Antiplasmodial activity of root extract and fractions of Croton zambesicus

Aim of the study

Antiplasmodial activity of root extract and fractions of Croton zambesicus were evaluated to ascertain the folkloric claim of its antimalarial activity and elucidate its antiplasmodial mechanism of action.

Material and method

The crude ethanolic root extract (27–81 mg/kg) and gradient fractions ( n- hexane, chloroform, ethyl acetate and methanol; 54 mg/kg) of Croton zambesicus were investigated for antiplasmodial activity against chloroquine - sensitive Plasmodium berghei infections in mice. The antiplasmodial activity during early and established infections as well as the prophylactic activity were investigated. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Oxidant generation potentials of the crude extract and fractions was also evaluated to elucidate their mechanism of action.

Results

The crude root extract (27 – 81 mg/kg) demonstrated significant (P < 0.01–0.001) schizonticidal activity during early and established infections and also had prophylactic activity. The activity was comparable to that of the standard drug used (chloroquine 5 mg/kg, pyrimethamine 1.2 mg/kg). Methanol, ethyl acetate and chloroform fractions had comparative in vivo antiplasmodial activity and oxidant generation potentials.

Conclusion

The antiplasmodial activity of this root extract and fractions which is likely to be through peroxidation confirms the folkloric use of this plant.     

Sesquiterpene lactones with antinociceptive and antipyretic activity from two Centaurea species

Ethnopharmacological relevance

Several Centaurea species are used to alleviate pain and inflammatory symptoms in rheumatoid arthritis, high fever, and head ache in Turkish folk medicine.

Aim of the study

The effectiveness of extracts, fractions and subfractions from dried Centaurea solstitialis L. subsp. solstitialis (CSS) (Asteraceae) roots and aerial parts were studied on mice.

Materials and methods

The antinociceptive and antipyretic effects of Centaurea solstitialis L. subsp. solstitialis have been investigated by using p-benzoquinone-induced writhing reflex for antinociceptive activity and Freund's Complete Adjuvant-induced pyrexia model for antipyretic activity assessment in mice.

Results

The ethanolic extract from the aerial parts of the plant was shown to possess significant antinociceptive (p < 0.01) and antipyretic activities (p < 0.01). The extract was then submitted to subsequent solvent extractions and chromatographic processes. Through bioassay-guided fractionation and isolation procedures two sesquiterpene lactones, solstitialin A and acetyl solstitialin, were isolated and defined as the active components of CSS. On the other hand, a comparative study was conducted on another species, Centaurea depressa Bieb., which has no similar folkloric utilization. Following the same fractionation chart same compounds were defined as the active ingredients.

Conclusion

Results of the present study proved that aerial part of CSS possesses antinociceptive and antipyretic activities supporting the folkloric assertion in Turkish folk medicine. However, these effects seem not limited to CSS, some other Centaurea species, in fact, having no folkloric use might be equally active.     

Analgesic and antimalarial activities of crude leaf extract and fractions of Acalypha wilkensiana

Aim of the study

Antiplasmodial and analgesic activities of leaf extract and fractions of Acalypha wilkensiana were evaluated to ascertain the folkloric claim of its antimalarial and analgesic activities.

Materials and methods

The crude leaf extract (220–659 mg/kg) and fractions (chloroform and aqueous; 440 mg/kg) of Acalypha wilkensiana were investigated for antiplasmodial activity against chloroquine sensitive Plasmodium berghei infections in mice and for analgesic activity against chemical and heat-induced pains. The antiplasmodial activity during early and established infections as well as prophylactic activity were investigated. Chloroquine (5 mg/kg) and pyrimethamine (1.2 mg/kg) were used as positive controls. Thin films made from tail blood of each mouse were used to assess the level of parasitaemia of the mice. Analgesic activity of the crude extract was also evaluated against acetic acid, formalin and heat-induced pains.

