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Anti-nociceptive activity of the aqueous extract of leaves
Fitoterapia, 2005
Bauhinia cheilantha (Leguminosae: Caesalpinioideae) is a common plant of the Brasilian Caatinga widely used in folk medicine as an analgesic. In order to verify this effect pharmacologically, the antinociceptive activity of the plant was evaluated through the administration of its aqueous extract in mice. The extract was administered orally (400 mg/kg) 60 minutes before a writhing test, and was found to reduce nociception by 54.4%. The effects of formalin (1%) were also reduced by the extract at all doses. Naloxone (5 mg/kg, i.p.) and caffeine (10 mg/kg, i.p) reverted the effect of the extract. In a hot plate test, the extract (100mg, 200mg and 400 mg/kg) increased latency time by 39.8%, 30.7% and 32.8%, respectively. There was no acute toxicity in doses up to 3g/kg. The aqueous extract of the B. cheilantha bark revealed antinociceptive activity in all the models tested, effects that are possibly associated with the opioid and adenosine systems.
Potential Activity of Medicinal Plants as Pain Modulators
This review aims to demonstrate the relevance that medicinal plants and their promising results have in prevention and treatment of pain. The neurophysiological bases of pain have been analyzed and the potential mechanisms of action have been proposed, it has also been determined that the main experimental models used for the evaluation of the analgesic potential are: acetic acid-induced writhing test, formalin test, hot-plate test, capsaicin-induced nociception, cinnamaldehyde-induced nociception, glutamate-induced nociception, tail-flick test and tail immersion test. There are countless medicinal plants with potential analgesic activity, in some of them main responsible compounds for the activity are flavonoids (vitexin, quercetin, naringenin, astragalin, eupatilin), alkaloids (scotanamine B, bullatine A, S-(+)dicentrine, stephalagine, lappaconitine), terpenoids (p-cymene, thymol, menthol, citronellol, myrcene, carvacrol, linalool) and saponins (siolmatroside I, cayaponoside D, cayaponoside B4, cayaponoside A1); however, all studies have only been carried out up to pre-clinical stages. Therefore, it is recommended to carry out kinetic studies of the most remarkable natural compounds, evaluate mixtures of active compounds for diminishing doses to avoide possible side effects, and continue with clinical studies of medicinal plants whose safety has already been reported.
Antinociceptive activity of ethanolic extract and isolated compounds of Urtica circularis
Lancet, 2011
Cnidoscolus quercifolius is a species native to the Brazilian Caatinga (semi-arid vegetation) popularly known as "favela" and "faveleira" and used in folk medicine to treat pain. The objective of this work was to evaluate the antinociceptive effect of the ethanolic extract from barks (Cqb-EtOH) and leaves (Cql-EtOH) of C. quercifolius in mice using experimental models of nociception. The antinociceptive activity was evaluated by writhing, hot plate and formalin tests. In addition, the rota-rod test was used to evaluate motor coordination. In the acetic acid-induced writhing test, the Cqb-EtOH (100, 200 and 400 mg/kg, i.p.) reduced the number of writhing by 83.70, 81.40 and 88.10%, respectively, while Cql-EtOH reduced by 71.30, 79.40, and 98.70%, respectively. In the formalin test, the extracts reduced the paw licking time in the fi rst and second phases, but the best results were observed in the second phase (infl ammatory pain), reducing by 66.08, 78.26 and 73.97%, as well as 60.11, 75.58, and 79.46% for Cqb-EtOH and Cql-EtOH, respectively. In the hot plate test, the extracts increased the reaction time when compared to control only at dose of 400 mg/kg. Using the rota-rod test, mice treated did not demonstrate any signifi cant motor performance changes. It can be concluded that Cqb-EtOH and Cql-EtOH of C. quercifolius have antinociceptive activity, which supports the popular use of this plant to treat pain.
