Antinociceptive activity of I3,II8-binaringenin, a biflavonoid present in plants of the guttiferae

GB1a Activates SIRT6 to Regulate Lipid Metabolism in Mouse Primary Hepatocytes

Lipid accumulation, oxidative stress, and inflammation in hepatocytes are features of nonalcoholic fatty liver disease (NAFLD). Garcinia biflavonoid 1a (GB1a) is a natural product capable of hepatic protection. In this study, the effect of GB1a on anti-inflammatory, antioxidant, and regulation of the accumulation in HepG2 cells and mouse primary hepatocytes (MPHs) was investigated, and its regulatory mechanism was further explored. The result showed that GB1a reduced triglyceride (TG) content and lipid accumulation by regulating the expression of SREBP-1c and PPARα; GB1a reduced reactive oxygen species (ROS) and improved cellular oxidative stress to protect mitochondrial morphology by regulating genes Nrf2, HO-1, NQO1, and Keap1; and GB1a reduced the damage of hepatocytes by inhibiting the expression of inflammatory cytokines interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) p65. The activities of GB1a were lost in liver SIRT6-specific knockout mouse primary hepatocytes (SIRT6-LKO MPHs). This indicated that activating SIRT6 was critical for GB1a to perform its activity, and GB1a acted as an agonist of SIRT6. It was speculated that GB1a may be a potential drug for NAFLD treatment.

GB1a Ameliorates Ulcerative Colitis via Regulation of the NF-κB and Nrf2 Signaling Pathways in an Experimental Model

Ulcerative colitis (UC) is an inflammatory bowel disease. The intake of African Garcinia Kola nuts has been reported as a therapy for diarrhea and dysentery in the African population. However, the mechanism of action through which Garcinia Kola nuts act to ameliorates UC remains unknown. GB1a is the main active component of Garcinia Kola nuts. In this study, we explored the therapeutic effects and underlying mechanism of GB1a on dextran sodium sulfate (DSS)-induced UC. Human Colonic Epithelial Cells (HCoEpic) were challenged with TNF-α to test the effects of GB1a in protecting against oxidative stress and inflammation in vitro. Our data showed that GB1a significantly attenuated DSS-induced colonic inflammatory injury manifested as reversed loss of body weight and disease activity index (DAI) scores in UC mice. We also showed that GB1a improved the permeability of the intestinal epithelium by modulating the expression of tight junction proteins (ZO-1, Occludin). Mechanistically, GB1a may activate the Nrf2 antioxidant signaling pathway and suppress the nuclear translocation of NF-κB in reduced oxidative stress and expression of inflammatory genes induced by TNF-α in HCoEpic cells. Our study suggests that GB1a alleviates inflammation, oxidative stress and the permeability of the colonic epithelial mucosa in UC mice via the repression of NF-κB and activation of Nrf2 signaling pathway.

Costus spiralis (Jacq.) Roscoe leaves fractions have potential to reduce effects of inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Since drugs currently used to manage pain and inflammatory conditions present several side effects, the investigation of new anti-inflammatory and antinociceptive agents from folk-medicine plants is an important approach. Costus spiralis (Costaceae) has been used in Brazilian medicinal teas to treat urinary infection, cough, inflammation, arthritis, among others.

AIM OF THE STUDY

The current study focused on investigating anti-inflammatory and antinociceptive effects of fractions from C. spiralis leaves using animal models.

MATERIALS AND METHODS

Adults Swiss mice were used in the following experimental models: acetic acid-induced abdominal writhing, formalin-induced nociception, hot plate, zymosan-induced peritonitis, and arthritis induced by complete Freund's adjuvant.

RESULTS

The presence of steroids was confirmed in all fractions. Flavonoids, condensed tannins and saponins were observed in EFL. In methanolic fraction leaves (MFL), the presence of flavonoids and pentacyclic triterpenoids was confirmed. Orally administered leaf fractions significantly reduced abdominal writhing. Fractions were ineffective in the neurogenic stage of the formalin test, but in the inflammatory stage, ethyl acetate fraction levaes (AcFL), ethanolic fraction leaves (EFL), and MFL significantly reduced paw licking time by 69.6 ± 11.9%, 58.2 ± 9.4%, and 79.6 ± 8.3%, respectively. In the hot plate test, the reaction latency was similar for treated animals and controls. However, in the peritonitis test, cell migration was significantly reduced in animals treated with chloroform fractions leaves ClFL (61.8 ± 11.4%), AcFL (58.7 ± 8.3%), EFL (39.2 ± 5.0%), and MFL (64.8 ± 4.4%). This was similar to the result observed in the chronic inflammation model, this time only the chloroform fraction was able to reduce paw edema.

CONCLUSION

Our results show that leaf fractions of Costus spiralis are capable of modulating peripheral nociceptive and inflammatory responses without effects on central nervous system being potential substrates for phytochemical purification, structural and mechanistic studies.

Salix tetrasperma Roxb. Extract Alleviates Neuropathic Pain in Rats via Modulation of the NF-κB/TNF-α/NOX/iNOS Pathway

Patients with neuropathic pain experience chronic painful tingling, burning, and prickling sensations accompanied with hyperalgesia and/or allodynia. In this study, 38 secondary metabolites of a methanol extract from Salix tetrasperma flowers were identified by liquid chromatography-mass spectrometry (HPLC-MS/MS). The extract showed substantial anti-inflammatory, central and peripheral anti-nociceptive, antipyretic, and antioxidant activities in vitro and in different animal models. In the chronic constriction injury (CCI) rat model, the extract was able to attenuate and significantly relieve hyperalgesia and allodynia responses in a dose dependent manner and restore the myelin sheath integrity and Schwann cells average number in the sciatic nerve. The enzyme-linked immunosorbent assay (ELISA) showed that the extract significantly reduced the expression of various pro-inflammatory biomarkers including nuclear factor kabba B (NF-κB), tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2), 5-lipoxygenase (5-LOX), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and the oxidative stress biomarker NADPH oxidase 1 (NOX1), in brain stem and sciatic nerve tissues. These findings were supported by in vitro enzyme inhibition assays (COX-1, COX-2 and 5-LOX). Moreover, the extract significantly reduced p53 expression in the brain stem tissue. These findings support the use of S. tetrasperma in folk medicine to alleviate pain. It could be a promising natural product for further clinical investigations to treat inflammation, nociceptive pain and chronic neuropathic pain.

Saffron; An updated review on biological properties with special focus on cardiovascular effects

OBJECTIVE

Saffron as a natural product has long been used to impede and treat different disorders including cardiovascular disease (CVDs). Stigma is the most principal part of saffron. Various compounds such as carotenoids and flavonoids are the essential components of saffron stigma. The health benefits of saffron have been shown in previous studies; however, there is a lack of comprehensive data on the mechanistic aspects of its cardiovascular-health properties. This current comprehensive review focuses on the medicinal applications of saffron, and then the new findings regarding its cardiovascular-health effects and various cellular and molecular mechanisms of action will be debated.

