Effects of Myrcia pubipetala Miq (Myrtaceae) extract on innate inflammatory response

Myrcia is a genus widespread in South America with many species presenting anti-inflammatory and biological properties. We investigated the anti-inflammatory activity of crude hydroalcoholic extract of Myrcia pubipetala leaves (CHE-MP) using macrophages (RAW 264.7), and the air pouch model in mice to evaluate leukocyte migration and mediator's release. Adhesion molecule expression, CD49 and CD18, was evaluated in neutrophils. In vitro, the CHE-MP significantly reduced nitric oxide (NO), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF) levels in the exudate and the supernatant culture. CHE-MP did not present cytotoxicity and modulated the percentage of positive neutrophils for CD18 and its expression per cell, without modifying the expression of CD49, which corroborated with significantly reduced neutrophil migration to inflammatory exudate and subcutaneous tissue. Taken together, the data demonstrate that CHE-MP presents a potential activity on innate inflammatory.

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.

β-Caryophyllene Inhibits Oxaliplatin-Induced Peripheral Neuropathy in Mice: Role of Cannabinoid Type 2 Receptors, Oxidative Stress and Neuroinflammation

Peripheral neuropathy is an important adverse effect caused by some chemotherapeutic agents, including oxaliplatin (OXA). OXA-induced peripheral neuropathy (OIPN) is a challenging condition due to diagnostic complexities and a lack of effective treatment. In this study, we investigated the antiallodynic effect of β-caryophyllene (BCP), a cannabinoid type 2 (CB2) receptor agonist, in a mouse model of OIPN. BCP treatment inhibited OXA-induced mechanical and cold allodynia in both preventive and therapeutic drug treatment regimens. Experiments with the CB2 receptor agonist GW405833 confirmed the role of CB2 receptors in OIPN. The CB2 antagonist SR144528 abrogated the anti-nociceptive effect of BCP on mechanical allodynia, without impacting OXA-induced sensitivity to cold. BCP decreased neuroinflammation, as inferred from TNF, IL-1β, IL-6, and IL-10 profiling, and also reduced ROS production, lipid peroxidation, and 4-hydroxynonenal protein adduct formation in the spinal cords of OXA-treated mice. BCP did not affect the antitumor response to OXA or its impact on blood cell counts, implying that the cytotoxicity of OXA was preserved. These results underscore BCP as a candidate drug for OIPN treatment via CB2 receptor-dependent mechanisms, and anti-inflammatory and antioxidant responses in the spinal cord.

Neuroinflammation and hypersensitivity evidenced by the acute and 28-DAY repeated dose toxicity tests of ostrich oil in mice

The ostrich oil (OO) has been topically used for decades to treat skin diseases. Its oral use has been encouraged through e-commerce advertising several health benefits to OO without scientific evidence on its safety or effectiveness. This study presents the chromatographic profile of a commercially available OO and its acute and 28-day repeated dose in vivo toxicological profiles. OO anti-inflammatory and antinociceptive effects were also investigated. Omega-9 (ω-9; oleic acid; 34.6%) and -6 (linoleic acid; 14.9%) were detected as OO main constituents. A high single dose of the OO (2 g/kg of ω-9) demonstrated no or low acute toxicity. However, when orally treated with OO (30-300 mg/kg of ω-9) for 28 consecutive days, mice exhibited altered locomotor and exploratory activities, hepatic damage, and increased hindpaw sensitivity accompanied by increased levels of cytokine and brain-derived neurotrophic factor in their spinal cords and brains. Lack of anti-inflammatory or antinociceptive activities was also evidenced in 15-day-OO treated mice. These results indicate that chronic consumption of OO induces hepatic injury, in addition to neuroinflammation and subsequent hypersensitivity and behavioural changes. Thus, there is no evidence to support OO use to treating illness in humans.

Extract of Tagetes erecta L., a medicinal plant rich in lutein, promotes gastric healing and reduces ulcer recurrence in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Tagetes erecta L. (Asteraceae), popularly known as Aztec Marigold, is used in South America to treat several ailments. Despite reports that T. erecta flowers are used in folk medicine to treat gastrointestinal diseases, there is no study regarding its gastric healing effects.