2013
The present study examined the antinociceptive effects of a hydroalcoholic extract of Polygala paniculata in chemical and thermal behavioural models of pain in mice. The antinociceptive effects of hydroalcoholic extract was evaluated in chemical (acetic-acid, formalin, capsaicin, cinnamaldehyde and glutamate tests) and thermal (tail-flick and hot-plate test) models of pain or by biting behaviour following intratecal administration of both ionotropic and metabotropic agonists of excitatory amino acids receptors glutamate and cytokines such as interleukin-1 β (IL-1 β ) and tumour necrosis factor-α (TNF-α ) in mice. When given orally, hydroalcoholic extract (0.001-10 mg/kg), produced potent and dose-dependent inhibition of acetic acid-induced visceral pain. In the formalin test, the hydroalcoholic extract (0.0001-0.1 mg/kg orally) 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. The capsaicin-induced nociception was also reduced at a dose of only 1.0 mg/kg orally. The hydroalcoholic extract significantly reduced the cinnamaldehyde-induced nociception at doses of 0.01, 0.1 and 1.0 mg/kg orally. Moreover, the hydroalcoholic extract (0.001-1.0 mg/kg orally) caused significant and dose-dependent inhibition of glutamate-induced pain. However, only rutin, but not phebalosin or aurapten, isolated from P. paniculata , administered intraperitoneally to mice, produced dose-related inhibition of glutamate-induced pain. Furthermore, the hydroalcoholic extract (0.1-100 mg/kg orally) had no effect in the tail-flick test. On the other hand, the hydroalcoholic extract caused a significant increase in the latency to response at a dose of 10 mg/kg orally, in the hot-plate test. The hydroalcoholic extract (0.1 mg/kg orally) antinociception, in the glutamate test, was neither affected by intraperitoenal treatment of animals with l -arginine (precursor of nitric oxide, 600 mg/kg) and naloxone (opioid receptor antagonist, 1 mg/kg.) nor associated with non-specific effects such as muscle relaxation or sedation. In addition, oral administration of hydroalcoholic extract produced a great inhibition of the painrelated behaviours induced by intrathecal injection of glutamate, N -methyl-d -aspartate (NMDA), IL-1 β and TNF-α , but not by α -amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA), kainate or trans-1-amino-1.3-cyclopentanediocarboxylic acid (trans-ACPD). Together, our results suggest that inhibition of glutamatergic ionotropic receptors, may account for the antinociceptive action reported for the hydroalcoholic extract from P. paniculata in models of chemical pain used in this study.
Potential Activity of Medicinal Plants as Pain Modulators: A Review
Pharmacognosy Journal, 2021
This review aims to demonstrate the relevance that medicinal plants and their promising results have in prevention and treatment of pain. The neurophysiological bases of pain have been analyzed and the potential mechanisms of action have been proposed, it has also been determined that the main experimental models used for the evaluation of the analgesic potential are: acetic acid-induced writhing test, formalin test, hot-plate test, capsaicin-induced nociception, cinnamaldehyde-induced nociception, glutamate-induced nociception, tail-flick test and tail immersion test. There are countless medicinal plants with potential analgesic activity, in some of them main responsible compounds for the activity are flavonoids (vitexin, quercetin, naringenin, astragalin, eupatilin), alkaloids (scotanamine B, bullatine A, S-(+)dicentrine, stephalagine, lappaconitine), terpenoids (p-cymene, thymol, menthol, citronellol, myrcene, carvacrol, linalool) and saponins (siolmatroside I, cayaponoside D, cayaponoside B4, cayaponoside A1); however, all studies have only been carried out up to pre-clinical stages. Therefore, it is recommended to carry out kinetic studies of the most remarkable natural compounds, evaluate mixtures of active compounds for diminishing doses to avoide possible side effects, and continue with clinical studies of medicinal plants whose safety has already been reported.
Pharmacology Biochemistry and Behavior, 2009
The present study examined the antinociceptive effect of the ethanolic extract from Melissa officinalis L. and of the rosmarinic acid in chemical behavioral models of nociception and investigates some of the mechanisms underlying this effect. The extract (3-1000 mg/kg), given orally (p.o.) 1 h prior to testing, produced dosedependent inhibition of acetic acid-induced visceral pain, with ID50 value of 241.9 mg/kg. In the formalin test, the extract (30-1000 mg/kg, p.o.) also caused significant inhibition of both, the early (neurogenic pain) and the late (inflammatory pain), phases of formalin-induced licking. The extract (10-1000 mg/kg, p.o.) also caused significant and dose-dependent inhibition of glutamate-induced pain, with ID50 value of 198.5 mg/kg. Furthermore, the rosmarinic acid (0.3-3 mg/kg), given p.o. 1 h prior, produced dose-related inhibition of glutamate-induced pain, with ID50 value of 2.64 mg/kg. The antinociception caused by the extract (100 mg/kg, p. o.) in the glutamate test was significantly attenuated by intraperitoneal (i.p.) treatment of mice with atropine (1 mg/kg), mecamylamine (2 mg/kg) or L-arginine (40 mg/kg). In contrast, the extract (100 mg/kg, p.o.) antinociception was not affected by i.p. treatment with naloxone (1 mg/kg) or D-arginine (40 mg/kg). It was also not associated with non-specific effects, such as muscle relaxation or sedation. Collectively, the present results suggest that the extract produced dose-related antinociception in several models of chemical pain through mechanisms that involved cholinergic systems (i.e. through muscarinic and nicotinic acetylcholine receptors) and the L-arginine-nitric oxide pathway. In addition, the rosmarinic acid contained in this plant appears to contribute for the antinociceptive property of the extract. Moreover, the antinociceptive action demonstrated in the present study supports, at least partly, the ethnomedical uses of this plant.
