Comparative pharmacokinetics and the bioavailability of escin Ib and isoescin Ib following the administration of escin,pure escin Ib and isoescin Ib in rats

Ethnopharmacological relevance

Adequate pharmacokinetic data of escin, a natural mixture of triterpene saponins used for the treatment of chronic venous insufficiency, hemorrhoids, inflammation and edema, is of special interest in view of the growing use of escin agent in clinical medicine. However, pharmacokinetic data are inadequate to support their clinical indication. Escin Ib and isoescin Ib are the chief active ingredients in escin, pharmacokinetics study of them would be helpful for improving the practice of escin application. The goals of this study are to determine the plasma concentration of escin Ib and isoescin Ib using an established liquid chromatography tandem mass spectrometry (LC–MS/MS) method and to compare the pharmacokinetics and bioavailability of these compounds in rats when administered as pure isomers or as sodium escinate.

Materials and methods

Five groups of Wistar rats (n=6 per group) were treated with either an intravenous (IV) dose (2.78 mg/kg) of sodium escinate (corresponding to 0.5 mg/kg of escin Ib and 0.5 mg/kg of isoescin Ib), an IV dose (0.5 mg/kg) and an oral dose (4 mg/kg) of pure escin Ib or isoescin Ib. The concentrations of escin Ib and isoescin Ib in rat plasma were determined by LC–MS/MS at various times following the administration of the drugs. The pharmacokinetic parameters were estimated by a non-compartmental analysis and then subjected to statistical analysis.

Results

The administration of sodium escinate, which contains the two isomers, gave rise to higher terminal phase half-life (t_1/2) and mean residence time (MRT) values for both escin Ib and isoescin Ib compared to the corresponding compounds administered alone. The absorption of escin Ib and isoescin Ib was very poor, with the oral bioavailability (F) values of <2% observed for both compounds. The two compounds were found to isomerize in vivo, wherein the conversion of escin Ib to isoescin Ib was much easier than that of isoescin Ib to escin Ib.

Conclusions

A comparison of the pharmacokinetics of escin Ib and isoescin Ib administered alone and together in rats suggests that the administration of herbal preparations of escin in a clinical setting may result in a longer duration of action than the administration of each isomer alone. The interconversion of escin Ib and isoescin Ib when administered alone indicates that the administration of one isomer results in exposure to the other isomer.     

Beneficial effects of Aesculus hippocastanum L. seed extract on the body's own antioxidant defense system on subacute administration

Aim of the study

Seeds of Aesculus hippocastanum L. have long been used in European phytotherapy to treat inflammatory and vascular problems. In Turkish folk medicine, tea prepared from the crushed seeds was used to pass kidney stone and against stomach ache, while a fraction of seed was swallowed to alleviate hemorroids symptoms.In order to evaluate the in vivo effects of escin mixture from Aesculus hippocastanum seed on the blood and tissue antioxidant defense systems in standard pellet diet (SPD) and in high-fat diet (HFD) consumed male mice.

Materials and methods

Escin mixture was obtained from the ethanol extract of seeds. Escin mixture was administered orally to male mice fed either standard pellet diet (SPD) or high-fat diet (HFD) at 100 mg/kg doses daily for 5 weeks and the tissue (liver, kidney and heart) and blood samples were collected at the end of experimental period. The effect of escin mixture on the plasma antioxidant activity; blood and tissue malondialdehyde (MDA) and reduced glutathione (GSH) levels; erythrocyte and tissue superoxide dismutase (SOD) and catalase activity (CAT) in SPD and HFD consumed animals were experimentally studied.

Results

Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Escin mixture prohibited the adverse effects of oxidative stress and showed a protective effect on the liver architecture both in SPD and HFD consumed male mice. Combined administration of high-fat diet with escin mixture decreased blood (p < 0.01), liver (p < 0.01), kidney (p < 0.05), and heart (p < 0.05) of MDA, liver SOD (p < 0.01) and CAT (p < 0.05) levels and increased blood (p < 0.01) and liver GSH (p < 0.001) levels in mice.