Results

The extract and its fractions dose-dependently reduced parasitaemia induced by chloroquine sensitive Plasmodium berghei infection in prophylactic, suppressive and curative models in mice. These reductions were statistically significant (p < 0.001). They also improved the mean survival time (MST) from 16 to 22 days relative to control (p < 0.01–0.001). The activities of extract/fractions were incomparable to that of the standard drugs used (chloroquine and pyrimethamine). On chemically and thermally induced pains, the extract inhibited acetic acid and formalin-induced inflammation as well as hot plate-induced pain in mice. These inhibitions were statistically significant (p < 0.001) and in a dose-dependent fashion.

Conclusion

The antiparasitaemic and analgesic effects may in part be mediated through the chemical constituents of the plant.     

Evaluation of the diuretic and analgesic activities of the rhizomes of Rumex abyssinicus Jacq in mice

Aim of the study

Rumex abyssinicus Jacq (Polygonaceae) has been used traditionally for treatment of hypertension, inflammatory and painful conditions in Ethiopia. The present study aimed to evaluate the diuretic and analgesic activities of extracts of Rumex abyssinicus at different doses in mice.

Materials and methods

The effect on urine volume and urinary electrolyte (Na⁺, K⁺ and Cl⁻) was assessed for a period of 5 h following oral administration of aqueous (500 mg/kg, 750 mg/kg or 1000 mg/kg) or 80% methanolic (250 mg/kg, 500 mg/kg or 750 mg/kg) extract or furosemide (10 mg/kg). Acetic acid-induced writhing and hot-plate tests were employed to study the analgesic effect of 80% methanolic extracts (250 mg/kg, 500 mg/kg or 1000 mg/kg, P.O.) and compared with that of aspirin (100 mg/kg, P.O.) or morphine (10 mg/kg, sc).

Results

The extracts displayed dose-dependent diuretic and analgesic effects. The highest doses of both extracts markedly and significantly increased (P < 0.001) urine volume and urinary electrolytes, qualitatively similar to that of furosemide. 1000 mg/kg of the extract reduced the number of writhing by 67.6% (P < 0.001) and conferred more than 70% protection against thermally induced pain stimuli after 45 min of treatment comparable to that of aspirin and morphine, respectively.

Conclusion

These findings collectively indicate that the extracts exhibited significant diuretic and analgesic activities, providing evidence, at least in part, for its folkloric use.     

Anti-inflammatory and analgesic properties of Heracleum persicum essential oil and hydroalcoholic extract in animal models

Ethnopharmacological relevance

Fruits of Heracleum persicum (Apiaceae) are used as pain killer in Iranian folkloric medicine.

Aims of study

To evaluate the anti-inflammatory and analgesic effects of the hydroalcoholic extract and essential oil of the plant fruits and analyzing the essential oil.

Materials and methods

Essential oil and hydroalcoholic extracts of the fruits were prepared according to standard methods and the components of essential oil were identified using GC–MS method. The acetic acid-induced writhing response and formalin test were used in male mice to assess analgesic activity. For evaluation of anti-inflammatory effect, carrageenan-induced rat paw edema was used.

Results

Hexyl butyrate (56.5%), octyl acetate (16.5%), hexyl 2-methylbutanoate (5.2%) and hexyl isobutyrate (3.4%) were identified as the major constituents of the oil. Oral or intraperitoneal administration of Heracleum persicum essential oil (HPEO) at doses of 50–200 mg/kg and Heracleum persicum hydroalcoholic extract (HPHE) at doses of 250 and 500 mg/kg significantly reduced acetic acid-induced abdominal constrictions. HPEO and HPHE also significantly attenuated the pain response of the second phase of formalin test.In carrageenan test HPEO at doses of 100 and 200 mg/kg and HPHE at a dose of 400 mg/kg induced a significant reduction of paw edema.

Conclusions

These results clearly show the analgesic and anti-inflammatory effects of the plant essential oil and hydroalcoholic extract. Further studies are needed to clarify the mechanism of action and the components responsible for these pharmacological effects.     

Antispasmodic and bronchodilator activities of Artemisia vulgaris are mediated through dual blockade of muscarinic receptors and calcium influx

Aim of the study

The present study describes antispasmodic, antidiarrheal, bronchodilatory and tracheo-relaxant activities of Artemisia vulgaris to rationalize some of its traditional uses.

