. flavicarpa O. Deg. is a native Brazilian fruit known as sour or yellow passion fruit. From its peel, mainly in the northeast of Brazil, is produced a flour that is largely used as folk medicine to treat diabetes and other metabolic conditions. AIM OF THE STUDY: The aim of the study was to show the effects of P. edulis peel flour (PEPF) in metabolic disorders caused by cafeteria diet in mice. MATERIAL AND METHODS: The antioxidant activity in vitro of PEPF extract was determined by ferric reducing/antioxidant power, ß-carotene/linoleic acid system and nitric oxide scavenging activity assay. C57BL/6 mice divided in 3 groups: Control group, fed on a standard diet (AIN); Cafeteria diet (CAF) group, fed on a cafeteria diet, and PEPF group, fed on a cafeteria diet containing 15% of PEPF, during 16 weeks. The glucose tolerance and insulin sensitivity were evaluated through the glucose tolerance test (GTT) and the insulin tolerance test (ITT). After the intervention period, blood, hepatic, pancreatic and adipose tissues were collected for biochemical and histological analysis. Cholesterol, triglyceride, interleukins and antioxidant enzymes were measured in the liver tissue. RESULTS: PEPF extract presented antioxidant activity in the higher concentrations in the performed assays. The PEPF intake decreased the body weight gain, fat deposition, predominantly in the liver, improved the glucose tolerance and insulin sensitivity in metabolic changes caused by cafeteria diet. CONCLUSION: Together, the data herein obtained points out that P. edulis peel flour supplementation in metabolic syndrome condition induced by CAF-diet, prevents insulin and glucose resistance, hepatic steatosis and adiposity.

Effects of Eugenia umbelliflora O. Berg (Myrtaceae)-leaf extract on inflammation and hypersensitivity.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Eugenia species are widely used in popular medicine to treat several diseases, such as arthritis, rheumatism and diabetes. Eugenia umbelliflora O. Berg is popularly known in Brazil as "baguaçu", name also conferred to Eugenia jambolana probably due to their apparent similarity. Although the popular use scientifically proved of E. jambolana as anti-diabetes and also as anti-inflammatory, there are only two scientific studies demonstrating anti-ulcer and bactericide activities of E. umbelliflora leaves extract, without reference to its possible anti-inflammatory activity. AIM OF THE STUDY: The aim of this study was to show the anti-oxidant and anti-inflammatory activity of the methanol extract obtained from E. umbelliflora leaves (EuL) using in vitro and in vivo protocols. MATERIALS AND METHODS: The total phenolic content was evaluated using the folin-Ciocalteu colorimetric method and phloroglucinols content by HPLC. The anti-oxidant activity was evaluated by ORAC, ABTS•+, DPPH, and metal chelation methods. The anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally pre-treated with the EuL (0.3, 1 or 3 mg/kg). The leukocyte influx (optical microscopy) and secretion of chemical mediators (TNF, IL-6, IL-1ß and CXCL1, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. Histological analysis of the pouches was also performed. The anti-hypersensitive activity was investigated using carrageenan-induced mechanical hypersensitivity and mice were then evaluated using the von Frey filaments. The Open Field test was used to evaluate possible interference of adverse effect of EuL on locomotor activity that could lead to misinterpretation of the hypersensitivity evaluation. RESULTS: The EuL demonstrated important and moderate reducing capacity on ABTS•+ and DPPH assays, respectively, but with slight activity in ORAC test. It reflects low protection against cell damage. The EuL also presented 30% of phenolic compounds. The phloroglucinols content of EuL was 25.9 mg/g, 18.4 mg/g and 16.6 mg/g of eugenial C, eugenial D and eugenial E, respectively. The in vivo analysis of the inflammatory exudate of EuL-treated mice demonstrated reduction in the polymorphonuclear cells (PMN) migration to the inflamed tissue, as well as the reduction of the pro-inflammatory cytokine IL-1ß. Histologically, it was observed evident decrease in the oedema, formed essentially by non-haemorrhagic fibrin exudate, as well as PMN infiltrate, when compared with control mice injected with carrageenan. Furthermore, the extract also presented effective reduction of the mechanical hypersensitivity induced by carrageenan without any interference in animal's locomotor and exploratory activity. CONCLUSIONS: Together, the results herein obtained show that EuL presented anti-inflammatory activity by decreasing the influx of PMN to the inflamed tissue, as well as the cytokine IL-1ß level. This anti-inflammatory activity was also accompanied by significant anti-hypersensitive effect. The effects presented by EuL seem not to be correlated with an antioxidant activity. However other extract chemical compounds could be responsible for its important anti-inflammatory effects.

