Antidepressant-like effect of Lafoensia pacari A. St.-Hil. ethanolic extract and fractions in mice

Ethnopharmacological relevance

Lafoensia pacari A. St.-Hil. (Lythraceae) has been referred in Brazilian traditional medicine for the treatment of different diseases, among them depression. Nevertheless, there are not studies about this possible effect on the central nervous system (CNS).

Aim of the study

To evaluate the antidepressant-like effects of the ethanolic extract of Lafoensia pacari (PEtExt) and its fractions on the performance of male mice.

Materials and methods

Antidepressant activity was studied using forced swimming (FST) and tail suspension (TST) tests, and motor activity in the open-field test. The ethanolic extract of Lafoensia pacari (PEtExt) were administered acutely (1.0 g/kg, p.o.), for 21 days (100, 300 mg, and 1.0 g/(kg day), p.o.), three administration in a 24-h period (1.0 g/kg, p.o.), and the fractions for 21 days. Imipramine (15 mg/(kg day), p.o.) was used as the control positive.

Results

The PEtExt significantly reduced immobility time in FST and TST, without affecting the motor activity. Only the chloroformic fraction (50 mg/(kg day), p.o.) increase the latency to immobility and decrease the immobility time in the FST.

Conclusions

These data indicate that the extract of Lafoensia pacari A. St.-Hil. possesses antidepressant-like properties in mice.     

Antidepressant-like effect of the ethanolic extract from Suanzaorenhehuan Formula in mice models of depression

Ethnopharmacological relevance

Suanzaorenhehuan Formula (SHF) is a Chinese herbal formula for the treatment of depression-like disorders. It contains four herbs: Semen Ziziphi spinosae, Cortex Albiziae, Radix Paeoniae Alba and Semen Platycladi. The present study is to investigate the antidepressant-like effect of the ethanolic extract of SHF and its possible mechanisms.

Materials and methods

Mouse models of depression including the tail suspension test (TST), forced swimming test (FST) and chronic unpredicted mild stress (CUMS) were used to evaluate the effects of SHF extract. The mechanisms were examined by measuring monoamine neurotransmitters in mice hippocampus and frontal cortex, testing monoamine oxidase enzyme (MAO) activities in brain of CUMS-exposed mice.

Results

After one-week treatment, SHF extract (50, 100 and 200 mg/kg) induced a significant decrease on immobility time in TST. After two-week treatment, SHF extract (50, 100 and 200 mg/kg) led to a reduction in the immobility period in TST and FST. The 5-HT levels in mice hippocampus were increased only after 200 mg/kg SHF extract treatment. The noradrenaline (NE) levels were increased after 200 mg/kg SHF extract treatment in mice hippocampus and frontal cortex. SHF extract (50, 100 and 200 mg/kg) significantly inhibited monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) after 21-day CUMS exposure.

Conclusion

These findings demonstrated that ethanolic SHF extract produced an antidepressant-like effect and the mechanism of action involves the serotonergic, noradrenergic and monoamine oxidase enzyme systems although underlying mechanism still remains to be further elucidated.     

Inhibitory effects of citrus extracts on the experimental pulmonary fibrosis

Aim of the study

A Chinese herbal formula, Hu-qi-yin possessed an anti-pulmonary fibrosis effect. Pericarp of Citrus reticulata, one of the herbal drugs contained in this formula showed the most potent inhibitory activity on the proliferation of human embryonic lung fibroblasts (HELF). The present study was designed to clarify the active principles responsible for the activity and further explore the anti-pulmonary fibrosis effect in vivo.

Materials and methods

The water, 75% ethanol and flavonoids-enriched extracts of Citrus reticulata were prepared and screened for their anti-proliferation activity using HELF culture system. The ethanol extract was further administered orally at doses of 100 and 200 mg/(kg day) to bleomycin (BLM)-induced pulmonary fibrosis rats. The analyses of the rat body weight, hydroxyproline levels in serum and lung, scores of alveolitis and fibrosis, as well as the expression of transforming growth factor-β₁ (TGF-β₁) at the protein and the messenger ribonucleic acid (mRNA) levels in lung were performed.

