Antipruritic and antinociceptive effects of Chenopodium album L in mice

Extract of Chenopodium album lowers blood pressure in rats through endothelium-dependent and -independent vasorelaxation

OBJECTIVES

To investigate the antihypertensive effect of crude extract of Chenopodium album (Ca.Cr), based on its medicinal use in hypertension.

METHODS

Ca.Cr and its fractions were tested in-vivo in normotensive anesthetized rats for blood pressure-lowering effect. In-vitro experiments were performed on isolated rat aortae to explore the vascular mechanism(s).

RESULTS

In normotensive anesthetized rats, Ca.Cr produced a dose-dependent (1-300mg/kg) fall (30%mmHg) in mean arterial pressure (MAP). Among the fractions, nHexane was the most potent (46% fall). In rat aortic rings precontracted with phenylephrine (PE), Ca.Cr and its fractions (except Ca.Aq) produced endothelium-dependent vasorelaxation, which was partially reversed with endothelium removal and by pretreating intact aortic rings with L-NAME (10μM) and atropine (1μM). This relaxation to Ca.Cr and fractions (nHexane, ethylacetate and chloroform) was also eliminated with indomethacin pretreatment, however, it unmasked a vasoconstriction effect with Ca.Cr only. Surprisingly, the aqueous fraction produced a calcium sensitive strong vasoconstriction instead of vasorelaxation. The crude extract and its fractions (except Ca.Aq) also antagonized vasoconstriction induced with high K+ (80mM), suggesting calcium antagonistic effect. The aqueous fraction produced mild vasorelaxation against high K+. This effect was further confirmed when pretreatment of the aortic rings with different concentrations of crude extract and fractions suppressed CaCl2 concentration response curves, similar to verapamil. In acute toxicity test, Ca.Cr extract was found safe up to 5g/kg body weight in mice.

CONCLUSION

These findings suggest that crude extract and fractions of C. album produced vasorelaxant effect through muscarinic receptors linked-NO pathway, prostaglandin (endothelium-dependent) and calcium antagonism (endothelium-independent), which explains the blood pressure lowering effect of C. album in rats.

Buchanania cochinchinensis (Lour.) M.R. Almedia habitat exhibited robust adaptability to diverse socioeconomic scenarios in eastern India

One of the greatest challenges to ecosystems is the rapidity of climate change, and their ability to adjust swiftly will be constrained. Climate change will disrupt the ecological balances, causing species to track suitable habitats for survival. Consequently, understanding the species' response to climate change is crucial for its conservation and management, and for enhancing biodiversity through effective management. This research intends to examine the response of the vulnerable Buchanania cochinchinensis species to climate change. We modeled the potential suitable habitats of B. cochinchinensis for the present and future climatic scenario proxies based on the Shared Socioeconomic Pathways (SSP), i.e. SSP126, 245, 370 and 585. Maxent was used to simulate the potential habitats of B. cochinchinensis. The study found that ~28,313 km2 (~10.7% of the study area) was a potentially suitable habitat of B. cochinchinensis for the current scenario. The majority of the suitable habitat area ~25,169 km2 occurred in the central and southern parts of the study area. The future projection shows that the suitable habitat to largely increase in the range of 10.5-20% across all the SSPs, with a maximum gain of ~20% for SSP 126. The mean temperature of the wettest quarter (Bio_08) was the most influential contributing variable in limiting the distribution of B. cochinchinensis. The majority of the suitable habitat area occurred in the vegetation landscape. The study shows a southward shifting of B. cochinchinensis habitat by 2050. The phytosociological analysis determined B. cochinchinensis as Shorea robusta's primary associate. Our research provides significant insight into the prospective distribution scenario of B. cochinchinensis habitat and its response to diverse socioeconomic scenarios, and offers a solid foundation for management of this extremely important species.

