Assessment of health claims, content, and safety of herbal supplements containing Ginkgo biloba

Ginkgo biloba leaf extract EGb 761® as a paragon of the product by process concept

It is an often-neglected fact that extracts derived from the very same plant can differ significantly in their phytochemical composition, and thus also in their pharmacokinetic and pharmacodynamic properties which are the basis for their clinical efficacy and safety. The Ginkgo biloba L. [Ginkgoaceae] special extract EGb 761^® is one of the best-studied plant extracts in the world. In the present review, using that extract as a paradigm, we describe insights how climate, the harvest region, processing of the plant material, the drying process, the extraction solvents, and the details of the subsequent process steps substantially impact the quality and uniformity of the final extract. We highlight the importance of regulating active constituent levels and consistent reduction of undesired substances in herbal extracts. This is accomplished by a controlled production process and corresponding analytical specifications. In conclusion, since extracts derived from the same plant can have very different phytochemical compositions, results from pharmacological, toxicological and clinical studies gained with one specific extract cannot be extrapolated to other extracts that were generated using different production processes. We propose that the heterogenous nature of extracts should be meticulously considered when evaluating the efficacy and safety of plant-derived remedies.

Isovitexin Inhibits Ginkgolic Acids-Induced Inflammation Through Downregulating SHP2 Activation

It has been reported that Celtis sinensis Pers. is employed as a folk medicine for the treatment of inflammatory diseases. But the mechanism supporting its use as anti-inflammatory remains unclear. To investigate the anti-inflammatory of Celtis sinensis Pers. ICR mice were provided Celtis sinensis Pers. leaf extract (CLE) at 100, 200 mg/kg after ginkgolic acids (GA) sensitization. Our data showed that CLE and the main flavonoid isovitexin in CLE could ameliorate GA-induced contact dermatitis in mice. Ear swelling, inflammatory cell infiltration and splenomegaly were inhibited significantly by isovitexin, while the weight loss of mice in the isovitexin-treated group was much better than that in the dexamethasone-treated group (positive control drug). It has been reported in previous research that GA-induced inflammation is closely related to the T cell response. Therefore, T cells were the focus of the anti-inflammatory effect of isovitexin in this paper. The in vivo results showed that isovitexin (10, 20 mg/kg) inhibited the expression of proinflammatory cytokines (TNF-α, IFN-γ, IL-2 and IL-17A) in lymph nodes, inhibited the secretion of cytokines into the serum from mice with contact dermatitis and promoted the expression of apoptosis-related proteins. In vitro, isovitexin also induced apoptosis and inhibited proinflammatory cytokine expression in Con A-activated T cells. Further study showed that the MAPK and STAT signaling pathways and the phosphorylation of SHP2 were inhibited by isovitexin. Both molecular docking and biological experiments indicated that SHP2 may be an anti-inflammatory target of isovitexin in T cells. Taken together, isovitexin can serve as a potential natural agent for the treatment or prevention of GA-induced inflammatory problems.

Medicinal plants and their preparations in the European market: Why has the harmonization failed? The cases of St. John's wort, valerian, ginkgo, ginseng, and green tea

BACKGROUND

Botanical ingredients based on plants, algae, fungi or lichens have become widely available on the European Union market offering numerous preparations with considerable differences in classification. They are under the categories of food supplements, herbal medicinal products, cosmetics or medical devices.

PURPOSE

The aim of the present work is to highlight how the European regulations concerning the different categories of botanicals can lead to different commercial choices such as time/cost for product development, application for a marketing authorisation, permitted indication (medical or health claim), and as a consequence, the same botanical products are sold in European Union as herbal medicinal products, food supplements, cosmetics or medical devices. Five different widely used botanicals, namely St. John's wort, valerian, ginkgo, ginseng, and green tea were selected to better explain the failure of harmonization through European Union.

