Pharmacological effects of Eugenia uniflora (Myrtaceae) aqueous crude extract on rat's heart

The effect of aqueous crude extract (ACE) of Eugenia uniflora L. (Myrtaceae) was studied on rat's perfused ventricles. This plant is used in South American traditional medicine as an antihypertensive and we already demonstrated previously its hypotensive properties. In this paper, maximal left intraventriclular pressure (P) of rat's hearts beating at 0.2 Hz firstly increased to 162.1+/-11.1% of basal value during 1-3 min of perfusing ACE 0.6%. Maximum rate of contraction (+P) also increased to duplicating +P/P ratio. Both types of effect were significantly decreased by either propranolol 0.35 microM, and pre-treatment with reserpine (5 mg/kg), suggesting that they were caused by a compound that releases cathecolamines with beta-adrenergic action. Nevertheless, after 20 min of perfusing ACE, ventricles decreased P to about 50% of their basal value, suggesting a negative-inotropic compound present in the extract. The perfusion of 1.2% ACE decreased P in a pressure-[Ca](o) curve (0.5-2 mM) in a non-competitive manner, suggesting that an irreversible Ca-blocking compound is also present in the extract. In summary, E. uniflora ACE has a dual effect on the heart related to its hypotensive action and is probably responsible for the therapeutic or adverse effects in patients under cardiac risk.     

Pharmacological basis for the empirical use of Eugenia uniflora L. (Myrtaceae) as antihypertensive.

The rational basis for the use of Eugenia uniflora L. (Myrtaceae) as antihypertensive in Northeastern Argentina was assessed in normotensive rats. Intraperitoneal administration of the aqueous crude extract (ACE) decreased blood pressure (BP) of normotensive rats dose-dependently until 47.1 +/- 8.2% of control. The effective-dose 50 was 3.1 +/- 0.4 mg dried leaves/kg (d.l./kg) (yielding of ACE: 17% w/w). To determine the origin of hypotensive activity. Alpha-adrenergic antagonistic and vasorelaxant ACE activities were tested. The dose-response curve for phenylephrine on BP was inhibited non-competitively until 80% of its maximal effect (at 8 mg d.l. ACE/kg). Perfusion pressure (PP) of rat hindquarters (previously vasoconstricted by high-K+) was decreased by ACE in a concentration-dependent manner until -32.3 +/- 11.5% of tonic contraction at 1.2 g d.l. ACE/100 ml. In addition, A.C.E demonstrated diuretic activity at a dose (120 mg d.l./kg) higher than the hypotensive one. It was almost as potent as amiloride, but while amiloride induced loss of Na+ and saving of K+, ACE induced decrease in Na+ excretion. The results suggest that the empirical use of Eugenia uniflora L. (Myrtaceae) is mostly due to a hypotensive effect mediated by a direct vasodilating activity, and to a weak diuretic effect that could be related to an increase in renal blood flow.     

Involvement of monoaminergic systems in the antidepressant-like effect of Eugenia brasiliensis Lam. (Myrtaceae) in the tail suspension test in mice

Ethnopharmacological relevance

Several species of Eugenia L. are used in folk medicine for the treatment of various diseases. Eugenia brasiliensis is used for the treatment of inflammatory diseases, whereas Eugenia. uniflora is used for the treatment of symptoms related to depression and mood disorders, and is used in Brazil by the Guarani Indians as a tonic stimulant.

Aim of the study

To investigate the antidepressant-like effect of hydroalcoholic extracts of different plant species of genus Eugenia and to characterize the participation of the monoaminergic systems in the mechanism of action of the specie that afforded the most prominent antidepressant-like efficacy.

Materials and methods

In the first set of experiments, the effects of hydroalcoholic extracts of Eugenia beaurepaireana, Eugenia brasiliensis, Eugenia catharinae, Eugenia umbelliflora and Eugenia uniflora and the antidepressant fluoxetine (positive control) administered acutely by p.o. route were evaluated in the tail suspension test (TST) and locomotor activity was assessed in the open-field test in mice. In the second set of experiments, the involvement of the monoaminergic systems in the antidepressant-like activity of Eugenia brasiliensis was evaluated by treating mice with several pharmacological agonists and antagonists. The effects of the combined administration of sub-effective doses of Eugenia brasiliensis and the antidepressants fluoxetine, imipramine and bupropion were also evaluated.