Investigation of the anti-inflammatory and analgesic activities of promising pyrazole derivative

The development of new COX-2 inhibitors with analgesic and anti-inflammatory efficacy as well as minimal gastrointestinal, renal and cardiovascular toxicity, is of vital importance to patients suffering from chronic course pain and inflammatory conditions. This study aims at evaluating the therapeutic activity and adverse drug reactions associated with the use of the newly synthesized pyrazole derivative, compound AD732, E-4-[3-(4-methylphenyl)-5-hydroxyliminomethyl-1H-pyrazol-1-yl]benzenesulfonamide, as compared to indomethacin and celecoxib as standard agents. Anti-inflammatory activity was assessed using carrageenan-induced rat paw edema and cotton pellet granuloma tests; formalin-induced hyperalgesia and hot plate tests were done to study analgesic activity. In vitro tests to determine COX-1/COX-2 selectivity and assessment of renal and gastric toxicity upon acute exposure to AD732 were also conducted. Compound AD732 exhibited promising results; higher anti-inflammatory and analgesic effects compared to standard agents, coupled with the absence of ulcerogenic effects and minimal detrimental effects on renal function. Additionally, compound AD732 was a less potent inhibitor of COX-2 in vitro than celecoxib, which may indicate lower potential cardiovascular toxicity. It may be concluded that compound AD732 appears to be a safer and more effective molecule with promising potential for the management of pain and inflammation.

Polymethoxyflavones from Nicotiana plumbaginifolia (Solanaceae) Exert Antinociceptive and Neuropharmacological Effects in Mice

Polymethoxylavones (PMFs) are known to exhibit significant anti-inflammatory and neuroprotective properties. Nicotiana plumbaginifolia, an annual Bangladeshi herb, is rich in polymethoxyflavones that possess significant analgesic and anxiolytic activities. The present study aimed to determine the antinociceptive and neuropharmacological activities of polyoxygenated flavonoids namely- 3,3′,5,6,7,8-hexamethoxy-4′,5′-methylenedioxyflavone (1), 3,3′,4′,5′,5,6,7,8-octamethoxyflavone (exoticin) (2), 6,7,4′,5′-dimethylenedioxy-3,5,3′-trimethoxyflavone (3), and 3,3′,4′,5,5′,8-hexamethoxy-6,7-methylenedioxyflavone (4), isolated and identified from N. plumbaginifolia. Antinociceptive activity was assessed using the acetic-acid induced writhing, hot plate, tail immersion, formalin and carrageenan-induced paw edema tests, whereas neuropharmacological effects were evaluated in the hole cross, open field and elevated plus maze test. Oral treatment of compounds 1, 3, and 4 (12.5–25 mg/kg b.w.) exhibited dose-dependent and significant (p < 0.01) antinociceptive activity in the acetic-acid, formalin, carrageenan, and thermal (hot plate)-induced pain models. The association of ATP-sensitive K⁺ channel and opioid systems in their antinociceptive effect was obvious from the antagonist effect of glibenclamide and naloxone, respectively. These findings suggested central and peripheral antinociceptive activities of the compounds. Compound 1, 3, and 4 (12.5 mg/kg b.w.) demonstrated significant (p < 0.05) anxiolytic-like activity in the elevated plus-maze test, while the involvement of GABA_A receptor in the action of compound 3 and 4 was evident from the reversal effects of flumazenil. In addition, compounds 1 and 4 (12.5–25 mg/kg b.w) exhibited anxiolytic activity without altering the locomotor responses. The present study suggested that the polymethoxyflavones (1–4) from N. Plumbaginifolia could be considered as suitable candidates for the development of analgesic and anxiolytic agents.

Chenopodium album Linn. leaves prevent ethylene glycol-induced urolithiasis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Chenopodium album Linn. are traditionally used for correction of kidney diseases and urinary stones. The present work investigated the effect of methanolic and aqueous extracts of leaves of Chenopodium album on experimentally-induced urolithiasis in rats to substantiate its traditional use as antilithiatic agent.