METHODS

A search of PubMed, ScienceDirect, European Medicines Agency and European commission web sites for medical devices and cosmetics, and European Food Safety Authority websites were conducted and the available information on regulation of herbal medicinal products, food supplements, medical devices and cosmetics in the European Union was collected. In addition, a market survey of all the sold botanical products in Europe was analysed by consultation of the medicines, medical devices, cosmetic and food agencies websites of the European countries.

RESULTS

The current European legislation needs implementation and follow up because in the different countries the legal positions of the botanical products varied and it is possible to find the same product classified in the different categories, namely registered medicinal product including prescription only medicine, traditional herbal medicinal product, well established herbal medicinal products or food supplement, or medical device, or homoeopathic/anthroposophical medical product, cosmetic.

CONCLUSIONS

There is an urgent need of harmonization, together with the implementation of interoperable vigilance databases, to avoid borderline options.

Comparison of phytochemical composition of Ginkgo biloba extracts using a combination of non-targeted and targeted analytical approaches

Ginkgo biloba extract (GbE) is a dietary supplement derived from an ethanolic extract of Ginkgo biloba leaves. Unfinished bulk GbE is used to make finished products that are sold as dietary supplements. The variable, complex composition of GbE makes it difficult to obtain consistent toxicological assessments of potential risk. The National Toxicology Program (NTP) observed hepatotoxicity in its rodent studies of a commercially available, unfinished GbE product, but the application of these results to the broader GbE supplement market is unclear. Here, we use a combination of non-targeted and targeted chromatographic and spectrophotometric methods to obtain profiles of 24 commercially available finished GbE products and unfinished standardized and unstandardized extracts with and without hydrolysis, then used principal component analysis to group unfinished products according to their similarity to each other and to National Institute of Standards and Technology (NIST) standard reference materials (SRM), and the finished products. Unfinished products were grouped into those that were characteristic and uncharacteristic of standardized GbE. Our work demonstrates that different analytical approaches produced similar classifications of characteristic and uncharacteristic products in unhydrolyzed samples, but the distinctions largely disappeared once the samples were hydrolyzed. Using our approach, the NTP GbE was most similar to two unfinished GbE products classified as characteristic, finished products, and the NIST GbE SRM. We propose that a simple analysis for the presence, absence, or amounts of compounds unique to GbE in unhydrolyzed samples could be sufficient to determine a sample’s authenticity.

Graphical abstract

SCIENTIFIC SUBSTANTIATION OF TECHNOLOGY OF PASTA BASED ON FRESHWATER MUSSELS ENRICHED WITH SELENIUM

The possibility of using dietary selenium-protein additive "Neoselen" for enrichment of pastes based on mussels with organic selenium has been investigated. The formulation of the pastes involved the use of the soft body of the freshwater mmussels of the genus Anodonta. The influence of the introduction of different percentage of the additive "Neoselen" on the organoleptic properties of the developed pastes based on freshwater mussels was investigated. It is found that the addition of additive "Neoselen" even more than 5% does not impair the taste and color of the developed pastes. Moisture content, moisture retention, fat-holding capacity and active acidity of the developed pastes were investigated. The moisture-holding and fat-holding capacity of the developed paste is determined. The difference in the consistency of pastes based on freshwater mussels with different percentage of unpowered additives was investigated by determining the values of plastic viscosity and modulus of elasticity. The regularities of the influence of the additive "Neoselen" on the general chemical and mineral composition of pastes based on freshwater mussels have been established. It is established that the addition of 1%, 3% or 5% in the paste of additive "Neoselen" can enrich it by 7.8, 23.4 and 39 mkg of selenium, respectively. Studies have shown that in the composition of both the control and experimental samples of pastes in the amount of protein, minerals and water content. With the increase of the content of the additive "Neoselen" in the formulation of pastes, the content of protein and minerals increases. The complex of qualitative characteristics of the developed pastes is investigated. The regularities of the influence of the component composition on the organoleptic and physicochemical and functional-technological characteristics of the minced systems based on freshwater mussels and the additive "Neoselen" have been established. It is established that the optimal doses of the use of additive "Neoselen" in the formulation of pastes ranges from 3-5%.