Materials and methods

Crude extract of Artemisia vulgaris (Av.Cr) was studied in the isolated tissue preparations of rabbit jejunum and guinea-pig trachea, as well as in the in vivo castor oil-induced diarrhea and bronchodilatory techniques.

Results

Av.Cr which tested positive for alkaloids, coumarins, flavonoids, saponins, sterols, tannins and terpenes caused concentration-dependent (0.03–10 mg/mL) relaxation of jejunum spontaneous contractions. Av.Cr inhibited the carbachol (CCh, 1 μM) and K⁺ (80 mM)-induced contractions in a pattern, similar to that of dicyclomine. Av.Cr shifted the Ca²⁺ concentration–response curves to right, like that caused by verapamil and dicyclomine. Av.Cr produced rightward parallel shift in CCh-curves, followed by non-parallel shift at higher concentration with the suppression of the maximum response, similar to that caused by dicyclomine. It exhibited protective effect against castor oil-induced diarrhea and CCh-mediated bronchoconstriction in rodents. In trachea, Av.Cr relaxed the CCh (1 μM) and K⁺ (80 mM)-induced contractions and shifted the CCh-curves to right.

Conclusion

These results indicate that Artemisia vulgaris exhibits combination of anticholinergic and Ca²⁺ antagonist mechanisms, which provides pharmacological basis for its folkloric use in the hyperactive gut and airways disorders, such as abdominal colic, diarrhea and asthma.     

Leucas cephalotes regulates carbohydrate and lipid metabolism and improves antioxidant status in IDDM and NIDDM rats

Ethnopharmacological relevance

Leucas cephalotes (Roth.) Spreng. (Laminaceae) is an ayurvedic traditional medicinal plant used in India, Nepal and Pakistan to treat several ailments including diabetes.

Aim of the study

The aim of the present study is to investigate the antidiabetic, antihyperlipaemic and antioxidant activities of Leucas cephalotes for its purported use in diabetes.

Materials and methods

The ethanol extract of leaves of Leucas cephalotes was administered (150, 300 and 450 mg kg⁻¹ bw) to diabetes induced (IDDM and NIDDM) rats and carbohydrate, lipid, antioxidant, urea and creatinine profiles were assessed.

Results

All the three doses of extract decreased plasma glucose and lipid profiles and, improved the antioxidant status of both types of diabetic rats. The extract administration improved hepatic glycogen content and hexokinase activity, decreased glucose-6-phosphatase activity, blood urea, creatinine contents and decreased lipid peroxidation in diabetic rats. Of the three doses used, 450 mg kg⁻¹ bw dose was found to be more potent in its effects comparable to those of glibenclamide and metformin.

Conclusion

Leucas cephalotes regulates both carbohydrate and lipid metabolism and, improves body antioxidant defense systems in both types of diabetes.     

Anticonvulsant activity of Benkara malabarica (Linn.) root extract: In vitro and in vivo investigation

Aim of the study

To systematically investigate the anticonvulsant activity of methanol extract of Benkara malabarica roots and to provide a biochemical basis elucidating its mode of action.

Methods

The median lethal dose (LD₅₀) of Benkara malabarica extract was determined. The anticonvulsant activity of the extract was assessed in strychnine-induced and isoniazide-induced convulsion models; phenytoin (20 mg/kg) and diazepam (1 mg/kg) were used as standards, respectively. Percentage protection provided by the drug was accounted as decrease in the number of convulsions within 8 h of observation. Mechanism of action was studied by performing GABA transaminase (GABA-T) assay, isolated from rat brain. Active constituent was isolated and characterized from the plant extract.

Results

The median lethal dose (LD50) of Benkara malabarica was found to be more than 500 mg/kg. It demonstrated 30% and 35% protection against strychnine-induced convulsions and 60% and 80% protection against isoniazide-induced convulsions, at doses of 25 mg/kg and 50 mg/kg, respectively. Enzyme assay results revealed that Benkara malabarica extract possesses GABA-T inhibitory activity (IC50 = 0.721 mg/ml). Scopoletin which was identified as the major constituent of the extract was found to be an inhibitor of GABA-T (IC50 = 10.57 μM).