MATERIALS AND METHODS

The leaf extract was standardized by HPLC. Urolithiasis was induced in rats by administration of 0.75% v/v of ethylene glycol (EG) in distilled water and in addition, vehicle or methanol (CAME) or aqueous (CAAE) extract of the leaves of Chenopodium album each in the dose 100, 200 and 400mg/kg or Cystone (750mg/kg) were administered daily orally for 28 days. Urolithiasis was assessed by estimating the calcium, phosphorus, urea, uric acid, and creatinine in both urine and plasma. The volume, pH and oxalate levels were also estimated in urine. The renal oxalate content was estimated in kidney while calcium oxalate deposits were observed histologically.

RESULTS

The treatment with CAME or CAAE for 28 days significantly attenuated the EG-induced elevations in the urine and plasma levels of calcium, phosphorus, urea, uric acid and creatinine along with decrease in urine volume, pH and oxalates. The treatments also decreased renal tissue oxalate and deposition of oxalate crystals in kidney due to EG treatment. The effects of CAME and CAAE were comparable to standard antilithiatic agent, cystone. The findings indicate the preventive effect of CAME and CAAE which can be due to inhibitory effect on crystallization and stone dissolution. The effect was attributed to the presence of phytochemicals like flavonoids and saponins.

CONCLUSION

In conclusion, Chenopodium album leaves exhibited antilithiatic effect and validates its ethnomedicinal use in urinary disorders and kidney stones.

HPLC-DAD analysis, antinociceptive and anti-inflammatory properties of the ethanolic extract of Hyptis umbrosa in mice

Hyptis umbrosa (syn. Mesosphaerum sidifolium) (Lamiaceae Family) has been used to treat several conditions such as gastrointestinal disorders, skin infections, nasal congestion, fever and cramps. The objective of this study was to evaluate the chemical composition, analgesic and anti-inflammatory profiles of ethanol extract from leaves of Hyptis umbrosa (EEB). HPLC-DAD was used to determine the fingerprint chromatogram of the extract. Male Swiss mice were orally pretreated with EEB (100, 200 or 400 mg/kg; 60 min before initiating algesic stimulation) and antinociceptive activity was assessed using the acetic acid-induced writhing model, formalin test and hyperalgesia induced by glutamate or capsaicin. Also, peritonitis was induced by the intrathoracic injection of carrageenan to quantify the total number of leukocytes. The presence of phenolic compounds in the extract was confirmed using HPLC-DAD. The treatment with EEB, at all doses, produced a significant analgesic effect against acetic acid-induced antinociceptive activity. In the formalin test, only the 400-mg/kg-dose of EEB had a significant effect in the first phase. However, all doses tested were able to reverse nociception in the second phase. The effect of all doses of EEB also showed a significant antinociceptive effect in the glutamate and capsaicin tests and inhibited the carrageenan-induced leukocyte migration to the peritoneal cavity. The present study suggests that the EEB possesses peripheral analgesic action and showed potential in reducing the spreading of the inflammatory processes. Also, it seems to be related with vanilloid and glutamate receptors.

Petroleum ether extract of Chenopodium album L. prevents cell growth and induces apoptosis of human lung cancer cells

Chenopodium album L. is a common edible herb distributed in China that has been used as a traditional Chinese medicine for antiviral, antifungal, anti-inflammatory and cancer treatment. However, to the best of our knowledge no previous reports have investigated its the function of its phytochemical extracts in lung cancer cells. The purpose of the present study was to assess the anticancer activities of the phytochemical extracts of C. album L. on human non-small cell lung cancer A549 cells. The present findings demonstrated that the petroleum ether (PE) extract of C. album L. exhibited significant growth inhibitory effects on A549 with an IC₅₀ value of 33.31±2.79 µg/ml. As determined by MTT and colony formation assays, its growth inhibitory effects were dose- and time-dependent. Furthermore, PE extract-treated A549 cells exhibited dose-dependent cell growth arrest at the G1 phase of the cell cycle and cell apoptosis was induced. These results provide useful data on the anticancer activities of C. album L. in human lung cancer and demonstrated the novel possibilities of this plant in developing lung cancer therapies.

