Recent findings on natural products with erectile-dysfunction activity

An overview of the history, current strategies, and potential future treatment approaches in erectile dysfunction: a comprehensive review

INTRODUCTION

Erectile dysfunction (ED) is one of the most common urologic problems in men worldwide, with an approximately high incidence rate, significantly affecting patients' quality of life and their sexual partners.

OBJECTIVES

Due to the association of this disorder with essential diseases such as cardiovascular disease and diabetes, its prevention and treatment are vital for overall human physiologic and psychological health. Along with reviewing the history of treatment and current methods, we seek new approaches to curb this issue in the future.

METHODS

In this review, investigations were based on the focus of each section's content or conducted on an ad hoc basis. Searches were performed in Scopus and PubMed.

RESULTS

In recent years, many treatments for ED have been reported besides oral administration of phosphodiesterase 5 inhibitors such as sildenafil and tadalafil (approved by the Food and Drug Administration). Common oral medications, intracavernous injections, herbal therapies (eg, herbal phosphodiesterase 5 inhibitors), and topical/transdermal medications are routine ED treatment approaches. Moreover, some novel medications are innovative candidates for completing ED's treatment protocols: stem cell injection, low-intensity extracorporeal shock wave therapy, platelet-rich plasma injection, gene therapy, amniotic fluid matrices, rho-kinase inhibitors, melanocortin receptor antagonists, maxi-K channel activators (ie, large-conductance calcium-activated potassium channels), guanylate cyclase activators, and nitric oxide donors.

CONCLUSION

Due to the importance of this complicated problem in men's society, a faster course of treatment trends toward new methods is needed to increase efficiency. Combining the mentioned treatments and attentively examining their efficacy through programmed clinical trials can be a big step toward solving this global problem.

Ameliorative Sexual Behavior and Phosphodiesterase-5 Inhibitory Effects of Spondias mangifera Fruit Extract in Rodents: In Silico, In Vitro, and In Vivo Study

The ethanolic extracts of Spondias mangifera fruit (SMFE) were evaluated for aphrodisiac activity. The in-vitro phosphodiesterase-5 (PDE-5) inhibition was assessed based on in-silico molecular docking and simulation studies. In addition, the in-vivo sexual behavior was analyzed in the form of mount (MF, ML), intromission (IF, IL), and ejaculation (EF, EL) frequencies and latencies to validate the in-vitro results. Some biochemical parameters, including PDE-5, nitric oxide, and testosterone, were also observed. The above extract constituted β-amyrin, β-sitosterol, and oleanolic acid and showed tremendous binding with phosphodiesterase-5 and sildenafil. Both the sildenafil and ethanolic extracts (200 and 400 mg/kg/d bodyweight) significantly (p < 0.1, p < 0.05) increased MF, IF, and EF, respectively. In contrast, ML and IL significantly (p < 0.1) decreased, and EL significantly (p < 0.1) increased compared with a normal group of animals. The ethanolic extracts (200 and 400 mg/kg/d bodyweight) and sildenafil further significantly (p < 0.05, p < 0.1) diminished PDE-5 activity significantly (p < 0.05, p < 0.1) and enhanced nitric oxide and testosterone levels, as compared with normal rodents. Therefore, the S. mangifera ethanolic extract might be a valuable alternate aphrodisiac for erectile dysfunction.

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.

Iridoids and Amino Acid Derivatives from the Paraguayan Crude Drug Adenocalymma marginatum (ysypó hû)

The crude drug ysypó hû (Adenocalymma marginatum DC., Bignoniaceae) is used traditionally by the Guarani of Eastern Paraguayan as a male sexual enhancer. The aim of the present study was to identify the main constituents of the crude drug and to evaluate the in vitro inhibitory activity towards the enzyme phosphodiesterase-5 (PDE-5). The main compounds were isolated by counter-current chromatography (CCC). The metabolites were identified by spectroscopic and spectrometric means. The chemical profiling of the extracts was assessed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). The crude extract and main isolated compounds were tested for their PDE-5 inhibitory activity using commercial kits. The iridoid theviridoside and 4-hydroxy-1-methylproline were isolated as the main constituent of the crude drug. Four chlortheviridoside hexoside derivatives were detected for the first time as natural products. Chemical profiling by HPLC-MS/MS led to the tentative identification of nine iridoids, six phenolics, and five amino acids. The crude extracts and main compounds were inactive towards PDE-5 at concentrations up to 500 µg/mL. Iridoids and amino acid derivatives were the main compounds occurring in the Paraguayan crude drug. The potential of ysypó hû as a male sexual enhancer cannot be discarded, since other mechanisms may be involved.