Conclusions

The anticonvulsant activity of the plant extract is predominantly GABA mediated and may be due to the action of scopoletin alone or is a result of synergy of different compounds in the extract in which scopoletin is the major constituent.     

Immunomodulatory potential of rhizome and seed extracts of Nelumbo nucifera Gaertn.

Ethnopharmacological relevance

Nelumbo nucifera Gaertn. (Nymphaeaceae) is a well-known aquatic plant which has been used for the treatment of several disorders including skin disease, cough, inflammation, fever and many other disorders.

Aim of the study

To explore the immunomodulatory activity of extract of rhizome (NNRE) and seed (NNSE) of the plant.

Materials and methods

The immunomodulatory activity of NNRE and NNSE was evaluated using various in vivo models including the total and differential leukocyte count (TLC and DLC), nitroblue-tetrazolium reduction (NBT) test, neutrophil adhesion test, phagocytic response and delayed type hypersensitivity (DTH) reaction. Sheep red blood cells (SRBC, 5 × 10⁹ cells/ml) were used to immunize the animals. NNRE and NNSE at the doses of 100 and 300 mg/kg were administrated.

Result

The TLC and lymphocyte count increased significantly but the neutrophil count was decreased for NNRE and NNSE treated groups compared to the control. A dose-dependent potentiation of DTH reaction induced by SRBC was observed from the extracts. The percentage of neutrophil adhesion to the nylon fiber was increased in NNRE treated groups (63.22 and 62.91%) compared to the NNSE treated group (54.86 and 54.23%). A potential phagocytic response was seen on treatment of the extracts, and significant changes were observed in the formation of formazone crystals.

Conclusion

This finding suggests that the extract of rhizome and seed Nelumbo nucifera stimulate defense system by modulating several immunological parameters.     

In vitro antimicrobial activity of Caesalpinia ferrea Martius fruits against oral pathogens

Aim

In the Amazon region of Brazil, the fruits of Caesalpinia ferrea Martius (Brazilian ironwood) are widely used as an antimicrobial and healing medicine in many situations including oral infections. This study aimed to evaluate the antimicrobial activity of Caesalpinia ferrea Martius fruit extract against oral pathogens.

Materials and methods

Polyphenols estimation and spectral analysis (¹H NMR) of the methanol extract were carried out. The microorganisms Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were tested using the microdilution method for planktonic cells (MIC) and a multispecies biofilm model. Chlorhexidine was used as positive control.

Results

Polyphenols in the extract were estimated at 7.3% and ¹H NMR analysis revealed hydroxy phenols and methoxilated compounds. MIC values for Candida albicans, Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis and Lactobacillus casei were 25.0, 40.0, 66.0, 100.0, 66.0 μg/mL, respectively. For the biofilm assay, chlorhexidine and plant extract showed no growth at 10⁻⁴ and 10⁻⁵ microbial dilution, respectively. At 10⁻⁴ and 10⁻⁵ the growth values (mean ± SD) of the negative controls (DMSO and saline solution) for Streptococcus mutans, Streptococcus sp. and Candida albicans were 8.1 ± 0.7, 7.0 ± 0.6 and 5.9 ± 0.9 × 10⁶ CFU, respectively.

Conclusion

Caesalpinia ferrea fruit extract can inhibit in vitro growth of oral pathogens in planktonic and biofilm models supporting its use for oral infections.     

The effect of total extract of Securigera securidaca L. seeds on serum lipid profiles,antioxidant status,and vascular function in hypercholesterolemic rats

Aim of the study

Seeds of Securigera securidaca are used for the treatment of disorders such as hyperlipidemia, diabetes, and epilepsy in Iranian folk medicine. The possible hypolipidemic and antioxidative effects of hydroalcoholic extract of S. securidaca seeds as well as the effect of the extract on vascular reactivity were investigated in hypercholesterolemic rats.