Results

The ethanol extract showed the strongest inhibitory activity on HELF proliferation. Further research using BLM-induced rat model revealed that the ethanol extract at the doses of 100 and 200 mg/(kg day) caused a marked increase of body weight at first 7 days, significantly lowered the hydroxyproline levels in lung, greatly improved the pathologic scores, as well as inhibited the overexpressions of TGF-β₁ protein and mRNA.

Conclusions

The results suggest that the ethanol extract of Citrus reticulata has anti-pulmonary fibrosis effects and might have a great potential for the treatment of fibrosis of lung.     

Analgesic and anti-arthritic effects of Lingzhi and San Miao San supplementation in a rat model of arthritis induced by Freund's complete adjuvant

Aim of study

In this study, we have investigated the analgesic and anti-arthritic effects of a traditional Chinese medicine (TCM) combination of Lingzhi and San Miao San (SMS) in a rat model of arthritis induced by Freund's complete adjuvant (FCA).

Materials and methods

Sprague–Dawley rats were induced with monoarthritis by single unilateral injection of FCA into the knee joint. The TCM combination was administered to the rats daily by intraperitoneal injection (50 mg/(kg day)) or via oral administration (500 mg/(kg day)) for 7 days before induction of arthritis and 7 days after. Extension angle that provoked struggling behavior, and size and blood flow of the rat knees were measured to give indexes of allodynia, edema, and hyperemia, respectively. The extent of cell infiltration, tissue proliferation, and erosions of joint cartilage provided additional indexes of the arthritis condition.

Results

FCA injection produced significant allodynia, edema, hyperemia, immune cell infiltration, synovial tissue proliferation, and erosions of joint cartilage in the ipsilateral knees compared with the contralateral saline-injected knees. Intraperitoneal injection of the TCM combination (50 mg/(kg day)) suppressed allodynia, edema, and hyperemia in the inflamed knees, and oral administration (500 mg/(kg day)) suppressed edema and hyperemia. Histological examination showed that the TCM administered by either route reduced immune cell infiltration and erosion of joint cartilage.

Conclusions

These findings suggest the Lingzhi and SMS formulation has analgesic and anti-inflammatory effects in arthritic rat knees, and concur to previous clinical studies that showed the TCM combination reduced pain in rheumatoid arthritis patients, and extends its possible benefit to suppression of inflammatory symptoms in these patients.     

Subchronic administration of Trichilia catigua ethyl-acetate fraction promotes antidepressant-like effects and increases hippocampal cell proliferation in mice

Ethnopharmacological relevance

Trichilia catigua preparations have been popularly used in Brazil as a tonic for the treatment of fatigue, stress, impotence, and memory deficits. We recently demonstrated an antidepressant-like effect of acute administration of the Trichilia catigua ethyl-acetate fraction (EAF) in mice. The aim of the present study was to evaluate whether subchronic Trichilia catigua EAF administration maintains its antidepressant-like effects and whether these effects are related to hippocampal neurogenesis.

Material and methods

Trichilia catigua EAF (200 and 400 mg/kg) was orally administered to mice for 14 day. The animals were tested in the forced swim test (FST) or tail suspension test (TST). After behavioral testing, the animals received bromodeoxyuridine (BrdU; 200 mg/kg, i.p.) and were euthanized 24 h, 7 day, or 15 day later. The brains were assayed for BrdU and doublecortin (DCX) immunohistochemistry to detect cell proliferation/survival and neurogenesis, respectively.

Results

Subchronic administration of 400 mg/kg Trichilia catigua EAF promoted antidepressant-like effects in mice in both the FST and TST. The antidepressant-like effect was accompanied by an increase in cell proliferation in the dentate gyrus (DG) of the hippocampus 24 h after the treatments were discontinued. This proliferative effect, however, did not influence cell survival or neurogenesis because no change in the number of BrdU- or DCX-positive cells was detected 7 or 15 day after the last EAF administration compared with controls.

Conclusions

Trichilia catigua EAF produced antidepressant-like effects and induced hippocampal cell proliferation in mice. The results contribute information on the pharmacological and molecular mechanisms involved in the antidepressant-like effect of Trichilia catigua EAF.     

Bioactivity-directed isolation, identification of diuretic compounds from Polyporus umbellatus

Aim of the study

Polyporus umbellatus is a fungus used as a diuretic medicine. The objective of this study was to isolate and elucidate the diuretic constituents of n-hexane, ethyl acetate, n-butanol and water extracts of Polyporus umbellatus and to evaluate their diuretic activity.