Chemical Constituents, Biological Properties, and Uses of Tribulus terrestris: A Review

Tribulus terrestris L. (TT) (puncturevine) is a common weed that grows in many countries worldwide and in some places is considered as a noxious weed. The plant has been used in traditional Chinese and Indian medicines and is now considered as one of the most popular aphrodisiacs. It is known for its healing properties for sexual difficulties, impotence, and human and animal hormonal imbalance. It is also used as a sexual booster. Because of the plant’s active substances that can be used for curing sexual and other disorders, interest in it is increasing, and it is currently one of the most studied medicinal plants. The products and preparations manufactured from the aboveground plant parts are especially popular among athletes and people with health issues and diseases such as hormonal imbalance, sexual problems, heart problems, and various kidney and skin diseases. The aim of this review is a comprehensive and critical assessment of the scientific publications involving TT, with special reference to its chemical constituents and biological properties that may facilitate current understanding and future studies of this fascinating plant species. The objectives of this review were (1) to find knowledge gaps, (2) to discuss critically relevant publications and issues with materials and methods that may be prerequisites for contradictory results, and (3) to identify research and development areas. It was found that some of the studies on TT extracts as aphrodisiacs are controversial. A significant number of research publications claim that TT extracts and nutritional supplements containing TT improve muscle tone, have a common biostimulating effect, and improve spermogenesis. However, there are a growing number of publications that dispute these claims, as there are no empirical data on commonly accepted mechanisms of action. The main biologically active substances in TT are steroidal saponins, flavonoids, alkaloids, and lignan amides, the most studied being the steroidal saponins. Multiyear data on the metabolic profile of the species are generally lacking. There are a variety of methods used for extracting plant material, differences in methodologies and saponin analyses, and scientific instruments that were used. Lack of common standards could be a reason for differences in the pharmacological activity and composition of the TT preparations. Development of standard procedures and methods for collection of plant material and analyses are recommended. Selection and breeding efforts and agronomic studies of promising clones of TT would need to be conducted in order to develop TT as a new crop. This will provide consistency of supply and quality of the feedstock for the pharmaceutical industry and could provide a new cash crop for growers.

Alkaloid extracts from Bitter leaf (Vernonia amygdalina) and Black nightshade (Solanum nigrum) inhibit phosphodiesterase-5, arginase activities and oxidative stress in rats penile tissue

The erectogenic potential of alkaloids extracted from Bitter leaf (Vernonia amygdalina) and Black nightshade (Solanum nigrum) was investigated in this study. Fresh leaves obtained from Bitter leaf and Black night shade were air-dried, pulverized, and extracted for alkaloids. The inhibitory potential of the alkaloid extracts on arginase and phosphodiesterase-5 (PDE-5) activities in rats penile tissue was determined in vitro. The antioxidant properties were also evaluated and the constituent alkaloids quantified using GC-MS. The alkaloid extracts inhibited arginase (0-30.51 μg/ml) and PDE-5 (0-133.69 μg/ml) activities in a concentration-dependent pattern. Similarly, the alkaloid extracts inhibited Fe²⁺ -induced lipid peroxidation in rats penile tissues, scavenged DPPH, OH, and NO radicals as a function of concentration. GC-MS characterization revealed over 20 alkaloid compounds. The inhibition of PDE-5-, arginase-, pro-oxidant-induced lipid peroxidative-, and free radicals-scavenging activities by the alkaloids is suggestive of putative mechanisms underlying their therapeutic use for managing erectile dysfunction in folklore medicine. PRACTICAL APPLICATIONS: Alkaloids extracted from Black nightshade (Solanum nigrum) and Bitter leaf (Vernonia amygdalina) were characterized and investigated by standard procedures for inhibitory action against key erectile dysfunction-linked enzymes and antioxidant activity. The alkaloids inhibited erectile dysfunction-linked enzymes (arginase and PDE-5) and showed considerable antioxidant activity in a concentration-dependent manner. In view of this, we suggest the application of these results in the development of erectile dysfunction drugs in the pharmaceutical industry, with probable minimal or no adverse effect.

Male sexual enhancers from the Peruvian Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Selected Peruvian Amazon plants are macerated into sugar cane distillates to prepare alcoholic beverages used to improve male sexual performance. The tree bark from Campsiandra angustifolia Spruce ex Benth (Fabaceae), Swartzia polyphylla DC (Fabaceae), Minquartia guianensis Aubl. (Olacaceae) and Thynantus panurensis (Bureau) Sandwith (Bignoniaceae) usually are used as crude drugs in mixtures of several ingredients.

AIM OF STUDY

Describe the chemical composition of the most traded traditional male enhancer beverages, namely "Levántate Lazaro" and "Siete veces sin sacarla", and their single crude drug constituents, as well as their inhibitory activity towards the enzyme phosphodiesterase-5. The presence of pro-sexual drugs such as Sildenafil® and derivatives was assessed in the samples.

MATERIALS AND METHODS

Single plant constituents and the preparation mixtures were purchased in the Mercado Belen (Iquitos, Peru). Chemical profiling was carried out by HPLC-DAD-ESI-MS/MS. The extracts were assessed for phosphodiesterase-5 inhibition. The occurrence of pro-sexual drugs was determined by HPLC-DAD-ESI-MS/MS.