Shikimic acid inhibits LPS-induced cellular pro-inflammatory cytokines and attenuates mechanical hyperalgesia in mice

BACKGROUND AND AIMS

Shikimic acid (SA) is present in a wide variety of plants and microorganisms used in traditional and folk medicine and also is an essential starting material for the synthesis of the antiviral drug Oseltamivir (Tamiflu®). Some pharmacological actions observed in SA-enriched products include antioxidant and anti-inflammatory activities. Here, we investigated the anti-inflammatory and antinociceptive actions of isolated SA.

METHODS

RAW 264.7 macrophage cells were treated with bacterial LPS (1μg/mL) and the effect of SA on the modulation of cell viability, nitric oxide (NO) production, TNF-α, and IL-1β content and MAPK (ERK1/2 and p38) activation was evaluated. Besides, the anti-hyperalgesic actions of SA on in vivo model of mechanical hyperalgesia induced by carrageenan (CG), dopamine (DA), TNF-α and prostaglandin (PGE2) were assessed.

RESULTS

In RAW 264.7 cells, SA suppressed LPS-induced decrease in cell viability and nitrite accumulation to control values and inhibited up-regulation of TNF-α (65%) and IL-1β (39%). These effects may be mediated at least in part by inhibition of LPS-induced ERK 1/2 (22%) and p38 (17%) phosphorylation. In mice, SA at 50, 100, and 200mg/kg decreased formalin-induced nociceptive behavior (around 50%) and inhibited the inflammatory nociception induced by TNF-α and PGE2 (50 to 75% each). Moreover, SA (100 and 200mg/kg) significantly attenuated the mechanical hyperalgesia induced by CG and DA (25 to 40% each).

CONCLUSIONS

These results indicate that SA presents anti-inflammatory actions with potential for development of drugs to treat pro-inflammatory and painful conditions.

Anti-nociceptive activity of the crude extract of Myrianthus arboreus P. Beauv (Cecropiaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Myrianthus arboreus P. Beauv (Cecropiaceae) is a shrub or a tree plant widely distributed in Tropical Africa. In the South Eastern part of Nigeria, the leaves are used in traditional medicine as an analgesic for muscular pains, and also as an enema to relieve pain in the back and loins. Although no scientific study has been performed to validate its traditional use in pain management, this study therefore aims at investigating the anti-nociceptive activity of M. arboreus leaves extract in mice.

MATERIALS AND METHODS

Anti-nociceptive activity of M. arboreus was investigated using acetic acid induced writhing, formalin induced paw licks, hot plate, and tail flick tests. Acute toxicity was determined using a slightly modified Lorkes method.

RESULTS

The extract of M. arboreus produced a significant dose-dependent [F (4, 20)=13.48 p<0.001] inhibition of abdominal writhings induced by acetic acid. In the formalin paw licking test, it produced a significant dose-dependent inhibition of neurogenic and inflammatory pain [F (4, 17.5)=60.13 p<0.001]. It also produced a significant dose dependent [F (4, 20)=30.5 p<0.001; F (4, 20)=0.321 p<0.0001] prolongation of the latency and reaction time in the hot plate and tail immersion tests. Peak effect was observed at the highest dose (40 mg/kg). LD50 of the plant was found to be 894 mg/kg.

CONCLUSION

M. arboreus possesses potent antinociceptive activity mediated centrally and peripherally, an effect which may justify its traditional use in the management of pain.

Analgesic and Anti-inflammatory action of Opuntia elatior Mill fruits

Background:

Opuntia elatio Mill is a xerophytic plant with potentially active nutrients. It is traditionally appreciated for its pharmacological properties; however, the scientific information on this plant is insufficient.

Objective:

The present study evaluates the antinociceptive and anti-inflammatory action of prickly pear.

Materials and Methods:

Writhing and tail-immersion tests were carried out to evaluate analgesic action, while the carrageenan-induced paw edema and neutrophil adhesion tests were conducted in Albino wistar rats to assess anti-inflammatory action.

Results:

ED₅₀ values of the fruit juice in writhing, tail immersion, and paw edema test were 0.919, 2.77, and 9.282 ml/kg, respectively. The fruits of Opuntia produced analgesic and anti-inflammatory action in a dose-dependent manner.