Materials and methods

The n-hexane, ethyl acetate, n-butanol and water extracts of Polyporus umbellatus were tested by diuretic experiment of normal rats in metabolic cage. The n-hexane extract and n-butanol extract were prepared separately by the bioassay-guided approach. Three isolated compounds doses (5, 10 and 20 mg/kg BW) were orally administered to normal rats. Water excretion rate, pH and content of Na⁺, K⁺ and Cl⁻ were measured in the urine of saline-loaded rats.

Results

n-Hexane extract (P < 0.05), n-butanol extract (P < 0.05) and three isolated compounds (ergosta-4,6,8(14),22-tetraen-3-one, ergosterol and d-mannitol) displayed diuretic activity.

Conclusions

The ergosta-4,6,8(14),22-tetraen-3-one was the strongest diuretic constituent in the three compounds. Ergosterol and d-mannitol were found to be also responsible for duiretic effects in Polyporus umbellatus for the first time. Data show that 20 mg/kg dose of the ergosterol for urine out put became significantly higher than in the control rats, but the ratio of Na⁺/K⁺ almost unaltered in the three doses. The highest dose of the d-mannitol was significant and increased the cumulative urine output. Regarding the electrolyte excretion, data show that the doses 10 and 20 mg/kg produce significant increase for excretion of Na⁺ and Cl⁻. The present results provide a quantitative basis explaining application of Polyporus umbellatus as a diuretic medicine. The result proved that its diuretic effects were also due to the contribution of multi-components in clinical application.     

Endothelium-independent relaxation and contraction of rat aorta induced by ethyl acetate extract from leaves of Morus alba (L.)

Aim of the study

Based on screening for vasoactive traditional Chinese medicinal herbs, the present study was performed to investigate the vasoactive effects of an ethyl acetate extract from leaves of Morus alba (L.) (ELM) on rat thoracic aorta and the mechanisms underlying these effects.

Materials and methods

Isolated rat thoracic rings were mounted in an organ bath system and the effects of ELM on their responses were evaluated.

Results

ELM (0.125–32.000 g/l) induced a concentration-dependent relaxation (P < 0.01 vs. control) both in endothelium-intact and -denuded aortas precontracted by high K⁺ (6 × 10⁻² M) or 10⁻⁶ M phenylephrine (PE). In endothelium-denuded aortas, ELM at the EC₅₀ concentration reduced Ca²⁺-induced contraction (P < 0.01 vs. control) after PE or KCl had generated a stable contraction in Ca²⁺-free solution. And after incubation with verapamil, ELM induced contraction in endothelium-denuded aortas precontracted by PE (P < 0.01 vs. control); this was abolished by ruthenium red (P < 0.01 vs. ELM-treated endothelium-denuded group; P > 0.05 vs. control), but not by heparin (P > 0.01 vs. ELM-treated endothelium-denuded group; P < 0.01 vs. control).

Conclusions

The results showed that ELM had dual vasoactive effects, and the relaxation was greater than the contraction. The relaxation was mediated by inhibition of voltage- and receptor-dependent Ca²⁺ channels in vascular smooth muscle cells, while the contraction occurred via activation of ryanodine receptors in the sarcoplasmic reticulum.     

Effect on blood pressure of a dietary supplement containing traditional medicinal plants of Côte d'Ivoire

Ethnopharmacological relevance

A medicinal composition containing salt (sodium chloride) is given as a traditional dietary supplement to hypertensive patients (TDSHP) in Côte d’Ivoire. It consists of whole plant of Bidens pilosa (Asteraceae) and fresh leaves of Moringa oleifera (Moringaceae).

Aim of the study

The aim of this study was to establish the scientific basis for the use of this traditional recipe rich in sodium chloride in hypertension settings.

Materials and methods

We used a total aqueous extract of this traditional dietary supplement containing medicinal plants (Bidens pilosa, Moringa oleifera) and salt (sodium chloride). Experiment was carried out to evaluate its effect on arterial blood pressure of rabbits. The experimental device used for recording blood pressure in rabbits is based on the principle of Ludwig mercury manometer.