Evidence for a role of 5HT 1A receptor on antinociceptive action from Geissospermum vellosii
Journal of Ethnopharmacology, 2009
Ethnopharmacological relevance: Geissospermum vellosii is a tree widely found throughout the Amazonic forest and frequently used by the native population for painful disorders. Aim of the study: The present study examined the antinociceptive effects of Geissospermum vellosii in behavioral models of nociception. Materials, methods and results: Oral administration of crude extract of Geissospermum vellosii or its dichloromethane fraction (1-100 mg/kg) inhibited formalin-induced inflammatory nociception and acetic acid-induced visceral nociception. The antinociceptive effect of Geissospermum vellosii was unrelated with motor dysfunctions. Furthermore, the alkaloid 12-metoxy-1-methyl-aspidospermidine (0.001-1 mg/kg), isolated from the dichloromethane fraction, also produced antinociception. The antinociception caused by the dichloromethane fraction was significantly attenuated by pre-treatment of mice with p-chlorophenylalanine methyl ester (PCPA, an inhibitor of serotonin synthesis, 100 mg/kg once a day for 4 consecutive days) and WAY-100635 (a 5-HT 1A receptor antagonist, 0.3 mg/kg). In contrast, dichloromethane fraction antinociception was not affected by pre-treatment of animals with ketanserin (a 5-HT 2 receptor antagonist, 0.3 mg/kg) or ondansetron (a 5-HT 3 receptor antagonist, 0.5 mg/kg). Conclusions: Together, these results indicate that Geissospermum vellosii produces antinociception through an interaction with 5-HT 1A receptors. Furthermore, the alkaloid 12-metoxy-1-methyl-aspidospermidine contributes to the antinociceptive properties reported for Geissospermum vellosii.
Journal of Pharmacy and Pharmacology, 2006
We have previously verified that niga-ichigoside F 1 (NI), a triterpene isolated from Rubus imperialis, exhibits significant and potent antinociceptive action when evaluated in some pharmacological models of pain in mice. This effect was confirmed in other experimental models and also the mechanism of action has been evaluated. The antinociception caused by NI (60 mg kg −1 ) in both phases of the formalin test was significantly attenuated by intraperitoneal injection of mice with haloperidol (a dopaminergic antagonist, 0.20 mg kg −1 ) and L-arginine (precursor of nitric oxide, 600 mg kg −1 ). Regarding the cholinergic system, atropine (a cholinergic antagonist 60 mg kg −1 ) reverted only the second phase. The effect of NI was not affected by treatment of mice with yohimbine (an alpha2-adrenoceptor antagonist, 0.15 mg kg −1 ). The same pharmacological profile was observed for the administration of naloxone (an opioid receptor antagonist, 1 mg kg −1 ). On the other hand, intraperitoneal injection caused dose-related and significant effects against glutamate-and capsaicin-induced pain, respectively. In conclusion, the marked antinociception of NI appears to be related to the dopaminergic, cholinergic, glutamatergic, tachykininergic and oxinitrergic systems, supporting the ethnomedical use of Rubus imperialis (Rosaceae).
Scientific investigation of crude alkaloids from medicinal plants for the management of pain
BMC complementary and alternative medicine, 2016
Tissue damage is associated with pain, which is an alarming sign. Aspirin and morphine have been widely used in recent decades for management of pain. Medicinal herbs have been in use for treatment of different diseases for centuries. Many of these herbs possess analgesic activity with relatively less incidences of adverse effects. The strong positive correlation of alkaloids in medicinal plants for analgesic activity persuades an intention to determine possible analgesic activity of total alkaloids extracted from the selected medicinal plants using animal models to answer its possible mechanisms. Crude alkaloids from selected medicinal plants (Woodfordia fruticosa, Adhatoda vasica, Chenopodium ambrosioides, Vitex negundo, Peganum harmala and Broussonetia papyrifera) were extracted as per reported literature. The test crude alkaloids were screened foracute toxicity study. Writhings induced by acetic acid, tail immersion method and formalin-induced nociception assay procedures were u...