Results

The administration of the extracts from Eugenia brasiliensis, Eugenia catharinae and Eugenia umbelliflora, but not Eugenia beaurepaireana and Eugenia uniflora, exerted a significant antidepressant-like effect, without altering locomotor activity. The behavioral profile was similar to fluoxetine. Pre-treatment of mice with ketanserin, haloperidol, SCH23390, sulpiride, prazosin and yohimbine prevented the reduction of immobility time induced by Eugenia brasiliensis. Treatment with sub-effective doses of WAY100635, SKF38393, apomorphine, phenylephrine, but not clonidine, combined with a sub-effective dose of Eugenia brasiliensis decreased the immobility time in the TST. Furthermore, the combined administration of sub-effectives doses of Eugenia brasiliensis with fluoxetine, imipramine and bupropion produced an antidepressant-like effect.

Conclusions

This study show, for the first time, the antidepressant-like effect of species of the genus Eugenia, especially Eugenia brasiliensis, whose effects in the TST seem to be mediated by serotoninergic (5-HT_1A and 5-HT₂ receptors), noradrenergic (α₁-adrenoceptor) and dopaminergic (dopamine D₁ and D₂ receptors) systems.     

Antibacterial activities of the leaf extracts of Eugenia uniflora Linn. (Synonym Stenocalyx michelli Linn.) Myrtaceae

The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited.     

丁香

本文报道丁香在海南岛的引种情况及其栽培技术,指出丁香在海南岛的万宁、陵水、保亭、崖县、屯昌、琼中等县的比较静风、高温、高湿地区栽培,有可能形成生产基地提供商品。     

Eugenia punicifolia (Kunth) DC. as an Adjuvant Treatment for Type‐2 Diabetes Mellitus: A non‐Controlled,Pilot Study

Type‐2 diabetes mellitus (DM) is a highly prevalent disease with significant morbidity and mortality around the world. However, there is no universally effective treatment, because response to different treatment regimens can vary widely among patients. In this study, we aimed to investigate whether the use of the powdered dried leaves of Eugenia punicifolia (Kunth) DC. (Myrtaceae) is effective as an adjuvant to the treatment of patients with type‐2 DM. Fifteen patients were enrolled in a pilot, non‐controlled study, and received E. punicifolia for 3 months. After treatment, we observed a significant decrease in glycosylated hemoglobin, basal insulin, thyroid‐stimulating hormone, C‐reactive protein, and both systolic and diastolic blood pressure. There were no changes in fasting and postprandial glycemia. The compounds myricetin‐3‐O‐rhamnoside, quercetin‐3‐O‐galactoside, quercetin‐3‐O‐xyloside, quercetin‐3‐O‐rhamnoside, kaempferol‐3‐O‐rhamnoside, phytol, gallic acid, and trans‐caryophyllene present in the powdered dried leaves of E. punicifolia may be responsible for the therapeutic effect. In conclusion, the powdered leaves of E. punicifolia are promising as an adjuvant in the treatment of type‐2 DM and deserve further investigation. Copyright © 2014 John Wiley & Sons, Ltd.     

The chemical composition and biological activity of clove essential oil, Eugenia caryophyllata (Syzigium aromaticum L. Myrtaceae): a short review

The essential oil extracted from the dried flower buds of clove, Eugenia caryophyllata L. Merr. & Perry (Myrtaceae), is used as a topical application to relieve pain and to promote healing and also finds use in the fragrance and flavouring industries. The main constituents of the essential oil are phenylpropanoids such as carvacrol, thymol, eugenol and cinnamaldehyde. The biological activity of Eugenia caryophyllata has been investigated on several microorganisms and parasites, including pathogenic bacteria, Herpes simplex and hepatitis C viruses. In addition to its antimicrobial, antioxidant, antifungal and antiviral activity, clove essential oil possesses antiinflammatory, cytotoxic, insect repellent and anaesthetic properties. This short review addresses the chemical composition and biological effects of clove essential oil, and includes new results from GC/MS analysis and a study of its antimicrobial activity against a large number of multi-resistant Staphylococcus epidermidis isolated from dialysis biomaterials.     