AIM OF THE STUDY

The effect of dry extract of T. erecta L. (DETe) in gastric healing and gastric ulcer recurrence was evaluated, contributing to the validation of the antiulcer potential of this medicinal plant.

METHODS

Rats were treated orally with vehicle (1 ml/kg), omeprazole (20 mg/kg), or DETe (3, 30 or 300 mg/kg) for 7 days, twice a day. The lesion area was evaluated, and the levels of reduced glutathione (GSH) and lipoperoxides (LOOH) and the activity of the superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and myeloperoxidase (MPO) were measured. The ulcer recurrence was evaluated in mice and induced by interleukin (IL)-1β (1 μg/kg, i.p). The recurred area, gastric wall thickness, GSH and cytokines levels, MPO and N-acetylglucosaminidase (NAG) activities were measured.

RESULTS

DETe accelerated the healing of gastric ulcers only at 300 mg/kg, reducing the ulcerated area by 66%. In parallel, DETe reduced LOOH levels, SOD, CAT and MPO activities, while increasing GST activity and mucin amount. In the recurrence model, DETe reduced the lesion area by 94%, and in parallel decreased the gastric wall thickness and TNF levels, while increasing IL-10 amount.

CONCLUSIONS

Corroborating the popular use of T. erecta, DETe favors the antioxidant system and reduce gastric inflammation, accelerating the gastric healing process and reducing the ulcer recurrence.

Sambucus nigra: A traditional medicine effective in reducing inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sambucus nigra L. is a plant of European origin and popularly known as elder, elderberry, black elder, European elder, European elderberry, and European black elderberry, being described in pharmacopoeia of several countries. Its flowers and berries have been used in folk medicine to treat feverish conditions, coughing, nasal congestion, and influenza besides its popular use as anti-inflammatory, analgesic, and diuretic agent.

AIM OF THE STUDY

The aim of this investigation was to elucidate the anti-inflammatory and the relaxant effect of the lyophilized aqueous extract obtained from S. nigra's flowers on in vivo and in vitro inflammation assays and on the isolated rat vascular and airway smooth muscle tissue.

MATERIAL AND METHODS

The anti-inflammatory activity of the extract was investigated using carrageenan-induced inflammation model in the subcutaneous tissue of male Swiss mice orally treated with S. nigra extract (30, 100, 300 or 600 mg/kg). Leukocyte influx and the secretion of chemical mediators were quantified in the inflamed exudate. Additionally, histological analysis of the pouches was performed. N-Formyl-methionine-leucine-phenylalanine-induced chemotaxis, lipopolysaccharide-induced TNF, IL-6, IL-1β, IL-10 and NO production, and adhesion molecule expression (CD62L, CD49d and CD18, flow cytometry) were analyzed in vitro using oyster glycogen-recruited peritoneal neutrophils or macrophages (RAW 264.7) stimulated with LPS and 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. Finally, the effect of the extract was evaluated in isolated rat aorta and trachea rings.

RESULTS

The oral treatment with S. nigra promoted reduction in the neutrophil migration as well as the decrease of TNF, IL-1β and IL-6 levels in the inflamed exudate. In vitro treatment with S. nigra decreased NO₂^-, TNF, IL-1β and IL-6 and promoted increase of IL-10 in LPS-stimulated neutrophils. Similarly, the extract reduced the NO₂^-, TNF and IL-6 in LPS-stimulated macrophages. Rutin, the major constituent of S. nigra extract reduced NO₂^-, TNF, IL-1β, and IL-6 and promoted the increase of IL-10 in LPS-stimulated neutrophils supernatant. The extract also shed CD62L and CD18 expressions. The extract was able to increase the efferocytosis of apoptotic neutrophils by increasing the IL-10 and decreasing the TNF levels. Additionally, the extract reduced the hypersensitivity induced by carrageenan and promoted a relaxant effect in isolated vascular and non-vascular rat tissue.

CONCLUSIONS

S. nigra flowers extract presents anti-inflammatory effect by modulating macrophage and neutrophil functions including the production of inflammatory mediators and cell migration, by promoting efferocytosis and consequently the resolution of acute inflammation, besides exerting antinociceptive effects, scientifically proving its popular use as medicinal plant. Allied to the relaxant effect in both vascular and non-vascular smooth muscle tissue, S. nigra extract represents an important tool for the management of acute inflammation.

