Analytical methods for the detection and characterization of unapproved phosphodiesterase type 5 inhibitors (PDE-5i) used in adulteration of dietary supplements- a review.

This article is an up-to-date review of 112 unapproved phosphodiesterase type 5 inhibitors (PDE-5i) found as adulterants in sexual enhancement dietary supplements and other products from 2003 to July 2023. Seventy-five of these unapproved PDE-5i are analogues of sildenafil (67%), followed by 26 analogues of tadalafil (23%), 9 analogues of vardenafil (8%) and 2 other type of compounds (2%). The products have been formulated in various packaging, primarily in capsule, tablet, and powder forms. Common screening techniques allowing detection of such analogues include high performance or ultra-high performance liquid chromatography in tandem with ultra-violet detector (HPLC-UV or UPLC-UV) (50%) and thin-layer chromatography in tandem with ultra-violet detection (TLC-UV) (7%). Screening by mass spectrometry (MS) is relatively less common with the use of single-, triple-quadrupole or time-of-flight (TOF) mass spectrometers (9%). Meanwhile, the combined detection by UV-MS has been recorded at 10% usage. Screening by proton nuclear magnetic resonance spectroscopy (NMR) (11%) has also been applied. For compound characterization, i.e. structural elucidation, NMR spectroscopy has been preferred (100 out of 112 compounds), followed by high-resolution mass spectrometry (HRMS) (74 out of 112 compounds) and Fourier-transform infrared spectroscopy (FTIR) (44 out of 112 compounds). Over the past two decades, analytical technology has been evolving with enhanced sensitivity and resolution. Despite this, structural elucidation of the new emerging analogues in adulterated dietary supplements remains a challenge, especially when the analogues involve complex structural modification. Therefore, the above-mentioned techniques may not be adequate to characterize the analogues. Additional work involving chiroptical methods, two-dimensional (2D) NMR experiments and X-ray crystallography are likely to be required in the future.

The POWER saga from 2007 to 2022: An example of a sexual enhancement dietary supplement tainted by different adulterants and still on the market.

Ten POWER dietary supplements, chronologically called tabs, pills then caps, and advertised as 100% natural aphrodisiacs, were analyzed by 1H NMR from 2007 to 2022. They were all tainted by PDE-5 inhibitors. Eight different adulterants were identified (sildenafil (1), sildenafil analogues (6), and vardenafil analogue (1)). Their amounts ranged from 15 to 145 mg/capsule. Four supplements contained at least 100 mg/capsule of PDE-5 inhibitor or analogue, the maximal recommended dose of sildenafil. The nature of the adulterant has changed over time, probably to evade its detection by regulatory agencies routine screening tests. Despite several warnings and/or seizures from several European food and/or health authorities, the dietary supplement POWER is still on sale on the Internet, thus demonstrating the impossibility of controlling this market. Faced with this situation, the consumer should be better informed by establishing at the European level a public database of tainted dietary supplements on the model of that of the US Food and Drug Administration. It should indicate the product name, its photo, the adulterant name, and be easily accessible to everyone.

Screening and Determination of Synthetic PDE-5 Inhibitors in Adulterated Sexual Enhancement Supplements.

This paper reports an important investigation and quantification of adulteration of sexual enhancement supplements with prescription medicines available in United Arab Emirates (UAE): tadalafil, sildenafil and vardenafil. A total of 158 sexual enhancement supplements were collected and analyzed in the current study. The samples were screened using REVERSE-phase liquid chromatography tandem high-resolution mass spectrometry/mass spectrometry (RP-HPLC-MS/MS). Of all sexual enhancements, 12.7% (95% CI: 7.4-18) contained undeclared sildenafil, 3.8% (95% CI: 0.78-6.81) contained undeclared tadalafil and 1.9% (95% CI: 0.25-4.05) contained undeclared vardenafil. Of all sexual enhancement supplements, 13.9% (95% CI: 8.5-19.4) contained significant concentrations of sildenafil, tadalafil or vardenafil. While the study found relatively low levels of undeclared pharmaceutical ingredients in the sexual enhancement dietary supplements available on the UAE market, it is likely that patients with ED tend to consume multiple such supplements daily, thereby exposing themselves to highly elevated cumulative levels.

HPLC/Fluorescence-Diode Array Detection for Rapid and Reliable Determination of Illegal Synthetic Drugs in Male Sexual Herbal and Honey Remedies: Comparative Study with UFLC-MS.