Conclusion

The present results indicate that Aesculus hippocastanum increase the antioxidative defense system of the body and prevent HFD-induced lipid peroxidation in male mice.     

日本七叶树化学成分的研究△Ⅱ．七叶树皂苷IVc和异七叶树皂苷Ia、Ib的分离和鉴定

从日本七叶树Aesculus turbinata B1．种子的90％乙醇提取物中分得3个二萜皂化合物,经光谱学分析鉴定了它们的结构分别为：七叶树皂苷IVc：22α-O-巴豆酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)][β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(I)、异七叶树皂苷Ia：21β-O-巴豆酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)[β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(Ⅳ)和异七叶树皂苷Ib：21β-O-当归酰基-28-O-乙酰基原七叶树皂苷配基-3β-O-[β-D-吡喃葡萄糖基(1→2)[β-D-吡喃葡萄糖基(1→4)]-β-D-吡喃葡萄糖醛酸(V),均为首次从日本七叶树种子中分得。七叶树皂苷Ia、Ib、IVc和异七叶树皂苷Ia、Ib在100 μmol／L浓度的体外试验中对HIV-1蛋白酶活性具有一定的抑制作用。     

Studies on anti-inflammatory and analgesic activities of betel nut in rodents

Ethnopharmacological relevance

Areca catechu, commonly known as betel nut, is very famous for its medicinal use in multiple disorders. It is also popular as a remedy against inflammatory disorders in the Unani (Greco-Arab) system of medicine.

Objective of the study

This study was aimed at investigating the anti-inflammatory and analgesic activities of the crude extract of Areca catechu and its respective fractions.

Materials and methods

Paw edema, formalin-induced nociception and acetic acid-induced writhing assays were carried out in vivo. Free radical scavenging activity of the plant extract was performed in vitro.

Results

Preliminary experiments using a single dose (100 mg/kg) of Areca catechu and its respective fractions demonstrated an anti-inflammatory effect on carrageenan-induced edema in mice and rats, the aqueous fraction being distinctly more effective. When studied on prostaglandin E₂ (PGE₂), arachidonic acid, histamine, or serotonin (5HT)-induced edema in rats, Areca catechu and its aqueous fraction markedly repressed only the PGE₂ and arachidonic acid-induced inflammation. When studied for analgesic activity, the crude extract and its aqueous fraction produced a dose-dependent (10-100 mg/kg) inhibitory effect on formalin-induced nociception in mice and acetic acid-induced writhing in rats, similar to aspirin. In DPPH assay, Areca catechu and its aqueous fraction exhibited free radical scavenging activity with respective IC₅₀ values of 5.34 μg/ml (4.93-5.78, CI; 95%, n = 5) and 7.28 μg/ml (6.04-7.95, n = 4), like that of rutin with IC₅₀ value of 4.75 μg/ml (3.89-5.42, n = 4).

Conclusion

These results indicate the anti-inflammatory and analgesic effects of Areca catechu and provide a rationale for its medicinal use in inflammatory disorders.     

Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

Aim of the study

A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors.

Materials and methods

Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM.

Results

From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC₅₀ = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition.

Conclusions

Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors.     

Evaluation of antinociceptive effect of Aegiceras corniculatum stems extracts and its possible mechanism of action in rodents

Ethnopharmacological relevance

Aegiceras corniculatum (Linn.) Blanco is used in various traditional medicinal system(s) for the treatment of rheumatism, painful arthritis and inflammation. Therefore, the pharmacological studies of its antinociceptive effect was undertaken to validate its traditional use.

Materials and methods

n-Hexane, ethyl acetate and methanol extract(s) derived from Aegiceras corniculatum (stems) were studied using various nociceptive model(s) induced chemically or thermally in mice including acetic acid-induced writhing, formalin-induced paw licking and hot plate test.