Systemic exposure to Ginkgo biloba extract in male F344/NCrl rats: Relevance to humans

Ginkgo biloba extract (GBE) is a popular botanical dietary supplement used worldwide and the safety of use is a public health concern. While GBE is a complex mixture, the terpene trilactones and flavonol glycosides are believed to elicit the pharmacological and/or toxicological effects of GBE. In a National Toxicology Program (NTP) 2-year rodent bioassay with GBE, hepatotoxicity was observed in rodents (≥100 mg/kg in rats, ≥ 200 mg/kg in mice). Subsequently, questions arose about whether or not the GBE used in NTP studies was representative of other GBE products and how rodent doses are related to human doses. To address these, we generated systemic exposure data for terpene trilactones in male rats following oral administration of 30, 100, and 300 mg/kg GBE test article from the 2-year bioassay. Dose-normalized C_max and AUC_∞ for terpene trilactones from the current study were within 5-fold of published rodent studies using a standardized GBE preparation. Comparison of our rat systemic exposure data at 100 mg/kg GBE to published human data following ingestion of 240 mg GBE-containing product showed that the rat/human exposure multiple was 3-22, for terpene trilactones. These data demonstrate the relevance of NTP rodent toxicity data to humans.

Effects of β-glucosidase and α-rhamnosidase on the Contents of Flavonoids, Ginkgolides, and Aroma Components in Ginkgo Tea Drink

Ginkgo tea is a kind of health food produced from Ginkgo biloba leaves. The market of Ginkgo tea encountered many difficulties because of its bad palatability and vague function statement. In this study, two kinds of glycosidase were used to improve the flavor of Ginkgo tea, and three kinds of bioactivities were selected to investigate the health care function of the tea infusion. The aroma components extracted by headspace absorb (HSA) method during the making of Ginkgo tea were analyzed by GC-MS. The flavonoids and ginkgolides released into the tea infusion were studied by HPLC. A combination of β-glucosidase (β-G) and α-rhamnosidase (α-R) was applied during the making of the tea. The contents of characteristic aroma components and the release of total flavonoids and ginkgolides were increased significantly by adding β-G and α-R. The composition of flavone glycosides was changed greatly. The free radical scavenging, inhibition of inflammatory cell activation, and tumor cytotoxicity activities of the tea were demonstrably improved. According to the release of active components, Ginkgo tea can be brewed repeatedly for at least three times. The enzymes used here show potential application prospects in the making of Ginkgo tea or tea drink to get higher contents of flavonoids, ginkgolides, and aroma components.

How similar is similar enough? A sufficient similarity case study with Ginkgo biloba extract

Botanical dietary supplements are complex mixtures that can be highly variable in composition and quality, making safety evaluation difficult. A key challenge is determining how diverse products in the marketplace relate to chemically and toxicologically characterized reference samples (i.e., how similar must a product be in order to be well-represented by the tested reference sample?). Ginkgo biloba extract (GBE) was used as a case study to develop and evaluate approaches for determining sufficient similarity. Multiple GBE extracts were evaluated for chemical and biological-response similarity. Chemical similarity was assessed using untargeted and targeted chemistry approaches. Biological similarity was evaluated using in vitro liver models and short-term rodent studies. Statistical and data visualization methods were then used to make decisions about the similarity of products to the reference sample. A majority of the 26 GBE samples tested (62%) were consistently determined to be sufficiently similar to the reference sample, while 27% were different from the reference GBE, and 12% were either similar or different depending on the method used. This case study demonstrated that approaches to evaluate sufficient similarity allow for critical evaluation of complex mixtures so that safety data from the tested reference can be applied to untested materials.

