Argentinian plant extracts with relaxant effect on the smooth muscle of the corpus cavernosum of guinea pig

The genus Haplopappus: botany, phytochemistry, traditional uses, and pharmacological properties

Background

The genus Haplopappus Cass. [Asteraceae] comprises a large number of species distributed mainly in Chile and with various traditional medicinal uses.

Purpose

The present review addresses the botany, traditional uses, chemistry, biological and pharmacological activities of the genus, aiming to further potentiate the associated research and applications.

Study design and Methods

Literature data on the chemistry and bioactivity of the genus Haplopappus were mainly retrieved from digital databases such as SciFinder®, PubMed®, and Google Scholar®, as well as from the scientific journal publishers' platforms linked with these databases.

Results and discussion

Although the majority of the botanical taxa of the genus Haplopappus has been understudied, available information is promising regarding its phytochemistry and bioactivity. A total of more than 400 compounds are present in different Haplopappus species, mostly terpenoids and phenolic compounds. Scientific literature supports various health promoting effects of Haplopappus extracts and isolated compounds, principally their effect against human pathogenic bacteria and their high antioxidant capacity. The existing limitations highlighted hereby are mainly associated to the lack of modern investigation regarding a wider number of Haplopappus species and chemical compounds, as well as to the absence of in vivo bioactivity results and clinical trials.

Conclusion

Scientific literature supports the ethnopharmacological, phytochemical and bioactive potential of the genus Haplopappus, however the aforementioned limitations need to be addressed in order to further promote and broaden both scientific research and future applications and uses.

The traditional use of native Brazilian plants for male sexual dysfunction: Evidence from ethnomedicinal applications, animal models, and possible mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Sexual dysfunction is a multifactorial health condition characterized by distressing disturbances in the sexual response and libido, leading to an inability to maintain penile erection and achieve pleasure. Considering the huge Brazilian biodiversity, many plants are traditionally used for aphrodisiac purposes. However, the use of native medicinal plants as sexual boosters in Brazil has been poorly studied.

AIM OF THE STUDY

This review focuses on the composition, pharmacology, and results of experimental trials of the main native plants used in Brazilian folk medicine with alleged aphrodisiac effects. We aimed to provide a state-of-the-art reference for research on herbs for the treatment of male sexual dysfunction by summarizing and discussing the main studies found.

MATERIALS AND METHODS

The relevant information was collected by searching keywords (aphrodisiac, sexual tonic, sexual stimulant, sexual vigor stimulant, sexual impotency, erectile dysfunction, etc.) from books containing primary surveys conducted in the original communities and bibliographic surveys prepared by authors linked to the national academic and scientific environment edited in Brazil. Preclinical and clinical studies of the compiled plant species were performed using scientific databases (Scopus, PubMed, SciELO, and SciFinder).

RESULTS

Seventy-four plant species belonging to 44 families used in Brazil to treat sexual dysfunction were compiled from ethnopharmacological literature. Fourteen plants, including Pfaffia glomerata (Spreng.) Pedersen, Aspidosperma quebracho-blanco Schltdl., Anemopaegma arvense (Vell.) Stellfeld ex de Souza, Mimosa pudica L., Heteropterys tomentosa A. Juss., Trichilia catigua A. Juss., and Turnera diffusa Willd. ex Schult. were pharmacologically studied to confirm these therapeutic properties. Probable modes of action include antioxidant and androgenic activities, inhibition of the PDE5 enzyme, increase in NO levels, and activation of dopaminergic and noradrenergic pathways. In addition, several different species popularly known as "catuaba" were identified, leading to adulterations and controversial effects.

CONCLUSION

The overall results of the present review of Brazilian folk literature reveal that Brazil has a long tradition of using plants with potential aphrodisiac effects. However, further research is required to identify, characterize, and standardize the active ingredients and herbal preparations used in aphrodisiacs.

Bioactivity of the Genus Turnera: A Review of the Last 10 Years

Turnera is a genus of plants whose biological activity has been widely studied. The importance of this genus, particularly Turnera diffusa, as a source of treatment for various conditions is evidenced by the large number of new studies that have evaluated its biological activity. Accordingly, the objective of this review was to compile the information published in the last ten years concerning the biological activities reported for Turnera spp. The present work includes 92 publications that evaluate 29 bioactivities and toxicological and genotoxic information on five species of this genus. Among the pharmacological effects reported, the antioxidant, hepatoprotective, neuroprotective, hypoglycemic, and aphrodisiac activities seem more promising. Phytochemicals and standardized plant extracts could offer alternative therapeutic remedies for various diseases. Although several flavonoids, cyanogenic glycosides, monoterpenoids, triterpenoids, and fatty acids have been isolated for Turnera plants, future research should focus on the identification of the main active principles responsible for these pharmacological activities, as well as to perform clinical trials to support the laboratory results.

