Medicinal plant Combretum leprosum mart ameliorates motor, biochemical and molecular alterations in a Parkinson's disease model induced by MPTP.

ETHNOPHARMACOLOGICAL RELEVANCE: Combretum leprosum is a popular medicinal plant distributed in north and northeastern regions of Brazil. Many different parts of this plant are used in traditional medicine to treat several inflammatory diseases. Parkinson's disease (PD) is a disorder associated with inflammatory toxic factors and the treatments available provide merely a delay of the neurodegeneration. AIM OF THE STUDY: We investigated the potential neuroprotective properties of the C. leprosum ethanolic extract (C.l.EE) in a murine model of PD using the toxin 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP). MATERIALS AND METHODS: The mice were split into four groups: V/S (vehicle/saline), E/S (extract/saline), V/M (vehicle/MPTP) and E/M (extract/ MPTP). Mice received MPTP (30mg/kg, i.p.) or vehicle (10ml/kg, i.p.) once a day for 5 consecutive days and vehicle (10ml/kg) or C.l.EE (100mg/kg) orally by intra-gastric gavage (i.g.) during a 14-d period, starting 3 days before the first MPTP injection. All groups were assessed for behavioural impairments (amphetamine-induced locomotor activity and muscle strength), dopamine content in striatum using high performance liquid chromatography (HPLC), tyrosine hydroxylase (TH) and dopamine transporter (DAT) gene expressions using qPCR. RESULTS: Animals were injected with d-amphetamine (2mg/kg) and the activity was recorded. Amphetamine-induced hyperlocomotion was observed in all groups; however animals treated with MPTP showed exacerbated hyperlocomotion (approximately 3 fold increase compared to control groups). By contrast, mice treated with MPTP that received C.l.EE exhibited attenuation of the hyperlocomotion and did not differ from control groups. Muscle strength test pointed that C.l.EE strongly avoided muscular deficits caused by MPTP (approximately 2 fold increase compared to V/M group). Dopamine and its metabolites were measured in the striatum. The V/M group presented a dopamine reduction of 80%. On the other hand, the E/M group exhibited an increase in dopamine and its metabolites levels (approximately 3 fold increase compared to V/M group). Tyrosine hydroxylase (TH) and dopamine transporter (DAT) gene expressions were significantly reduced in the V/M group (60%). Conversely, C.l.EE treatment was able to increase the mRNA levels of those genes in the E/M group (approximately 2 fold for TH and DAT). CONCLUSIONS: These data show, for the first time, that C. leprosum ethanolic extract prevented motor and molecular changes induced by MPTP, and partially reverted dopamine deficit. Thus, our results demonstrate that C.l.EE has potential for the treatment and prevention of PD.

Anti-inflammatory effect of triterpene 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene obtained from Combretum leprosum Mart & Eich in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The 3ß, 6ß, 16ß-trihydroxylup-20(29)-ene (TTHL) is a pentacyclic triterpene obtained from a medicinal plant named Combretum leprosum. In folk medicine, this plant is used to treat several diseases associated with inflammation and pain. We previously demonstrated that TTHL presents a significant antinociceptive effect, suggesting the involvement of the glutamatergic system. AIM OF THE STUDY: This study was designed to investigate the effect of TTHL on nociception and vascular permeability induced by acetic acid. We also evaluated the effect of TTHL on carrageenan-induced peritonitis and the levels of cytokines (interleukin 1-ß [IL-1ß], tumor necrosis factor α [TNF-α] and interleukin 10 [IL-10]) on peritoneal fluid. MATERIALS AND METHODS: TTHL was administered orally by intra-gastric gavage (i.g.) 60 min prior to experimentation. Abdominal contractions and vascular permeability were induced by an intraperitoneal (i.p.) injection of acetic acid (0.6%). We also investigated whether TTHL decreases carrageenan-induced peritonitis (750 µg/cavity) by measuring leukocyte migration and vascular permeability. In addition, we evaluated the effects of TTHL on TNF-α, IL-1ß and IL-10 release induced by carrageenan on peritoneal fluid. The levels of these cytokines were measured by ELISA. RESULTS: TTHL (0.01-10 mg/kg) administered by intra-gastric (i.g.) gavage inhibited (69±3%) acetic acid-induced abdominal constrictions, with an ID50 of 0.15 (0.03-0.8) mg/kg. TTHL (10mg/kg) also reduced the leukocyte infiltration induced by acetic acid, with an inhibition of 59±9 but had no effect on abdominal vascular permeability. In addition, indomethacin (10 mg/kg, i.p.) reduced the nociceptive behavior (92±1%), total leukocyte migration (29±3%) and capillary permeability (71±3%) induced by acetic acid. While the glucocorticoid dexamethasone (2 mg/kg, s.c.) reduced partially but significantly the nociception (31±1%), besides to promote a marked reduction on total leukocyte migration (60±2%) to the peritoneal cavity caused by acetic acid. In a model of peritonitis induced by carrageenan, TTHL also reduced total leukocyte migration, mainly neutrophils (inhibition of 84±3% and 85±2% at 30 mg/kg and 100 mg/kg, respectively). Likewise, dexamethasone (0.5 mg/kg, i.p.) resulted in an inhibition of 93±3%. Nevertheless, carrageenan-induced abdominal vascular permeability was reduced by dexamethasone but was not altered by TTHL. Furthermore, dexamethasone and TTHL significantly reduced the TNF-α and IL-1ß levels in peritoneal fluid, whereas the IL-10 levels were unchanged. CONCLUSIONS: Altogether, our data confirm the antinociceptive effect of TTHL and demonstrate its effect in inflammatory animal models, providing novel data about this compound, which could be useful as an anti-inflammatory drug.

