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.     

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.     

Hypoglycemic effects of Cecropia pachystachya in normal and alloxan-induced diabetic rats

Ethnopharmacological relevance

Leaves of Cecropia pachystachya are described in the folk medicine as possessing antitusive, expectorant, antiasthmatic and hypoglycemic effects.

Aim of the study

To investigate the hypoglycemic and antioxidant effects of methanolic extract from the leaves of Cecropia pachystachya. The total amount of phenolic and flavonoids compounds was determined and the qualitative composition of the extract was analyzed.

Materials and methods

The hypoglycemic effect of the extract was tested in normal, glucose loading and alloxan-induced diabetic rats. The antioxidant activity was assessed by DPPH free radical scavenging and reduction power assays. The total amount of phenolic and flavonoids compounds was determined by Folin-Denis and AlCl₃ reagent method, respectively. The qualitative composition of the extract was analyzed using a HPLC-DAD system.

Results

The glucose tolerance test showed that in diabetic rats, the extract caused a significant hypoglycemic effect with a blood glucose reduction of 68% after 12 h. The administration of the extract in alloxan-induced diabetic rats also produced a significant reduction in the blood glucose levels at all points being more pronounced at 90 min (reduction of 60%). After 120 min, no significant difference was observed between the blood levels of the rats treated with the extract and those treated with the standard drugs (metformin and glibenclamide). The extract also presented relevant antioxidant activity with IC₅₀ = 3.1 μg/ml (DPPH assay) and EC₅₀ = 10.8 μg/ml (reduction power). Results were compared with the reference antioxidants quercetin, rutin, and ascorbic acid. The content of flavonoids was 83 mg/g plant and that of phenolics was 326 mg/g plant. Chlorogenic acid and the C-glycosylated flavones, orientin and isoorientin, were identified in the extract.

Conclusions

In conclusion, the findings showed that the folk medicinal plant Cecropia pachystachya possesses hypoglycemic and antioxidant effects which confirmed the traditional use of the plant in the treatment of diabetes. Chlorogenic acid and the C-glycosylated flavonoids may explain these activities.     

Studies on the analgesic,anti-inflammatory and antipyretic effects of Parquetina nigrescens leaf extract

Ethnopharmacological relevance

Parquetina nigrescens is a shrub that is commonly used in different parts of West Africa for the treatment of several ailments which includes pain, fever and inflammatory conditions.

Aim of the study

The present study was designed to investigate the analgesic, anti-inflammatory and antipyretic effects of the aqueous extract of Parquetina nigrescens leaves in rats.

Materials and methods

Five groups were used for each study, groups 1 and 5 served as control (saline) and reference (indomethacine) respectively, while groups 2–4 received the extract (50–200 mg/kg) orally. Formalin paw licking and hot plate latency tests were used for analgesic studies. Carrageenan oedema, cotton pellet granuloma and formaldehyde arthritis models were used to quantify the anti-inflammatory activities while the brewer’s yeast was used for inducing pyrexia.

Results

The results of the analgesic study show that the extract produced significant (p < 0.05) analgesia in the hot plate and in the formalin tests. In the anti-inflammatory study, Parquetina nigrescens produced significant (p < 0.05) inhibition of the various types of inflammation. The extract also inhibited the pyrexia induced by brewer’s yeast.

Conclusion

The result justifies the traditional uses of Parquetina nigrescens for the treatment of fever, inflammatory and painful conditions.     

Inhibitory effects of Duchesnea chrysantha extract on ovalbumin-induced lung inflammation in a mouse model of asthma

Ethnopharmacological relevance

Duchesnea chrysantha (D. chrysantha) is a herb with anti-oxidative, anti-inflammatory and immune-enhancing properties.