Conclusion:

The results establish the folklore use of prickly pear may be due to the presence of betacyanin and/or other phenolic compounds.

Chenopodium album Linn: review of nutritive value and biological properties

Green leafy vegetables have generated interest worldwide as they exhibit multiple benefits for health of human beings. Vegetables can form the cheapest and most readily available sources of important vitamins, minerals, fibres and essential amino acids particularly. In most of the developing countries where the daily diet is dominated by starchy staple foods, vegetables can form the cheapest and most readily available sources of important vitamins, minerals, fibres and essential amino acids. Across the globe there are several local and wild vegetables which are under-exploited because of inadequate scientific information on knowledge of their nutritional potentials. A resurgence of interest has developed in wild vegetables for their possible medicinal values in diets. C. album is under exploited vegetable which has high functional potential apart from basic nutritional benefits. The plant is used in diet not only to provide minerals, fibre, vitamins and essential fatty acids but also enhance sensory and functional value of the food. The plant has been traditionally used as a bloodpurifier, diuretic, sedative, hepatoprotective, antiscorbutic laxative and as an anthelmentic against round and hookworms. Pharmacological studies have revealed that the plant possesses anthelmentic, sperm immobilizing and contraceptive properties. It is also claimed to be antipruritic and antinociceptive in action. Therefore C. album holds a great potential for in depth biological evaluation. No significant work has ever been carried out for processing parameters for this potentially useful plant. Significance and future scope of C. album for public and dietary awareness of its nutritional status has been discussed in this review.

Evaluation of antibacterial, antioxidant and DNA protective capacity of Chenopodium album's ethanolic leaf extract

We have investigated the antibacterial effects of Chenopodium album's ethanolic leaf extract (CAE) on all the Gram (+) and Gram (-) microorganisms and evaluated the protective effects of CAE on both yeast and human mononuclear leukocytes' genomic DNA upon oxidative shock. Antibacterial activity was recorded on Bacillus subtilis with 13 mm of inhibition zone. Total oxidative status (TOS) and the total antioxidative status (TAS) levels were determined to evaluate the antioxidant activity of CAE. Results indicated that there was a good correlation between dose of CAE and TAS levels. We also observed that CAE protect the DNA of both yeast and mononuclear leukocytes against the damaging effect of hydrogen peroxide. The comet assay, applied on both Saccharomyces cerevisiae BY4741 (MATa his3Δ1 leu2Δ0 met15Δ0 ura3Δ0) and human leukocytes, results suggested that there was statistically significant correlation between CAE dilutions and antigenotoxic activity.

Ethanolic extract of Aconiti Brachypodi Radix attenuates nociceptive pain probably via inhibition of voltage-dependent Na⁺ channel

Aconiti Brachypodi Radix, belonging to the genus of Aconitum (Family Ranunculaceae), are used clinically as anti-rheumatic, anti-inflammatory and anti-nociceptive in traditional medicine of China. However, its mechanism and influence on nociceptive threshold are unknown and need further investigation. The analgesic effects of ethanolic extract of Aconiti Brachypodi Radix (EABR) were thus studied in vivo and in vitro. Three pain models in mice were used to assess the effect of EABR on nociceptive threshold. In vitro study was conducted to clarify the modulation of the extract on the tetrodotoxin-sensitive (TTX-S) sodium currents in rat's dorsal root ganglion (DRG) neurons using whole-cell patch clamp technique. The results showed that EABR (5-20 mg/kg, i.g.) could produce dose-dependent analgesic effect on hot-plate tests as well as writhing response induced by acetic acid. In addition, administration of 2.5-10 mg/kg EABR (i.g.) caused significant decrease in pain responses in the first and second phases of formalin test without altering the PGE₂ production in the hind paw of the mice. Moreover, EABR (10 µg/ml -1 mg/ml) could suppress TTX-S voltage-gated sodium currents in a dose-dependent way, indicating the underlying electrophysiological mechanism of the analgesic effect of the folk plant medicine. Collectively, our results indicated that EABR has analgesic property in three pain models and useful influence on TTX-S sodium currents in DRG neurons, suggesting that the interference with pain messages caused by the modulation of EABR on TTX-S sodium currents in DRG neurones may explain some of its analgesic effect.