Results

TDSHP between 5 × 10⁻⁸ and 5 × 10⁻² mg/kg caused a dose-dependent hypotension. TDSHP elicited drops in blood pressure ranging between 7.14 ± 4 and 100 ± 7.5%, compared to normal blood pressure of rabbits. Fifty percent effective dose of TDSHP was 3.95 × 10⁻⁴ mg/kg. Similarly as the hypotension induced by acetylcholine, the one caused by TDSHP at dose of 3.95 × 10⁻⁴ mg/kg in rabbit was progressively inhibited by atropine, dosed between 5 × 10⁻⁴ to 5 × 10⁻² mg/kg. The percentage drop of recorded blood pressure ranged from 50.3 ± 1.87 to 3.71 ± 1.09% compared to the normal value of blood pressure. In the presence of atropine, TDSHP effect was partially inhibited. The same increasing doses of TDSHP reduced significantly the increase of blood pressure induced by adrenaline dosed at 4.76 × 10⁻⁴ mg/kg from 89.3 ± 2.19 to 1.19 ± 0.59%.

Conclusion

The consumption of this traditional dietary supplement is justified in hypertensive patients according to its composition and its ability to reduce blood pressure has been demonstrated experimentally. TDSHP should not be considered as an antihypertensive drug, it remains to us a salt substitute to be taken with moderation with strict adherence to the traditional dose.     

Evaluation of diuretic activity of Amaranthus spinosus Linn. aqueous extract in Wistar rats

Ethnopharmacological relevance

Traditional Siddha medicine literature claims that the Amaranthus spinosus Linn. (family: Amaranthaceae) whole plant possesses diuretic property.

Aim of the study

To evaluate the diuretic potential of Amaranthus spinosus aqueous extract (ASAE) in rats.

Material and methods

Different concentrations of ASAE (200, 500, 1000, 1500 mg/kg), thiazide (10 mg/kg) and vehicle were orally administered to rats (n = 6 animals per group) and their urine output was collected after 24 h. Volume, pH, Na⁺, K⁺ and Cl⁻ concentrations of urine were estimated.

Results

ASAE produced increase in Na⁺, K⁺, Cl⁻ excretion, caused alkalinization of urine, showed strong saluretic activity and carbonic anhydrase inhibition activity. These effects were observed predominantly at 500 mg/kg dose and there was no dose–response relationship.

Conclusion

Our study strongly suggests that the Amaranthus spinosus is acting as a thiazide like diuretic with carbonic anhydrase inhibitory activity which restates the claim as diuretic herb in Siddha medicine.     

Aegiceras corniculatum extract suppresses initial and late phases of inflammation in rat paw and attenuates the production of eicosanoids in rat neutrophils and human platelets

Aim of the study

The present study is designed to explore the anti-inflammatory potential of Aegiceras corniculatum Linn. Blanco stems extracts and their mechanism of action against various pro-inflammatory mediators and to validate its traditional use against inflammatory diseases.

Materials and methods

Rat paw edema and peritonitis models were employed for in vivo studies. For in vitro studies human platelets and rat neutrophils were stimulated with Ca²⁺-ionophore A23187 leading to the production of various pro-inflammatory metabolites, i.e., 12-HTT, 12-HETE and LTB₄ and 5-HETE which were quantified by HPLC.

Results

The highly polar methanol extract (100 mg/kg) caused ∼90% reduction in the carrageenan- and prostaglandin E2-induced paw edema in rats. It also caused the inhibition of cycloxygenase-1 metabolite, 12-HHT (IC₅₀ 41.1 ± 1.5 μg/ml) with a concomitant rise in 12-lipoxygenase metabolite, 12-HETE in A23187 stimulated human platelets. Conversely, the non-polar hexane extract attenuated (IC₅₀ 0.36 ± 0.12 μg/ml) 12-HETE formation with a parallel rise in 12-HHT, thereby displaying a selectivity towards 12-lipoxygenase. Non-polar hexane extract also antagonized the production of 5-lipoxygenase metabolites, i.e., leukotriene B₄ and 5-HETE in the rat neutrophils. Furthermore, ethyl acetate extract inhibited both COX and 5-LOX with a marked decline in the production of 12-HHT (IC₅₀ 0.08 ± 0.002 μg/ml) and LTB₄ (IC₅₀ 0.86 ± 0.03 μg/ml), respectively. The anti-inflammatory effect of hexane and ethyl acetate extracts was also reflected by the diminution of carrageenan-induced cell infiltration in rat peritoneum. Additionally, plant extracts caused ∼60% suppression in dextran-induced paw edema implying that they also ameliorate histamine and serotonin release.