Medicinal plants as a potential source of Phosphodiesterase-5 inhibitors: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence and distress caused by erectile dysfunction (ED) to both male and female partners are increasing at a steady rate. ED has now become the most treated sexual disorder for men among young and old age groups due to varying physical and psychological factors. The treatment with synthetic Phosphodiesterase-5 (PDE5) inhibitors are cost-effective but due to adverse effects such as priapism, loss of vision, heart attack and syncope, the daily life patterns of these patients are distressed and hence the need for alternative medicaments or sources are of utmost important. Therefore, the exploration of medicinal plants as PDE5 inhibitors will be worthwhile in tackling the problems as many plant extracts and fractions have been long used as aphrodisiacs and sexual stimulants which may be found to be active against PDE5 enzyme.

AIM OF THE STUDY

To provide a review on the different medicinal herbs traditionally used as natural aphrodisiacs, libido or sexual enhancers which are proven for their PDE5 inhibitory effect.

MATERIALS AND METHODS

Ethnobotanical and scientific information was procured, reviewed and compiled from the literature search of electronic databases and search engines.

RESULTS

A total of 97 medicinal plants exhibiting PDE5 inhibitory effect are reviewed in this paper which is supported by preclinical experimental evidence. Among them, 77 plants have been selected according to their traditional and ethnobotanical uses as aphrodisiacs and the rest are screened according to their effectiveness against predisposing factors responsible for ED and sexual dysfunction such as diabetes and hypertension or due to the presence of phytochemicals having structural similarity towards the identified natural PDE5 inhibitors. In addition, sixteen alkaloids, sixty-one phenolics and eight polycyclic aromatic hydrocarbons have been isolated or identified from active extracts or fractions that are exhibiting PDE5 inhibitory activity. Among them, isoflavones and biflavones are the major active constituents responsible for action, where the presence of prenyl group for isoflavones; and the methoxy group at C-5 position of flavones are considered essential for the inhibitory effect. However, the prenylated flavonol glycoside, Icariin and Icariside II isolated from Epimedium brevicornum Maxim (hory goat weed) are the most effective inhibitor, till date from natural sources. Traditional medicines or formulations containing extracts of Ginkgo biloba L., Kaempferia parviflora Wall. ex Baker, Clerodendrum colebrookianum Walp., Eurycoma longifolia Jack and Vitis vinifera L. are also found to be inhibitors of PDE5 enzyme.

CONCLUSION

The review suggests and supports the rational use of traditional medicines that can be further studied for the development of potential PDE5 inhibitors. Many traditional medicines are still used in various regions of Africa, Asia and South America that are poorly characterized and experimented. Despite the availability of a vast majority of traditional formulations as aphrodisiacs or sexual stimulants, there exists a need for systemic evaluation on the efficacy as well as the mechanism of action of the herbal constituents for the identification of novel chemical moieties that can be further developed for maximum efficacy.

Extracting and Analyzing Pyrrolizidine Alkaloids in Medicinal Plants: A Review

Pyrrolizidine alkaloids (PAs) are distributed in plant families of Asteraceae, Boraginaceae, and Fabaceae and serve in the chemical defense mechanism against herbivores. However, they became a matter of concern due to their toxicity associated with the high risk of intake within herbal preparations, e.g., phytopharmaceutical formulations, medicinal teas, or other plant-derived drug products. In 1992, the German Federal Ministry of Health established the first limits of PA content for fourteen medicinal plants. Because of the toxic effects of PAs, the Federal Institute of Risk Assessment (BfR) established more stringent limits in 2011, whereby a daily intake <0.007 µg/kg body weight was recommended and valid until 2018. A threefold higher limit was then advised by BfR. To address consumer safety, there is the need for more efficient extraction procedures along with robust, selective, and sensitive analytical methods to address these concerns. With the increased prevalence of, e.g., phytopharmaceutical formulations, this timely review comprehensively focuses on the most relevant extraction and analysis strategies for each of those fourteen plant genera. While a variety of extraction procedures has been reported, differences in PA content of up to 1110 ppm (0.11% (w/w)) were obtained dependent on the nature of the solvent and the applied extraction technique. It is evident that the efficient extraction of PAs requires further improvements or at least standardization of the extraction conditions. Comparing the various analytical techniques applied regarding selectivity and sensitivity, LC-MS methods appear most suited. This review shows that both standardized extraction and sensitive determination of PAs is required for achieving appropriate safety levels concerning public health in future.