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application.

A novel COX-2 inhibitor pyrazole derivative proven effective as an anti-inflammatory and analgesic drug

The introduction of new COX-2 inhibitors with high efficacy and enhanced safety profile would be a great achievement in the development of anti-inflammatory drugs. This study was designed to screen and assess the anti-inflammatory and analgesic activities as well as some of the expected side effects of some pyrazole derivatives, newly synthesized as potential COX-2 inhibitors at the Faculty of Pharmacy, Alexandria University and compared to indomethacin and celecoxib. Twelve compounds were screened for their anti-inflammatory activity using carrageenan-induced paw oedema and cotton pellet granuloma tests. On the basis of their apparent anti-inflammatory activity, four compounds with different substitutions were selected for the evaluation of their analgesic activity using the formalin-induced hyperalgesia and hot-plate tests. Compound AD 532, ((4-(3-(4-Methylphenyl)-4-cyano-1H-pyrazol-1-yl)benzenesulfonamide)), showed very promising results. In the single-dose and subchronic toxicity studies, compound AD 532 showed no ulcerogenic effect and produced minimal effects on renal function. Furthermore, compound AD 532 was a less potent inhibitor of COX-2 in vitro than celecoxib, which may indicate lower potential cardiovascular toxicity. It is concluded that compound AD 532 appears to be a promising and safe option for the management of chronic inflammatory conditions. This study recommends more in-depth investigation into the therapeutic effects and toxicity profile of this compound including its cardiovascular toxicity.

Antinociceptive effect of the monoterpene R-(+)-limonene in mice

In the present study were studied the antinociceptives properties of monoterpene R-(+)-limonene (LM) in chemical and thermal models of nociception in mice. The R-(+)-limonene was administered, intraperitoneally (i.p.), at doses of 25 and 50 mg/kg. The results showed significant inhibition produced on chemical nociception induced by intraperitoneal acetic-acid and in the second phase of subplantar formalin test, but did not manifest a significant effect in hot-plate test. The R-(+)-limonene-induced antinociception in second phase of formalin test was insensitive to naloxone (1 mg/kg, s.c.). It was also demonstrated that R-(+)-limonene (25, 50 mg/kg) neither significantly enhanced the pentobarbital-sleeping time nor impaired the motor performance in rota-rod test, indicating that the observed antinociception is unlikely to be due to sedation or motor abnormality. In conclusion it may be suggested that the R-(+)-limonene presented antinociceptive activity and that, probably, this action can be related with peripheral analgesia, but, not with the stimulation of opioids receptors.

An anthropological study about headache and migraine in native cultures from Central and South America

OBJECTIVE

To describe the ritual and ethnobotanical treatments about migraine performed by shamans from several native cultures.

METHODS

Anthropological field study conducted with Tzeltal Maya (Mexico), Kamayurá (Brazil), and Uru-Chipaya (Bolivia) American Indians.

RESULTS

Migraine is called yaxti-wanjol chawaj by Tzeltal shamans. They wash the head of the patient with an herbal solution to treat headache. The boiled leaves of a shrub called payté wamal (Tagetes nelsonii) are used to relieve migraine. Migraine is called monkey's disease by Kamayurá natives. The disease is originated by the revenge of the killed monkey's spirit, striking to Kamayurá hunter on his head. It is treated with an herbal infusion applied in the eyes of the patient. Migraine is called eskeclamix by Chipaya people, and is treated by drinking the cañahua plant (Chenopodium palludicale) boiled with water. The patient's head may also be washed with shaman's fermented urine.

CONCLUSIONS

Cultural equivalents of migraine exist in the healing system of isolated American cultures.