Materials and methods

High-fat fed wistar rats received orally different doses of the extract for 20 days. At the end of the experiment vein blood and liver were collected to measure the lipid profile, lipid peroxidation, and antioxidative enzyme activities. The thoracic aorta was excised and used for isolated vessel preparation and histological study.

Results

The extract produced significant reductions (p < 0.05) in the level of low-density lipoprotein (LDL) and triglyceride with concomitant reduction in lipid deposition in the liver. The extract also suppressed markedly (p < 0.001) the hypercholesterolemia-induced elevation of malondialdehyde levels both in serum and liver. In hypercholesterolemic rats the endothelium-dependent vasodilatation was improved significantly (p < 0.05) by 100 mg/kg/day of the extract. However, in histological study no atherosclerotic lesion was observed.

Conclusion

These results suggest that S. securidaca seed in addition to decrease lipid levels and peroxidation, is able to improve vascular endothelium-dependent relaxation in hypercholesterolemia.     

Acute effects of Fraxinus excelsior L. seed extract on postprandial glycemia and insulin secretion on healthy volunteers

Aim of the study

Fraxinus excelsior L. (Family: Oleaceae) seeds are consumed as a food, condiment, and folk medicine. The seeds are traditionally used as a potent hypoglycemic agent, but no clinical evidence exists in as to this regard. We assessed the clinical efficacy and safety of the seed extract (FraxiPure™, Naturex), containing 6.8% of nuzhenide and 5.8% of GI3 (w/w), on plasma glucose and insulin levels against glucose (50 g) induced postprandial glycemia.

Materials and methods

Preselected dose (1.0 g) was used in a double blind, randomized, crossover, placebo (wheat bran) controlled study on 16 healthy volunteers. Each treatment was given immediately after a fasting blood glucose sample (0 min). Postprandial plasma glucose levels were estimated at 0, 15, 30, 45, 60, 90 and 120 min; and postprandial plasma insulin at 0, 30, 60, 90 and 120 min.

Results

The extract lowered the incremental postprandial plasma glucose concentration as compared to placebo at 45 min (P = 0.06) and 120 min (P = 0.07). It statistically (P = 0.02) reduced the glycemic area under the blood glucose curve. The seed, also, induced a significant (P = 0.002) secretion of insulin at 90 min after glucose administration. However, the insulinemic area under the blood insulin curve was not different than the placebo. No adverse events were reported.

Conclusions

Our findings confirm the hypoglycemic action of Fraxinus excelsior L. seed extract. These promising results, thus, encourage conducting long-term clinical studies to further evaluate the efficacy and safety of Fraxinus excelsior L. seed extract in healthy and diabetic volunteers and also to explore the possible mechanism(s) of action.     

Toxicity and potential anti-trypanosomal activity of ethanolic extract of Azadirachta indica (Maliacea) stem bark: An in vivo and in vitro approach using Trypanosoma brucei

Aim of the study

To determine the toxicity and anti-trypanosomal activity of the ethanolic extract of Azadirachta indica (Maliacea) stem bark, through in vivo and in vitro approach using Trypanosoma brucei brucei.

Materials and methods

Graded concentrations (100, 200, 400, 800, 1600 and 3200 mg/kg) of the crude stem bark ethanolic extract of Azadirachta indica, Hochst ex. A. Dc. (Maliacea) was tested for acute toxicity in 35 out bred Swiss (Wister) adult albino rats of both sexes. Secondly, the in vitro activity in test tubes and in vivo activity of the extract in 30 out bred Swiss (Wister) adult albino rats against Trypanosoma brucei brucei strain NITR/14 (Federe) was evaluated in a graded dose manner.

Results

The calculated intra-peritoneal LD₅₀ of the extract was 870 mg/kg and produced toxicity at high doses (>800 mg/kg). Graded concentrations of the ethanolic extract produced remarkable in vitro activity against Trypanosoma brucei brucei within seconds of inoculation. It also suppressed the establishment of parasitaemia at 100 mg/kg when administered simultaneously with infection in vivo. Similarly, at 200 and 400 mg/kg, the extract administered at the onset of parasitaemia for 4 consecutive days reduced parasitaemia, modulated declined packed volume (PCV) changes by day 48 post-infection in vivo.