In vitro inhibition of phosphodiesterase-5 and arginase activities from rat penile tissue by two Nigerian herbs (Hunteria umbellata and Anogeissus leiocarpus)

BACKGROUND

Anogeissus leiocarpus and Hunteria umbellata have been reportedly used in traditional medicine for the management of erectile dysfunction (ED). However, the scientific basis for their use has not been well established. Therefore, this study was designed to investigate the inhibitory effects of water extractable phytochemicals of H. umbellata and A. leiocarpus on phosphodiesterase-5 (PDE-5) and arginase as well as pro-oxidants induced lipid peroxidation in rat penile tissue.

METHODS

The effects of the extracts on important enzymes (PDE-5 and arginase) linked with ED and pro-oxidants (Fe2+ and sodium nitroprusside) induced lipid peroxidation were investigated. Also, radicals scavenging and metal chelating abilities were determined. In addition, phenolic contents were determined and characterized using HPLC.

RESULTS

The results showed that both extracts inhibited PDE-5 and arginase activities in a dose-dependent manner. Inhibitory property of A. leiocarpus (IC50 - 174.19 μg/mL) was significantly better (p<0.05) than that of H. umbellata (IC50 - 537.72 μg/mL) in PDE-5 assay. The extracts were potent inhibitors of arginase than PDE-5, and these extracts were equally potent in inhibiting arginase. Furthermore, Fe2+ and sodium nitroprusside caused a significant increase in malondialdehyde content; however, both extracts reduced malondialdehyde level in concentration-dependent manner. It is noteworthy that both extracts scavenged radicals (OH* and ABTS*) and chelated Fe2+. HPLC analysis revealed abundance of rutin, chlorogenic acid, gallic acid, caffeic acid, and quercetin, among others.

CONCLUSIONS

The ability of the extracts to inhibit PDE-5, arginase and pro-oxidant induced lipid peroxidation, and chelate metal might suggest their folkloric use for the management of ED.

Hydroalcoholic extract and pure compounds from Senecio nutans Sch. Bip (Compositae) induce vasodilation in rat aorta through endothelium-dependent and independent mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Senecio nutans Sch. Bip. (Compositae) is an endemic plant of South America, and is used in herbal medicine in Andean communities for treating acute mountain sickness. Currently, the direct effects of hydroalcoholic extract of S. nutans (HAE S. nutans) or its isolated compounds on the vascular system are not well described. The aim of this study was to determine the effects and mechanism of action of S. nutans on vascular function in healthy rats.

MATERIAL AND METHODS

Seven compounds were isolated from the HAE S. nutans, and their structures were characterized using spectroscopic techniques as 1D and 2D NMR, and mass spectrometry. Vascular reactivity experiments were carried out in rat aorta. S. nutans-dependent vasodilation and phenylephrine-dependent contraction were measured in endothelium-intact and endothelium-denuded aortic rings of male rats.

RESULTS

Seven pure compounds were isolate from HAE S. nutans, but two pure compounds showed significant vasodilation in rat aorta: 4-hydroxy-3-(3-methyl-2-butenyl)acetophenone (compound E) and 5-acetyl-6-hydroxy-2-isopropenyl-2,3-dihydrobenzofurane (compound G). Although HAE S. nutans induced vasodilation in absence of endothelium, the vasodilation in intact aorta, via NO, was higher. HAE S. nutans reduced calcium-dependent contraction in endothelium-intact, but not in endothelium-denuded aortic rings.

CONCLUSION

HAE S. nutans and its isolated compounds caused vasodilation in rat aorta in absence of endothelium, suggesting its vasodilator properties is endothelium-dependent (NO) and or independent, and may involve a modulation of the calcium channels. This result is of clinical interest as potential therapy control of blood pressure.