Aim of the study

Asthma is an inflammatory disease of the lungs, and the hallmarks of the disease are increased inflammatory cell infiltration into the airways and poor respiratory function. Although there is the possibility that D. chrysantha may have an inhibitory effect on lung inflammation, the effects of D. chrysantha on asthma have not been fully investigated. In the present study, we investigated the anti-inflammatory activity of D. chrysantha extract (Dc extract) on lung inflammation in a murine model of ovalbumin-induced asthma.

Materials and methods

Dc extract was obtained from dried and powdered whole plants of D. chrysantha using 80% ethanol. BALB/c mice induced by ovalbumin sensitization and nebulization were used as a mouse model of asthma. RT-PCR and ELISA were performed to measure mRNA and protein expression of cytokines. We examined the effects of Dc extract on leukocyte infiltration and mucus secretion using periodic acid-Schiff staining as well as hematoxylin and eosin staining.

Results

Dc extract significantly inhibited leukocytosis and eosinophilia in the bronchoalveolar lavage (BAL) fluid (p < 0.01). Dc extract significantly reduced the elevated infiltration of inflammatory cells (p < 0.05) and inhibited the increased mucus secretion, despite the absence of significant value. Although Dc extract weakly inhibited the mRNA expression of IL-4, IL-5, IL-13, and eotaxin, it strongly inhibited the protein expression of IL-5 (p < 0.05) and eotaxin (p < 0.01) in BAL fluid. Ovalbumin-specific IgE levels in the serum and BAL fluid were blocked by Dc extract (p < 0.05).

Conclusions

These results suggest the possibility that Dc extract can exert suppressive effects on asthma and may provide evidence that Dc extract is a useful agent for the treatment of allergic airway disease.     

Antihypertensive activity of Salvia elegans Vahl. (Lamiaceae): ACE inhibition and angiotensin II antagonism

Ethnopharmacological relevance

Salvia elegans Vahl. (Lamiaceae), recognized with the popular name of “mirto” is widely used in Mexico for healing purposes, and also them as antihypertensive treatment.

Aim of the study

The high prevalence of this illness and the side effects of antihypertensive drugs conducted us to the evaluation of the Salvia elegans extract on angiotensin II action.

Materials and methods

The acute response of blood pressure to angiotensin II administration was measured in mice. We also tested in vitro the inhibitory effect on angiotensin convertase enzyme. Additionally, characterization of the pharmacological effect of the extract fraction was obtained.

Results

We obtained dose–response curve for the administration of complete extract and extract fractions. Due to the hydroalcoholic extract (SeHA) treatment blood pressure decreased significantly from systolic dose of 0.75 mg kg⁻¹ (p < 0.05) and even had an antihypertensive effect that was greater than that treatment with losartan. SeHA extract decreased the E_max of the AG II hypertensive effect by about 20% in both systolic and diastolic pressures, treatment with losartan also decreased the same parameter between 6% and 8% for systolic and diastolic pressures, respectively. Fractions SeF8 and SeF8-8 showed similar levels of AG II ED₅₀ for both pressures compared with losartan, these fractions showed major compounds with maximum absorbance peaks at 221, 289 and 330 nm typical of flavonoids. In the inhibition assay the activity of angiotensin converting enzyme (ACE), the extract SeHA showed percentage inhibition (%IACE) of 50.27 ± 5.09% (n = 5). SeBuOH fraction is found to have greater inhibitory capacity of achieving a IACE 78.40 ± 2.24% (n = 5), which was similar to the values obtained in the presence of the SeF8-22 fraction (82.61 ± 1.74%) and lisinopril (87.18 ± 1.16%). The changes in the value of K_M suggest that components of the extracts and fractions were recognized by the enzyme's active site. The main compounds of the fractions SeBuOH, SeF8-22 were by flavonoid and phenyl propanoid types, according to UV absorption spectra of the fractions.

Conclusions

The experimental results demonstrated the antihypertensive effect of Salvia elegans and it was due to the AG II antagonism and inhibition of angiotensin converting enzyme.     

Fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats

Ethnopharmacological relevance

The aerial parts of Coccinia cordifolia L. are used to treat female infertility in West Bengal state of India.