Conclusion

Hexane, ethyl acetate and methanol extracts derived from Aegiceras corniculatum possess significant anti-inflammatory activity via multiple mechanisms and validate their traditional use against inflammation-related diseases.     

The mechanism of vasorelaxation induced by Schisandra chinensis extract in rat thoracic aorta

Aim of the study

Schisandra chinensis (SC) is a known medical herb for the treatment of cardiovascular symptoms associated with menopausal symptoms in Korea. However, the pharmacological action mechanisms involved have not been well studied. This study was aimed to investigate the vascular effects of SC in rat thoracic aorta.

Materials and methods

We isolated the hexane, chloroform, and methanol extracts from SC and evaluated their vasodilatory effects in the rat thoracic aorta.

Results

Hexane extracts of SC (SCHE, 5 × 10⁻⁵ to 10⁻³ g/L) caused a concentration-dependent relaxation in both endothelium-intact and -denuded aortas. The relaxant effect of SCHE on the endothelium-intact aorta was more prominent than on the endothelium-denuded aorta. The former was significantly attenuated by L-NAME, a nitric oxide synthase inhibitor, and ODQ, a soluble guanyl cyclase inhibitor, but not by tetraethylammonium, a nonselective blocker of K⁺ channels, and indomethacin, a cyclooxygenase inhibitor. Furthermore, SCHE caused nitrite production as well as eNOS activation in aortic segments, suggesting implication of NO signal pathway in SCHE-induced relaxation. In endothelium-denuded aorta, SCHE-induced vasorelaxation was also attenuated by calyculin A, an inhibitor of myosin light chain (MLC) phosphatase, but not by ML-9, a MLC kinase inhibitor, suggestive of implication of MLC phosphatase activation. Phenylephrine-enhanced MLC phosphorylation ratio was significantly attenuated by SCHE, which was recovered to the control level by pretreatment with calyculin A.

Conclusions

Taken collectively, these findings suggest that the vascular relaxation evoked by SCHE was mediated by not only endothelium dependent NO pathway but also direct effect on vascular smooth muscle cell via dephosphorylation of MLC.     

Immunosuppressive effects of an ethyl acetate extract from Urtica dentata Hand on skin allograft rejection

Aim of the study

To investigate the immunosuppressive effects of HPLC qualitied ethyl acetate extract (EAE) from Urtica dentate Hand on skin allograft rejection in a murine model.

Materials and methods

Allo-skin transplantation model was established by placing skin allograft of C57BL/6 mice in the wound bed which was on the back of Balb/c mice. We used FACS to study the effects of EAE on dendritic cells (DCs) maturation and CD4⁺CD25⁺T regulatory cells (Tregs) differentiation. We also studied spleen lymphocyte proliferation and T-bet gene expression in DCs. Concentration of Th1/Th2 cytokines was monitored as markers of Th1/Th2 responses by ELISA.

Results

A significant prolongation of skin allografts survival was observed as a dose-dependent manner in the animals treated with EAE. By FACS, we found that treatment with EAE (200 mg kg⁻¹) resulted in an immature statement of DCs and stimulated the differentiation of CD4⁺CD25⁺Tregs. Additionally, the expression of T-bet gene and the proliferation of spleen lymphocytes were efficiently abated in EAE treated mice. Comparing to the model control, EAE-treated recipients showed a significant down-regulation (P < 0.01) of Th1 cytokines (IL-2, IFN-γ) and an obviously increase (P < 0.01) of Th2 cytokine (IL-10) in the serum, which presented in a dose-related way.

Conclusions

The anti-allograft rejection effect of EAE by enhancing CD4⁺CD25⁺Tregs differentiation and sustaining DCs immaturation makes EAE to be a possible choice for treating autoimmune diseases in a way of inducing a stable immunological tolerance state.     