Antibacterial triterpenes from Syzygium guineense (Myrtaceae)

Antibacterial bioassay-guided fractionation of Syzygium guineense leaf extracts afforded 10 triterpenes, namely betulinic acid 1, oleanolic acid 2, a mixture of 2-hydroxyoleanolic acid 3a, 2-hydroxyursolic acid 3b, arjunolic acid 4a, asiatic acid 4b, a mixture of terminolic acid 5a, 6-hydroxyasiatic acid 5b, and a mixture of arjunolic acid 28-beta-glucopyranosyl ester 6a and the asiatic acid 28-beta-glucopyranosyl ester 6b. Isolated compounds were submitted to an antibacterial assay system against gram-positive and -negative bacteria and human pathogen bacteria. Compounds 4a and 4b showed the most significant antibacterial activity against Escherichia coli, Bacillus subtilis and Shigella sonnei. The fraction 5a-5b was the least active, whereas compounds 1, 2 and the mixtures of 3a-3b and 6a-6b were inactive in the assays.     

Pharmacological effects of Chinese herb aconite (Fuzi) on cardiovascular system

Fuzi (aconite, Radix Aconiti praeparata), a widely used Chinese herb, plays a significant role in the cardiovascular system. This is mainly reflected by Fuzi's cardiotonic effect, its protective effect on myocardial cells, and its effect on heart rate and rhythm, blood pressure, and hemodynamics. In this article, the pharmacological effects and the corresponding mechanisms of Fuzi (aconite) and its active components on cardiovascular system are reviewed.     

Antidermatophytic triterpenoids from Syzygium jambos (L.) Alston (Myrtaceae)

Chemical investigation of the EtOAc extract of the stem bark of Syzygium jambos (L.) Alston (Myrtaceae) afforded a number of known triterpenes such as friedelin, beta-amyrin acetate, betulinic acid and lupeol. Friedelin was submitted to a Baeyer-Villiger oxidation, and was also reduced with LiAlH(4) to give the known friedelolactone and friedelanol, respectively. These compounds were identified by comparison of NMR spectral data with those from the literature. The EtOAc extract and the isolated compounds were tested for their antidermatophytic activity against three dermatophyte species: Microsporum audouinii, Trichophyton mentagrophytes and Trichophyton soudanense, commonly found in Cameroon. Betulinic acid and friedelolactone were the most active compounds, and the most sensitive fungi were Trichophyton soudanense and Trichophyton mentagrophytes.     

Evaluation of the molluscicidal properties of Myrtus communis L. (Myrtaceae)

Crude water extract and a flavonoid fraction of Myrtus communis were found to possess molluscicidal activity against the aquatic snail Biomphalaria glabrata involved in the transmission of schistosomiasis.     

Evaluation of gastroprotective activity of Plinia edulis (Vell.) Sobral (Myrtaceae) leaves in rats

Plinia edulis, an arboreous species popularly known as "cambucá", is native to the Brazilian Atlantic Rain Forest. Despite its traditional uses, no reports are available on the safety of this utilization or on the relationship between the antiulcer activity of its extract and its phytochemical compounds. This paper reports on the investigation of the acute toxicity and gastroprotective effect of the aqueous ethanol extract of leaves of Plinia edulis on HCl/ethanol-induced ulcers. In order to correlate the secondary metabolites and the efficacy of the crude drug in traditional medicine, the extract was submitted to chromatographic fractionation after solvent partition. The extract did not show acute toxicity in mice treated with 5 g/kg p.o., but exhibited significant antiulcer activity in rats at doses of 100, 200, and 400mg/kg p.o., more active than the reference drug lansoprazole.The ethyl acetate fraction yielded beta-amyrin, oleanolic acid, ursolic acid, and maslinic acid, which were identified based on spectrometric analyses. Since antiulcerogenic activity is not restricted to one class of compounds in plants, the triterpenoids isolated in the extract can be associated with the observed effect.     