Results

In acetic acid-induced writhing test, plant extracts dose dependently decreased the writhing numbers. The methanolic extract (1-10 mg/kg, i.p. in mice) of the plant was more potent than acetaminophen and acetyl salicylic acid, with an IC₅₀ of 4.2 ± 0.99 mg/kg. Moreover, the time of nociceptive behaviors induced by intraplantar formalin injection was also suppressed during 1st and 2nd phases in the presence of ethyl acetate extract whereas, n-hexane and methanolic extracts inhibited the paw licking in mice during the 1st (IC₅₀ 12 ± 0.76 mg/kg) and 2nd phases (IC₅₀ 3.8 ± 0.55 mg/kg). Naloxone, β-funaltrexamine, and naltrindole antagonized the n-hexane extract-induced antinociception in the first phase of formalin test indicating its non-selective analgesic response via opioid receptor(s). However, ethyl acetate extract was devoid of any opioid action. Additionally, these extracts significantly inhibited the pain stimulation in hot plate test. Withdrawal syndrome of morphine dependence was also diminished in the presence of plant extracts via potentiation of GABAergic system.

Conclusion

These results suggested that Aegiceras corniculatum extract(s) possesses analgesic properties and acts on the central nervous system, thereby suppressing the inflammatory pain justifying its folklore use.     

Effects of Scutellariae radix and Aloe vera gel extracts on immunoglobulin E and cytokine levels in atopic dermatitis NC/Nga mice

Aim of the study

The present study aimed to investigate the effects of Scutellariae radix (SR) and Aloe vera gel (AV), alone or in combination, on levels of immunoglobulin E (IgE) and inflammatory cytokines in spontaneous atopic dermatitis(AD)-like skin lesions.

Materials and methods

After spontaneous AD-like skin lesion was developed by adaptation to conventional conditions, mice were randomly assigned to control, SR (50 mg/kg, p.o.), AV (0.8 mg/kg, p.o.) and SRAV (50 mg of SR and 0.8 mg of AV/kg, p.o.) groups, and were treated for 6 weeks.

Results

SR and SRAV suppressed IL-5 levels compared with control, but had no effects on IgE levels (P < 0.05). AV increased IgE levels, but decreased both IL-5 and IL-10 compared with control (P < 0.05).

Conclusion

These results suggest that SR and AV modulate immunological responses in AD, mainly through influencing IL-5 or IL-10 levels.     

Antidepressant-like effects of the active acidic polysaccharide portion of ginseng in mice

Aim of the study

The biological of activity of Panax ginseng C.A. Meyer (ginseng) is complex but some of its known effects are related to affective and anxiety disorders, including the enhancement of neuroprotection, cellular resilience and plasticity. Whereas such effects suggest that ginseng might have antidepressant activity, previous studies show incongruent results. The sources of contrasting results might be many but one possibility is the utilization of different ginseng preparations in different studies. The current study was therefore designed to examine the effects of a very specific component of ginseng extract, the acidic polysaccharide portion of the plant (WGPA), containing arabinogalactan, type-I rhamnogalacturonan (RG-I)- and homogalacturonan (HG)-rich pectins.

Materials and methods

WGPA was extracted from ginseng roots and administered orally to mice at 100 mg/kg and 200 mg/kg doses. WGPA was administered chronically, once daily for 1 week before the start of experiments and throughout the behavioral tests battery. Mice were tested for spontaneous activity, social interactions, anxiety-like behavior in the elevated plus-maze (EPM) and despair-like behavior in the forced swim test (FST).

Results

WGPA had no effects on spontaneous activity or behavior in the EPM. In contrast, 100 mg/kg (but not the 200 mg/kg) WGPA significantly reduced immobility time in the FST and both doses significantly increased social interactions and decreased aggressive behaviors in mice.