Conclusion

The results confirm that the folkloric medicinal application of the extract of Azadirachta indica (Maliacea) has a pharmacological basis. Further investigation is however, needed to optimize the effectiveness of the extract.     

Gastroprotective activity of the ethanol extract from the inner bark of Caesalpinia pyramidalis in rats

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae), known as “catingueira”, has been used in folk medicine in the treatment of various disorders such as gastritis, heartburn, indigestion, and stomach ache. However, the gastroprotective properties of this species have not yet been studied.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in rats via oral route, at the doses of 30, 100, and 300 mg/kg. The antiulcer assays were performed using the ethanol- and nonsteroidal anti-inflammatory drug-induced ulcer models. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligated model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of the ethanol extract of Caesalpinia pyramidalis was performed using the agar-well diffusion and broth microdilution methods.

Results

The ethanol extract (30, 100, and 300 mg/kg) produced dose dependent inhibition (P<0.01) on the ulcer lesion index, the total lesion area, and the percentage of lesion area in the ethanol-induced ulcer model. The ethanol extract (30, 100, and 300 mg/kg) also reduced (P<0.001) the ulcer index in the indomethacin-induced ulcer model. In the model ligature pylorus, the treatment with Caesalpinia pyramidalis ethanol extract failed to significantly change the gastric secretion parameters. However, after treatment with the ethanol extract of Caesalpinia pyramidalis (30, 100, and 300 mg/kg), there was a significant increase (P<0.05) in mucus production. The ethanol extract showed anti-Helicobacter pylori activity, with inhibition halos of 12.0±1.7 mm at 10,000 μg/mL. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the ethanol extract were of 625 and 10,000 μg/mL, respectively.

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis displays gastroprotective actions, supporting the folkloric usage of the plant to treat various gastrointestinal disturbances.     

Evaluation of mechanisms involved in the antinociception of the ethanol extract from the inner bark of Caesalpinia pyramidalis in mice

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae) is an endemic tree of the Northeast region of Brazil, mainly in the Caatinga region. More commonly, inner bark or flowers are traditionally used to treat many painful and inflammatory processes. A common use of this plant is made by macerating a handful of its stem bark in a liter of wine or sugarcane brandy. It is drunk against stomachache, dysenteries, and diarrheas.

Materials and methods

The ethanol extract of Caesalpinia pyramidalis inner bark was used in mice via oral route, at the doses of 10, 30, and 100 mg/kg, in behavioral models of nociception and investigates some of the mechanisms underlying this effect.

Results

The ethanol extract (30 and 100 mg/kg, P<0.001), given orally, produced dose dependent inhibition of acetic acid-induced visceral pain. The ethanol extract also caused significant and dose-dependent inhibition of capsaicin-(100 mg/kg, P<0.001) and glutamate-(10, 30, and 100 mg/kg, P<0.01) induced pain. The antinociception caused by the ethanol extract (30 mg/kg) in the abdominal constriction test was significantly attenuated (P<0.001) by intraperitoneal treatment of mice with l-arginine (600 mg/kg).

Conclusions

Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis produced dose-related antinociception in several models of pain through mechanisms that involved both glutamatergic system and/or the l-arginine–nitric oxide pathway, supporting the folkloric usage of the plant to treat various painful processes.     

Anti-inflammatory activity of Markhamia tomentosa (Benth.) K. Schum. Ex Engl. ethanolic leaf extract

Ethnopharmacological relevance

The leaves of Markhamia tomentosa (Benth.) K. Schum (Bignoniaceae) are used traditionally for the treatment of oedema and rheumatoid arthritis in Nigeria.

Aim of the study

The aim of the work was to investigate the anti-inflammatory activity of the ethanolic leaf extract of Markhamia tomentosa.