RESULTS

Chemical profiling allowed the identification of condensed tannins as the main constituents of C. angustifolia and S. polyphylla, hydrolysable tannins for M. guianensis, and C-glycosides for T. panurensis. The traditional preparations showed similar composition compared to the crude drugs. At 200 µg/mL, the traditional preparation "Levántate Lázaro" and "Siete veces sin sacarla" inhibited the phosphodiesterase-5 by 49.88% and 27.90%, respectively. No adulterations with pro-sexual drugs were found in the samples. From the crude drugs, low effect was found for the extracts of S. polyphylla and T. panurensis and high activity for C. angustifolia which inhibited the enzyme by 89.37% and 81.32% at 200 and 100 µg/mL, respectively.

CONCLUSION

The traditional preparations used to improve sexual performance in the Peruvian Amazon showed activity as phosphodiesterase-5 inhibitors. The most active ingredient of the traditional preparations was C. angustifolia, with some contribution from T. panurensis. These results encourage additional studies, including animal models to confirm the male enhancer effect of the preparations.

Parquetina nigrescens leaves: chemical profile and influence on the physical and biochemical indices of sexual activity of male Wistar rats

OBJECTIVE

The leaves of Parquetina nigrescens have been claimed in folk medicine to be useful for managing sexual dysfunction, but there is inadequate scientific evidence for this claim. This investigation was conducted to assess the effects of aqueous leaf extract of Parquetina nigrescens (AEPN) in rats induced with sexual dysfunction.

METHODS

Male rats were allocated into various groups after being induced into sexual dysfunction with paroxetine hydrochloride. The groups were treated with distilled water, PowMaxM (reference drug), and the AEPN at 20, 40 and 80 mg/kg body weight (BW) respectively for 7 d. Frequencies of mount (MF), intromission (IF), ejaculation (EF), as well as latencies of mount (ML), intromission (IL) and post-ejaculatory interval (PEI) were progressively monitored with receptive female rats on days 1, 3 and 7. The precentage of mounted, intromitted, and ejaculated rats, intromission ratio (IR), copulatory efficiency (CE) and intercopulatory interval (ICI) were also computed. Standard methods were employed to determine the levels of serum luteinizing and follicle stimulating hormones (LH and FSH), testosterone, nitric oxide (NO) and the activity of phosphodiesterase V (PDE5).

RESULTS

The plant contained alkaloids, saponins, flavonoids, cardiac glycosides, steroids, tannins, phlobatannins, cardenolides, phenolics, anthraquinones and triterpenes with alkaloids (2.32 mg/g) occurring in greatest quantity while flavonoids, anthraquinones and cardenolides (0.01 mg/g, each) were the least. All the 20 standard amino acids were detected in the plant leaf, with the lowest concentration being 0.30 mg/g for methionine and the highest being 2.12 mg/g for cysteine. Furthermore, P. nigrescens leaves contained Na, K, Fe, Mg, Zn, Ca, Cu, Mn, P, Pb, Cd, Ni, Cr, and Co, with Fe present in the highest and Co the lowest concentrations. Paroxetine significantly (P<0.05) reduced MF, IF, EF, percentage mounted , intromitted, ejaculated, IR, CE, serum testosterone, LH, FSH and NO, while ML, IL, PEI, IF and PDE5 were significantly (P<0.05) increased and/or prolonged. The AEPN significantly reversed these paroxetine-treatment-related alterations with most profound activity at the highest dose of 80 mg/kg BW, similar to that of the PowMaxM-treated animals.

CONCLUSION

The AEPN restored both the physical and biochemical indices of male sexual activity/competence via changes in reproductive hormones, NO and PDE5 activity. The pro-sexual activity, attributed to a myriad of mineral, amino acid and secondary metabolite constituents, was best at 80 mg/kg BW of AEPN.

Ethnomedicobotanical study of indigenous knowledge on medicinal plants used for the treatment of reproductive problems in Nalbari district, Assam, India

ETHNOPHARMACOLOGICAL RELEVANCE

Reproductive problems are becoming the most predominant health care problems in many countries. World Health Organization (WHO), in 2012, also exemplified maternal illnesses, for instance, birth asphyxia and post birth difficulties are rising at an alarming rate. In addition, not all abnormalities of the human reproductive system have the same origin; the effects of reproductive problems would likely been affected by both male and female. For easy accessibility and affordability, medicinal plants are playing crucial role in primary healthcare services in India and their use is moreover, an integral part of the cultural heritage. However, our growing understanding of the human reproductive problems are segregated and scanty for herbal medications.

AIM OF THE STUDY

To document the local name of the medicinal plants used by both male and female from indigenous knowledge for the treatment of reproductive ailments and to explore their biological and pharmacological confirmation and to address the class of secondary metabolites present therein.