Conclusion

These results suggest that chronic WGPA treatment might have antidepressant-like effects that are unrelated to generalized behavioral changes. The results are discussed in the context of the known ability of the active ingredients of ginseng to increase neuroprotection, similar to many of the current antidepressant and mood stabilizing drugs.     

Lycium barbarum polysaccharides protect mice liver from carbon tetrachloride-induced oxidative stress and necroinflammation

Ethnopharmacological relevance

Lycium barbarum has been used as a traditional Chinese medicine to nourish liver, kidneys and the eyes.

Aim of the study

We investigated the protective mechanisms of Wolfberry, Lycium barbarum polysaccharides (LBP) in carbon tetrachloride (CCl₄)-induced acute liver injury.

Materials and methods

Mice were intraperitoneally injected with a 50 μl/kg CCl₄ to induce acute hepatotoxicity (8 h) and were orally fed with LBP 2 h before the CCl₄ injection. There were six experimental groups of mice (n = 7-8 per group), namely: control mice (vehicle only; 1 mg/kg LBP or 10 mg/kg LBP), CCl₄-treated mice and CCl₄ + LBP treated mice (1 mg/kg LBP or 10 mg/kg LBP).

Results

Pre-treatment with LBP effectively reduced the hepatic necrosis and the serum ALT level induced by CCl₄ intoxication. LBP remarkably inhibited cytochrome P450 2E1 expression and restored the expression levels of antioxidant enzymes. It also decreased the level of nitric oxide metabolism and lipid peroxidation induced by CCl₄. LBP attenuated hepatic inflammation via down-regulation of proinflammatory mediators and chemokines. Furthermore, LBP promoted liver regeneration after CCl₄ treatment. The protective effects of LBP against hepatotoxicity were partly through the down-regulation of nuclear factor kappa-B activity.

Conclusion

LBP is effective in reducing necroinflammation and oxidative stress induced by a chemical toxin, thus it has a great potential use as a food supplement in the prevention of hepatic diseases.     

Bronchospasm potentiating effect of methanolic extract of Ficus religiosa fruits in guinea pigs

Ethnopharmacological relevance

The sacred tree Peepal (Ficus religiosa family: Moraceae) has numerous therapeutic utility in folk medicine.

Aim of the study

It has been reported to be used in ethno medical treatment of asthma and also in epilepsy due to its high serotonin content, which has been implicated in pathophysiology of asthma, this led us to carry out the present study.

Materials and methods

The in vivo studies of histamine induced bronchospasm in guinea pigs and in vitro isolated guinea pig tracheal chain and ileum preparation.

Results

Pre-treatment of guinea pigs with ketotifen (1 mg/kg, p.o.) has significantly delayed the onset of histamine aerosol induced pre-convulsive dyspnea, compared with vehicle control (281.8^a ± 11.7 vs. 112.2 ± 9.8). The administration of methanolic extract (125, 250 and 500 mg/kg, p.o.) did not produced any significant effect on latency to develop histamine induced pre-convulsive dyspnea. On the other hand, methanolic extract of the fruits at the doses employed (i.e., 0.5, 1 and 2 mg/ml) has significantly potentiate the EC₅₀ doses of both histamine and acetylcholine in isolated guinea pig tracheal chain and ileum preparation. In addition, HPLC analysis of the methanolic extract showed the presence of high amounts of serotonin (2.89%, w/w).

Conclusions

On the basis of data, it may be concluded that Ficus religiosa fruits have been found to be ineffective against histamine induced bronchospasm in guinea pigs. In addition, methanolic extract of the fruits have shown to potentiate the bronchoconstriction induced by both histamine and acetylcholine on guinea pig tracheal chain preparation.     

Antidiabetic effect of Symplocos cochinchinensis (Lour.) S. Moore. in type 2 diabetic rats

Aim

Symplocos cochinchinensis (Lour.) S. Moore. is used in Indian system of traditional medicine to treat diabetes mellitus. The present study aims to investigate the antidiabetic efficacy of the hexane extract of Symplocos cochinchinensis leaves in high fat diet-low streptozotocin (STZ) induced type 2 diabetic rats.