Neuropharmacological study of Dracocephalum moldavica L. (Lamiaceae) in mice: sedative effect and chemical analysis of an aqueous extract

Ethnopharmacological relevance

Dracocephalum moldavica is used as a tranquilizer and as remedy for nervous conditions relief in the Mexican traditional medicine. Despite its intensive use no literature reported neuropharmacological studies on Dracocephalum moldavica as yet.

Aim of the study

The sedative, anxiolytic-like and antidepressant-like effects of the aqueous extract of aerial parts of Dracocephalum moldavica (Lamiaceae) (DM) were evaluated in behavioral models in mice. The general toxic effects of DM were evaluated as well as their chemical analysis was performed.

Materials and methods

DM effects were evaluated on pentobarbital-induced sleeping time (SPT), the hole-board (HBT), and the avoidance exploratory behavior (AEBT) tests and on the forced swimming test (FST). General activity and motor coordination were evaluated in the open field (OFT) and Rota-rod tests, respectively. The acute toxicity of DM was determinate by its LD₅₀ dose. The chemical analyses DM were performed by chromatographic and HPLC–ESI-MS techniques.

Results

DM prolonged the pentobarbital-induced sleeping time, induced sedation in the HBT, decreased spontaneous activity and produced motor coordination impairment in mice. However, DM did not show anxiolytic effects in the AEBT or HBT and it was not effective in FST. The DM-treatment produced mortalities with LD₅₀ = 470 mg/kg body weight.The HPLC–ESI-MS analysis of DM revealed that (acacetin, apigenin and luteolin)-7-O-β-d-(6″-O-malonyl)-glucoside derivates are the main compounds of DM.

Conclusions

DM induced sedative actions and a general inhibition of CNS activity observed by the decrease of animals’ general activity, motor coordination and exploration.     

Antiulcerogenic activity of hydroalcoholic fruit extract of Pithecellobium dulce in different experimental ulcer models in rats

Ethnopharmacological relevance

The ethnopharmacological importance of Pithecellobium dulce is evidenced by its traditional use for gastric complications. The aim of the study is to evaluate the gastroprotective activity and the mechanism of action of hydroalcoholic fruit extract of P. dulce (HAEPD) in rats by using chemical and stress induced ulcer models.

Materials and methods

Gastric ulcer was induced by administering alcohol (or) acetylsalicylic acid (or) hypothermic restraint stress to rats pretreated with HAEPD (200 mg/kg b wt for 30 day). Volume of gastric fluid, pH, acidity, activities of pepsin, H⁺, K⁺-ATPase, myeloperoxidase, mucin content, nucleic acids, glycoproteins and prostaglandin E₂ (PGE₂) levels were assessed in gastric tissues.

Results

Ulcer score was significantly minimized in HAEPD administered animals. pH and acidity of gastric fluid were significantly minimized and the mucin, PGE₂ levels were significantly maintained in drug pre administered animals. The activities of H⁺, K⁺- ATPase and myeloperoxidase were found to be significantly elevated in ulcer control animals and found to be decreased in drug pretreated animals. The cell proliferation was found to be enhanced in drug received animals. The total protein bound carbohydrate to total protein ratio was found to be significantly maintained by HAEPD. The effects were found to be comparable with that of standard drug omeprazole.

Conclusion

It is concluded that HAEPD possess a potent antiulcer activity probably by acting as cytoprotective and antiacid secretory agent.     

Diuretic activity of some Smilax canariensis fractions

Ethnopharmacological relevance

Smilax canariensis is an endemic species of the Canary Islands, popularly known as “Zarzaparrilla sin espinas”. The rhizome, leaves and stem of this species has wide use in folk medicine practice on the islands, where they are habitually employed as diuretic.

Aim of the study

In this paper we report on the diuretic activity in experimental animals of several fractions of the methanol extract of this species.

Materials and methods

Four fractions of the methanol extract of the rhizomes, leaves and stem of Smilax canariensis (50 and 100 mg/kg), Furosemide and Hydrochlorotiazide (10 mg/kg), were orally administered to laboratory animals to evaluate their diuretic activity. Water excretion rate, pH, conductivity, and content of Na⁺, K⁺ and Cl⁻ were measured in the urine of saline-loaded mice.