Pentacyclic triterpenoids, alpha,beta-amyrins, suppress the scratching behavior in a mouse model of pruritus

In the search for natural compounds useful against pruritus, alpha,beta-amyrins, the pentacyclic triterpenes isolated from the resin of popular medicinal plant Protium heptaphyllum were examined on scratching behavior induced by dextran T40 and compound 48/80 in mice. The animals were pretreated orally with alpha,beta-amyrins (50, 100 and 200 mg/kg) or cyproheptadine (10 mg/kg), an antagonist of histamine and serotonin receptors and 2 h later, they were given subcutaneous injections of dextran T40 (75 mg/kg) or compound 48/80 (3 mg/kg) into the rostral back, and scratching was quantified for 20 min. The scratching behavior induced by dextran T40 and compound 48/80 was significantly inhibited in mice pretreated with alpha,beta-amyrins (100 and 200 mg/kg) or cyproheptadine (10 mg/kg), In addition, the compound 48/80-elicited degranulation of rat peritoneal mast cells (ex vivo) was also markedly reduced in animals pretreated with alpha,beta-amyrins (100 mg/kg) or ketotifen (1 mg/kg), a known mast cell stabilizer. In the open-field test, alpha,beta-amyrins (100 and 200 mg/kg)-pretreated mice showed no impairment of spontaneous locomotion, suggesting that these triterpenoids possess no sedative activity that could account for suppression of scratching behavior. These results clearly indicate the antipruritic effect of alpha,beta-amyrins and suggest that this effect may be related to a stabilizing action on mast cell membrane.

Antipruritic and Antierythema Effects of Ascomycete Bulgaria inquinans Extract in ICR Mice

The effect of ethanol extract obtained from Bulgaria inquinans on the scratching behavior and vascular permeability changes induced by compound 48/80, histamine and serotonin in ICR mice was studied. The extract dose-dependently inhibited scratching behavior induced by compound 48/80 and serotonin. A significant inhibition was observed at doses of 300 and 600 mg/kg when Bulgaria inquinans extract was administered orally. However, no inhibitory effect was observed on the histamine-induced scratching behavior by the extract, even at a dose of 600 mg/kg. In addition, it also inhibited the increase in the vascular permeability induced by compound 48/80 and serotonin at doses of 300 and 600 mg/kg; however, it failed to inhibit the increased vascular permeability induced by histamine, even at a dose of 600 mg/kg. Bulgaria inquinans extract showed a potent inhibitory effect on histamine release induced by compound 48/80. These results suggest that Bulgaria inquinans extract is effective in cutaneous pruritus and erythema, which were probably mediated by inhibiting the release of histamine from mast cells and antagonizing the effect on serotonin.

Antipruritic and antiinflammatory effects of aqueous extract from Si-Wu-Tang

Si-Wu-Tang (SWT), a traditional Chinese formula, has been clinically used in the treatment of cutaneous pruritus, chronic inflammation, and other diseases. The present study was carried out to observe the antipruritic and antiinflammatory effects of SWT aqueous extract using compound 48/80 and picryl chloride (PC) models in mice. SWT (500, 1000 mg/kg p.o.) clearly reduced the scratching responses elicited by compound 48/80 in normal mice. At doses of 250 and 500 mg/kg, it inhibited the scratching responses induced by PC in mice actively sensitized with 2,4-dinitrophenol (DNP)-ovalbumin (OVA) plus alum. Furthermore, SWT (250, 500, 1000 mg/kg) significantly inhibited the footpad swelling caused by compound 48/80 in mice. In the biphasic ear skin reactions induced by PC in actively sensitized mice, SWT (250, 500 mg/kg) reduced the immediate-phase reaction, but did not affect the late-phase reaction. In vitro, SWT (50-500 microg/ml) showed a concentration-dependent inhibition of the histamine release induced by compound 48/80 from rat peritoneal mast cells. The crude drugs contained in SWT, Paeoniae Radix (25, 100 microg/ml), Rehmanniae Radix, and Chuanxiong Rhizoma (100 microg/ml), also showed a clear inhibition, but Angelica Radix did not at the concentrations examined. These findings indicate that SWT aqueous extract has antipruritic and antiinflammatory effects in mice. SWT inhibits histamine release from rat mast cells, and Paeoniae Radix probably plays a crucial role in the formula.