Materials and methods

The doses for the study were fixed based on Irwin test. The hypoglycemic effect of the hexane extract of Symplocos cochinchinensis leaves were studied in normal rats. Oral glucose and insulin tolerance tests were carried out. The antihyperglycemic effect of the hexane extract at 250 and 500 mg/kg was studied in high fat diet-low STZ induced type 2 diabetic rats for 28 days.

Results

The extracts showed no adverse effects up to 5 g/kg concentration. In hypoglycemic study, after treatment with hexane extract at 250 and 500 mg/kg the blood glucose was mildly reduced. In oral glucose tolerance test, the treatment with the hexane extract at 250 and 500 mg/kg showed a highly significant reduction of 12.07% and 23.58% in plasma glucose levels, respectively 30 min after glucose load. The insulin tolerance test also showed improved insulin sensitivity after 60 min of insulin treatment. In high fat diet-low STZ induced type 2 diabetic rats, after 28 days treatment with the hexane extract at 250 and 500 mg/kg reduced the plasma glucose level by 17.04% and 42.10%, respectively. A significant reduction in plasma insulin, plasma and hepatic total cholesterol (TC), triglycerides (TG) and free fatty acids (FFA) and a significant increase in liver glycogen were observed in treated diabetic rats.

Conclusion

This study demonstrated the potential antidiabetic property of hexane extract of Symplocos cochinchinensis leaves on type 2 diabetes mellitus, thus justifying its traditional usage.     

Realgar and realgar-containing Liu-Shen-Wan are less acutely toxic than arsenite and arsenate

Ethnopharmacological relevance

Liu-Shen-Wan (LSW) is a widely-used traditional Chinese medicine containing realgar (As₄S₄).

Aim of the Study

Realgar has been included in many traditional medicines, and is often taken as arsenite for risk assessment in realgar-containing traditional remedies. Is realgar toxicologically similar to arsenite?

Materials and Method

Mice were orally given LSW (60 and 200 mg/kg; 200 mg LSW contains 27 mg realgar), realgar (30 mg/kg, equivalent to 21 mg As/kg), and the equivalent As dose as sodium arsenite (NaAsO₂), or as arsenate (Na₂HAsO₄). Acute toxicity and tissue As accumulation were determined 8 h later.

Results

Arsenite and arsenate increased serum alanine aminotransferase (ALT) levels, indicative of liver injury; blood urea nitrogen (BUN) was also increased by arsenite and arsenate, indicative of nephrotoxicity. No elevations of ALT and BUN were observed in LSW and realgar groups. Histopathology showed more damage in arsenite- and arsenate-treated liver and kidneys, while in realgar- and LSW- treated animals, only mild alterations were seen. Hepatic and renal As contents were dramatically increased to 6200 and 3350 ng/g, respectively, after arsenite, but only increased to 260 and 180 ng/g after LSW. The expressions of arsenic-sensitive stress genes, namely metallothionein-1 and heme oxygenase-1, were increased after arsenite or arsenate by 3-10-folds, but were unaltered after LWS and realgar.

Conclusions

Realgar and LSW are much less toxic than arsenite and arenate. The use of total As content to evaluate the safety of realgar-containing traditional medicines is not scientifically sound.     

Phytochemical analysis, antioxidant and anti-inflammatory activities of Phyllanthus simplex

Ethnopharmacological relevance

Phyllanthus simplex (Family: Euphorbiacae) is widely used in traditional medicines for treatment of various diseases including inflammation.