BACKGROUND: Nutraceuticals (NTCs), as honey and tablets with herbal extract are subjected to adulteration. OBJECTIVE: For NTCs claimed to enhance sexual performance, synthetic drugs (sildenafil, tadalafil, avanafil, vardenafil, and dapoxetine) are common adulterants, so they were selected to be simultaneously analyzed in the current study. Natural aphrodisiacs (icariin and yohimbine) are claimed to be present in many fake NTCs, so they were also included in the study. METHODS: In order to achieve the target of the current study, three liquid chromatographic methods with different unique detectors were developed and validated. RESULTS: High performance liquid chromatography (HPLC) with fluorescence detection enables rapid and reliable determination of natively fluorescent yohimbine, tadalafil vardenafil, and dapoxetine and it is the first report to analyze these compounds as adulterants in counterfeit NTC. Although the diode-array detector (DAD) enables the analysis of the seven adulterants, the fluorescence detector (FLD) shows better sensitivity and selectivity with lower LOQs and LODs. On the other hand, ultra-fast liquid chromatography-mass spectrometry (UFLC-MS) offers the advantages of peak identity confirmation, and it is of comparable sensitivity and selectivity to HPLC-FLD. CONCLUSION: One or more of these synthetic drugs were found in the analyzed NTCs while natural aphrodisiacs were absent. HIGHLIGHTS: Aphrodisiac nutraceuticals, NTCs, were analyzed for adulterants: five aphrodisiac synthetic drugs (adulterants) and two natural claimed aphrodisiacs. UFLC-MS and HPLC-DAD/FLD were compared for illicit NTCs analysis; all NTCs show the presence of synthetic aphrodisiacs and the absence of natural ones.

Detection of 94 compounds related to sexual enhancement including sildenafil, tadalafil, vardenafil and their analogues in various formulations of dietary supplements and food samples using HPLC and LC-MS/MS.

With an increase in the detection of structural and functional analogues of phosphodiesterase type 5 inhibitors (PDE-5i) in dietary supplements (DS) and foods, public health is threatened. Some products advertise natural ingredients despite containing PDE-5i that can cause serious adverse effects on human health. To avoid detection during routine screening, novel PDE-5i have been synthesised and added to DS and foods. The purpose of this study was to detect, identify, and quantify 94 PDE-5i and related compounds in DS and foods. Furthermore, the study investigated the detection cases and compared them by sample type, formulation, and compounds. The HPLC and LC-MS/MS methods were validated for limit of detection (LOD), limit of quantification (LOQ), linearity, and recovery in solid and liquid type samples. Both HPLC and LC-MS/MS showed satisfactory results, which were in conformance with the ICH guidelines. A total of 404 samples, including DS (99), and foods (305) were purchased from online and offline markets. Samples divided into 5 types of formulation were analysed; tablet, capsule, pilula (herbal medicine pill), powder and liquid type. Of these 130 samples (47 of 99 DS, and 83 of 305 foods) contained one or more PDE-5i or related compounds. Among the five types of formulation, the tablet type showed the highest detection rate (61.1%) in DS, whereas the capsule type showed the highest detection rate (53.8%) in food samples. This study will be helpful for monitoring illegal ED-related products, providing information to consumers, and ultimately contributing to protecting public health.

Identification of Erectile Dysfunction Drugs in Dietary Supplements by Liquid Chromatography Ion Trap Mass Spectrometry.

With the rise in consumption of dietary supplements for various ailments such as erectile dysfunction (ED), there is concern that these supplements may contain illegally added phosphodiesterase type 5 (PDE-5) inhibitor and its analogs. HPLC or LC is a general separation method, and MS is a detection technique, together LC/MS/MS technology provides the mass spectral confirmation in identifying sildenafil, vardenafil, tadalafil and their analogs. In our present study, a sample extraction technique with 1:1 acetonitrile: water solvents and sonication was used for screening, then identification was performed using an LC coupled with Velos Pro linear ion trap mass spectrometry. This was a simple and reliable method for a variety of matrices of dietary supplements and pharmaceutical formulations in tablet, capsule or liquid form. The run time is only 6.5 min, allowing for a quick screening and identification of all of analytes of ED drugs using full scan and data-dependent scan MS/MS, except for tadalafil and aminotadalafil (MS/MS/MS). To conclude this study, Sildenafil, tadalafil, vardenafil, and other 16 analogs in dietary supplements could be quickly screened and identified by HPLC coupled with ion trap MS using data dependent scanning function. The main method using the short column is very rapid, and saves a lot of running time and solvents, and the identification is further confirmed by MS/MS information. The current study develops and validates a quick and reliable method to screen for ED drugs.

Reliable screening and classification of phosphodiesterase type 5 inhibitors in dietary supplements using gas chromatography / mass spectrometry combined with specific common ions.