MATERIALS AND METHODS

The results stem in September 2015-April 2016 from an array of informations that were collected by direct interviews of the traditional medicinal practitioners in three villages, viz. Jaha, Niz-Bahjani and Madhupur of the southern Nalbari district, Assam. Both semi-structured and open-ended interview schedule was carried out with purposively selected individuals and focus group discussion (FGD) in the three selected sites for this study. Systematic analysis of fidelity level percentage (FL %), preference ranking percentage (PR %) and formulation scoring (FS) were calculated. Electronic databases such as Google, Google Scholar, and ScienceDirect were also been used to search existing pharmacological citations. Finally, qualitative chemical profiling were executed for the plants whose PR % scores ≥ 65.

RESULTS

A total of 71 plant species belonging to 48 families and 64 genera are reported to be used for the treatment of several reproductive problems such as, infertility in male, impotence, erectile dysfunctioning, retrograde ejaculation and sexual potency in men and in women, aphrodisiac, metrorrhagia, infertility, dysmenorrhea and/or post birth difficulties under mono (57), di (17) and poly (8) herbal formulations. Herbs (40.85%) were reported as the most common lifeform, whereas leaves (22.54%) and the roots (22.54%) were the commonly used plant parts against different ailments. Extracts of Abroma augusta L. (stem) (FL: 66.67%, PR: IM-77.33%, L-65.33, FS: 2), Morinda angustifolia Roxb. (bark) (FL: 64.29%, PR: L-68%, FS: 1), Hodgsonia heteroclita Roxb. (fruit) (FL: 63.64%, PR: IF-65.33, FS: 0.25) and Hibiscus mutabilis L. (stem) (FL: 40%, PR: IM-68%, IIM: 65.33%, IML-68%, FS: 2) were than selected for further phytochemical analysis.

CONCLUSIONS

Of the 71 plants used for reproductive management system, the highest number of plants were used for the treatment of irregular menstruation (22) followed by infertility (in both men and women) (19), vaginal disorder and leucorrhoea (9) and sexual potency (8). The qualitative chemical profiling have demonstrated the presence of alkaloids, carbohydrates, phenolic compounds, flavonoids and phytosterols, in maximum concentrations. Additionally, these data may be the most important resource for the new discovery of many bioactive principles.

Functional study of Cordyceps sinensis and cordycepin in male reproduction: A review

Cordyceps sinensis has various biological and pharmacological functions, and it has been claimed as a tonic supplement for sexual and reproductive dysfunctions for a long time in oriental society. In this article, the in vitro and in vivo effects of C. sinensis and cordycepin on mouse Leydig cell steroidogenesis are briefly described, the stimulatory mechanisms are summarized, and the recent findings related to the alternative substances regulating male reproductive functions are also discussed.

Prequels to Synthetic Biology: From Candidate Gene Identification and Validation to Enzyme Subcellular Localization in Plant and Yeast Cells

Natural compounds extracted from microorganisms or plants constitute an inexhaustible source of valuable molecules whose supply can be potentially challenged by limitations in biological sourcing. The recent progress in synthetic biology combined to the increasing access to extensive transcriptomics and genomics data now provide new alternatives to produce these molecules by transferring their whole biosynthetic pathway in heterologous production platforms such as yeasts or bacteria. While the generation of high titer producing strains remains per se an arduous field of investigation, elucidation of the biosynthetic pathways as well as characterization of their complex subcellular organization are essential prequels to the efficient development of such bioengineering approaches. Using examples from plants and yeasts as a framework, we describe potent methods to rationalize the study of partially characterized pathways, including the basics of computational applications to identify candidate genes in transcriptomics data and the validation of their function by an improved procedure of virus-induced gene silencing mediated by direct DNA transfer to get around possible resistance to Agrobacterium-delivery of viral vectors. To identify potential alterations of biosynthetic fluxes resulting from enzyme mislocalizations in reconstituted pathways, we also detail protocols aiming at characterizing subcellular localizations of protein in plant cells by expression of fluorescent protein fusions through biolistic-mediated transient transformation, and localization of transferred enzymes in yeast using similar fluorescence procedures. Albeit initially developed for the Madagascar periwinkle, these methods may be applied to other plant species or organisms in order to establish synthetic biology platform.

Anti-inflammatory Cerebrosides from Cultivated Cordyceps militaris

Cordyceps militaris (bei-chong-chaw, northern worm grass) is a precious and edible entomopathogenic fungus, which is widely used in traditional Chinese medicine (TCM) as a general booster for the nervous system, metabolism, and immunity. Saccharides, nucleosides, mannitol, and sterols were isolated from this fungus. The biological activity of C. militaris was attributed to the saccharide and nucleoside contents. In this study, the aqueous methanolic fraction of C. militaris fruiting bodies exhibited a significant anti-inflammatory activity. Bioactivity-guided fractionation of the active fraction led to the isolation of eight compounds, including one new and two known cerebrosides (ceramide derivatives), two nucleosides, and three sterols. Cordycerebroside A (1), the new cerebroside, along with soyacerebroside I (2) and glucocerebroside (3) inhibited the accumulation of pro-inflammatory iNOS protein and reduced the expression of COX-2 protein in LPS-stimulated RAW264.7 macrophages. This is the first study on the isolation of cerebrosides with anti-inflammatory activity from this TCM.