Aim of the study

The present study was undertaken to evaluate the fertility inducing effect of aerial parts of Coccinia cordifolia L. in female rats.

Materials and methods

The effect of aqueous extract of Coccinia cordifolia L. on hyperprolactinemia induced infertility, endometriosis induced infertility and androgen-induced infertility was studied. The effect on serum estrogen level, serum progesterone level and reproductive tract was also evaluated in normal healthy female rats. The extract was administered orally at two different doses of 500 mg/kg and 1000 mg/kg.

Results

In hyperprolactinemia induced infertility model, the numbers of uterine implants were almost 10 times more in the extract treated groups as compared to control. The high dose of extract also produced a significant increase in serum estrogen levels (p < 0.01) and number of corpus luteum (p < 0.05) in healthy female rats. The extract at both doses was effective in reducing the weight of endometrial implants by 70–80%, but failed to induce fertility in rats with endometriosis. The extract was ineffective in inducing fertility in androgen-induced infertility model.

Conclusions

The aqueous extract of Coccinia cordifolia L. induces fertility in hyperprolactinemia induced infertility model in female rats.     

Effect of Tectona grandis Linn. on dexamethasone-induced insulin resistance in mice

Ethnopharmacological relevance

The bark of Tectona grandis Linn. is traditionally used in the treatment of diabetes.

Aim

The present study was undertaken to investigate the effect of ethanolic extract of bark of Tectona grandis Linn. (TG) in dexamethasone-induced insulin resistance in mice.

Materials and methods

Mice were treated with prestandardised dose of dexamethasone for 22 days and effect of TG at the doses of 50, 100 and 200 mg/kg, p.o. on plasma blood glucose level, serum triglyceride level, glucose uptake in skeletal muscle, levels of hepatic antioxidant enzymes (GSH, SOD, catalase and LPO), and body weight were observed.

Results

TG showed significant decrease in plasma glucose and serum triglyceride levels (p < 0.01) at the dose of 100 and 200 mg/kg, p.o. and also stimulated glucose uptake in skeletal muscle. The levels of antioxidant enzymes GSH, SOD, and catalase were significantly increased (p < 0.01) and there was significant decrease (p < 0.01) in level of LPO.

Conclusion

Hence it can be concluded that Tectona grandis may prove to be effective in the treatment of Type-II Diabetes mellitus owing to its ability to decrease insulin resistance.     

Evaluation of anti-inflammatory potential of Chloranthus erectus (Buch.-Ham.) Verd. leaf extract in rats

Aim of the study

Chloranthus erectus (Buch.-Ham.) Verdcourt (Chloranthaceae) is a shrub native to tropical and temperate zone of Eastern Himalaya of India and South-East Asia and have traditionally been used as a folklore medicine to treat localised swelling, joint pain, skin inflammation, fever and bodyache. In this study, an attempt has been made to demonstrate the anti-inflammatory activity of methanol extract obtained from Chloranthus erectus leaves (MECEL) in acute, sub-acute and chronic mouse models.

Materials and methods

Inflammation in the hind paw of Wistar albino rat was induced by carrageenan, histamine and serotonin, and tissue granuloma pouch was induced by cotton pellet method. Anti-inflammatory drug—phenylbutazone was used as standard drug for comparison.

Results

In acute carrageenan-induced rat hind paw edema, oral administration of MECEL at 200 mg/kg produced significant inhibition of edema by 38.34% (p < 0.01) while the histamine- and serotonin-induced sub-acute model, the inhibition of paw edema reached 52.54% (p < 0.001) and 25.5% (p < 0.01), respectively. In a 7-day study, MECEL at 20 and 50 mg/kg produced significant suppression of cotton pellet-induced tissue granuloma formation in rats.

Conclusions

This preliminary study revealed that the methanol extract of Chloranthus erectus exhibited significant anti-inflammatory activity in the tested models, and may provide the scientific rationale for its popular folk medicine as anti-inflammatory agent.     