Materials and methods

Petroleum ether extract (PSPE) and ethanol extract (PSEE) of the whole plant of Phyllanthus simplex were characterized for their total phenolics, tannins and flavonoids content. These extracts were standardized by HPTLC using phyllanthin and gallic acid respectively as markers. Antioxidant activity of extracts was evaluated by the DPPH, hydroxyl and superoxide radicals scavenging assay. The total antioxidant capacity of extracts was determined. Anti-inflammatory activity was evaluated by their effect on nitric oxide (NO) production in isolated rat peritoneal macrophages; carragennan-induced paw edema and formation of cotton pellet-induced granuloma in rats.

Results

Abundance of phenolics was found in PSEE. Phyllanthin and gallic acid content in PSPE and PSEE were found to be 14.5 and 0.65% (w/w) respectively. PSEE showed concentration dependent significant scavenging of DPPH, hydroxyl and superoxide radicals with IC₅₀ values 102.219, 171.485 and 24.73 μg/ml respectively. PSEE significantly inhibited NO production in isolated rat peritoneum macrophages. Moreover, it also exhibited significant inhibition of carragennan-induced paw edema (58.48 ± 0.028%, p < 0.001, at 6 h, 200 mg/kg oral dose) and cotton pellet-induced granuloma formation (45.671 ± 0.712%, p < 0.001, at 200 mg/kg oral dose). Anti-inflammatory activity of PSEE was found to be comparable to diclofenac sodium.

Conclusions

Significant antioxidant and anti-inflammatory activities were found in PSEE which may be attributed to its high phenolic content.     

Safety evaluation of tea (Camellia sinensis (L.) O. Kuntze) flower extract: assessment of mutagenicity, and acute and subchronic toxicity in rats

Ethnopharmacological relevance

Tea (Camellia sinensis (L.) O. Kuntze, Theaceae) flowers possess many physiological functions and have been used in traditional medicines for deodorization, skin care, cough suppressant and expectorant in China. However, there is a little information about its possible toxicity.

Aim of the study

The present investigation was carried out to evaluate the safety of tea flower extract by mutagenicity and acute and subchronic toxicity studies.

Materials and methods

Mutagenicity of tea flower extract was evaluated by the Ames test in Salmonella typhimurium strains TA97, TA98, TA100 and TA102 at concentrations of 0.008, 0.04, 0.2, 1.0, 5.0 mg/plate. In the acute toxicity study, Sprague-Dawley rats were administered a single dose of 12.0 g/kg of body weight by gavage, and were monitored for 14 days. In the subchronic toxicity study, tea flower extract was administered by gavage at doses of 1.0, 2.0 and 4.0 g/kg body weight daily for 13 weeks to Sprague-Dawley rats.

Results

In the Ames test, there was no mutagenic effect of tea flower extract (up to 5.0 mg/plate) towards four tested strains (TA97, TA98, TA100, TA102), with or without metabolic activation (S9). In the acute toxicity study, all animals gained weight and appeared active and normal, so the LD₅₀ value must be >12.0 g/kg body weight. In the subchronic toxicity study, no dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or pathologic lesions were observed.

Conclusion

These results indicate that tea flower extract does not possess mutagenic potential, and that both acute and subchronic toxicity towards animals is very low. A no-observed adverse-effect level (NOAEL) for tea flower extract is 4.0 g/kg bw/day for rats under the conditions of this study.     

Antibacterial, antioxidant and fibroblast growth stimulation activity of crude extracts of Bridelia ferruginea leaf, a wound-healing plant of Nigeria

Aim of the study

Determination of pharmacological activity relevant to wound healing of Bridelia ferruginea leaf, a traditional medicine used to treat wounds in rural Nigeria.

Materials and methods

Aqueous and ethanolic leaf extracts were tested against bacterial species of relevance to wound infections: Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ethanolic extracts were assessed for their ability to stimulate the growth of human dermal fibroblasts (FS5) and protect against damage induced by hydrogen peroxide. Antioxidant activity was also assessed using the DPPH assay.