METHODS

The literature search of MEDLINE, Embase, PubMed, Google Scholar and Cochrane Library was performed for all comparative studies since 2000-2018 with the limitations of the English language.

RESULTS

The results provided new evidence about antioxidant, anti-inflammatory, anti- atherogenic, anti- apoptotic, anti- hypertensive, and hypolipidemic effects of saffron. Pharmacological effects of saffron are due to a number of ingredients contained within this spice, including safranal, crocetin and crocins.

CONCLUSIONS

Our study concludes that saffron with wide range of usefulness in medicine may be the potent candidate in the process of new drug production for the treatment of CVDs.

Analgesic Activity, Chemical Profiling and Computational Study on Chrysopogon aciculatus

Present study was undertaken to evaluate the analgesic activity of the ethanol extract of Chrysopogon aciculatus. In addition to bioassays in mice, chemical profiling was done by LC-MS and GC-MS to identify phytochemicals, which were further docked on the catalytic site of COX-2 enzymes with a view to suggest the possible role of such phytoconstituents in the observed analgesic activity. Analgesic activity of C. aciculatus was evaluated by acetic acid induced writhing reflex method and hot plate technique. Phytochemical profiling was conducted using liquid chromatography mass spectrometry (LC-MS) and gas chromatography mass spectrometry (GC-MS). In docking studies, homology model of human COX-2 enzyme was prepared using Easy Modeler 4.0 and the identified phytoconstituents were docked using Autodock Vina. Preliminary acute toxicity test of the ethanol extract of C. aciculatus showed no sign of mortality at the highest dose of 4,000 mg/kg. The whole plant extract significantly (p < 0.05) inhibited acetic acid induced writhing in mice at the doses of 500 and 750 mg/kg. The extract delayed the response time in hot plate test in a dose dependent manner. LC-MS analysis of the plant extract revealed the presence of aciculatin, nudaphantin and 5α,8α-epidioxyergosta-6,22-diene-3β-ol. Three compounds namely citronellylisobutyrate; 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one and nudaphantin were identified in the n-hexane fraction by GC-MS. Among these compounds, six were found to be interacting with the binding site for arachidonic acid in COX-2 enzyme. Present study strongly supports the traditional use of C. aciculatus in the management of pain. In conclusion, compounds (tricin, campesterol, gamma oryzanol, and citronellyl isobutyrate) showing promising binding affinity in docking studies, along with previously known anti-inflammatory compound aciculatin can be held responsible for the observed activity.

Anti-inflammatory and analgesic activities of cupressuflavone from Cupressus macrocarpa: Impact on pro-inflammatory mediators

Hit, Lead & Candidate Discovery Inflammation is a complex biological process that is generally occurs in response to pathological triggers. Both neurodegenerative diseases and cancer have been linked to inflammation. The analgesic and anti-inflammatory effects of cupressuflavone (CUF) isolated from Cupressus macrocarpa were examined. The analgesic effects of CUF (40, 80 and 160 mg/kg po) were assessed in the acetic acid-induced writhing and hot plate models in mice with diclofenac sodium as the reference standard (100 mg/kg). CUF dose-dependently inhibited the writhing response in mice by 25, 48, and 62%, at the three CUF doses with 160 mg/kg being equivalent to the diclofenac control. CUF dose-dependently increased the hot plate model reaction time with a maximal effect after 120 min. In the carrageenan-induced paw edema model of inflammation, CUF demonstrated anti-inflammatory activity by inhibiting paw edema by 55, 60, and 64% at doses of 40, 80, and 160 mg/kg po, respectively. CUF also reduced the plasma pro-inflammatory mediators PGE₂ (44, 54, and 58%), TNF-α (26, 37, and 53%), IL-1β (19, 33, and 41%), and IL-6 (32, 44, and 55%) at the three doses tested with the highest dose having similar effects to diclofenac sodium (100 mg/kg). This finding from this study indicates that CUF has both analgesic and anti-inflammatory effects.

Pharmacological mechanisms involved in the analgesia induced by ethanol extract of Hybanthus enneaspermus leaves

Background

Hybanthus enneaspermus (HE) leaves are being used traditionally to relieve pain, and scientific studies have demonstrated their analgesic potential. This study attempted to elucidate the pharmacological mechanism(s) involved in the analgesic action of ethanol extract of H. enneaspermus leaves (EEHE).

Materials and methods

Forty-two male Wistar rats were separately randomized into seven groups (n=6 rats in each group) for tail immersion and formalin tests. Group I (control) received distilled water (10 mL/kg) while groups II and III received acetaminophen (the reference drug, 100 mg/kg ip) and EEHE (1000 mg/kg po), respectively. Groups IV–VII were pretreated with cimetidine (50 mg/kg ip), naloxone (5 mg/kg ip), propranolol (0.15 mg/kg ip), and prazosin (0.15 mg/kg ip), respectively, 1 hour before EEHE (1000 mg/kg po) treatment.

Results

The EEHE-induced increase in tail-flick latency was reduced by blockade of histamine and adrenergic receptors but prevented by blockade of opiate receptor in the tail-flick test. However, the EEHE-induced decrease in paw licking time was prevented only by blockade of opiate receptor but unaffected by histamine and adrenergic receptors blockers.

Conclusion

These findings suggest that the analgesic effect of EEHE in different pain types may involve different neural mechanisms and that the opioidergic pathway contributes more to EEHE-induced analgesia than the other pathways.

Natural Flavonoids as Promising Analgesic Candidates: A Systematic Review

Due to the chemical structural diversity and various analgesic mechanisms, an increasing number of studies indicated that some flavonoids from medicinal plants could be promising candidates for new natural analgesic drugs, which attract high interests of advanced users and academic researchers. The aim of this systematic review is to report flavonoids and its derivatives as new analgesic candidates based on the pharmacological evidences. Sixty-four papers were found concerning the potential analgesic activity of 46 flavonoids. In this case, the evidence for analgesic activity of flavonoids and total flavonoids was investigated. Meanwhile, the corresponding analgesic mechanism of flavonoids was discussed by generalizing and analyzing the current publications. Based on this review, the conclusion can be drawn that some flavonoids are promising candidates for painful conditions and deserve particular attention in further research and development.

Analgesic and free radical scavenging activities of hydromethanolic extract of Crateva adansonii stem bark

BACKGROUND

Crateva adansonii is a moderately sized deciduous tree found throughout the tropics especially along the river banks. This study was aimed at the evaluation of the analgesic and antioxidant activities of the methanolic extract of C. adansonii stem-bark.

METHODS

The analgesic activity of Crateva extract was investigated using both chemical and thermal models of nociception in rodents while the antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) photometric model.