Semi-synthetic derivatives of natural isoflavones from Maclura pomifera as a novel class of PDE-5A inhibitors

Natural (iso)flavonoids have been recently reported to inhibit cyclic nucleotide phosphodiesterases (PDEs) and induce vasorelaxation, albeit the results described in the literature are discordant. The cGMP-selective isoform PDE-5A, in particular, represents the target of sildenafil and its analogues in the treatment of erectile dysfunction (ED) and pulmonary hypertension by promoting relaxation in vascular smooth muscle through the activation of the NO/cGMP pathway. We undertook this study to verify if osajin and pomiferin, two natural prenylated isoflavones and major constituents of Maclura pomifera extracts previously investigated for their anticancer, antibacterial and antidiabetic properties, show inhibitory activity on PDE-5A. These two isoflavones were isolated from the plant extracts and then synthetically modified to obtain a set of semi-synthetic derivatives with slight and focused modifications on the natural scaffold. The compounds were at first screened against PDE-5A in vitro and, based on the encouraging results, further tested for their relaxant effect on isolated rat artery rings. Computational docking studies were also carried out to explore the mode of interaction with the target protein. The obtained data were compared to the behaviour of the well-known PDE-5A inhibitor sildenafil. Our results demonstrate that semi-synthetic derivatives of osajin and pomiferin show an inhibitory effect on the isolated enzyme that, for some of the compounds, is accompanied by a vasorelaxant activity. Based on our findings, we propose the here described isoflavones as potential lead compounds for the development, starting from natural scaffolds, of a new class of PDE-5A inhibitors with vasorelaxant properties.

Indigenous knowledge of folk medicines among tribal minorities in Khyber Pakhtunkhwa, northwestern Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

Mapping ethnomedicinal plants and associated indigenous knowledge of folk medicines can provide a comprehensive overview of individual herbs employed in health care. Reliance on medicinal plants in remote parts of northern Pakistan is high, especially among women, but no research has investigated specifically which plants are used. This study investigated indigenous knowledge of folk medicines among tribal minorities in selected sites in upper Swat, Buner and Chitral Districts in Khyber Pakhtunkhwa Province.

MATERIALS AND METHODS

Interviews were conducted with gender-specific focus groups using questionnaires and standardized data sheets, followed by forest walks in each of the visited areas. General medicinal herb use, preparations, storage, marketing and collection habits for each gender group were ascertained from the questionnaires.

RESULTS

In total 168 women and 390 men were interviewed and provided information on 127 different shared medicinal species. Species use consensus among the informants ranged from 2.3% to 83.3%, with Cynodon dactylon, Avena sativa, Celtis australis, Datura stramonium, Solanum nigrum, Skimmia laureola, Spiraea nervosa, Ziziphus jujuba, Rumex hastatus, Plantago lanceolata, Lathyrus aphaca and Ficus palmata having the highest reported consensus. The survey also revealed that a number of medicinal species were exploited by the community for both marketing and personal use, and many of these species were reported as being rare, vulnerable or even endangered.

CONCLUSIONS

The results revealed that women in all the three districts were important custodians of medicinal plant knowledge, but elder women in general and the women from Buner district in particular had a superior understanding of folk medicine. The forest walks revealed that women׳s traditional medicinal knowledge was based on a more limited diversity of plant species. People in tribal communities have an expressed interest in learning efficient techniques for medicinal plant collection, preparation, storage and cultivation advice, and to learn more about the potential of marketing medicinal herbs and ways to reach local market centers. Education and awareness were considered to be essential for improved health care and successful marketing.

The Old Made New: Natural Compounds against Erectile Dysfunction

The interest toward sex-related diseases keeps growing through the years. In this review, we focus our attention on erectile dysfunction (ED), a condition that caught much attention especially after the introduction on the market of phosphodiesterase 5 inhibitors such as the well-known sildenafil. Here, we briefly describe both the etiology of ED and the available treatments, examining then extensively some natural derivatives that, coming from traditional medicine, could represent promising starting points for the development of alternative remedies. In fact, herbal remedies from several parts of the world have been traditionally known for long, and were recently reconsidered and are now being studied to demonstrate their eventual potential in the treatment of ED. Among the various examples reported in the literature and reviewed here, plants and extracts containing polyphenols—especially a class of compounds called kraussianones—appear to be particularly effective and promising against ED.

Phosphodiesterase Inhibitory Activity of the Flavonoids and Xanthones from Anaxagorea luzonensis

Five flavonoids, one isoflavone and five xanthones were isolated from Anaxagorea luzonensis. Of these eleven isolated compounds, 1,3,5-trihydroxy-4-prenylxanthone (3) was a relatively potent inhibitor of phosphodiesterase type 5 (PDE5), with an IC50 value of 3.0 μM. This is the first report showing that natural xanthones can exhibit promising PDE5 inhibitory activity. Moreover, this study revealed that the presence of the C-4 prenyl residue attached to the xanthone core is correlated with the significant PDE5 inhibitory activity.