Sesquiterpenes from clove (Eugenia caryophyllata) as potential anticarcinogenic agents.

Bioassay-directed fractionation of clove terpenes from the plant Eugenia caryophyllata has led to the isolation of the following five active known compounds: beta-caryophyllene [1], beta-caryophyllene oxide [2], alpha-humulene [3], alpha-humulene epoxide I [4], and eugenol [5]. Their structures were determined on the basis of spectral analysis (hreims, 1H and 13C nmr). These compounds showed significant activity as inducers of the detoxifying enzyme glutathione S-transferase in the mouse liver and small intestine. The ability of natural anticarcinogens to induce detoxifying enzymes has been found to correlate with their activity in the inhibition of chemical carcinogenesis. Thus, these sesquiterpenes show promise as potential anticarcinogenic agents.     

Pharmacological effects of rutin

It is well-known that flavonoids including rutin exert a wide range of pharmacological effects. This study was carried out for further characterization of the pharmacological effect of rutin. A significant rise in the serum 5-HT levels was found 2 h after the administration of rutin (25 mg kg^?1 i.p.). The same dose of rutin caused no significant change in the serum 5-hydroxytryptomine levels after 8 and 72 h when compared to controls. In the in vivo experiments, rutin (25 mg kg^?1 i.p.) was ineffective on the blood pressure and respiratory tract of the guinea-pigs in spite of its smooth muscle relaxant effects in the in vitro preparations. These findings strongly suggest a physiological antagonism in the effects of rutin in intact animals.     

Pharmacological effects of butylidenephthalide

The pharmacological effects of synthetic butylidenephthalide (Bdph), the most potent antispasmodic agent found in the neutral oil of Ligusticum wallichii Franch., were examined in this study. In vivo, Bdph exerted a significant antihypertensive effect in anaesthetized renal hypertensive rats at a dose of 30 mg/kg (i.v. or i.p.), or 60 mg/kg (p.o.). Bdph antagonized noradrenaline (NA) induced increases in blood pressure in anaesthetized normotensive rats. In addition, Bdph prevented the pituitrin-induced T-wave lowering of the ECG in anaesthetized rats. It also dose-dependently decreased coronary arterial pressure in dogs. It is concluded that Bdph dilates coronary vessels. In vitro, Bdph non-competitively antagonized adrenaline-induced contraction in isolated rabbit aortic strips. It also significantly antagonized the NA-induced maximum decrease in perfusion rate of isolated rabbit ears. However, the vasodilator effect may cause a heat loss because Bdph significantly lowered the rectal temperature of rats at ambient temperature of 20°C, but not at 30°C. Bdph might be a useful coronary dilator and antihypertensive drug.     

Antimicrobial activity of bark extracts of Syzygium jambos (L.) alston (Myrtaceae)

Syzygium jambos (L.) Alston (Myrtaceae) is a widespread medicinal plant traditionally used in sub-Saharan Africa to treat infectious diseases. Acetone and aqueous extracts from the bark of S. jambos were tested for antimicrobial activity in vitro by the agar dilution method in petri dishes. Both extracts showed some activity against the tested micro-organisms. They proved to be particularly effective on Staphylococcus aureus, Yersinia enterocolitica and coagulase negative staphylococci among which Staphylococcus hominis, Staphylococcus cohnii and Staphylococcus warneri. These properties seem to be related to the high tannin content of S. jambos extracts (77 and 83% for the aqueous and acetone extracts, respectively, determined according to the European Pharmacopoeia method) which were generally more active than Hamamelis virginiana, Krameria triandra, Alchemilla vulgaris and Rubus fruticosus extracts containing 48, 44, 46 and 28% tannins, respectively. Furthermore, elimination of tannins totally suppressed these antimicrobial activities.     