RESULTS

The extract produced a minute concentration-dependent increase in free radical scavenging activities. The extract (100, 200, and 400 mg/kg) caused a significant (P < 0.05) dose-dependent reduction in the number of writhing in treated rats when compared to the negative control. The extract at 100, 200, 400 mg/kg, and pentazocine (3 mg/kg) increased the pain reaction time in the treated rats by 58.05%, 66.67%, 94.76%, and 79.40%, respectively, when compared to the negative control.

CONCLUSION

The C. adansonii stem bark possesses analgesic activity against peripheral and central mediated pain sensation and also antioxidant properties. This study justifies the ethnomedical use of C. adansonii in pain treatment.

Evaluation of analgesic activity of Terminalia arjuna (Roxb.) Wight and Arn bark: A tribal claim

Background:

Plants occupy an important place in folk medicine all over the world for centuries and indigenous communities have developed their own specific knowledge on plant resources, uses, management, and conservation. Research interest and activities in the area of ethno medicine have increased tremendously in the last decade. Currently, scientists are evincing keen interest in the scientific evaluation of ethno medical claims. Bark powder of Arjuna (Terminalia arjuna [Roxb.] Wight and Arn) is used by tribals for the management of some painful conditions.

Aim:

To evaluate analgesic activity of T. arjuna bark in rodents.

Materials and Methods:

For evaluation of analgesic activity, different experimental models, that is, the acetic acid-induced writhing syndrome in mice, formaldehyde-induced paw licking response and tail flick test in rats were designed. Experiments were carried out at two-dose levels, that is, therapeutically equivalent dose (TED) and TED × 2. Animals were divided into three groups (six animals in each group), first group serving as a control group, second and third group labeled as test drug group.

Results:

Test drug at both the doses significantly decreased the writhing syndrome in comparison to control the group. In comparison to control the group, incidences of formalin-induced paw licking were reduced in test drug groups in both early and late phases of pain. In tail flick response, threshold was significantly increased in both test drug groups at every time intervals.

Conclusion:

Study showed that stem bark of T. arjuna possesses analgesic activity in all experimental models.

Analgesic and free radical scavenging activities of hydromethanolic extract of Crateva adansonii stem bark

Background:

Crateva adansonii is a moderately sized deciduous tree found throughout the tropics especially along the river banks. This study was aimed at the evaluation of the analgesic and antioxidant activities of the methanolic extract of C. adansonii stem-bark.

Methods:

The analgesic activity of Crateva extract was investigated using both chemical and thermal models of nociception in rodents while the antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) photometric model.

Results:

The extract produced a minute concentration-dependent increase in free radical scavenging activities. The extract (100, 200, and 400 mg/kg) caused a significant (P < 0.05) dose-dependent reduction in the number of writhing in treated rats when compared to the negative control. The extract at 100, 200, 400 mg/kg, and pentazocine (3 mg/kg) increased the pain reaction time in the treated rats by 58.05%, 66.67%, 94.76%, and 79.40%, respectively, when compared to the negative control.

Conclusion:

The C. adansonii stem bark possesses analgesic activity against peripheral and central mediated pain sensation and also antioxidant properties. This study justifies the ethnomedical use of C. adansonii in pain treatment.

Exploring new pharmacology and toxicological screening and safety evaluation of one widely used formulation of Nidrakar Bati from South Asia region

BACKGROUND

Nidrakar Bati (NKB) is an herbal remedy consisted with seven medicinal herbs widely used to cure Somnifacient (sleeping aid) in South Asia as Ayurvedic medicinal system. In the present study, pharmacological and toxicological effects of this medicine was investigated in mice to validate the safety and efficacy of the herb.

METHODS

Organic solvent extracts NKB were prepared using maceration method. Effect of extracts on the central nervous system was evaluated using hypnotic activity assay. Effect of the extracts on metabolic activity, assessing involvement of thyroid was conducted using hypoxia test. analgesic and anti-inflammatory activities were assessed in mice using acetic acid induced writhing, formalin induced paw edema, xylene induced ear edema assays. Anxiolytic activity was performed using plus maze, climbing out and forced swimming tests. Effect of the extracts on psychopharmacological effect was carried out using locomotor activity tests (open field, Hole-board and Hole-cross tests). Neuropharmacological effect of the extracts was performed using motor coordination (rotarod test). Toxicological potential of the extract was evaluated using gastro-intestinal activity (gastric emptying and gastrointestinal motility tests).

RESULTS

The studied formulation reduced the CNS stimulant effects dose independently. In the hypoxia test, only a dose of 100 mg/kg of NKB decreased the survival time. Orally administration of the NKB (200 and 400 mg/kg) produced significant inhibition (P < 0.01) of the acetic acid-induced writhing in mice and suppressed xylene induced ear edema and formalin-induced licking response of animals in both phases of the test. NKB showed locomotor activity (p < 0.05) both in higher and lower doses (100 and 400 mg/kg). NKB increased the total ambulation dose dependently (p < 0.05). NKB, at all tested doses (100, 200 and 400 mg/kg) increased some locomotion activity parameters (ambulation, head dipping and emotional defecation) in hole board test. At higher doses (200 and 400 mg/kg), NKB showed a significant increase in hole cross test. NKB showed an increase in the time on the open arms of the maze at low to medium doses (100 and 200 mg/kg). When using the Rotarod method, NKB showed a considerable increase on motor coordination of the mice. NKB produced marked gastric emptying effect and decreased gastrointestinal motility in mice at low dose.

CONCLUSIONS

NKB demonstrated various pharmacological effects and toxicological effects due to presence of several herbs in the formulation those are not closely fit for the effect of CNS depressants.

Antinociceptive activity of methanolic extract of Muntingia calabura leaves: further elucidation of the possible mechanisms

Background

Muntingia calabura (Elaecoparceae) is a medicinal plant traditionally used, particularly, by the Peruvian people to alleviate headache and cold, pain associated with gastric ulcers or to reduce the prostate gland swelling. Following the recent establishment of antinociceptive activity of M. calabura leaf, the present study was performed to further elucidate on the possible mechanisms of antinociception involved.

Methods

The methanol extract of M. calabura (MEMC) was prepared in the doses of 100, 250 and 500 mg/kg. The role of bradykinin, protein kinase C, pottasium channels, and various opioid and non-opioid receptors in modulating the extract’s antinociceptive activity was determined using several antinociceptive assays. Results are presented as Mean ± standard error of mean (SEM). The one-way ANOVA test with Dunnett's multiple comparison was used to analyze and compare the data, with P < 0.05 as the limit of significance.