Materials and methods

The extract was screened using the carrageenan-induced paw oedema in rats, xylene-induced oedema in mice and the formalin-induced oedema in mice at 50, 100, 200 mg/kg doses p.o respectively. The mechanism by which the extract mediated the anti-inflammatory activity was assessed using the histamine-induced rat paw oedema and serotonin-induced rat paw oedema at the highest dose (200 mg/kg).

Results

The results showed that the extract produced a significant dose-dependent inhibition in carrageenan-induced, xylene-induced and the formalin tests. The extract exerted a significant inhibition of 54.55% (P<0.0001) and 42.11% (P<0.01) at 90 min in the histamine-induced and serotonin-induced rat paw oedema models respectively.

Conclusions

These findings suggest that the ethanolic leaf extract of Markhamia tomentosa possesses anti-inflammatory activity possibly mediated by histamine. The results justify the use of the plant in the preparation of ethno medicines used in the treatment of ailments associated with inflammation.     

Trapa natans L. root extract suppresses hyperglycemic and hepatotoxic effects in STZ-induced diabetic rat model

Ethnopharmacological relevance

Trapa natans L. has a folkloric reputation as nutrient, appetizer and astringent. Its utility as antidiabetic, anticancer, diuretic, aphrodisiac, antidiarrhoeal and in many other maladies is well reported in the literature. Therefore, the present study has been carried out to study the antihyperglycemic effect of root extract of Trapa natans L. and its various fractions. Furthermore, hepatotoxic effects and lipid peroxidation risks have also been evaluated.

Methods

The ethanol extract and its successive fractions obtained from roots of Trapa natans have been administered in sucrose loaded and STZ- induced diabetic Wistar rats at doses of 50, 100 and 200 mg/kg b.w. Glibenclamide was used as positive control. The evaluation of protective effects of extract as well as fractions against hepatotoxicity and lipid peroxidation at 600 mg/kg b.w. has also been carried out.

Results

The methanol fraction emerged as the most potent antihyperglycemic fraction. It has also been found that the ethanolic extract as well as its fractions did not cause any lipid peroxidation and hepatotoxicity risks.

Conclusion

It can be concluded that the intense investigations of the methanol fraction obtained from Trapa natans root extract can be done to provide an alternative natural therapy for hyperglycemia.     

Inhibitory effects of Bulnesia sarmienti aqueous extract on agonist-induced platelet activation and thrombus formation involves mitogen-activated protein kinases

Ethnopharmacological relevance

B. sarmienti has long been recognized in folk medicine as a medicinal plant with various medicinal uses. Traditionally, it has been appreciated for the skin-healing properties of its essence. The bark has also been employed to treat stomach and cardiovascular disorders and reported to have antitumor, antioxidant and anti-inflammatory activities. However, information on its antiplatelet activity is limited.

Aim of the study

To examined the effects of B. sarmienti aqueous extract (BSAE) in platelet physiology.

Materials and methods

The anti-platelet activity of BSAE was studied using rat platelets for in vitro determination of the extract effect on agonist-induced platelet aggregation, ATP secretion, [Ca²⁺]_i mobilization and MAP kinase phosphorylation. The extract in vivo effects was also examined in arterio-venous shunt thrombus formation in rats, and tail bleeding time in mice.

Result

HPLC chromatographic analysis revealed that B. sarmienti extract contained (+)-catechin (C), (−)-epigallocatechin (EGC), (−)-epicatechin (EC), and (−)-epicatechin gallate (ECG). BSAE, significantly and dose dependently, inhibited collagen, thrombin, or ADP-induced platelet aggregation. The 50 percent inhibitory concentrations (IC₅₀) of the extract for collagen, thrombin and ADP-induced platelet aggregation were 45.3 ± 2.6, 100 ± 5.6 and 110 ± 4.6 μg/ml, respectively. Collagen activated ATP release and thrombin-induced intracellular Ca²⁺ concentration were reduced in BSAE-treated platelets. In addition, the extract in vivo activity showed that BSAE at 100 mg/kg significantly attenuated thrombus formation in rat extracorporeal shunt model while mice tail bleeding time was not affected. Moreover, BSAE attenuated p38 mitogen-activated protein kinase (p38 MAPK), c-Jun N-terminal kinase 1 (JNK1) and extracellular-signal-regulated protein kinase 2 (ERK2) phosphorylations.