龙牙楤木药理作用研究进展

目的总结龙牙楤木近年来的药理作用研究进展。方法围绕龙牙楤木的药理作用对近十年的文献报道进行系统的总结,并对其研究进展进行归纳分类。结果现代药理研究显示,龙牙楤木所含的皂苷类化合物、多糖等主要成分具有保护心血管、抗肿瘤、保肝、抗炎等多种药理作用,其作用机制多与离子通道、细胞凋亡、炎症因子等有关。结论龙牙楤木对多种疾病具有重要的药理作用且其作用靶点多样,今后应从细胞、分子水平进一步揭示其作用机制,为龙牙楤木作为药品的开发利用提供科学依据。     

Improving effects of the extracts from Eugenia uniflora on hyperglycemia and hypertriglyceridemia in mice

EtOH (70%) extracts from the leaves of Eugenia uniflora were separated into six fractions with different polarity and molecular size, i.e. NP-1-NP-6. In an oral glucose tolerance test, NP-1 and 4 inhibited the increase in plasma glucose level. However, in an intraperitoneal glucose tolerance test, such an inhibitory effect was not seen. Thus, the effects of NP-1 and 4 were apparently due to the inhibition of glucose absorption from the intestine. In a sucrose tolerance test, all fractions inhibited the increase in plasma glucose level. In an oral corn oil tolerance test, NP-3 and 4 showed an inhibitory effect on the increase in plasma triglycerides level. On the other hand, NP-3, 4, 5 and 6 inhibited maltase and sucrase activities and all fractions except for NP-1 showed an inhibitory effect on lipase activity dose-dependently. The inhibition of the increase in plasma glucose level by NP-3, 4, 5 and 6 in the oral sucrose tolerance test and the inhibition of the increase in plasma triglycerides by NP-3 and 4 in the oral corn oil tolerance test were apparently due to the inhibition of the decomposition of carbohydrates and fats in the intestine, respectively.     

Xanthine Oxidase Inhibitory Activity of Flavonoids and Tannins from Hexachlamys edulis (Myrtaceae)

The acetone-water extract of Hexachlamys edulis (Myrtaceae) inhibited the enzyme xanthine oxidase (XO) in vitro . Bioassay-guided isolation led to the gallic acid ester in 2″ of myricitrin (desmanthin-1), (-)-epigallocatechin-3-O-gallate (EGG) and pentagalloylglucose as the main XO inhibitors of H. edulis . Desmanthin-1 and EGG were mixed-type inhibitors of XO with K _i values of 1.6×10⁻⁴ M and 1.8×10⁻⁴ M , respectively. Pentagalloylglucose was an uncompetitive XO inhibitor with a K _ESI of 6.7×10⁻⁶M . From the active n -butanol soluble part of the aqueous acetone extract of H. edulis , several flavonoids were isolated. The flavonoids were mainly myricetin-3-O-monoglycosides with the quercetin glycoside avicularin as a minor compound displaying a weak inhibitory activity towards XO.     

Pharmacological effects of fermented red pepper

The pharmacological effects were investigated of fermented red pepper (HF-S), which consisted of 14.7% carbohydrate, 1.5% lipid, 4.9% protein, 0.3% ash, 78.2% moisture content, with 0.15% capsaicin and 0.06% dihydrocapsaicin. Oral administration of 0.25 mL HF-S for 3 weeks produced significant changes of the perirenal fat pad weight compared with the HF-control group, suggesting a suppressive effect on lipid accumulation and a significant decrease in the risk of arteriosclerosis. The HF-S (0.25 mL) group also showed a lower plasma TG, TC level and atherogenic index than that of the HF-control. In addition, the HF-S (0.25 mL) group showed a marked increase in the production of glutathione, which is the major endogenous antioxidant, and a decrease in the production of lipid peroxide as the product of chemical damage by oxygen free radicals. It is assumed that the effect of HF-S might relate to high glutathione production on the suppression of lipid peroxidation. HF-S stimulated not only the proliferation of macrophages (as high as the positive control, LPS at 1000 microg/mL) but also mitogenic activity (1.2-fold of LPS at 100 microg/mL).