Effects of Tithonia diversifolia (Asteraceae) extract on innate inflammatory responses.

ETHNOPHARMACOLOGICAL RELEVANCE: Tithonia diversifolia (Helms.) A. Gray, popularly known in Brazil as "margaridão" or "mão-de-Deus" has been used in the folk medicine as anti-inflammatory and against other illnesses in several countries. Indeed, many studies show de effect of T. diversifolia in the inflammatory process, however, any of them have demonstrated the mechanism of cell migration. AIM OF THE STUDY: The aim of this investigation was to show the in vivo and in vitro effects of T. diversifolia leaves ethanol extract on neutrophil trafficking from the blood to the inflamed tissue and on cell-derived secretion of chemical mediators, as well as, the effects on inflammatory resolution and inflammatory pain. MATERIALS AND METHODS: Anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally treated with the T. diversifolia extract (0.1, 1 or 3 mg/kg). The leukocyte influx (optical microscopy) and the secretion of chemical mediators (TNF, IL-6, IL-1ß and CXCL1, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. Histological analysis of the pouches was performed. N-Formyl-methionine-leucine-phenylalanine-induced chemotaxis, lipopolysaccharide-induced TNF, IL-6, IL-1ß, CXCL1 and NO production, and adhesion molecule expression (CD62L and CD18, flow cytometry) were in vitro quantified using oyster glycogen recruited peritoneal neutrophils previous treated with the extract (1, 10, or 100 µg/mL). The resolution of inflammation was accessed by efferocytosis assay, and the antinociceptive activity was investigated using carrageenan-induced mechanical hypersensitivity. RESULTS: The oral treatment with T. diversifolia promoted reduction in the neutrophil migration as well as the decrease in total protein, TNF, IL-1ß and CXCL1 levels in the inflamed exudate. In vitro treatment with T. diversifolia shedding of ß2 integrin expressions, without alter CD62L expression. The extract was able to increase the efferocytosis of apoptotic neutrophils, and the increase of the IL-10 and the decrease of TNF secretion. Additionally, the extract reduced the hypersensitivity induced by carrageenan. CONCLUSIONS: Together, the data herein obtained showed that T. diversifolia extract presented anti-inflammatory activity by inhibiting the cytokine and NO production, and also the leukocyte migration. The mechanisms involved in the extract anti-inflammatory effects include the impairment in the leukocyte migration to the inflamed tissue, the pro-resolution activity, and consequently the anti-hypersensitivity.

The role of kinins in the proliferation of fibroblast primed with TNF in scratch wound assay: Kinins and cell proliferation.

The aim of this study was to evaluate the involvement of both B1 and B2 kinins receptors (B1R and B2R) in the fibroblast proliferation induced by the cytokine tumour necrosis factor (TNF) attempting to establish an in vitro model of wound healing. Murine fibroblasts L-929 were cultivated in 24 wells plaque until total confluence (DMEM (Vitrocell®); 5% fetal bovine serum, 5% CO2, 37 °C) and then submitted to the scratch assay. The cells were treated with PBS, TNF (2 ng/mL) and/or mr-TNF antibody (200 µg/mL), or PDTC. The cells received the second set of treatment (3 h later): PBS; 1 µM HOE-140; 1 µM des-Arg9-Leu8-BK (DALBK) or 100 µM PDTC. TNF was able to increase the cell proliferation when compared with the group treated with PBS. The co-treatment with the TNF antibody completely reversed the TNF effect. The TNF-proliferative effect was blocked by B1 (DALBK) and B2 (HOE-140) kinin receptor antagonists administered separately or along, suggesting the involvement of both receptors in the TNF mechanism of action. Furthermore, the treatment with a NF-ĸB inhibitor PDTC completely blocked the cell proliferation. The TNF cell proliferation was incremented with BK (1 µM) treatment, and its effect was totally reversed by HOE-140 treatment. No effect was observed for TNF plus DABK. Eventually, TNF treatment was able to increase TNF level in the growing medium; however, this increase was suppressed by BK treatment. These results suggest that TNF induces cell proliferation and the induced signalling cascade has the B2R participation. All these events seem to be totally dependent on the NF-ĸB activation. These inflammatory mediators can improve the wound healing in the resolution of inflammation.