Vasorelaxant Effect of aBaccharis TrimeraInfusion on Precontracted Rat Aortic Rings

Baccharis trimera (Less.) DC is a South American plant that in folk medicine is considered to produce reduction in blood pressure. One aspect of this putative effect is the vasorelaxation. The aim of this work was to evaluate the ability of a B. trimera extract to relax rat aortic rings precontracted with noradrenaline. As the infusion is the usual way of intake of this plant, an infusion of B. trimera was prepared using 100g of the plant (leaves) boiled in water, frozen and lyophilized. Working solutions were prepared using different concentrations of the dried extract diluted in Krebs Henseleit solution. It was proved that the infusion relaxed the aortic rings in a dose dependent manner 100 minutes after adding the extract to the bath. Considering as 100% the maximum contraction achieved with noradrenaline, a relaxation of 101.1±2.3% was observed with the highest dose of the infusion used in these experiments (0.32mg/mL). While in control rings relaxation was 12.9±2.4%. In aortic rings denuded from endothelium the percentage of vasoralaxation did not show statistically significant differences when compared to intact rings. These data support the hypothesis of a vasorelaxant effect of this plant and constitutes the first approach to the scientific basis of a potential antihypertensive effect.

Hypotensive and antihypertensive effects of a hydroalcoholic extract from Senecio nutans Sch. Bip. (Compositae) in mice: Chronotropic and negative inotropic effect, a nifedipine-like action

ETHNOPHARMACOLOGICAL RELEVANCE

Senecio nutans Sch. Bip. (Compositae) is an endemic plant of South America used in the management of acute mountain sickness in the Andean communities. Currently, the direct effects of hydroalcoholic extract from S. nutans on the cardiovascular system are unknown. The aim of this study was to determine the effects and mechanism of action of S. nutans on cardiovascular function in normotensive and Angiotensin II (1μg/mL) hypertension mice models.

MATERIAL AND METHODS

Blood pressure and ECG measurements were simultaneously carried out on the mice and rats. The isolated right atrium, papillary muscle of the left ventricle and isolated heart of rat were used to study the cardiac functions and mechanisms.

RESULTS

S. nutans (40mg/Kg) induced a 30% and 12% significant (p<0.05) reduction of the mean arterial pressure (MAP) in normotensive and hypertensive mice respectively. This decrease was as a result of decrease in heart rate (HR) in normotensive (25%) and hypertensive model (31%). It also decreased the sinus rhythm in isolated right atrium of rat. Compared with Losartan, a known anti-hypertensive, S. nutans caused a dose-dependent negative inotropic effect (dP/dtmax) on Langendorff isolated heart system. While Losartan, decreased the MAP by 30% but had no effect on heart rate. The calcium blocker nifedipine had similar effects as S. nutans, decreasing the beat frequency of isolated right atrium and contractility of papillary muscle of the left ventricle of rat.

CONCLUSION

The results suggest an important clinical function in hypertension therapy, as S. nutans could decrease the blood pressure in hypertensive mice by decreasing the HR and contractility, leading to a reduction in myocardial oxygen demand.

Herbs to curb cyclic nucleotide phosphodiesterase and their potential role in Alzheimer's disease

Cyclic nucleotides viz., cAMP/cGMP has been well known to play important role in cellular function and deficiency in their levels has been implicated in the pathogenesis of various neurodegenerative disorders including Alzheimer's disease (AD). Phosphodiesterases (PDE) are the enzymes involved in the metabolism of cyclic nucleotides and the inhibition of phosphodiesterases is considered to be viable strategy to restore the level of cyclic nucleotides and their functions in the brain. Various synthetic PDE inhibitors had been used clinically for various disorders and also suggested to be useful candidates for treating neurological disorders. However, side effects of these synthetic PDE inhibitors have limited their use in clinical practice. Natural plant extracts or their bio-active compounds are considered to be safe and are widely acceptable. During the last decade, many plant extracts or their bio-active compounds were tested pre-clinically for PDE inhibitory activity and are reported to be equally potent in inhibiting PDE's, as that of synthetic compounds. The present review is aimed to discuss the potential plant extract/compounds with PDE inhibitory activity and critically discuss their potential role in Alzheimer's disease.

A pharmacological and phytochemical overview on Satureja

CONTEXT

Satureja (Lamiaceae) species are used as flavoring compounds in food, pharmaceutical, and cosmetic industries because of its sweetness and simple cultivation characteristics. They have traditionally been used as muscle pain relievers, tonic, and carminative agents to treat stomach and intestinal disorders such as cramps, nausea, indigestion, and diarrhea, due to their considerable phytochemical characteristics.