Review of Ginkgo biloba-induced toxicity, from experimental studies to human case reports

Ginkgo biloba seeds and leaves have been used as a traditional herbal remedy for thousands of years, and its leaf extract has been consumed as a botanical dietary supplement for decades. Ginkgo biloba extract is a complex mixture with numerous components, including flavonol glycosides and terpene lactones, and is one of the most widely sold botanical dietary supplements worldwide. Concerns about potential health risks for the general population have been raised because of the widespread human exposure to Ginkgo biloba and its potential toxic and carcinogenic activities in rodents. The National Toxicology Program conducted 2-year gavage studies on one Ginkgo biloba leaf extract and concluded that there was clear evidence of carcinogenic activity of this extract in mice based on an increased incidence of hepatocellular carcinoma and hepatoblastoma. Recently, Ginkgo biloba leaf extract has been classified as a possible human carcinogen (Group 2B) by the International Agency for Research on Cancer. This review presents updated information on the toxicological effects from experimental studies both in vitro and in vivo to human case reports (caused by ginkgo seeds or leaves), and also summarizes the negative results from relatively large clinical trials.

Moderate doses of commercial preparations of Ginkgo biloba do not alter markers of liver function but moderate alcohol intake does: A new approach to identify and quantify biomarkers of 'adverse effects' of dietary supplements

It is difficult to determine if certain dietary supplements are safe for human consumption. Extracts of leaves of Ginkgo biloba trees are dietary supplements used for various purported therapeutic benefits. However, recent studies reported they increased risk of liver cancer in rodents. Therefore, this study assessed the association between ginkgo consumption and liver function using NHANES 2001-2012 data (N = 29,684). Since alcohol is known to adversely affect liver function, association of its consumption with liver function was also assessed. Alcohol and ginkgo extract intake of adult consumers and clinical markers of liver function (alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, bilirubin) were examined. Moderate consumers of alcohol (0.80 ± 0.02 drinks/day) had higher levels of aspartate aminotransferase and gamma glutamyl transferase than non-consumers (P < 0.001). There was no difference (P > 0.01) in levels of markers of liver function in 616 ginkgo consumers (65.1 ± 4.4 mg/day intake) compared to non-consumers. While moderate alcohol consumption was associated with changes in markers of liver function, ginkgo intake as typically consumed by U.S. adults was not associated with these markers. Biomarkers measured by NHANES may be useful to examine potential adverse effects of dietary supplements for which insufficient human adverse event and toxicity data are available.

TRIAL REGISTRATION NUMBER

Not applicable, as this is secondary analysis of publicly released observational data (NHANES 2001-2012).

The Ginkgo biloba Extract Reverses the Renal Effects of Titanium Dioxide Nanoparticles in Adult Male Rats

The Ginkgo biloba extract (GbE) is a commercial product used as a nutraceutic herbal remedy in Europe and US. It contains 27% of the polyphenols isorhamnetin, kaempferol, and quercetin, as antioxidants. We used male adult Wistar rats (200-300 g), divided into four groups: control group (treated with 5.0 mg/kg of sodium chloride, intravenous), titanium dioxide nanoparticles (TiO2-NPs) group (5.0 mg/kg, intravenous), GbE group (10 mg/kg, intraperitoneal), and GbE + TiO2-NPs group (treated 24 h before with 10 mg/kg of GbE, intraperitoneal), followed, 24 h later, by 5.0 mg/kg of TiO2-NPs intravenously. The statistical analysis was performed using Student's t-test for grouped data with ANOVA posttest. The GbE protected renal cells against the effects of TiO2-NPs because it reversed the increased activity of γ-glutamyltranspeptidase and the enzymatic activity of dipeptidylaminopeptidase IV at all times tested (0-5, 5-24, 24-48, and 48-72 h). Also it reversed the glucosuria, hypernatriuria, and urine osmolarity at three times tested (5-24, 24-48, and 48-72). Thus, we conclude that GbE has a beneficial activity in the cytoplasmic membranes of brush border cells on the renal tubules, against the adverse effects that can be produced by some xenobiotics in this case the TiO2-NPs, in experimental rats.