Substantiation of the ethnopharmacological use of Conyza sumatrensis (Retz.) E.H.Walker in the treatment of malaria through in-vivo evaluation in Plasmodium berghei infected mice

Ethnopharmacological relevance

Scientific validation of ethnopharmacologically used plants and their utilization for therapeutic interventions can be a source of affordable treatment especially for neglected diseases in endemic areas. Conyza sumatrensis is a plant which finds its use in treating malaria like fevers but lacks proper scientific validation. Our study has tried to address this gap by authenticating its traditional use for the treatment of malaria.

Aim of the study

Evaluate the antimalarial activity of extracts derived from Conyza sumatrensis for its ethnopharmacological validation.

Materials and methods

Shade dried leaves were extracted with varying concentrations of ethanol and concentrated for bio-evaluation. Swiss albino mice infected with 1×10⁶ parasitized red blood cells, were orally administered with test extracts for 7 days in two sets of experiments. The first set was used to evaluate alcoholic, hydroalcoholic and aqueous extracts while the second set was used to evaluate the dose response of alcoholic extract ranging from 500–1600 mg/kg. Mean survival time, parasitaemia and haemoglobin levels were considered to interpret the antimalarial potential. Phytochemical analysis for the presence of flavonoids, alkaloids tannins, total phenolics, riboflavin and thiamine was also carried out.

Results

Among the three extracts administered at 1000 mg/kg, chemo suppression was significantly (p<0.001) observed in the alcoholic extract (62.59±12.52%) followed by hydroalcoholic (41.81±19.04%, p<0.01) and aqueous (32.04±19.04%, P<0.05) indicating that the active constituents leach out in ethanol. The dose response study involving the ethanol extract concluded the optimum dose to be 1000 mg/kg, as also evidenced by the haemoglobin levels.

Conclusion

The plant exhibits moderate antimalarial activity which can be further prospected for active fractions or pure molecules for adjunctive therapy.     

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.     

The effect of Dodonaea viscosa var. angustifolia on Candida albicans proteinase and phospholipase production and adherence to oral epithelial cells

Aim of the study

This study investigated effect of a crude extract of Dodonaea viscosa on the proteinase and phospholipase production and adherence to epithelial cells by Candida albicans isolated from HIV positive and HIV negative patients.

Materials and methods

Twenty Candida albicans strains isolated from HIV positive and 20 from HIV negative patients were investigated. The isolates were exposed to subinhibitory concentration of crude plant extract and adherence, proteinase and phospholipase production were assessed. The results were analysed using Student's t-test and a two-way ANOVA.

Results

Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells (p = <0.01) but no significant effect of the plant extract on proteinase and phospholipase production was observed. Results from Candida albicans strains isolated from HIV positive and HIV negative patients were similar.

Conclusions

Dodonaea viscosa var. angustifolia inhibited the adherence of Candida albicans to oral epithelial cells, which is the initial step of colonization in the infection process. This plant has a therapeutic potential at subinhibitory concentration.     

Artemisia copa aqueous extract as vasorelaxant and hypotensive agent

Ethnopharmacological relevance

Artemisia copa Phil. (Asteraceae) is a medicinal plant commonly used in traditional medicine in Argentina.

Aim of the study

The vasorelaxant and hypotensive activities of the aqueous extract of Artemisia copa have been investigated.

Materials and methods

The in vitro effect of the extract and isolated compounds from Artemisia copa was investigated using isolated rat aortic rings. The acute effect caused by the intravenous (i.v.) infusion (0.1–300 mg/kg) on blood pressure and heart rate was evaluated in spontaneous hypertensive rats. In addition, a phytochemical analysis of the extract was performed by HPLC.