OBJECTIVE

This review evaluates some information published since 1989 on Satureja genus from a systematic perspective in terms of its pharmacological and phytochemical characteristics.

MATERIALS AND METHODS

Web of Science, PubMed, Scopus, and Google Scholar databases were searched up to March 2014. "Satureja" was used as a research term without narrowing or limiting research elements. After obtaining all reports from database (a total number is about 637), the papers were carefully analyzed in order to find data related to the topic of this review.

RESULTS

In this review, 453 reports were used which were published between 1989 and 2014. The study was compiled into two sections (Pharmacology and Phytochemistry). In the pharmacology section, more than 50 different activities were studied. In the second section, in addition to other compounds and inorganic substances, volatiles, phenolic acids, and flavonoids were discussed.

DISCUSSION AND CONCLUSION

According to our contemporary information, Satureja species have been evaluated for their wide range of biological activities. However, a small part of these studies have been carried out on the active principles. Therefore, in the future, more studies should be carried out to identify responsible phytochemicals for the various activities.

Huperzia saururus Lam. Trevis. (Lycopodiaceae) facilitates ejaculation in spinal cord transected male rats

ETHNOPHARMACOLOGICAL RELEVANCE

Huperzia saururus (Lam.) Trevis. has an extensive ethnopharmacological use, mainly because of its aphrodisiac properties. The species is consumed as decoctions or infusions in traditional medicine. The purpose of the present research was to determine if Huperzia saururus is able to increase sexual potency by evaluating the ejaculatory response, in the presence of a decoction in spinal cord transected male rats.

MATERIALS AND METHODS

The fictive ejaculation model to record the rhythmic contractions of the bulbospongiosus muscles that accompany ejaculation as an indicator of ejaculation occurrence was used. Sexually experienced male Wistar rats were used. The activation of the fictive ejaculation by the i.v. administration of a decoction was tested, as well as the effects of the oxytocinergic, cholinergic, adrenergic and nitrergic antagonism upon the pro-ejaculatory activity of Huperzia saururus.

RESULTS

Decoction (3µg/animal) was able to activate the fictive ejaculation in spinal male rats, producing a statistically significant diminution on the latency of discharge parameter and a statistically significant augment for the number of discharges. Moreover, when sequential treatments using antagonists plus decoction were administered, the effects produced showed that prazosin prevent the pro-ejaculatory effect of the decoction and that the four antagonists assayed blocked the facilitatory effect of Huperzia saururus since the facilitation in the latency of response was prevented, and the number of discharges was reduced. Together these findings support the notion that the decoction exerts an aphrodisiac effect influencing the ejaculatory potency which is partially mediated by oxytocinergic, cholinergic, adrenergic and nitrergic spinal mechanisms.

CONCLUSION

In agreement to the ethnopharmacological uses, Huperzia saururus decoction has aphrodisiac properties by influence on the ejaculatory potency.

Ethnobotany, phytochemistry, and bioactivity of the genus Turnera (Passifloraceae) with a focus on damiana--Turnera diffusa

ETHNOPHARMACOLOGICAL RELEVANCE

Half a dozen of the currently accepted 135 Turnera species are used in traditional medicine, most notably Turnera diffusa Willd. ex Schult. which is one of the most highly appreciated plant aphrodisiacs. Other traditional uses of Turnera L. species include the treatment of anaemia, bronchitis, cough, diabetes, fever, fungal disease, gastrointestinal complaints, pain, pulmonary and respiratory diseases, skin disorders, and women׳s health problems. Additionally, Turnera species are used as abortives, expectorants, and laxatives.

PHYTOCHEMISTRY

Flavonoids (22 different compounds), maltol glucoside, phenolics, cyanogenic glycosides (7 different compounds), monoterpenoids, sesquiterpenoids, triterpenoids, the polyterpene ficaprenol-11, fatty acids, and caffeine have been found in the genus Turnera.