Commonly Used Dietary Supplements on Coagulation Function during Surgery

BACKGROUND

Patients who undergo surgery appear to use dietary supplements significantly more frequently than the general population. Because they contain pharmacologically active compounds, dietary supplements may affect coagulation and platelet function during the perioperative period through direct effects, pharmacodynamic interactions, and pharmacokinetic interactions. However, in this regard, limited studies have been conducted that address the pharmacological interactions of dietary supplements. To avoid possible bleeding risks during surgery, information of potential complications of dietary supplements during perioperative management is important for physicians.

METHODS

Through a systematic database search of all available years, articles were identified in this review if they included dietary supplements and coagulation/platelet function, while special attention was paid to studies published after 1990.

RESULTS

Safety concerns are reported in commercially available dietary supplements. Effects of the most commonly used natural products on blood coagulation and platelet function are systematically reviewed, including 11 herbal medicines (echinacea, ephedra, garlic, ginger, ginkgo, ginseng, green tea, kava, saw palmetto, St John's wort, and valerian) and 4 other dietary supplements (coenzyme Q₁₀, glucosamine and chondroitin sulfate, fish oil, and vitamins). Bleeding risks of garlic, ginkgo, ginseng, green tea, saw palmetto, St John's wort, and fish oil are reported. Cardiovascular instability was observed with ephedra, ginseng, and kava. Pharmacodynamic and pharmacokinetic interactions between dietary supplements and drugs used in the perioperative period are discussed.

CONCLUSIONS

To prevent potential problems associated with the use of dietary supplements, physicians should be familiar with the perioperative effects of commonly used dietary supplements. Since the effects of dietary supplements on coagulation and platelet function are difficult to predict, it is prudent to advise their discontinuation before surgery.

Toxicity and carcinogenicity studies of Ginkgo biloba extract in rat and mouse: liver, thyroid, and nose are targets

Ginkgo biloba extract (GBE) is a popular herbal supplement that is used to improve circulation and brain function. In spite of widespread human exposure to relatively high doses over potentially long periods of time, there is a paucity of data from animal studies regarding the toxicity and carcinogenicity associated with GBE. In order to fill this knowledge gap, 3-month and 2-year toxicity and carcinogenicity studies with GBE administered by oral gavage to B6C3F1/N mice and F344/N rats were performed as part of the National Toxicology Program's Dietary Supplements and Herbal Medicines Initiative. The targets of GBE treatment were the liver, thyroid, and nose. These targets were consistent across exposure period, sex, and species, albeit with varying degrees of effect observed among studies. Key findings included a notably high incidence of hepatoblastomas in male and female mice and evidence of carcinogenic potential in the thyroid gland of both mice and rats. Various nonneoplastic lesions were observed beyond control levels in the liver, thyroid gland, and nose of rats and mice administered GBE. Although these results cannot be directly extrapolated to humans, the findings fill an important data gap in assessing risk associated with GBE use.

Mechanistic evaluation of Ginkgo biloba leaf extract-induced genotoxicity in L5178Y cells