Conclusion

BSAE inhibits platelet activation, granule secretion, aggregation, and thrombus formation without affecting bleeding time, and that this effect is mediated by inhibition of P38, JNK1 and ERK2 phosphorylations. The ability of BSAE to inhibit platelet function might be relevant in cases involving aberrant platelet activation where the plant extract could be considered as a candidate to anti-platelet and antithrombotic agent.     

Antinociceptive and anti-inflammatory activities of Bowdichia virgilioides (sucupira)

Ethnopharmacological relevance

Bowdichia virgilioides Kunth (Leguminosae Papilonoideae) is a plant with anti-inflammatory activity used in folk medicine. The importance of this plant promoted its inclusion in Brazilian Pharmacopoeia.

Aim of the study

In order to evaluate the actions of this plant, studies were performed on antinociceptive and anti-inflammatory activities.

Materials and methods

The aqueous extracts (AE) of Bowdichia virgilioides inner bark and leaves were used at 100, 200, and 400 mg/kg. Antinociceptive activity of plant extract was evaluated by writhing, hot-plate and formalin tests. Anti-inflammatory activity was evaluated using paw oedema and peritonitis methods.

Results

Oral treatment with the AE of inner bark or leaves elicited inhibitory activity (P < 0.01) on acetic acid effect at 200 and 400 mg/kg, and reduced the formalin effect at the second-phase (200 and 400 mg/kg, P < 0.01), however it did not elicit any inhibitory effect on hot-plate test. The indomethacin inhibited the acetic acid-induced writhing and the formalin effect at the second-phase (P < 0.001), and the morphine reduced the both phases of formalin test (P < 0.001). Carrageenan-induced oedema formation and neutrophil migration into the peritoneal cavity were reduced with the AE of inner bark or leaves at 100, 200, and 400 mg/kg (P < 0.05), and by the reference compounds aspirin (P < 0.001) and dexamethasone (P < 0.001), respectively.

Conclusions

The AE of Bowdichia virgilioides shows antinociceptive and anti-inflammatory activities, supporting the folkloric usage of the plant to treat various inflammatory diseases.     

Vasorelaxant and anti-platelet aggregation effects of aqueous Ocimum basilicum extract

Aim of the study

In this work the endothelium-dependant vasorelaxant and anti-platelet aggregation activities of an aqueous extract from Ocimum basilicum were studied.

Materials and methods

The vasorelaxant effect was undertaken in thoracic aorta from three experimental groups of rats: one of them (NCG) fed with standard diet, the second (HCG) with hypercholesterolemic diet (HCD) and the third (BTG) with hypercholesterolemic diet together with an intragastric administration of Ocimum basilicum extract at a dose of 0.5 g/kg body weight for a period of 10 weeks. The in vitro anti-platelet aggregation of Ocimum basilicum extract was studied using thrombin (0.5 U/ml) and ADP (5 μM) as agonists.

Results

The results show that the HCD statistically decreases vascular relaxation in HCG compared to NCG (p < 0.001) and increases the vascular responses to phenylephrine (p < 0.02). Ocimum basilicum extract exerts a significant vasorelaxant effect at 10⁻⁵ M (p < 0.01) and 10⁻⁴ M carbachol (p = 0.001). The plant extract also tends to suppress the elevated contractions induced by HCD (p = 0.05). The extract inhibits ADP-induced platelet aggregation by 13%, 28.2%, 30.5%, 44.7% and 53% at a dose of 1, 2, 3, 4 and 5 g/l, respectively. Thrombin-induced platelet activation was also reduced by 15%, 23%, 40%, 38.4%, and 42% at the same doses of extract described above.

Conclusion

The use of Ocimum basilicum as medicinal plant could be beneficial for cardiovascular system.