Illegal dietary supplements adulterated with phosphodiesterase type 5 inhibitors (PDE-5i) are increasingly widely distributed through internet markets and underground routes. For this reason, it demands development of reliable screening methods to determine a wide range of PDE-5i drugs in various types of dietary supplements. Herein, we developed a screening method using gas chromatography-mass spectrometry (GC-MS) for simultaneous detection of 53 PDE-5i drugs in supplements. Common formulations (such as capsule, powder, pill, and tablet) of supplements with complicated matrices were treated by simple liquid-liquid extraction and trimethylsilyl (TMS) derivatization. With the aid of TMS derivatization, 53 PDE-5i drugs could be successfully separated and detected within 15 min, using a short microbore GC column (15 m). Moreover, owing to enhanced detection sensitivity and selectivity of PDE-5i TMS derivatives, 0.5 mg of sample was sufficient to screen and confirm targeted PDE-5i drugs. In this study, specific common ions according to structural characteristics of PDE-5i drugs were found under the electron ionization (EI) of their TMS derivatives. These specific common fragments could reflect the common pharmacophores for 4 classes of PDE-5i drugs (sildenafil, other sildenafil, vardenafil, and tadalafil analogues). Based on characteristic EI fragment ions, extracted common ion chromatograms (ECICs) and discriminant analysis (DA) were effectively used for reliable screening and classification of various types of PDE-5i drugs. Specific ECICs and DA using characteristic EI fragments here will aid in identification of newly emerging PDE-5i counterfeits in supplements. This study will be helpful to supervise illegal adulteration of PDE-5i drugs in dietary supplements to protect public health and consumer safety.

Screening of Phosphodiesterase-5 Inhibitors and Their Analogs in Dietary Supplements by Liquid Chromatography-Hybrid Ion Trap-Time of Flight Mass Spectrometry.

An accurate and reliable method based on ion trap-time of flight mass spectrometry (IT-TOF MS) was developed for screening phosphodiesterase-5 inhibitors, including sildenafil, vardenafil, and tadalafil, and their analogs in dietary supplements. Various parameters affecting liquid chromatographic separation and IT-TOF detection were investigated, and the optimal conditions were determined. The separation was achieved on a reversed-phase column under gradient elution using acetonitrile and water containing 0.2% acetic acid at a flow rate of 0.2 mL/min. The chromatographic eluents were directly ionized in the IT-TOF system equipped with an electrospray ion source operating in the positive ion mode. The proposed screening method was validated by assessing its linearity, precision, and accuracy. Sequential tandem MS was conducted to obtain structural information of the references, and the fragmentation mechanism of each reference was proposed for providing spectral insight for newly synthesized analogs. Structural information, including accurate masses of both parent and fragment ions, was incorporated into the MSn spectral library. The developed method was successfully applied for screening adulterated dietary supplement samples.

Early administration of phosphodiesterase 5 inhibitors after induction of diabetes in a rat model may prevent erectile dysfunction.

BACKGROUND: The possible role of phosphodiesterase 5 inhibitors (PDE5Is) in prevention of negative effect of diabetes mellitus (DM) on erectile function is not well settled. OBJECTIVES: To investigate the effect of early administration of vardenafil on erectile function, cavernosal structure, and genes expression in a rat model of DM. MATERIALS AND METHODS: This experimental study was carried out at Suez Canal University's research laboratory. This study was conducted on a total of 60 adult male Albino Wistar rats, aged 60-80 days and weighing an average of 200 g. Rats were equally divided into six groups of 10 rats each: Group I (sham); Group II (DM with no treatment); Groups III, IV, V, and VI received vardenafil started at day 1, week 4, week 8, and week 12 after induction of DM, respectively. Functional study assessment of all groups was performed before euthanization, and then tissues were harvested for histopathological, ultrastructural, and molecular examinations. RESULTS: There was a significant difference of intracavernosal pressure between early (94 ± 2.18) and late (40.5 ± 1.94) treatment groups (p = 0.011). Histopathological and ultrastructural changes of DM with no treatment and late treatment groups showed distorted cavernous architecture and extensive fibrosis. There was significant difference of smooth muscle to collagen ratio between early and late treatment groups (p = 0.035). There was significant upregulation of nNOS(p = 0.021) and iNOS (p = 0.047) in early vs. late treatment group. The difference was insignificant in eNOS (p = 0.386) or TGF-ß1(p = 0.149). DISCUSSION AND CONCLUSION: Early treated rats with vardenafil had preserved erection and normal cavernosal structure, ultrastructure and gene expression of iNOS, nNOS, eNOS, and TGF-ß1. Quantification of gene expression would improve our knowledge regarding cytokines expression and molecular background of DM-associated ED. Clinical application of this result may encourage early administration of PDE5I to prevent deleterious effects of DM on erectile function in newly diagnosed DM patients with probable uncontrolled blood glucose.