Results

Artemisia copa had a relaxant effect in endothelium-intact aortic rings that had been pre-contracted with 10⁻⁷ M phenylephrine (E_max=96.7±1.3%, EC₅₀=1.1 mg/ml), 10⁻⁵ M 5-hydroxytriptamine (E_max=96.7±3.5%, EC₅₀=1.5 mg/ml) and 80 mM KCl (E_max=97.9± 4.4%, EC₅₀=1.6 mg/ml). In denuded aortic rings contracted by phenylephrine, a similar pattern was observed (E_max=92.7±6.5%, EC₅₀=1.8 mg/ml). l-NAME, indomethacin, tetraethylammonium and glibenclamide were not able to block the relaxation induced by the extract. Nevertheless, the pre-treatment with Artemisia copa attenuated the CaCl₂-induced contraction in a concentration-dependent manner (E_max: 86% of inhibition for 3 mg/ml and 52% de-inhibition for 1 mg/ml). This pre-treatment also induced a significant attenuation of the norepinephrine-induced contraction in a concentration-dependent manner (E_max: 72.7% of inhibition for 3 mg/ml and 27% de inhibition for 1 mg/ml) in a Ca²⁺ free medium. Upon analyzing the composition of the extract, the presence of p-coumaric acid, isovitexin, luteolin and chrysoeriol were found. Luteolin (CE₅₀: 1.5 μg/ml), chrysoeriol (CE₅₀: 13.2 μg/ml) and p-coumaric acid (CE₅₀: 95.2 μg/ml), isolated from the aqueous extract, caused dilatation of thoracic aortic rings pre-contracted with phenylephrine. Artemisia copa administered i.v. also induced a decrease in the mean arterial pressure but did not affect the heart rate in hypertensive rats.

Conclusions

The aqueous extract of Artemisia copa proved to have vasorelaxing and hypotensive effects through the inhibition of Ca²⁺ influx via membranous calcium channels and intracellular stores. The presence of luteolin, chrysoeriol and p-coumaric acid found in this plant could be involved in this effect.     

Evaluation of the anti-stress and anticonvulsant activities of leaf extract of Alchornea cordifolia in mice

Aim of the study

The extract of the leaves of Alchornea cordifolia (AC) is extensively used in ethnomedicine for ulcers, rheumatic pains, febrile convulsions and for enhancing physical performance. In this study, the anti-stress and anticonvulsant activities of the aqueous leaf extract of Alchornea cordifolia were investigated in mice.

Materials and methods

The anti-stress activity was assessed based on the ability of the extract to alter the duration of immobility, in the forced swim endurance test, whilst a picrotoxin-treated animal, was employed as the model for convulsive seizures.

Results

The extract (100–400 mg/kg) given orally was found to significantly (p < 0.05) reduce the duration of immobility, which suggest an anti-stress/anti-fatigue property. However, AC when tested at doses between 100 and 400 mg/kg did not prevent convulsions induced by picrotoxin in mice. The acute toxicity study carried out in mice revealed that the extract was well tolerated by the animals, as no death was observed at oral doses of 500–4000 mg/kg.

Conclusions

The results of this preliminary study provide evidence, which may support the use of Alchornea cordifolia against stress or fatigue in ethnomedicine.     

The effect of Salvia divinorum and Mitragyna speciosa extracts,fraction and major constituents on place aversion and place preference in rats

Ethnopharmacological relevance

Consumer use of botanicals has increased despite, in many instances, the paucity of research demonstrating efficacy or identifying liabilities. This research employed the place preference/aversion paradigm to characterize the psychoactive properties of Salvia divinorum extract (10, 30, 100 mg/kg), salvinorin A (0.1, 0.3, 1.0 mg/kg), Mitragyna speciosa MeOH extract (50, 100, 300 mg/kg), Mitragyna speciosa alkaloid-enriched fraction (12.5, 25, 75 mg/kg) and mitragynine (5, 10, 30 mg/kg) in rats.

Material and methods

Following apparatus habituation and baseline preference scores, male Sprague-Dawley rats were given eight counter-balanced drug versus vehicle conditioning trials followed by a preference test conducted under drug-free states. S(+)-amphetamine (1 mg/kg) served as the positive control (in Exp. 2) and haloperidol (0.8, 1.0 mg/kg) served as the negative control in both studies.