Ginkgo biloba has been used for many thousand years as a traditional herbal remedy and its extract has been consumed for many decades as a dietary supplement. Ginkgo biloba leaf extract is a complex mixture with many constituents, including flavonol glycosides and terpene lactones. The National Toxicology Program 2-year cancer bioassay found that G. biloba leaf extract targets the liver, thyroid gland, and nose of rodents; however, the mechanism of G. biloba leaf extract-associated carcinogenicity remains unclear. In the current study, the in vitro genotoxicity of G. biloba leaf extract and its eight constituents was evaluated using the mouse lymphoma assay (MLA) and Comet assay. The underlying mechanisms of G. biloba leaf extract-associated genotoxicity were explored. Ginkgo biloba leaf extract, quercetin, and kaempferol resulted in a dose-dependent increase in the mutant frequency and DNA double-strand breaks (DSBs). Western blot analysis confirmed that G. biloba leaf extract, quercetin, and kaempferol activated the DNA damage signaling pathway with increased expression of γ-H2AX and phosphorylated Chk2 and Chk1. In addition, G. biloba leaf extract produced reactive oxygen species and decreased glutathione levels in L5178Y cells. Loss of heterozygosity analysis of mutants indicated that G. biloba leaf extract, quercetin, and kaempferol treatments resulted in extensive chromosomal damage. These results indicate that G. biloba leaf extract and its two constituents, quercetin and kaempferol, are mutagenic to the mouse L5178Y cells and induce DSBs. Quercetin and kaempferol likely are major contributors to G. biloba leaf extract-induced genotoxicity.

Mixtures research at NIEHS: an evolving program

The National Institute of Environmental Health Sciences (NIEHS) has a rich history in evaluating the toxicity of mixtures. The types of mixtures assessed by the Division of the National Toxicology Program (DNTP) and the extramural community (through the Division of Extramural Research and Training, DERT) have included a broad range of chemicals and toxicants, with each study having a unique set of questions and design considerations. Some examples of the types of mixtures studied include: groundwater contaminants, pesticides/fertilizers, dioxin-like chemicals (assessing the toxic equivalency approach), drug combinations, air pollution, metals, polycyclic aromatic hydrocarbons, technical mixtures (e.g., pentachlorophenol, flame retardants), and mixed entities (e.g., herbals, asbestos). These endeavors have provided excellent data on the toxicity of specific mixtures and have been informative to the human health risk assessment process in general (e.g., providing data on low dose exposures to environmental chemicals). However, the mixtures research effort at NIEHS, to date, has been driven by test article nominations to the DNTP or by investigator-initiated research through DERT. Recently, the NIEHS has embarked upon an effort to coordinate mixtures research across both intramural and extramural divisions in order to maximize mixtures research results. A path forward for NIEHS mixtures research will be based on feedback from a Request for Information (RFI) designed to gather up-to-date views on the knowledge gaps and roadblocks to evaluating mixtures and performing cumulative risk assessment, and a workshop organized to bring together mixtures experts from risk assessment, exposure science, biology, epidemiology, and statistics. The future of mixtures research at NIEHS will include projects from nominations to DNTP, studies by extramural investigators, and collaborations across government agencies that address high-priority questions in the field of mixtures research.

Hepatocellular carcinomas in B6C3F1 mice treated with Ginkgo biloba extract for two years differ from spontaneous liver tumors in cancer gene mutations and genomic pathways

Ginkgo biloba leaf extract (GBE) has been used for centuries in traditional Chinese medicine and today is used as an herbal supplement touted for improving neural function and for its antioxidant and anticancer effects. Herbal supplements have the potential for consumption over extended periods of time, with a general lack of sufficient data on long-term carcinogenicity risk. Exposure of B6C3F1 mice to GBE in the 2-year National Toxicology Program carcinogenicity bioassay resulted in a dose-dependent increase in hepatocellular tumors, including hepatocellular carcinoma (HCC). We show that the mechanism of hepatocarcinogenesis in GBE exposed animals is complex, involving alterations in H-ras and Ctnnb1 mutation spectra, WNT pathway dysregulation, and significantly altered gene expression associated with oncogenesis, HCC development, and chronic xenobiotic and oxidative stress compared to spontaneous HCC. This study provides a molecular context for the genetic changes associated with hepatocarcinogenesis in GBE exposed mice and illustrates the marked differences between these tumors and those arising spontaneously in the B6C3F1 mouse. The molecular changes observed in HCC from GBE-treated animals may be of relevance to those seen in human HCC and other types of cancer, and provide important data on potential mechanisms of GBE hepatocarcinogenesis.