Results

Both aqueous and ethanolic extracts had weak antibacterial activity (MIC > 470 μg/ml). A significant effect (p < 0.001) on the growth of FS5 fibroblasts was observed only at a concentration of 5 μg/ml (28% increase), above which the extracts appeared toxic to the cells. The ethanolic extract offered the highest protection against H₂O₂ damage to FS5 cells, comparable with catalase (82% at 250 μg/ml). The DPPH assay revealed antioxidant activity of the ethanolic leaf extract with IC₅₀ 12.5 ± 0.3 μg/ml comparable to l-ascorbic acid (7.3 ± 0.1 μg/ml).

Conclusion

The antibacterial, modest fibroblast stimulation activity and relatively strong antioxidant activity lend some support to the topical use of Bridelia ferruginea leaf for wound-healing in the traditional medicine of South-western Nigeria.     

Anti-inflammatory effect of a methanolic extract of leaves of Dregea volubilis

Aim of study

The aim of this study was to establish the anti-inflammatory activity of the methanolic extract of Dregea volubilis leaves (MEDV) with its fractions and to delineate the possible mechanism of action for MEDV.

Materials and methods

The anti-inflammatory activities of MEDV along with its petroleum ether and chloroform fractions were evaluated in a carrageenan induced model of acute inflammation. The effect of MEDV on lipopolysaccharide induced production of nitric oxide (NO) in macrophages was also studied.

Results

MEDV (100, 200 and 400 mg/kg body weight) significantly reduced carrageenan induced paw edema; chloroform fraction was most potent (66%, p < 0.001). MEDV was non-toxic up to 125 μg/ml in mouse peritoneal macrophages wherein it (0-100 μg/ml) reduced lipopolysaccharide induced NO production.

Conclusion

MEDV possesses significant anti-inflammatory activity. Chloroform fraction of MEDV showed best anti-inflammatory activity.     

Screening of Caesalpinia bonduc leaves for antipsoriatic activity

Ethnopharmacological relevance

Leaves of Caesalpinia bonduc (L.) Roxb. (Caesalpiniaceae) have been used by traditional Siddha healer of Malabar region for psoriasis treatment.

Aim of the study

To evaluate the Caesalpinia bonduc decoction (CBD), Caesalpinia bonduc hydroalcoholic extract (CBHA) for antipsoriatic activity.

Materials and methods

Mouse tail test for psoriasis was used for the evaluation of antipsoriatic activity. Extracts were tested at a dose of 500 mg/kg b.w. and fractions at 250 mg/kg b.w. in Swiss albino mice. Parameters studied in the mouse tail test were changes in epidermal thickness and percentage orthokeratotic values. In vitro antiproliferant assay on HaCaT cell lines and in vitro lipoxygenase inhibition were also carried out.

Results

Butanol fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAB) and water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW) produced significant orthokeratosis (p < 0.001). In relative epidermal thickness, a significant (p < 0.05) reduction with respect to control was observed in groups treated with retinoic acid, CBD, butanol fraction of Caesalpinia bonduc decoction (CBDB), water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW). Maximum antiproliferant activity was shown by CBHA (IC₅₀, 77.5 ± 12.7 μg/ml). In lipoxygenase inhibition assay, water fraction of Caesalpinia bonduc decoction (CBDW) showed maximum activity with an IC₅₀ value of 164.71 ± 4.57 μg/ml.

Conclusions

Among all the tested samples only CBHAW showed good activity in the mouse tail test, antiproliferant activity in HaCaT cells and lipoxygenase inhibition assay. Other extracts and fractions showed varying degrees of activity. The present study supports the traditional use of Caesalpinia bonduc leaves for psoriasis treatment.     

Acute, subacute toxicity and mutagenic effects of anacardic acids from cashew (Anacardium occidentale Linn.) in mice

Aim of the study

Anacardium occidentale Linn. (cashew) is a Brazilian plant that is usually consumed in natura and is used in folk medicine. Anacardic acids (AAs) in the cashew nut shell liquid are biologically active as gastroprotectors, inhibitors of the activity of various deleterious enzymes, antitumor agents and antioxidants. Yet, there are no reports of toxicity testing to guarantee their use in vivo models.