BIOACTIVITY

Bioactivities experimentally proven for members of the genus Turnera encompass antianxiety, antiaromatase, antibacterial including antimycobacterial, antidiabetic, antioxidant, adapatogenic, antiobesity, antispasmodic, cytotoxic, gastroprotective, hepatoprotective, and aphrodisiac activities. Most of these activities have so far been investigated only in chemical, cell based, or animal assays. In contrast, the antiobesity activity was also investigated in a study on healthy human subjects and with a herbal preparation containing among other ingredients Turnera diffusa leaves. Moreover, the enhancement of female sexual function was assessed in humans; again the product contained besides Turnera diffusa other potentially bioactive ingredients. However, with only few exceptions, most of the traditional uses and the experimentally verified bioactivities can currently not be related to a particular compound or compound class. A notable exception is the flavonoid apigenin, which was identified animal experiments as the antinociceptive principle of Turnera diffusa.

CONCLUSION

In this review, the current knowledge on ethnobotanical uses of members of the genus Turnera, the secondary metabolites reported from Turnera, and experimentally documented bioactivities from Turnera extracts and pure compounds derived from Turnera extracts are compiled. Moreover, some of the most interesting avenues for future research projects are being discussed briefly. These include in particular the aphrodisiac activity of Turnera diffusa and the antibiotic activity potentiating effect of Turnera ulmifolia L. against aminoglycoside resistant bacteria.

Pro-sexual effects of Turnera diffusa Wild (Turneraceae) in male rats involves the nitric oxide pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Turnera diffusa Wild has been used in folk medicine by its aphrodisiac and tranquilizing properties. Previously we experimentally showed the aphrodisiac effect of a chemically characterized aqueous extract of Turnera diffusa in male rats. However, the mechanism of action underlying such effects has not been studied.

STUDY AIMS

As part of our systematic studies of pharmacological properties of Turnera diffusa, we aimed to analyze whether the increased sexual motivation and the augmented sexual performance of sexually sluggish (SL) male rats treated with Turnera diffusa involves the NO pathway. Additionally we analyzed whether such effects were exerted at the level of the brain or the spinal cord. Finally, anxiety levels and ambulatory activity were also evaluated.

MATERIAL AND METHODS

Turnera diffusa (10-40 mg/kg) and sildenafil citrate (10 mg/kg) with or without a nonspecific inhibitor of NO synthase, Nω-nitro-L-arginine methyl esther (L-NAME, 12.5 mg/kg) were evaluated in SL rats, in a standard sexual behavior test and in the fictive ejaculation model in spinal cord transected and urethane-anaesthetized SL rats. Anxiety levels or ambulation were assessed in the burying behavior and open-field tests.

RESULTS

Turnera diffusa and sildenafil (both at 10 mg/kg) facilitated expression of male sexual behavior by shortening mainly ejaculation latency. Treatments also facilitated the number of discharges in the ejaculatory motor pattern as well as the number of ejaculatory motor patterns and its associated penile erections. L-NAME prevented the pro-sexual effects of treatments on both experimental models. Besides, the extract of Turnera diffusa (10 mg/kg) produced an anxiolytic-like effect in male rats without affecting ambulation.

CONCLUSIONS

Findings from the present work support the notion that pro-sexual effect of the aqueous extract of Turnera diffusa in rats involves the participation of NO pathway, mainly at central level. The anxiolytic-like effect of Turnera diffusa is an advantage to its use for improving sexual performance.

Erectogenic Effects of Clerodendron capitatum: Involvement of Phosphodiesterase Type-5 Inhibition

Clerodendron capitatum (Willd) (family: verbenaceae) is locally named as Gung and used traditionally to treat erectile dysfunction. Therefore, the current study was designed to investigate the erectogenic properties of C. capitatum. The relaxation effect of this plant was tested on phenylephrine precontracted rabbit corpus cavernosum smooth muscle (CCSM). The effects of C. capitatum were also examined on isolated Guinea pig atria alone, in the presence of calcium chloride (Ca(2+) channel blocker), atropine (cholinergic blocker), and glibenclamide (ATP-sensitive K(+) channel blocker). These effects were confirmed on isolated rabbit aortic strips. The extract, when tested colorimetrically for its inhibitory activities on phosphordiesterase-5 (PDE-5) in vitro towards p-nitrophenyl phenyl phosphate (PNPPP), was observed to induce significant dose-dependent inhibition of PDE-5, with an ID(50) of 0.161 mg/ml (P < .05). In conclusion, our results suggest that C. capitatum possesses a relaxant effect on CCSM, which is attributable to the inhibition of PDE-5, but not mediated by the release calcium, activation of adrenergic or cholinergic receptors, or the activation of potassium channels.