Results

The MEMC, at all doses, demonstrated a significant (p < 0.05) dose-dependent antinociceptive activity in both the bradykinin- and phorbol 12-myristate 13-acetate (PMA)-induced nociception. Pretreatment of the 500 mg/kg MEMC with 10 mg/kg glibenclamide (an ATP-sensitive K⁺ channel inhibitor), the antagonist of μ-, δ- and κ-opioid receptors (namely 10 mg/kg β-funaltrexamine, 1 mg/kg naltrindole and 1 mg/kg nor-binaltorphimine), and the non-opioid receptor antagonists (namely 3 mg/kg caffeine (a non-selective adenosinergic receptor antagonist), 0.15 mg/kg yohimbine (an α₂-noradrenergic antagonist), and 1 mg/kg pindolol (a β-adrenoceptor antagonist)) significantly (p < 0.05) reversed the MEMC antinociception. However, 10 mg/kg atropine (a non-selective cholinergic receptor antagonist), 0.15 mg/kg prazosin (an α₁-noradrenergic antagonist) and 20 mg/kg haloperidol (a non-selective dopaminergic antagonist) did not affect the extract's antinociception. The phytochemicals screening revealed the presence of saponins, flavonoids, tannins and triterpenes while the HPLC analysis showed the presence of flavonoid-based compounds.

Conclusions

The antinociceptive activity of MEMC involved activation of the non-selective opioid (particularly the μ-, δ- and κ-opioid) and non-opioid (particularly adenosinergic, α₂-noradrenergic, and β-adrenergic) receptors, modulation of the ATP-sensitive K⁺ channel, and inhibition of bradikinin and protein kinase C actions. The discrepancies in MEMC antinociception could be due to the presence of various phytochemicals.

Bioguided isolation of myricetin-3-O-β-galactopyranoside with antinociceptive activity from the aerial part of Davilla elliptica St.-Hil

ETHNOPHARMACOLOGICAL RELEVANCE

Davilla elliptica St.-Hil. (Dilleniaceae) is a medicinal plant traditionally used in Brazil to treat inflammatory processes, to relieve pain, as diuretic, gastro- and hepatoprotective agents.

AIM OF THE STUDY

To undertake the fractionation of the ethanolic extract from Davilla elliptica leaves guided by an antinociceptive assay.

MATERIALS AND METHODS

The antinociceptive activity was evaluated through the formalin test in mice. Extract fractionation was performed by percolation through silica gel and partition between immiscible solvents, followed by successive column chromatography over Sephadex LH-20 and preparative RP-HPLC. Structure elucidation of the isolated compound was accomplished by spectroscopic data.

RESULTS

The EtOAc and MeOH fractions derived from the crude extract reduced significantly the licking time in the late phase of the formalin test. The bioguided fractionation of the MeOH fraction resulted in the isolation of myricetin-3-O-β-galactopyranoside, which produced significant inhibition on nociception induced by formalin (ID50=0.26 mg/kg; p.o.).

CONCLUSIONS

These results point out that myricetin-3-O-β-galactopyranoside contributes for the antinociceptive effect of Davilla elliptica extract, a constituent considerably more potent than diclofenac, employed as reference drug.

Leaf extract from Clusia nemorosa induces an antinociceptive effect in mice via a mechanism that is adrenergic systems dependent

Previous studies on the genus Clusia have shown anti-inflammatory and antiproliferative effects of the leaf extracts, but its antinociceptive activity has never been characterized. In the present study, the antinociceptive activity of the hexane extract of the leaves of Clusia nemorosa G. Mey, called HECn, was examined. Antinociceptive activity was evaluated using acetic acid-induced writhing, formalin, and hot-plate tests. All experiments were carried out on male Swiss mice. The extract (1-400 mg·kg(-1)), given by intraperitoneal route (i.p.) 1 h prior to testing, produced a dose-dependent inhibition on the number of abdominal writhings, with an ID50 of 62 mg·kg(-1). In addition, HECn was able to prevent the visceral pain induced by acetic acid in mice for at least 2 h. In the formalin test, HECn had no effect in the first phase, but produced an analgesic effect on the second phase with the inhibition of licking time. The HECn did not show a significant analgesic effect in the hot plate test. Pretreatment with yohimbine attenuated the antinociceptive effect induced by HECn in the writhing test. However, naloxone, atropine, or haloperidol did not affect antinociception induced by HECn in the writhing test. Together, these results indicate that the extract from the leaves of Clusia nemorosa produces antinociception in models of chemical pain through mechanisms that suggest participation of the adrenergic systems pathway.

Analgesic effect of Lepidium sativum Linn. (Chandrashura) in experimental animals

Lepidium sativum Linn, which is known as "Aselio" locally, is frequently used by the villagers for the treatment of Sandhivata (osteoarthritis), with good therapeutic relief. Here, we have to observe the analgesic activity of the seed of Lepidium sativum Linn in albino rats and Swiss albino mice with different parameters. The analgesic study was performed with acetic acid-induced writhing response in mice, formaldehyde-induced paw licking response in rats and tail flick response in mice. Experiments were carried out in two groups - therapeutic dose group and double dose group - with comparison with the control group. In the acetic acid-induced writhing syndrome, latency of onset was highly significantly increased in the therapeutic dose group and significant increase was found in the double dose group. In the formaldehyde-induced paw licking response, the test drug produced significant inhibition of neurogenic pain in the double dose group and significant inhibition of inflammatory pain in the therapeutic dose group. In the tail flick response, the test drug produced a mild to moderate effect in the therapeutic dose group and also in the double dose group.

Antinociceptive and anti-inflammatory effects of ethanol extract from Vernonia polyanthes leaves in Rodents

The ethanol extract from Vernonia polyanthes leaves (EEVP) was investigated for antinociceptive and anti-inflammatory effects at the doses (p.o.) of 100, 200 and 400 mg/kg in animal models. The extract reduced the number of abdominal contortions by 16.75% and 31.44% at a dose of 200 and 400 mg/kg, respectively. The results obtained showed that EEVP exerted a significant antinociceptive effect in the two phases of formalin. The EEVP increased the reaction time on a hot plate at the doses of 100, 200 and 400 mg/kg after 90 min of treatment. The paw edema was reduced by EEVP at the doses of 100, 200 and 400 mg/kg after 4 h of application of carrageenan. Doses of 200 and 400 mg/kg, administered 4 h before the carrageenan injection, significantly reduced the exudate volume (29.25 and 45.74%, respectively) and leukocyte migration (18.19 and 27.95%, respectively). These results suggest that V. polyanthes can be an active source of substances with antinociceptive and anti-inflammatory activities.

Anti-inflammatory, analgesic and antipyretic properties of Thespesia populnea Soland ex. Correa seed extracts and its fractions in animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Thespesia populnea Sol. ex Correa (Malvaceae) is commonly known as "Indian tulip tree". The plant has been used as an astringent, antibacterial, anti-inflammatory, antinociceptive and hepatoprotective in Indian system of traditional medicine.

MATERIALS AND METHODS

Thespesia populnea seeds were successively extracted by soxhlet extraction using petroleum ether (40-60 °C) (TPO) and ethanol (TPE). Unsaponifiable matter (TPOUM) and fatty acids were separated from seed oil. A GC-MS analysis of fatty acid methyl esters was carried out. Ethanolic extract was fractionated using CHCl(3), EtOAc, n-BuOH and H(2)O. Acute arthritis was induced by sub-plantar injection of carrageenan into the left hind paw of rats. The paw volume was measured using plethysmometer. Analgesic activity was assessed by heat induced pains (tail immersion model) and antipyretic activity assessed using brewers yeast-induced pyrexia model.

