Lantana canescens (Kunth) inhibits inflammatory and hyperalgesic responses in murine models.

ETHNOPHARMACOLOGICAL RELEVANCE: Lantana canescens is popularly known in Brazil as "cidreirinha" or "chumbinho-branco". It is found in Pantanal biome and its flowers and leaves are used in traditional medicine to treat pain and inflammation. Information about this species is limited to the activity of isolated essential oils. Studies with different extracts, composition, and biological properties are still scarce. AIM OF THIS STUDY: The objective of this study was to evaluate the anti-inflammatory and anti-hyperalgesic activity of the hydroethanolic extract of L. canescens aerial parts. MATERIALS AND METHODS: The hydroethanolic extract L. canescens aerial parts (HELc) was analyzed using HPLC-DAD-EM. Male and female Swiss mice weighing 18-25 g were used in the in vivo assays. Acute toxicity was assessed (2000 mg/kg); anti-inflammatory activity through paw edema, mast cell degranulation and peritonitis, and anti-hyperalgesic activity through abdominal writhing assays induced by acetic acid and formalin sensitization, were evaluated using the doses of 3, 30 and 300 mg/kg. RESULTS: The phytochemical characterization of HELc confirmed the presence of glycosylated iridoids (theveside, theviridoside), verbascosides and flavonoids. The HELc did not present toxicity in the evaluated dose. HELc reduced formation of paw edema, degranulation of peritoneal mast cells and infiltration of polymorphonuclear cells into the animals peritoneal cavity. In addition, HELc decreased the number of abdominal writhing induced by acetic acid and the time of paw licking in the evaluation of formalin sensitization. CONCLUSIONS: These results confirm the anti-inflammatory and anti-hyperalgesic effects of hydroethanolic extract of L. canescens, validating the use of this plant in folk medicine.

Pharmacological Characterization of Mouse Hind Paw Edema Induced by Parachartergus fraternus Venom.

Stings from the wasp Parachartergus fraternus occur throughout Latin America, and edema followed by pain is the main symptom presented by victims. This often limited inflammatory event has not been characterized for this species. In this work, we identified the mechanisms and possible mediators involved in this response. P. fraternus venom (100, 200, and 400 µg/kg) was injected into the hind paws of mice, and edema was evaluated at intervals of 10 min for up to 60 min and at 120, 240, and 1440 min using a digital plethysmometer. The peak of edema was observed at 10 min with a dose of 200 µg/kg. A reduction in edema was observed with indomethacin (58.1%), celecoxib (44.5%), MK886 (30.8%), and dexamethasone (53.2%). Loratadine, cimetidine, and cyproheptadine treatment reduced the edema by 54.2%, 63.9%, and 84.4%, respectively, compared with the control. Captopril and L-NAME inhibited 42.5% and 69.8%, respectively, of the edema. These results showed that the edema induced in mice by P. fraternus venom occurs early and is mediated by arachidonic acid derivatives, vasoactive amines, and nitric oxide. Together, these mediators amplify the inflammatory process, with emphasis on histamine and serotonin in triggering the edematogenic response, being more effective the use of cyproheptadine in the therapeutic approach.

Effects of photobiomodulation therapy on Bothrops moojeni snake-envenomed gastrocnemius of mice using enzymatic biomarkers.

Bothropic venom contains a range of biologically active substances capable of causing severe local and systemic envenoming symptomatology within its victims. The snake anti-venom is effective against systemic effects but has no neutralizing effect against the fast developing local effects. Herein, mice gastrocnemius injected with Bothrops moojeni venom (40 µg/kg) or saline solution were irradiated with HeNe (632.8 nm) and GaAs (904 nm) lasers (daily energy density of 4 J/cm2; 0.03/0.21 power density; 0.07/0.16 spot size; 1.2/0.04 total energy, 1 cm off contact, for HeNe and GaAs lasers, respectively) and euthanized in periods ranging from 3 h to 21 days. Blood biochemistry for creatine kinase (CK), alkaline phosphatase (ALP), acid phosphatase (AP), lactate dehydrogenase (LDH), aspartate transaminase (AST), and myoglobin and histopathological analysis, for assessing the degree of myonecrosis and regeneration of gastrocnemius, were done at every time interval. GaAs laser promoted faster photobiomodulation therapy (PBMT) effects, and the GaAs group exhibited a better clinical outcome than the HeNe group. Within the GaAs group, the serum levels of CK, LDH, AP, AST, and myoglobin, which were increased by the physiological effects of the venom, were reduced to initial baseline before snake envenomation in less time than those irradiated by the HeNe laser. However, the group receiving irradiation from the HeNe laser returned the levels of ALP activity to baseline faster than those of the GaAs group. Histopathological analysis revealed enhanced muscle regeneration in mice groups treated with both lasers. PBM promoted by GaAs and HeNe showed well-developed centrally nucleate regenerating cells and an increased number of newly formed blood vessels when compared to unirradiated muscle. We therefore suggest that GaAs had the best outcomes likely derived from a deeper penetrating longer wavelength. We conclude that PMBT is a promising, non-invasive approach to be further tested in pre-clinical studies with a goal to further its clinical use in skeletal muscle recovery in snakebite victims.