Effects of 2',6'-dihydroxy-4'-methoxydihidrochalcone on innate inflammatory response

Chalcones present potential therapeutic activities reported on literature, which led us to evaluate the anti-inflammatory effects and the acute toxicity of 2',6'-dihydroxy-4'-methoxydihydrochalcone (DHMDC) using in vitro and in vivo models. The anti-inflammatory activity was firstly in vitro investigated using macrophages (RAW 264.7) and neutrophils previously treated with DHMCD activated with lipopolysaccharide (LPS). Nitrite, IL-1β, and TNF levels were measured in the macrophage culture supernatant, and the adhesion molecule expression (CD62L, CD49D, and CD18) was evaluated in neutrophils. Then, carrageenan-induced inflammation was performed in the subcutaneous tissue of male Swiss mice. Leukocyte migration and histological analysis were performed in the pouches. Toxicological studies were carried out on female Swiss mice (600 mg/kg) through biochemical parameters and histopathological analysis. In vitro, the DHMCD significantly reduced the IL-1β, TNF, and nitrite levels. The DHMCD was also able to modulate the percentage of positive neutrophils for CD62L, without modifying the expression of CD18 or CD49d. In vivo, DHMCD (3 mg/kg, p.o.) significantly reduced neutrophil migration to inflammatory exudate and subcutaneous tissue. No evidence of toxic effect was observed considering the biochemical parameters and histopathological analysis of liver and kidney. Together, the obtained data shows that DHMCD presents anti-inflammatory activity by modulating the macrophage inflammatory protein secretion and also by blocking the CD62L cleavage in neutrophils. Furthermore, there was not any evidence of toxic effect in acute toxicological analysis.

Wistar rats immature testicular tissue vitrification and heterotopic grafting

Objective

To evaluate the efficiency of two vitrification protocols for rat immature testicular tissue and heterotopic transplantation.

Methods

Twenty-four pre-pubertal Wistar rats were divided into three groups (n=8). After orchiectomy, testicular fragments (3mm) from Groups 1 and 2 were vitrified with different cryoprotectant concentration solutions, using sterile inoculation loops as support. After warming up, the fragments were submitted to cell viability assessment by Trypan blue and histological evaluation. Vitrified (Groups 1 and 2) and fresh (Group 3) fragments were grafted to the animals periauricular region. After 8 weeks of grafting, the implant site was histologically analyzed.

Results

The viability recovery rate from Group 1 (72.09%) was higher (p=0.02) than that from Group 2 (59.19%). Histological analysis showed similar tubular integrity between fresh fragments from Groups 1 and 3. Group 2 samples presented lower tubular integrity. We ran histological analyses in the grafts from the Groups. In all groups, it was possible to see the implant site, however, no fragment of testicular tissue or signs of inflammation were histologically found in most samples from Groups 1 and 3. In one sample from Group 2, we found degenerated seminiferous tubules with necrosis and signs of an inflammatory process. In another sample from Group 2, we found seminiferous tubules in the implant site.

Conclusion

The vitrification of pre-pubertal testicular tissue of rats showed little damage to cell viability through histological analysis when we used cryoprotectants in a lower concentration. Heterotopic transplantation could not preserve the structural organization of the testicular tissue.

[Value of pericardial biopsy in the etiologic diagnosis of pericardial diseases]

PURPOSE

To determine the value of pericardial biopsy as a complementary exam in the etiology of pericardial effusion.

METHODS

We analyzed retrospectively (from 1990 to 1997) 38 patients with pericardial effusion. The age ranged between 3 months and 79 years (mean 41.15 +/- 21.78 years). Pericardial biopsy was performed in all cases through a subxiphoid incision.

RESULTS

In 4 patients (10.5%) the biopsy was able to define etiology, 2 had tuberculosis and 2 neoplasias (1 undetermined adenocarcinoma, 1 mesotelioma). In 34 patients the biopsy showed non-specific chronic pericarditis.

CONCLUSION

Pericardial biopsy was not an effective method to determine the etiological diagnosis in pericardial effusion patients. We believe that we have to individualize the indication of pericardial biopsy especially if tuberculosis or neoplasia are suspected.