Analysis of L-citrulline and L-arginine in Ficus deltoidea leaf extracts by reverse phase high performance liquid chromatography

Background:

Ficus deltoidea (FD) is one of the native plants widely distributed in several countries in Southeast Asia. Previous studies have shown that FD leaf possess antinociceptive, wound healing and antioxidant properties. These beneficial effects have been attributed to the presence of primary and secondary metabolites such as polyphenols, amino acids and flavonoids.

Objective:

The aim was to develop a reverse phase high-performance liquid chromatography method with ultraviolet detection that involves precolumn derivatisation with O-phthaladehyde for simultaneous analysis of two amino acids L-citrulline and L-arginine in FD leaf extracts.

Materials and Methods:

An isocratic elution program consisting of methanol: acetonitrile: Water at 45:45:10 v/v (solvent A) and 0.1 M phosphate buffer pH 7.5 (solvent B) at A: B v/v ratio of 80:20 on Zorbax Eclipse C18 SB-Aq column (250 × 4.6 mm, 5 μm) were used. The flow rate was set at 1 ml/min and detection was carried out at 338 nm with 30 min separation time.

Results:

Good linearity for L-citrulline and L-arginine was obtained in the range 0.1-1000 μg/ml at R² ≥ 0.998. The limit of detection and limit of quantification values for both L-citrulline and L-arginine were 1 and 5 μg/ml, respectively. The average of recoveries was in the range 94.94-101.95%, with relative standard deviation (%RSD) less than 3%. Intra- and inter-day precision was in the range 96.36-102.43% with RSD less than 2%.

Conclusion:

All validation parameters of the developed method indicate the method is reliable and efficient for simultaneous determination of L-citrulline and L-arginine for routine analysis of FD.

Aphrodisiac activity of polyherbal formulation in experimental models on male rats

Objective:

To investigate the aphrodisiac potential of polyherbal formulations prepared from different parts of Tribulus terrestris, Curculigo orchioides, Allium tuberosum, Cucurbita pepo, Elephant creeper, Mucuna pruriens, and Terminalia catappa in Albino rats in specified ratio as suspension.

Materials and Methods:

The different concentrations of prepared polyherbal formulations i.e. 150, 300, and 600 mg/kg and sildenafil citrate as standard (5 mg/kg) and vehicle (control) were administered orally to rats (n = 6 animals per group) for 3 weeks. Mating behavior parameters in male rats was monitored in first week and third week week of treatment pairing with receptive females. After termination of drug treatment, the mating performance, hormonal analysis, sperm count, and testes-body weight ratio were also evaluated.

Results:

The polyherbal formulation showed a significant increase in mating behavior as well as mating performance, serum hormonal levels, sperm count, and testes-body weight ratio with dose-dependent relationship as compared to vehicle control. But the dose of 600 mg/kg of polyherbal formulation assumes closer resemblance of above parameters with the standard used.

Conclusion:

The results of the study strongly suggest that the polyherbal formulations have a good aphrodisiac activity on rats in the above experimental models, which may be an alternative weapon for various sexual dysfunctions in future.

Erectile dysfunction and fruit/vegetable consumption among diabetic Canadian men

OBJECTIVE

To evaluate the association between fruit/vegetable consumption and erectile dysfunction (ED) among Canadian men with diabetes.

METHODS

Data from the 2011 Survey on Living with Chronic Diseases in Canada - Diabetes Component were analyzed using Statistical Analysis System Enterprise Guide (SAS EG). Respondents were asked a series questions related to their sociodemographics, lifestyle, and chronic health conditions. The association between fruit/vegetable consumption and ED was examined using logistic regression after controlling for potential confounding factors. Bootstrap procedure was used to estimate sample distribution and calculate confidence intervals.

RESULTS

Overall, 26.2% of respondents reported having ED. The prevalence increased with age and duration of diabetes. Compared with respondents without ED, those with ED were more likely to be obese, smokers, physically inactive, and either divorced, widowed, or separated. Diabetes complications such as nerve damage, circulation problems, and kidney failure or kidney disease were also significantly associated with ED. After controlling for potential confounding factors, a 10% risk reduction of ED was found with each additional daily serving of fruit/vegetable consumed.

CONCLUSION

ED is common among Canadian men with diabetes. ED was highly associated with age, duration of diabetes, obesity, smoking, and the presence of other diabetes-related complications. Fruit and vegetable consumption might have a protective effect against ED.