RESULTS

Oral administration of TPO and TPE at 200 and 400 mg/kg b.w. and tested fractions at 200mg/kg significantly reduced carrageenan induced paw edema and brewers yeast-induced pyrexia. In tail immersion method also extracts and fractions showed significant analgesic activity. Amongst all fractions EtOAc showed most significant results. TPOUM showed significant anti-inflammatory and analgesic activity. GC-MS analyses showed the presence of fourteen fatty acids, predominant fatty acids were palmitic and stearic acid.

CONCLUSION

These results highlighted anti-inflammatory, analgesic and antipyretic effects of Thespesia populnea seeds.

Plant use in the medicinal practices known as "strict diets" in Chazuta valley (Peruvian Amazon)

AIM OF THE STUDY

Strict diets are traditional medicinal practices where plant remedies are consumed with nearly fasting and with some sort of social seclusion. The aim of this work was to describe these practices of Chazuta and the use of plants within, as well as to analyse the possible functions of the last.

MATERIAL AND METHODS

The information was obtained through interviews to the 6.3% of the district rural adult population (140 individuals, 75% of which was considered Quechua).

RESULTS

In total, 122 strict diets were recorded and 106 different plant species were reported to be used. Strict diets present a characteristic structure and plant use. The main effects reported in strict diets were antinflammatory, antiinfective, brain function alteration and depuration.

CONCLUSIONS

Strict diets are well structured traditional medicinal practices, also with a symbolic significance in the life cycle of chazutian men. Plants used in strict diets can contribute to the main effects through antinflammation, antiinfective actions, psychoactivity and depurative related activities. The correlation between literature evidence of activity of most used plants and effects reported for the correspondent diet (i.e. in which the plant was used) are 36% for antinflammatory activity, 29% for antimicrobial activity, 18% for psychoactivity and 5% for depurative related activities. The percentages go to 77%, 64%, 73% and 32%, respectively, when literature evidences on related taxa are also considered.

Chemical profile and antinociceptive efficacy of Rheedia longifolia leaf extract

Different species of the family Clusiaceae, including Rheedia longifolia, are used in folk medicine to treat inflammatory diseases. This family is largely distributed in tropical and subtropical areas of Brazil, but their chemical and pharmacological properties have been the subject of a few studies. In previous studies, we found that the aqueous extract from R. longifolia leaves presented important anti-inflammatory and analgesic activity. We investigated the chemical profile of R. longifolia and characterized the pharmacological effect of different chemically identified fractions in pharmacological models of neurogenic and inflammatory nociception. The pharmacological tests showed that oral treatment with aqueous crude extract and fractions of methanol extract of R. longifolia leaf induced a significant antinociceptive effect using von Frey filaments. In addition, the most polar fractions presented antinociceptive activity in a neurogenic model of nociception (capsaicin model). The chromatographic analysis indicated the presence of bisflavonoids in the fractions obtained from the methanol extract. These results suggest that bisflavonoids found in methanol-extracted fractions are involved in the inhibition of inflammatory and neurogenic nociception. It is important that the R. longifolia aqueous extract treatment inhibited ulcer formation induced by indomethacin, suggesting an anti-ulcerogenic activity closely associated with its analgesic effect.

Effect of Rheedia longifolia leaf extract and fractions on the P2X₇ receptor in vitro: novel antagonists?

Recently, the P2X(7) receptor has been reported to be associated with chronic inflammatory and neuropathic pain. Because Rheedia longifolia extract has analgesic and anti-inflammatory activity, we evaluated the in vitro inhibitory potential of methanol extract and fractions from its leaves on the P2X(7) purinergic receptor. The activity of P2X(7) was studied with a dye uptake assay and with the whole-cell patch clamp technique in mouse peritoneal macrophages treated with methanol extract of R. longifolia leaves and fractions. The dye uptake was evaluated by flow cytometry and fluorescence microscopy. The R. longifolia extract and some fractions showed an inhibitory effect on the P2X(7) purinergic receptor in a dose-dependent manner. The ethyl acetate fraction exhibited the most potent inhibitory effects. The methanol extract and the butanol fraction showed the same inhibitory effects, despite their lower potency compared with the other fractions. The R. longifolia extract and some of its fractions may be anti-inflammatory because of their inhibitory effect on the P2X(7) receptor. Further investigation is needed to determine the pattern of inhibition and selectivity. Chromatographic analysis indicated the presence of bisflavonoids in the methanol extract fractions. A member of this chemical family is the most probable active compound responsible for the P2X(7) inhibitory effects present in the R. Longifolia extract and fractions.

Anti-inflammatory activity of the aqueous extract of ficus deltoidea

Ficus deltoidea (Family Moraceae) leaves have been used traditionally by the Malays to treat ailments such as wounds, sores, and rheumatism. The aim of the present study was to determine the anti-inflammatory activity of the aqueous extract of F. deltoidea leaf (FDA) using acute and chronic inflammatory models. FDA, in the doses of 30, 100, and 300 mg/kg, was administered intraperitoneally in rats (n = 6) before the animals were subjected to the carrageenan-induced paw edema test, cotton pellet-induced granuloma test, and formalin test. The first two tests represent acute and chronic models of inflammation, respectively. The first and second phases of the formalin test represent neurogenic pain and inflammatory-mediated pain, respectively; thus, only the second phase was measured in the present study. Results showed that FDA exerted significant (p < .05) anti-inflammatory activity in all assays, with dose-response effects seen in the paw edema and formalin tests. In conclusion, the leaf of F. deltoidea possesses anti-inflammatory activity against acute and chronic inflammatory responses and against pain-associated inflammatory response. These findings justify the traditional uses of F. deltoidea leaves for treatment of inflammatory-mediated ailments.

Xanthones, Biflavanones and Triterpenes from Pentadesma grandifolia (Clusiaceae): Structural Determination and Bioactivity

Stem bark, roots, leaves and fruits of Pentadesma grandifolia Baker f. (Clusiaceae) have been analyzed for the presence of xanthones, biflavonoids and triterpenoids. Isolated and identified structures include the xanthones cowagarcinone B (1) and α-mangostin (2), further the two biflavanones 3,8″-binaringenin (3) and the corresponding 3,6″-binaringenin (4), which is here reported as natural constituent for the first time. Structures were determined by NMR and mass spectrometry, as well as by 13C-NMR CSEARCH and SPECINFO database systems. The triterpenes lupeol (5), ß-amyrin (6) and betulin (7) were also encountered. Compounds 2 - 4 exhibited antifungal activity against Cladosporium sphaerospermum. Results are discussed in context to organ-specific accumulation and to other bioactivities that may relate to the ethnomedicinal uses of this species.