Materials and methods

We evaluated AAs biosafety by measuring the acute, subacute and mutagenic effects of AAs administration in BALB/c mice. In acute tests, BALB/c mice received a single oral dose of 2000 mg/kg, whereas animals in subacute tests received 300, 600 and 1000 mg/kg for 30 days. Hematological, biochemical and histological analyses were performed in all animals. Mutagenicity was measured with the acute micronucleus test 24 h after oral administration of 250 mg/kg AAs.

Results

Our results showed that the AAs acute minimum lethal dose in BALB/c mice is higher than 2000 mg/kg since this concentration did not produce any symptoms. In subacute tests, females which received the highest doses (600 or 1000 mg/kg) were more susceptible, which was seen by slightly decreased hematocrit and hemoglobin levels coupled with a moderate increase in urea. Anacardic acids did not produce any mutagenic effects.

Conclusions

The data indicate that doses less than 300 mg/kg did not produce biochemical and hematological alterations in BALB/c mice. Additional studies must be conducted to investigate the pharmacological potential of this natural substance in order to ensure their safe use in vivo.     

Anti-inflammatory effect of Lithrea molleoides extracts and isolated active compounds

Aim of the study

In this study the anti-inflammatory activity of aqueous, dichloromethane (CH₂Cl₂) and methanolic (MeOH) extracts and two major compounds isolated from Lithrea molleoides (Vell.) Engl. (Anacardiaceae) were evaluated.

Materials and methods

Two classical experimental models were used, carrageenan-induced rat paw edema and 12-O-tetradecanoylphorbol-13 acetate (TPA) induced mouse ear edema.

Results

MeOH extracts exhibited a significant systemical anti-inflammatory effect in the carrageenan (inhibition of 46% at 3 h) and in the TPA-ear edema test (inhibition of 21%). The presence of methyl gallate (inhibition of 63% in TPA ear edema), as one of the main compounds in the active fraction from MeOH extract may be explained the effect observed. Also, 1,3-dihydroxy-(Z,Z)-5-(tridec-4′,7?dienyl) benzene obtained from CH₂Cl₂ extract showed a significant topical anti-inflammatory activity (inhibition of 68%). Furthermore, no signs of toxicity were observed with doses up to 3 g/kg in an acute toxicity assay.

Conclusions

The results of this study present evidence that Lithrea molleoides given either systemically or topically has anti-inflammatory properties.     

Antinociceptive activity of ethanolic extract and isolated compounds of Urtica circularis

Ethnopharmacological relevance

Urtica circularis (Hicken) Sorarú is a medicinal plant commonly used in traditional medicine to relieve pain in inflammatory processes.

Aim of the study

In the present study, the in vivo antinociceptive effect of Urtica circularis ethanolic extract and its isolated compounds has been investigated.

Materials and methods

Antinociceptive activity was evaluated through writhing, formalin and hot plate tests in mice. The phytochemical analysis was performed.

Results

The extract produced significant inhibition on nociception induced by acetic acid (ED50: 72.2 mg/kg, i.p.) and formalin (ED50: 15.8 mg/kg, i.p.) administered intraperitoneally and also orally. Atropine diminished the activity of the extract in the acetic acid test. In this model, at dose of 10 mg/kg i.p., vitexin was the most active of the isolated compounds (inhibition of 91%), and chlorogenic acid, caffeic acid and vicenin-2 (6,8-di-C-glucosyl apigenin) produced an inhibition of 72%, 41% and 41%, respectively, whereas apigenin did not show any activity.

Conclusions

These results suggest that Urtica circularis extract produced antinociception possibly related to the presence of vitexin, chlorogenic, caffeic acid and vicenin-2. The activation of cholinergic systems seems to be involved in the mechanism of antinociception of the extract.