Watermelon juice: potential functional drink for sore muscle relief in athletes

l-Citrulline is an excellent candidate to reduce muscle soreness, and watermelon is a fruit rich in this amino acid. This study investigated the potential of watermelon juice as a functional drink for athletes. An in vitro study of intestinal absorption of l-citrulline in Caco-2 cells was performed using unpasteurized (NW), pasteurized (80 °C for 40 s) watermelon juice (PW) and, as control, a standard of l-citrulline. l-citrulline bioavailability was greater when it was contained in a matrix of watermelon and when no heat treatment was applied. In the in vivo experiment (maximum effort test in a cycloergometer), seven athletes were supplied with 500 mL of natural watermelon juice (1.17 g of l-citrulline), enriched watermelon juice (4.83 g of l-citrulline plus 1.17 g from watermelon), and placebo. Both watermelon juices helped to reduce the recovery heart rate and muscle soreness after 24 h.

Garcinia kola seeds: is the aqueous extract a true aphrodisiac in male Wistar rats?

The age long acclaimed aphrodisiac potentials of Garcinia kola seeds in some parts of Western Nigeria has not been substantiated with scientific evidence. In this study, we have decided to evaluate the effect of aqueous seed extract of G. kola at the doses of 25, 50 and 100 mg/kg body weight on sexual behaviour of male rats. Male rats weighing 215.00 ± 18.58 g were randomized completely into four groups (A-D) of six animals each. Animals in group A received, orally, 0.5 ml of distilled water only while those in groups B, C and D received same volume containing 25, 50 and 100 mg/kg body weight of the seed extract respectively. Frequencies of mount (MF), intromission (IF), genital toilet (GTF) and ejaculation (EF) as well as latencies of mount (ML), intromission (IL) and ejaculation (EL) were evaluated following the pairing of male rats (1:1) with non-oestrous female rats. The parameters were monitored for the first (15-30 min), second (75-90 min) and third (180195 min) observatory periods. The levels of testosterone, luteinizing (LH) and follicle stimulating hormones (FSH) were also determined. Phytochemical screening of the extract revealed the presence of saponins (2.78%), cardiac glycosides (0.26%), cardenolides and dienolides (0.24%), flavonoids (1.28%) and steroids (1.14%). The 25 and 100 mg/kg body weight increased (P<0.05) the MF whereas the ML was decreased by all the doses of the extract. MF and ML were not altered during the second observatory period whereas the 50 mg/kg body weight increased these parameters during the third observatory period. Other sexual behaviour parameters as well as serum testosterone, FSH and LH were not significantly altered throughout the observatory periods. Overall, the results revealed that G. kola seeds did not have sex enhancing potential as claimed. Therefore, the acclaimed pro sexual effect of Garcinia kola seeds is scientifically untrue. This study has refuted the claim that one of the rationales for consuming the seeds by the aged population of Nigeria is to enhance sexual invigoration in males.

Effect of aqueous extract of Arctium lappa L. (burdock) roots on the sexual behavior of male rats

BACKGROUND

Arctium lappa L. root has traditionally been recommended as an aphrodisiac agent. It is used to treat impotence and sterility in China, and Native Americans included the root in herbal preparations for women in labor. However, its use has not been scientifically validated. The present study therefore investigated the effects of aqueous extract of Arctium lappa L. roots on sexual behavior in normal male rats.

METHODS

Seventy-five albino male rats were randomly divided into five groups of 15 rats each. Rats in group 1 (control) were administered 10 mL/kg body weight distilled water (vehicle), group 2 received 60 mg/kg body weight sildenafil citrate (Viagra), while those in groups 3, 4, and 5 were given 300, 600, and 1,200 mg/kg body weight, respectively, of aqueous extract of Arctium lappa L. roots in the same volume. Female albino rats were made receptive by hormonal treatment. Sexual behavior parameters in male rats were monitored on days 3, 7 and 15 by pairing with receptive females (1:3). Male serum testosterone concentrations and potency were also determined.

RESULTS

Oral administration of Arctium lappa L. roots extract at 600 and 1,200 mg/kg body weight significantly increased the frequencies of mount, intromission, and ejaculation frequency (p < 0.05). The latencies of mount and intromission were significantly reduced and ejaculation latency was prolonged. Administration of the extract also reduced the post-ejaculatory interval. The standard drug (Viagra) was more effective than the extract. The extract significantly increased the frequencies of all components of penile reflexes as well as serum testosterone levels, compared with the distilled water controls.

CONCLUSIONS

The results of this study demonstrate that aqueous extract of Arctium lappa L. roots enhances sexual behavior in male rats. The aphrodisiac effects of the plant extract may be related to the presence of flavonoids, saponins, lignans and alkaloids, acting via a multitude of central and peripheral mechanisms. These results thus support the traditional use of Arctium lappa L. root extract for treating impotence and sterility.

Effect of novel synthetic evodiamine analogue on sexual behavior in male rats

Currently phosphodiestrase5 (PDE5) inhibitors are the first-line treatment for erectile dysfunction. Drugs such as sildenafil and tadalafil are available as PDE5 inhibitors which are potent and reversible but lack selectivity with side effects such as headache, facial flushing, dyspepsia, and visual disturbances. We herein report for the first time novel condensed thienopyrimidines as evodiamine analogue and their effect on sexual behavior in male rats hitherto unreported. Novel synthetic evodiamine significantly showed improvement in male rat copulatory behavior. The test compound MKAC9 could be of promising importance in the treatment of sexual disorders like desire disorder or erectile dysfunction.FigureEvodiamine analogue on sexual behavior in male rats.