Antinociceptive properties of the ethanolic extract and of the triterpene 3beta,6beta,16beta-trihidroxilup-20(29)-ene obtained from the flowers of Combretum leprosum in mice.

The present study examined the antinociceptive effects of the ethanolic extract (EE) and of the triterpene 3beta,6beta,16beta-trihidroxilup-20(29)-ene obtained from the flowers of Combretum leprosum in chemical and thermal behavioural models of pain in mice. The EE (10-1000 mg/kg) given orally (p.o.), 1 h prior to testing, produced dose-dependent inhibition of acetic acid-induced visceral pain, with mean ID50 value of 131.9 mg/kg. In the formalin test, the EE (10-300 mg/kg, p.o.) also caused significant inhibition of both the early (neurogenic pain) and the late (inflammatory pain) phases of formalin-induced licking, however, it was more potent and efficacious in relation to the late phase of the formalin test, with mean ID50 values for the neurogenic and the inflammatory phases of approximately 300 and 88.8 mg/kg, respectively. The EE (10-1000 mg/kg, p.o.) also caused significant and dose-dependent inhibition of capsaicin- and glutamate-induced pain, with mean ID50 values of 160.5 and 38.3 mg/kg, respectively. Furthermore, the triterpene 3beta,6beta,16beta-trihidroxilup-20(29)-ene (1-30 mg/kg), given p.o., 1 h prior to testing, also produced dose-related inhibition of glutamate-induced pain, with a mean ID50 value of 5.6 mg/kg. When assessed in a thermal model of pain, the EE (10-300 mg/kg, p.o.) and fentanyl (100 microg/kg, s.c.) caused a significant and marked increase in the latency response on the hot-plate test (50 degrees C). The antinociception caused by EE (100 mg/kg, p.o.) in the glutamate test was significantly attenuated by intraperitoneal (i.p.) treatment of mice with naloxone (opioid receptor antagonist, 1 mg/kg), pindolol (a 5-HT 1A/1B receptor/beta adrenoceptor antagonist, 1 mg/kg), WAY100635 (a 5-HT 1A receptor antagonist, 0.7 mg/kg) or ketanserin (a 5-HT 2A receptor antagonist, 0.3 mg/kg). In contrast, EE (100 mg/kg, p.o.) antinociception was affected neither by L-arginine (precursor of nitric oxide, 600 mg/kg) nor by ondansetron (a 5-HT3 receptor antagonist, 0.5 mg/kg) i.p. treatment. It was not associated with non-specific effects such as muscle relaxation or sedation. Together, these results indicate that EE produces dose-related antinociception in several models of chemical and thermal pain through mechanisms that involve an interaction with opioid and serotonergic (i.e., through 5-HT 1A/1B and 5-HT 2A receptors) systems.