Results

Rats displayed place aversion to both Salvia divinorum and salvinorin A that exceeded that of haloperidol. Rats showed place preference to mitragynine that was similar to that of S(+)-amphetamine. This CPP effect was much less pronounced with the Mitragyna speciosa extract and its fraction.

Conclusions

These findings suggest that both botanicals possess liabilities, albeit somewhat different, that warrant caution in their use.     

Effect of Cydonia oblonga Mill. fruit and leaf extracts on blood pressure and blood rheology in renal hypertensive rats

Ethnopharmacological relevance

Quince, Cydonia oblonga Mill. (COM), is used in traditional Uyghur medicine to treat or prevent cardiovascular diseases. Uyghur people have greater longevity and lower blood pressure than other central Asian populations. We therefore tested COM fruit and leaf extracts on blood pressure and rheology in renal hypertensive rats (RHR).

Materials and methods

Two-kidney, one-clip (2K1C) renal hypertensive rats were divided randomly into eleven groups: sham, model, and model treated with daily doses of 80 and 160 mg/kg aqueous or ethanol extracts of COM fruit or leaves, or 25 mg/kg captopril (n=10 per group), given orally once daily for 8 weeks. Blood pressure was measured before treatment and every 2 weeks thereafter. Blood rheology was tested after 8 weeks.

Results

Model rats had higher blood pressure than sham 8 weeks after the procedure (systolic blood pressure 193±7 vs. 138±8 mmHg, p<0.05). Those treated with captopril had decreased blood pressure within 2 weeks but that did not return to the level found in the sham group at 8 weeks (167±7, p<0.05 vs. model). With the COM extracts, the effect on blood pressure was notable after 4 weeks. At 8 weeks blood pressure was similar with captopril and with 160 mg ethanol leaf extract (166±4, p<0.05 vs. model), the most effective of the extracts. Model rats had higher blood viscosity and lower erythrocyte deformability than sham. Captopril had little effect on blood rheology; whereas COM extracts reduced whole blood viscosity and improved erythrocyte deformability to levels approaching those found in sham.

Conclusions

COM extracts have antihypertensive activity in renal hypertensive rats. The additional effect on rheology, compared to captopril, may convey added interest. Further studies of these effects in man appear warranted.     

Anti-stress effect of astragaloside IV in immobilized mice

Ethnopharmacological relevance

Astragaloside IV, a major component extracted from the roots of Astragalus membranaceus (AM), possesses anti-inflammatory, anti-oxidative, anti-fibrotic, anti-infarction and immunoregulatory effects. To clarify anti-stress effect of AM, anxiolytic and anti-inflammatory effects of 80% ethanol extract of AM and astragaloside IV were investigated in immobilization stress model.

Materials and methods

The mice were orally administered with AM (50, 200, and 500 mg/kg), astragaloside IV (5, 10, and 20 mg/kg) and buspirone, a positive drug, 1 h before immobilization treated for 2 h. For anxiolytic activity assay, EPM test was performed in mice. For anti-inflammatory activity assay, serum levels of corticosterone, IL-6 and TNF-α were measured using ELISA kits.

Results

AM extract and astragaloside IV increased dose-dependently time spent on open arms and open arm entries in the EPM test. Anxiolytic effects of AM extract (500 mg/kg) and astragaloside IV (20 mg/kg) were comparable to those of buspirone (1 mg/kg). Their anxiolytic effects were blocked by WAY-100635 (0.5 mg/kg, i.p.), a 5-HT_1A receptor antagonist (p<0.01), but not by flumazenil (3 mg/kg, i.p.) and bicuculline (0.5 mg/kg, i.p.), GABA_A receptor antagonists. AM extract and astragaloside IV also reduced serum levels of corticosterone, IL-6 and TNF-α dose-dependently.