Crocus sativus L.: A comprehensive review

Crocus sativus L. belonging to the family Iridaceae (syn - kesar) comprises the dried red stigma and is widely cultivated in Iran and other countries such as India and Greece. Saffron contains more than 150 volatile and aroma-yielding compounds mainly terpenes, terpene alcohol, and their esters. The bitter taste and an iodoform or hay-like fragrance are caused by chemicals picrocrocin and safranal. C. sativus possesses a number of medicinally important activities such as antihypertensive, anticonvulsant, antitussive, antigenototoxic and cytotoxic effects, anxiolytic aphrodisiac, antioxidant, antidepressant, antinociceptive , anti-inflammatory, and relaxant activity. It also improves memory and learning skills, and increases blood flow in retina and choroid. The present review explores the historical background, chemical constituents, pharmacological actions, uses, substitutes and adulterants, and toxicity. It also deals with its evaluation, formulations, and chemical tests in detail.

Appraisal of antinociceptive and anti-inflammatory potential of extract and fractions from the leaves of Torreya grandis Fort Ex. Lindl

Torreya grandis (Taxaceae) was studied for antinociceptive and anti-inflammatory effects. Leaves were extracted with 80% ethanol at 80 degrees C for 3h and fractionated with petroleum ether, chloroform, ethylacetate and n-butanol. The aqueous ethanolic extract (aq.EE), ethylacetate fraction (EaF) and butanol fraction (BtF) at the doses of (100 and 200mg/kg, i.g.) body weight were used for study. Evaluation of antinociceptive activity was carried out by acetic acid-induced writhing response and formalin-induced paw licking time in the first and second phases of mice. The paw edema induced by formalin- and xylene-induced ear edema were used to assess anti-inflammatory activity. It was found that Torreya grandis extract and fractions at the doses of (100 and 200mg/kg, i.g.) were significantly attenuated the writhing responses induced by acetic acid and second phase of pain response induced by subplantar injection of formalin in mice. In addition, these extract and fractions inhibiting the formaldehyde-induced arthritis as well as xylene-induces edema prolifically. From acute oral toxicity studies no mortality was pragmatic even at highest dose (2500 mg/kg, i.g.). Furthermore, our phytochemical studies indicated that the aq. ethanolic extract of leaves contains alkaloids, flavonoids, tannins, terpenoids and saponins. The results provide justification for the folkloric uses of Torreya grandis in the treatment of analgesic and inflammatory-based diseases across the China.

Antinociceptive and anti-inflammatory effects of ethanolic extracts of Glycine max (L.) Merr and Rhynchosia nulubilis seeds

The aim of this study was to assess the in vivo potential of ethanolic extracts of Glycine max (L.) Merr. (SoRiTae) and Rhynchosia nulubilis (Yak-Kong) seeds as natural anti-nociceptive and anti-inflammatory agents. To assess the anti-nociceptive and anti-inflammatory potential, the ethanolic extracts of SoRiTae and Yak-Kong seeds were tested in arachidonic acid-induced ear edema, carrageenan induced paw edema, formalin-induced licking time, acetic acid induced writhing and hot plate-induced thermal stimulation in mice. The administration of ethanolic extracts of SoRiTae and Yak-Kong seeds evoked a significant effect of anti-nociceptive and anti-inflammatory activities as compared to standards aminopyrine and indomethacin. The ear edema, paw edema, paw licking time, pain and writhes in mice were significantly reduced (p < 0.05) as compared to the control. The results obtained in this study indicate that both SoRiTae and Yak-Kong soybeans possesses potential anti-nociceptive and anti-inflammatory activities.

Antinociceptive activity of Amaranthus spinosus in experimental animals

AIM OF THE STUDY

50% ethanol extract (ASE) of Amaranthus spinosus (whole plant) has been evaluated for antinociceptive and antiinflammatory activities.

MATERIALS AND METHODS

Analgesic and antiinflammatory activities were studied by measuring nociception by formalin, acetic acid, hot plate, tail immersion method while inflammation was induced by carrageenan.

RESULTS

ASE had significant dose dependent percentage protection against acetic acid (0.6% of 10 ml) induced pain and the effects were also compared to aspirin, morphine and naloxone while formalin induced pain (0.05 ml of 2.5%) was significantly blocked only at higher dose (400mg/kg) in first phase. ASE significantly blocked pain emanating from inflammation at all the doses in second phase. The reaction time in hot plate was increased significantly and dose dependently where as pretreatment with naloxone rigorously reduced the analgesic potentials of ASE. Further in tail immersion test the same dose dependent and significant activity was observed. Aspirin had no effect on thermal induced pain i.e. hot plate and tail immersion tests but showed an effect on writhing test.

CONCLUSIONS

Our investigation show that Amaranthus spinosus possess significant and dose dependant antiinflammatory activity, it has also central and peripheral analgesic activity.

Anti-diarrhoea and analgesic activities of the methanol extract and its fractions of Jasminum amplexicaule Buch.-Ham. (Oleaceae)

Jasminum amplexicaule Buch.-Ham. (Oleaceae) has been commonly used in the traditional medicine in dysentery, diarrhoea and bellyache in China. In the present work, the methanol extract of Jasminum amplexicaule and different fractions of this extract were studied for anti-diarrhoea and analgesic activities. The anti-diarrhoea activities were investigated using castor oil-induced, magnesium sulphate-induced diarrhoea models, antienteropooling assay and gastrointestinal motility models in mice. The analgesic activities were studied using hot-plate, writhing and formalin models in mice. At the doses of 100, 200 and 400mg/kg, the methanol extract (ME) showed significant and dose-dependent anti-diarrhoea and analgesic activity in these models. The chloroform fraction (CHF), ethyl acetate fraction (EAF) and the residual methanol fraction (RMF) exhibited similar activity using a dose of 200mg/kg in these models. The pharmacological activities of the n-butanol fraction (BUF) were lesser than the ME extract and other fractions. These results may support the fact that this plant is traditionally used to cure diarrhoea and pain.

Anti-nociceptive and anti-inflammatory effects of a Nigerian polyherbal tonic tea (PHT) extract in rodents

The study investigated the anti-nociceptive and anti-inflammatory properties of a Nigerian Polyherbal Health Tonic tea aqueous extract (PHT) in rodents of both sexes. 100-500 mg kg(-1) of the aqueous extract was administered via the intra-peritoneal (i.p.) and oral (p.o.) routes to 5 groups of mice using tail immersion, tail clip, formalin and acetic acid-induced writhing tests of experimental nociceptive models. Each of the models showed that PHT possesses a significant (p<0.05) anti-nociceptive effects which were peripherally and centrally mediated as both the early and late phases of pain significantly (p<0.05) were inhibited. However, the peripherally mediated analgesic effect of PHT, although similar to that of aspirin but was found to be more potent than aspirin. In assessing its anti-inflammatory potentials, 300-1340 mg kg(-1) PHT was also administered via oral and intraperitoneal routes, which, significantly (p<0.05) reduced the volume of carrageenan-induced oedema. Although, PHT administered via i.p. route was more effective than the oral but there was barely any difference between the percentage inhibition of oedema volume at both 600 and 1340 mg kg(-1) given orally. PHT anti-inflammatory effect was elucidated to be significantly (p<0.05) mediated via histaminergic, serotonergic, bradykinin and prostaglandin inhibition. PHT was also shown to be more protective than acetylsalicylic acid (ASA) in the castor oil-induced diarrhea model, which suggests the involvement of other mechanisms. Thus, lending supports to its folkloric use in pain and swelling management.