Results

All the studied extracts showed an interesting increase of the diuresis, although the n-buthanol (27%; p < 0.05) and ethyl acetate extract (35%; p < 0.01), at 100 mg/kg p.o., showed the most interesting diuretic activity, which suggested that this diuretic effect is associated with the compounds contained in the fractions of intermediate polarity (ethyl acetate and n-butanol), decreasing in the most extreme apolar and polar sub-extracts (dichloromethane and methanol: water respectively). The increase in diuresis produced by these two extracts was very close to the values of Hydrochlorothiazide (32%) or Furosemide (39%), used as reference diuretics.

Conclusions

These data, together with previous results on the aqueous and methanol extracts, reaffirm assertions made regarding the effectiveness of the extracts of this plant against urinary pathologies in the Canary Islands folk medicine.     

In vivo study of the anti-inflammatory and antitumor activities of leaves from Plectranthus amboinicus (Lour.) Spreng (Lamiaceae)

Ethnopharmacological relevance

Plectranthus amboinicus (Lour.) Spreng is a medicinal specie often used in Brazil, especially in Northeast Region, for the treatment of several diseases including inflammations and cancer.

Aim of the study

To evaluate the anti-inflammatory and antitumor activities of the hydroalcoholic extract from leaves of P. amboinicus in an attempt to determine whether the medicinal uses are supported by pharmacological effects.

Materials and methods

Anti-inflammatory activity was determined by carrageenan-induced paw edema method. The antitumor effect was evaluated in an in vivo experimental study, using the following tumors: Sarcoma-180 and Erlich ascite carcinoma.

Results

There were statistically significant decreases (p < .05) of edema paw in at the doses of 150, 250 and 350 mg/kg (i.p.) of the hydroalcoholic extract of P. amboinicus. Similarly, the administration of P. amboinicus at the doses of 100, 150, 250 and 350 mg/kg (i.p.) inhibited the growth of sarcoma-180 and Ehrlich ascite carcinoma tumors in mice.

Conclusion

The results suggest that the hydroalcoholic extract of P. amboinicus possesses anti-inflammatory and antitumor activities, supporting the folk use of this medicinal specie.     

Novel xanthones from Securidaca longepedunculata with activity against erectile dysfunction

Aim of study

Securidaca longepedunculata is used in the treatment of erectile dysfunction in South Africa. The aim of the study was to isolate and identify the active constituents and to determine their activity in the relaxation of corpus cavernosal smooth muscle.

Materials and methods

Bioassay guided isolation of the bioactive compounds using a smooth muscle relaxation bioassay and structural elucidation was carried out using different spectroscopic techniques including 2D NMR.

Results

Two new xanthones were isolated; one of them showed potent activity to relax the corpus cavernosal smooth muscle by 97 % in comparison to sildenafil (Viagra) at 1.8 × 10⁻⁵ mg/ml.

Conclusions

S. longepedunculata's xanthones stimulate the relaxation of corpus cavenosum smooth muscle, which supports the traditional use of its root bark.     

Nigella sativa inhibits intestinal glucose absorption and improves glucose tolerance in rats

Aim of the study

Nigella sativa L. (Ranunculaceae) seeds have been used traditionally for centuries, notably for treating diabetes.

Materials and methods

We studied the effects of the crude aqueous extract of Nigella sativa seeds on intestinal glucose absorption in vitro using a short-circuit current technique and in vivo using an oral glucose tolerance test.

Results

The aqueous extract of Nigella sativa (0.1 pg/ml to 100 ng/ml) exerted dose-dependent inhibition of sodium-dependent glucose transport across isolated rat jejunum. Maximal inhibition exceeded 80% and IC₅₀ was close to 10 pg/ml. An oral glucose tolerance test was carried out in rats after the initial dose and after a 6-week treatment of Nigella sativa (2 g/(kg day)), and compared to metformin (300 mg/(kg day)). Chronic Nigella sativa treatment improved glucose tolerance as efficiently as metformin. Nigella sativa and metformin also reduced body weight without any toxic effect.

Conclusions

To our knowledge, this is the first demonstration that Nigella sativa directly inhibits the electrogenic intestinal absorption of glucose in vitro. Together with the observed improvement of glucose tolerance and body weight in rats after chronic oral administration in vivo, these effects further validate the traditional use of Nigella sativa seeds against diabetes.