Documentation and quantitative analysis of the local knowledge on medicinal plants among traditional Siddha healers in Virudhunagar district of Tamil Nadu, India

ETHNOPHARMACOLOGICAL RELEVANCE

India has a population with high degree of medical pluralism. Siddha system of Indian traditional medicine is practiced dominantly by the people in Tamil Nadu. The traditionally trained Siddha healers still play an important role in the rural health care. Their knowledge is comparatively more vulnerable than the documented traditional knowledge. Thus, the present study was aimed to document and quantitatively analyze the local knowledge of the traditional Siddha healers in Virudhunagar district of Tamil Nadu, India.

MATERIALS AND METHODS

The results presented in this paper are the outcome of series of interviews conducted between January and August, 2010 consisting of 196 field days. After getting prior informed consent, interviews were conducted and successive free-listing was used in the interviews in order to make informants cite the medicinal plants that they have used. By this way 96 healers were interviewed and their data were quantitatively analyzed using various indices such as Informant Consensus Factor (F(ic)), Fidelity Level (FL), Informant Agreement on Remedies (IAR) and Cultural Importance Index (CII).

RESULTS

This study recorded the ethno-medicinal usage of 227 species which were used to prepare 611 formulations for the treatment of 36 illness categories. The knowledge holders had the experience of minimum 20 years. There was unevenness in male-female ratio. Regarding the medicinal plants, easily available plants were holding significantly high number of citations, IAR and CII values. Nine illness categories had a high F(ic) value, compared to others. Species with high citations in these groups were Moringa oleifera (aphrodisiacs), Acalypha indica (dermatological ailments), Dodonaea viscosa (musculo-skeletal disorders), Solanum trilobatum (pulmonary ailments), Phyllanthus amarus (jaundice), Piper nigrum (adjuvant) Allium cepa (hemorrhoids), Azadirachta indica (antiseptic) and Tribulus terrestris (urinary ailments).

CONCLUSION

Quantitative analysis of the data had revealed that the easily available species hold a high consensus and cultural importance. Future biomedical studies using the medicinal plants enumerated in this study, particularly those with high number of citations and high F(ic) values might yield some novel prototypes. Such studies will also be useful to assess the efficacy and safety of these herbal treatments to take decisions on the health care of rural India.

Évaluation des effets prosexuels des extraits de Bridelia ferruginea chez le rat mâle naïf

Bridelia ferruginea (BF, Euphorbiaceae) est un arbre dont les écorces du tronc et les feuilles sont utilisées en médecine traditionnelle pour remédier à plusieurs problèmes et en particulier l’impuissance masculine. La présente étude vise à identifier les effets prosexuels (fréquences d’érection, de monte, d’intromission et d’éjaculation) des extraits aqueux (100 mg/kg) et éthanolique (100 mg/kg) des écorces du tronc de BF administrés par voie orale à des rats Wistar adultes mâles (intacts ou castrés) sexuellement inexpérimentés pendant zéro, un et sept jours. Le comportement sexuel des rats normaux recevant une administration unique de l’extrait aqueux de BF (100 mg/kg) a été aussi évalué après prétraitement par le L-omega-nitro-arginine methyl ester (Lω-NAME, 10 mg/kg), l’halopéridol (10 mg/kg) ou l’atropine (10 mg/kg). Les animaux témoins ont reçu per os de l’eau distillée (10 ml/kg) pour le témoin neutre et une injection sous-cutanée de testostérone propionate (20 mg/kg par jour pendant trois jours avant le début du test) pour le témoin positif. Les résultats de l’étude montrent que la durée du traitement a un impact significatif (p < 0,05) sur les fréquences d’érection pénienne, de monte et d’intromission aussi bien chez les rats normaux que chez les animaux castrés. Une tendance à l’augmentation des paramètres de performance sexuelle a été aussi observée. La fréquence d’intromission des rats intacts était plus élevée (p < 0,05–0,01) à J1 et particulièrement chez les rats recevant l’extrait aqueux de BF. Chez les rats castrés, par contre, seuls les animaux traités par la testostérone ont présenté une augmentation statistique (p < 0,01–0,001) des paramètres copulatoires. Les effets prosexuels de l’extrait aqueux de BF étaient abolis par l’atropine et l’halopéridol, tandis qu’une préadministration de Lω-NAME était sans effet sur l’activité copulatoire des animaux. Ces effets stimulants sexuels de BF pourraient être attribués à la présence des flavonoïdes et des stérols, substances bioactives qui agiraient par voie dopaminergique et/ou cholinergique, et soutiennent l’intérêt de l’emploi de BF en médecine traditionnelle comme stimulant sexuel.

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.