Analgesic, anti-inflammatory and antipyretic activities of the ethanolic extract and its fractions of Cleome rutidosperma

Oral administration of the ethanolic extract (200 and 400 mg/kg, p.o) and its fractions (200 mg/kg each) of the aerial parts of Cleome rutidosperma produced significant analgesic activity in acetic acid-induced writhing and tail immersion tests, anti-inflammatory effect against carrageenin induced inflammation and adjuvant induced polyarthritis and antipyretic activity against yeast-induced pyrexia. Fractionation of the ethanolic extract potentiated the activities.

Analgesic activity of Ugni molinae (murtilla) in mice models of acute pain

Leaf extracts of Ugni molinae Turcz. (Myrtaceae) are used in Chilean folk medicine as analgesic and anti-inflammatory. The antinociceptive effect of dichloromethane (DCM), ethyl acetate (EA) and methanol (ME) leaf extracts was assessed by intraperitoneal, oral and topical administration in writhing, tail flick, and tail formalin tests in mice. The extracts showed a dose-dependent antinociceptive activity in all the assays under different administration routes. The ED(50) values for the different tests for the DCM, EA, ME extract and reference drug (ibuprofen) were as follows. Writhing test in acetic acid (i.p. administration): 0.21, 0.37, 1.37 and 0.85mg/kg, respectively; tail flick test (oral administration): 199, 189, 120 and 45.9mg/kg. The EC(50) values for tail flick test were (topical administration): 2.0, 0.35, 1.4 and 8.2% (w/v), respectively; and the topical analgesic effects were (formalin assay) 75.5, 77.5, 31.6 and 76.5%, respectively. Ugni molinae extracts produce antinociception in chemical and thermal pain models through a mechanism partially linked to either lipooxygenase and/or cyclooxygenase via the arachidonic acid cascade and/or opioid receptors. Flavonoid glycosides and triterpenoids have been isolated from the plant and can be associated with the observed effect. Our results corroborate the analgesic effects of Ugni molinae, and justify its traditional use for treating pain.

Ethnomedicines used in Trinidad and Tobago for reproductive problems

BACKGROUND

Throughout history women have tried to control or enhance their fertility using herbal remedies, with various levels of societal support. Caribbean folk medicine has been influenced by European folk medicine, either through the early Spanish and French settlers or through the continuous immigration of Spanish-speaking peoples from Venezuela. Some folk uses are ancient and were documented by Galen and Pliny the Elder.

METHODS

Thirty respondents, ten of whom were male were interviewed from September 1996 to September 2000. The respondents were obtained by snowball sampling, and were found in thirteen different sites, 12 in Trinidad (Paramin, Talparo, Sangre Grande, Mayaro, Carapichaima, Kernahan, Newlands, Todd's Road, Arima, Guayaguayare, Santa Cruz, Port of Spain and Siparia) and one in Tobago (Mason Hall). Snowball sampling was used because there was no other means of identifying respondents and to cover the entire islands. The validation of the remedies was conducted with a non-experimental method.

RESULTS

Plants are used for specific problems of both genders. Clusea rosea, Urena sinuata and Catharanthus roseus are used for unspecified male problems. Richeria grandis and Parinari campestris are used for erectile dysfunction. Ageratum conyzoides, Scoparia dulcis, Cucurbita pepo, Cucurbita maxima, Gomphrena globosa and Justicia pectoralis are used for prostate problems. The following plants are used for childbirth and infertility: Mimosa pudica, Ruta graveolens, Abelmoschus moschatus, Chamaesyce hirta, Cola nitida, Ambrosia cumanenesis, Pilea microphylla, Eryngium foetidum, Aristolochia rugosa, Aristolochia trilobata, Coleus aromaticus, Laportea aestuans and Vetiveria zizanioides. The following plants are used for menstrual pain and unspecified female complaints: Achyranthes indica, Artemisia absinthium, Brownea latifolia, Eleutherine bulbosa, Hibiscus rosa-sinensis, Eupatorium macrophyllum, Justicia secunda, Parthenium hysterophorus, Wedelia trilobata, Abelmoschus moschatus, Capraria biflora, Cordia curassavica, Croton gossypifolius, Entada polystachya, Leonotis nepetaefolia, Eryngium foetidum, Aristolochia rugosa, Aristolochia trilobata and Ambrosia cumanenesis.

CONCLUSION

Native Caribbean plants have been less studied that those from Africa, India and Europe. Chamaesyce hirta has scientific support but as a diuretic. Other plants with level 3 validity for reproductive issues are: Achyranthes indica, Coleus aromaticus, Hibiscus rosa-sinesis, Parthenium hysterophorus and Ruta graveolens. The non-experimental validation method can be used to advise the public on which plants are safe, effective and useful, and which are not; pending clinical trials. This is especially important since so few clinical trials are conducted on Caribbean plants.

Analgesic and anti-inflammatory activity of the aqueous extract of Rheedia longifolia Planch & Triana

Rheedia longifolia Planch et Triana belongs to the Clusiaceae family. This plant is widely distributed in Brazil, but its chemical and pharmacological properties have not yet been studied. We report here that leaves aqueous extract of R. longifolia (LAE) shows analgesic and anti-inflammatory effects. Oral or intraperitoneal administration of this extract dose-dependently inhibited the abdominal constrictions induced by acetic acid in mice. The analgesic effect and the duration of action were similar to those observed with sodium diclofenac, a classical non-steroidal analgesic. In addition to the effect seen in the abdominal constriction model, LAE was also able to inhibit the hyperalgesia induced by lipopolysaccharide from gram-negative bacteria (LPS) in rats. We also found that R. longifolia LAE inhibited an inflammatory reaction induced by LPS in the pleural cavity of mice. Acute toxicity was evaluated in mice treated with the extract for seven days with 50 mg/kg/day. Neither death, nor alterations in weight, blood leukocyte counts or hematocrit were noted. Our results suggest that aqueous extract from R. longifolia leaves has analgesic and anti-inflammatory activity with minimal toxicity and are therefore endowed with a potential for pharmacological control of pain and inflammation.

The antinociceptive action of aqueous extract from Muntingia calabura leaves: the role of opioid receptors

OBJECTIVE

The present study was carried out to investigate the antinociceptive activity of the aqueous extract of Muntingia calabura (MCAE) leaves and to determine the effect of temperature and the involvement of the opioid receptor on the said activity using the abdominal constriction test (ACT) and hot-plate test (HPT) in mice.