Conclusions

AM, particularly astragaloside IV, may ameliorate immobilized stress-induced anxiety and inflammation.     

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.     

Cinchonain Ib isolated from Eriobotrya japonica induces insulin secretion in vitro and in vivo

Aims of the study

Eriobotrya japonica leaves had been used traditionally for the treatment of diabetes mellitus by immersing the dried leaves in a hot water drink. Few studies have shown the hypoglycemic effect of Eriobotrya japonica using crude alcoholic extract and isolated methanolic compounds. These studies proposed that the mechanism of action could be by stimulating the β-islets of Langerhans to secrete insulin, however with no scientific evidence.

Methods

Eriobotrya japonica water extract (EJWE) and the compounds derived from it: cinchonain Ib, procyanidin B-2, chlorogenic acid and epicatechin, were tested for their effects on insulin secretion from INS-1 cells and following oral administration in rats.

Results

The present study showed that EJWE increased significantly (p < 0.05) insulin secretion from INS-1 cells in dose-dependent manner. Oral administration of EJWE at 230 mg/kg to rats, however, decreased plasma insulin level for as long as 240 min post-administration and caused a transient drop of blood glucose at 15 and 30 min post-administration. On the other hand, cinchonain Ib enhanced significantly (p < 0.05) insulin secretion from INS-1 cells, whereas epicatechin inhibited significantly (p < 0.05) insulin secretion from INS-1 cells. In addition, cinchonain Ib enhanced significantly (150%: p < 0.05) plasma insulin level in rats for as long as 240 min after 108 mg/kg oral administration but did not induce any change in blood glucose level.

Conclusion

These data indicate that cinchonain Ib has an insulinotropic effect and suggest the possible use of cinchonain Ib for managing type 2 diabetes.     

Renoprotective effects of the crude extract and solvent fractions of the leaves of Euclea divinorum Hierns against gentamicin-induced nephrotoxicity in rats

Ethnopharmacological relevance

Euclea divinorum Hierns (Ebenaceae) is used in Ethiopian folklore medicine to treat scabies, inflammation of the skin, eczema, abdominal pain, gonorrhea, and kidney problems. However, the claim has not been scientifically validated.

Aim of the study

To assess the renoprotective effects of the crude extract and solvent fractions of E. divinorum leaves against gentamicin-induced nephrotoxicity in rats.

Materials and method

Rats of either sex were divided into seven experimental groups, each comprising six animals. Group I served as control and given vehicle (Tween 80, 2%, v/v in water) and Group II were treated with gentamicin intraperitoneally (100 mg/kg/day) for eight days. Group III–V received crude extract at three different doses 100 mg/kg, 150 mg/kg and 200 mg/kg, respectively. Group VI received 100 mg/kg of the methanolic fraction and Group VII 100 mg/kg of the aqueous fraction. The extract was administered orally two days before and eight days concomitantly with gentamicin. Following treatment, blood and renal tissue were used to assess creatinine, blood urea nitrogen (BUN), malondialdehyde (MDA), antioxidant enzymes and tubular necrosis using recommended procedures. In addition, free radical scavenging activity was determined using in vitro methods.

Results

Gentamicin significantly increased serum creatinine and BUN, MDA and tubular necrosis in rats. It also decreased activity of catalase and superoxide dismutase as well as levels of gluthatione. Pre- and co-treatment with the crude extract and solvent fractions of Euclea divinorum leaves reversed gentamicin-induced alterations as evidenced by a decrease in tubular necrosis, serum and oxidant markers as well as by an increase in antioxidant molecules. Effect was found to decrease with dose when the crude extract was used and maximum protection was conferred by 100 mg/kg of the methanolic fraction in both in vivo and in vitro studies.

Conclusions

Euclea divinorum reversed gentamicin-induced nephrotoxicity, probably via its antioxidant activity. The fact that the methanol fraction conferred maximum protection suggests that semi-polar antioxidant principles might be responsible for the observed effect.