Effects of Ginkgo biloba on chemically-induced mammary tumors in rats receiving tamoxifen

Background

Ginkgo biloba extract (GbE) is used extensively by breast cancer patients undergoing treatment with Tamoxifen (TAM). Thus, the present study investigated the effects of GbE in female Sprague–Dawley (SD) rats bearing chemically-induced mammary tumors and receiving TAM.

Methods

Animals bearing mammary tumors (≥1 cm in diameter) were divided into four groups: TAM [10 mg/kg, intragastrically (i.g.)], TAM plus GbE [50 and 100 mg/kg, intraperitoneally (i.p.)] or an untreated control group. After 4 weeks, the therapeutic efficacy of the different treatments was evaluated by measuring the tumor volume (cm³) and the proportions of each tumor that were alive, necrotic or degenerative (mm²). In addition, labeling indexes (LI%) were calculated for cell proliferation (PCNA LI%) and apoptosis (cleaved caspase-3 LI%), expression of estrogen receptor-alpha (ER-α) and p63 biomarkers.

Results

Overall, the tumor volume and the PCNA LI% within live tumor areas were reduced by 83% and 99%, respectively, in all TAM-treated groups when compared to the untreated control group. GbE treatment (100 mg/kg) reduced the proportions of live (24.8%) and necrotic areas (2.9%) (p = 0.046 and p = 0.038, respectively) and significantly increased the proportion of degenerative areas (72.9%) (p = 0.004) in mammary tumors when compared to the group treated only with TAM. The expression of ER-α, p63 and cleaved caspase-3 in live tumor tissues was not modified by GbE treatment.

Conclusions

Co-treatment with 100 mg/kg GbE presented a slightly beneficial effect on the therapeutic efficacy of TAM in female SD rats bearing mammary tumors.

Evaluation of a multi-herb supplement for erectile dysfunction: a randomized double-blind, placebo-controlled study

Background

Evidence is lacking for multi-ingredient herbal supplements claiming therapeutic effect in sexual dysfunction in men. We examined the safety and efficacy of VigRX Plus (VXP) – a proprietary polyherbal preparation for improving male sexual function, in a double blind, randomized placebo-controlled, parallel groups, multi-centre study.

Methods

78 men aged 25–50 years of age; suffering from mild to moderate erectile dysfunction (ED), participated in this study. Subjects were randomized to receive VXP or placebo at a dose of two capsules twice daily for 12 weeks. The international index of erectile function (IIEF) was the primary outcome measure of efficacy. Other efficacy measures were: Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), Serum testosterone, Semen analysis, Investigator’s Global assessment and Subjects’ opinion.

Results

In subjects receiving VXP, the IIEF-Erectile Function (EF) scores improved significantly as compared to placebo. After 12 weeks of treatment, the mean (sd) IIEF-EF score at baseline increased from 16.08 (2.87) to 25.08 (4.56) in the VXP group versus 15.86 (3.24) to 16.47 (4.25) in the placebo group (P < 0.0001). Similar results were observed in each of the remaining four domains of the IIEF (orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction).There was a significant difference for VXP versus placebo comparison of mean (sd) EDITS scores of patients: 82.31(20.23) vs 36.78(22.53) and partners :(82.75(9.8) vs 18.50(9.44);P < 0.001. Thirty-five out of 39 (90%) subjects from the VXP group and one (3%) from the placebo group wished to continue with the treatment they received. Investigator’s global assessment rated VXP therapy as very good to excellent in more than 50% patients and placebo therapy as fair to good in about 25% of patients. Incidence of side effects and subject’s rating for tolerability of treatment was similar in both groups.

Conclusions

VigRX Plus was well tolerated and more effective than placebo in improving sexual function in men.

Trial Registration

Clinical Trial Registry India, CTRI/2009/091/000099, 31-03-2009