MATERIALS AND METHODS

The extract was prepared by soaking the dried powdered leaves of M. calabura in distilled water (dH(2)O) overnight, and the supernatant obtained was considered as a stock solution with 100% concentration. The stock solution was diluted to 1, 5, 10, 50 and 100% and used to determine the antinociceptive activity of MCAE. A further experiment was done with 50% concentration to determine the effect of temperature and naloxone involvement of the opioid receptor system in MCAE antinociceptive activity.

RESULTS

At the various concentrations MCAE showed significant antinociceptive activity in both tests. However, the concentration-dependent activity was observed only in the ACT but not in the HPT. The 50% concentration of MCAEs were also stable against the effect of various temperatures as indicated by the presence of activity in both tests. The temperatures (40, 60 and 100 degrees C) also showed an enhanced extract activity only in the HPT. Pre-treatment with naloxone (2 and 10 mg/kg) blocked the extract activity in both tests, indicating the involvement of the opioid receptor system in MCAE antinociceptive activity.

CONCLUSION

Our data indicate that M. calabura leaves possess antinociceptive activity against chemically and thermally induced noxious stimuli. The bioactive compound(s) responsible for its antinociceptive activity is/are heat-stable and work partly via the opioid receptor system.

Study on the antinociceptive effects of Thymus broussonetii Boiss extracts in mice and rats

In Morocco, Thymus broussonetii is widely used in folk medicine for the treatment of a variety of diseases including gastroenteric and bronchopulmonary disorders and to relieve dolorous process. The antinociceptive effect of the aqueous, butanolic and ethyl acetate extracts of this species was examined in rats and mice using chemical and thermal models. The results obtained showed that aqueous and butanolic extracts exerted an antinociceptive activity in the two phases of formalin (50-300 mg/kg), tail immersion and writhing tests. Whereas, the ethyl acetate extract reduced the nociceptive response only in the second phase of formalin (100-300 mg/kg) and writhing tests. The aqueous extract, which is the most effective, contains active analgesic principles acting both centrally and peripherally. Furthermore, this antinociceptive effect has been avoided by naloxone at a dose of 1mg/kg in the first phase of formalin and hot plate tests indicating that this extract acts partly through an opioid-mediated mechanism. The present results demonstrated that Thymus broussonetii contains active constituents which possess antinociceptive activity justifying its popular use to relieve some pains.

Comparative antiplasmodial, leishmanicidal and antitrypanosomal activities of several biflavonoids

The antiplasmodial, leishmanicidal and antitrypanosomal activities of eight natural biflavonoids were estimated in vitro on a chloroquine-resistant strain of Plasmodium falciparum, axenically grown Leishmania donovani amastigotes and Trypanosoma cruzi trypomastigotes and Trypanosoma brucei rhodesiense bloodstream forms. Lanaroflavone showed the highest antiplasmodial activity (IC(50) = 0.48 microM), isoginkgetin was the most active leishmanicidal compound (IC(50) = 1.9 microM), whereas ginkgetin (IC(50) = 11 microM) and isoginkgetin (IC(50) = 13 microM) showed the best antitrypanosomal activity in our assays. The cytotoxicity and the selectivity indices for the most active compounds were also estimated. Lanaroflavone exhibited a high selectivity index value (SI = 159), indicating selective antiplasmodial activity.

Antinociceptive and anti-inflammatory effects of Crocus sativus L. stigma and petal extracts in mice

BACKGROUND

Crocus sativus L. (saffron) is used in folk medicine, for example as an antiedematogenic agent. We aimed to evaluate the antinociceptive and anti-inflammatory activity of saffron extracts in mice.

RESULTS

We used aqueous and ethanolic maceration extracts of Crocus sativus L. stigma and petals. Antinociceptive activity was examined using the hot plate and writhing tests. The effect of extracts against acute inflammation was studied using xylene induced ear edema in mice. The activity of the extracts against chronic inflammation was assessed by formalin-induced edema in the rat paw. In the hot plate tests, intraperitoneal injection of both extracts showed no significant antinociceptive activity in mice. The extracts exhibited antinociceptive activity against acetic acid induced writhing. Naloxone partially blocked only the antinociceptive activity of the stigma aqueous extract. Only the stigma extracts showed weak to moderate effect against acute inflammation. In chronic inflammation, both aqueous and ethanolic stigma extracts, as well as ethanolic petal extract, exerted anti-inflammatory effects.

CONCLUSIONS

We conclude that aqueous and ethanolic extracts of saffron stigma and petal have an antinociceptive effect, as well as acute and/or chronic anti-inflammatory activity.

Antinociceptive, anti-inflammatory and acute toxicity effects of Zhumeria majdae extracts in mice and rats

Antinociceptive and anti-inflammatory effects and acute toxicity of aqueous infusion and ethanolic maceration extracts of the aerial parts of Zhumeria majdae were studied in mice and rats. Antinociceptive activity was determined using hot-plate and writhing tests. The effect of the extracts against acute inflammation was studied by acetic acid increased vascular permeability and xylene-induced ear edema in mice. The activity of the extracts against chronic inflammation was assessed using the cotton pellet test in rats. LD50 values of the infusion and maceration extracts were 3.09 g/kg body wt., and 3.94 g/kg body wt., respectively. Phytochemical screening of the extracts indicated the presence of flavonoids and tannins. In the hot-plate test, the intraperitoneal injection of both extracts showed significant and dose-dependent antinociceptive activity in mice. Naloxone, an opioid antagonist, on pretreatment inhibited the antinociceptive activity of the extracts. The extracts exhibited antinociceptive activity against acetic acid-induced writhing, which was partially blocked by naloxone. Both extracts showed significant effect against acute inflammation induced by acetic acid in mice. In the chronic inflammation test, efficacy of the extracts was similar to that of baclofen and dexamethasone in rats. It is concluded that the aqueous infusion and ethanolic maceration extract of the aerial parts of Zhumeria majdae have antinociceptive effects and this may be mediated by opioid receptors. The extracts also showed anti-inflammatory effects against acute and chronic inflammation.

Naturally occurring antinociceptive substances from plants

Despite the progress that has occurred in recent years in the development of therapy, there is still a need for effective and potent analgesics, especially for the treatment of chronic pain. One of the most important analgesic drugs employed in clinical practice today continues to be the alkaloid morphine. In this review, emphasis will be given to the important contribution and the history of Papaver somniferum, Salix species, Capsicum species and Cannabis sativa in the development of new analgesics and their importance in the understanding of the complex pathways related to electrophysiological and molecular mechanisms associated with pain transmission. Recently discovered antinociceptive substances include alkaloids, terpenoids and flavonoid. Plant-derived substances have, and will certainly continue to have, a relevant place in the process of drug discovery, particularly in the development of new analgesic drugs.