A review of the herbal phosphodiesterase inhibitors; future perspective of new drugs

Phosphodiesterase inhibitors (PDEIs) are a class of drugs that are widely used because of their various pharmacological properties including cardiotonic, vasodilator, smooth muscle relaxant, antidepressant, antithrombotic, bronchodilator, antiinflammatory and enhancer of cognitive function. In the recent years, interest in drugs of plant origin has been progressively increased. Some pharmacologically active substances that come from plants demonstrate PDEI activity. They mainly belong to alkaloids, flavonoids, and saponins. In this review, studies on herbal PDEI were reviewed and their possible therapeutic applications were discussed. Screening plants for PDE inhibitory activity may help to develop standardized phytotherapeutic products or find new sources for new lead structures with PDEI pharmacological activity. The studies discussed in this paper are mainly in vitro and for more reasonable and conclusive results, it is required to conduct in vivo and finally human and clinical tests.

Medicinal plants as potential male anti-infertility agents: a review

For millions of couples, the inability to have a child is a personal tragedy and a large proportion of childless people are confronted with social stigmatization (blame) and personal frustration. Formerly assigned to women, infertility of a couple is nowadays equitably distributed between the two sexes. Among the methods used to treat male infertility problems, medicinal plants have been used empirically as extracts, decoctions, fractions or semi-purified compounds. These herbal products are used in the treatment of a dysfunctioning of the libido, sexual asthenia, erection, and sperm disorders. Pharmacological activities of many of these plants have been shown in vitro using cells, in vivo (on laboratory animals) and human studies. For instance, extracts of Panax ginseng, Panax quinquefolius and Lepidium meyenii have shown positive effects on sexual desire; while extracts of Astragalus membranaceus, Asparagus racemous, Withania somnifera, Andrographis paniculata and Acanthopanax senticosus improved sperm parameters. Plants provide a treatment option that is affordable and available for infertile couples, and phytotherapy is an essential form of treatment in our health system. However, herbal products are still anarchically used in many regions and countries, and a great proportion of medicinal plants used traditionally to solve male reproductive disorders have not yet been scientifically evaluated. Therefore in this review, we have summarized most of the data dealing with the effects of plant extracts on mammalian reproductive functions.

Turnera diffusa Wild (Turneraceae) recovers sexual behavior in sexually exhausted males

ETHNOPHARMACOLOGICAL RELEVANCE

In folk medicine, Turnera diffusa Wild (Turnera diffusa, Turneraceae) is considered as an aphrodisiac, but its ability to restore copulation in sexually inhibited subjects has not been reported.

AIM OF THE STUDY

To determine whether Turnera diffusa recovers sexual behavior in sexually exhausted (SExh) male rats and to identify the main components in an aqueous extract.

MATERIALS AND METHODS

SExh males were treated with Turnera diffusa, 20-80 mg/kg, yohimbine, 2 mg/kg, or vehicle.

RESULTS

Yohimbine and Turnera diffusa (80 mg/kg) significantly increased the percentage of males achieving one ejaculatory series and resuming a second one. In addition, Turnera diffusa significantly reduced the post-ejaculatory interval. These effects were not associated to an increase in locomotor activity or anxiety-like behaviors. The HPLC-ESI-MS analysis showed the presence of caffeine, arbutine, and flavonoids as the main compounds in the active extract.

CONCLUSION

The results support the use of Turnera diffusa as an aphrodisiac in traditional medicine and suggest possible therapeutic properties of Turnera diffusa on sexual dysfunction. The flavonoids present in active extract may participate in its pro-sexual effect, which is analogous to those produced by yohimbine, suggesting a shared mechanism of action.

Brazilian plants as possible adaptogens: an ethnopharmacological survey of books edited in Brazil

In a survey, from Brazilian books, we searched plants that are in popular use for purposes resembling those of an adaptogen. This study focused on 24 books by authors from diverse regions in the country, resulting in a total of 1317 citations of uses related to a possible adaptogen effect from approximately 766 plants. Only species native to Brazil, cited in at least four books, were selected, resulting a total of 33 species, belonging to 24 families. Of these, four species have been studied previously in relation to effects that are considered as part of an adaptogen effect (anti-stress, memory enhancement, increased physical and/or sexual performance): Heteropterys aphrodisiaca (Malpighiaceae), Paullinia cupana (Sapindaceae), Ptychopetalum olacoides (Olacaceae), and Turnera diffusa (Turneraceae). Three others--Pfaffia glomerata, Pfaffia paniculata (Amaranthaceae), and Trichilia catigua (Meliaceae)--have also been the object of pharmacological studies that support their use as a possible adaptogen, but they are listed in less than four books. The overall results obtained in the present review of Brazilian folk literature reveals that Brazil is rich in plants with potential adaptogen-like effect, but lacks pharmacological studies (mostly clinical ones) to confirm these therapeutic properties.

Plants popularly used for loosing weight purposes in Porto Alegre, South Brazil

In this study, 14 herbalists (herb sellers) were interviewed about popular use of plants with weight loss purpose in Porto Alegre, a South Brazil city. For all identified species, scientific data were reviewed aiming to establish a correlation between popular use and biological properties. Seventy-eight samples were reported as having weigh loss properties. These samples come from 23 species and Asteraceae encompasses the greatest number of representatives. The greatest number of herbalist's citations was Baccharis articulata. The majority of plants have traditional use in Brazil but none is explicitly cited for loosing weight purposes. The pharmacological data are mainly from animal and in vitro studies and do not straight related to obesity. Only Ilex paraguariensis presents clinical data of efficacy in the treatment of obesity. Seven species present pre-clinical data that indicate a potential role in the control of certain conditions which are associated with obesity, such as hyperlipidemia (Campomanesia xanthocarpa, Cuphea carthagenensis, Cynara scolymus, Hibiscus sabdariffa, Ilex paraguariensis) and high levels of blood glucose (Achyrocline satureioides, Baccharis trimera, Campomanesia xanthocarpa). In conclusion, scientific data found are insufficient to guarantee the efficacy and safety of these plants for treating obesity. However, some of them present activities which could be useful to treat certain obesity comorbidities and deserve further studies.

Research into microscopic structure and essential oils of endemic medicinal plant species Satureja subspicata Bartl. ex Vis. (Lamiaceae)

In this study we looked into the cells and histological organization of leaves (Saturejae folium) as well as a phyto-chemical composition of overground parts (Saturejae herba) of endemic species Satureja subspicata Bartl. ex Vis. (Lamiaceae) collected during year 2003 on south slopes of mountain Velez in Herzegovina. Microscopic organization was analyzed in wet slides using light microscope. Estimation of stomata index was done according to Ph. Yug. IV. Chemical composition of overground material extracts was determined by thin layer chromatography (TLC) using thymol as a reference. In our research we found the following: Leaf structure of the analyzed species Satureja subspicata points at numerous specificities in anatomical and histological sense. In histological sense, leaf is of ventral type, with differentiated upper and lower epidermis and palisade and spongy tissue in between. Stoma index assigned according to Ph. Yug. IV leads to a conclusion that it is the case of diastitic stomata, which is common feature of most species from Lamiaceae family. Comparative qualitative analysis of essential oils in species Satureja subspicata showed similarities with other species from Lamiaceae family such as Thymus L. (thymol). In fact, we found more common substances that are part of the species Satureja montana L. extract, but in different concentrations.

Flavonoids from Achyrocline satureioides with relaxant effects on the smooth muscle of Guinea pig corpus cavernosum

Ethanol extract of the aerial parts of Achyrocline satureioides (Lam.) DC. (Asteraceae) showed a significant, dose dependent, relaxant effect on the smooth muscle of corpus cavernosum strips, obtained from Guinea pig (65.5 +/- 4.1% of relaxation at the dose of 25.0 mg/ml). Bioassay guided fractionation of this extract furnished two flavonoids, quercetin and quercetin 3-methyl ether, with important vasorelaxing effects on the corpus cavernosum strips (79.8 +/- 8.4 and 66.0 +/- 4.8% of relaxation respectively at the dose of 0.075 mg/ml). Two methyl derivatives of quercetin obtained by synthesis, quercetin 3,7,3',4'-tetramethylether and quercetin 3,5,7,3',4'-pentamethylether, showed similar relaxant effects at the dose of 0.075 mg/ml (86.4 +/- 8.5 and 67.31 +/- 1.4% of relaxation respectively). The results show that the ethanol extract of A. satureioides and the assayed compounds exhibit significant vasorelaxing properties. Additionally, it is shown that the number of methyl groups in the quercetin nucleus has no significant influence on the effectiveness of these compounds.