Development of a specific fragment pattern-based quadrupole-Orbitrap mass spectrometry method to screen adulterated products of phosphodiesterase-5 inhibitors and their analogues.

Recently, adulterated supplements with phosphodiesterase-5 inhibitors (PDE-5i) have frequently observed. New synthetic analogues obtained from the chemical modification of parent compounds are frequently found in illicit products despite continuous efforts to inspect for these adulterants. A rapid and accurate method based on quadrupole-Orbitrap mass spectrometry was developed for simultaneously confirming and quantifying 85 PDE-5i and derived analogues present in illicit products for erectile dysfunction (ED). Common ions of PDE-5i according to their similar structures were proposed based on MS/MS fragmentations. These common ions could be an important diagnosis of their presence targets or new emerging analogues in supplements. Several validation parameters were employed, resulting in a limit of detection and quantification of 0.09-8.55 ng/mL and 0.24-17.10 ng/mL, respectively. The linear correlation coefficient (r2) was higher than 0.995, and mean recoveries of target compounds were in the range of 82-118%. A total of 187 illicit products, obtained from on/offline markets over a period of 3 years (2015-2017), were screened by the established method. Approximately 53% of them were adulterated with PDE-5i or derived analogues at concentrations of 0.1-726.0 mg/g in the illicit products. In the interests of public health, this study describes a rapid and accurate method to determine PDE-5i and new emerging analogues in adulterated products.

Experimental study on prophylactic effects of vardenafil in ischemia-reperfusion model with intestinal volvulus injury in rats.

AIM: An experimental study was performed to evaluate the effects of Vardenafil on ischemia-reperfusion (I/R) injury in an experimental volvulus model by histochemical and biochemical methods. MATERIALS AND METHODS: Thirty-five male Wistar rats were divided in five groups (n = 7). In Group 1, a 5 cm segment of small intestine 2 cm proximal to cecum was excised to have a control group. In the second group, 5 cm segment of small intestine 2 cm proximal to cecum was rotated 360° clockwise direction and sutured with 4/0 polyglactin to generate an experimental model of volvulus. At the end of 2 h of ischemia, the same intestinal segment was sampled. In group 3, after achieving ischemia similar to group 2, two hours of reperfusion injury was obtained by removing the sutures. Rats in Group 4 received vardenafil after 1.5 h of ischemia and then 2 h of reperfusion. And finally, in Group 5, vardenafil was administered 2 h before laparotomy and 5 cm of intestine was removed without I/R injury. Intestinal segments were evaluated for total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) with biochemical and histopathological analysis. RESULTS: Serum TOS levels and OSI were not significantly different between groups (p = 0.910, P = 0,43 respectively). The serum TAS level was decreased in group 3 as compared to vardenafil groups 4 and 5, without a statistical significance (p = 0.428). In histopathologic analysis, we found that vardenafil, partially reduced I/R injury. The villus structure was preserved but, congestion and inflammation were moderate. CONCLUSION: Vardenafil partially reduced I/R injury histopathologically on intestine. Our study shows that it does not have statistically antioxidant effect on intestinal I/R injury in experimental model of volvulus. However, effects of vardenafil in I/R injury of liver, kidney, heart, testis, over and brain which were cited in literature were not confirmed with I/R injury on intestine.

Targeting Phosphodiesterase-5 by Vardenafil Improves Vascular Graft Function.

OBJECTIVES: Ischaemia reperfusion (IR) injury occurs during vascular graft harvesting and implantation during vascular/cardiac surgery. Elevated intracellular cyclic guanosine monophosphate (cGMP) levels contribute to an effective endothelial protection in different pathophysiological conditions. The hypothesis that the phosphodiesterase-5 inhibitor vardenafil would protect vascular grafts against IR injury by upregulating the nitric oxide-cGMP pathway in the vessel wall of the bypass graft was investigated. METHODS: Lewis rats (n = 6-7/group) were divided into Group 1, control; Group 2, donor rats received intravenous saline; Group 3, received intravenous vardenafil (30 µg/kg) 2 h before explantation. Whereas aortic arches of Group 1 were immediately mounted in an organ bath, aortic segments of Groups 2 and 3 were stored for 2 h in saline and transplanted into the abdominal aorta of the recipient. Two hours after transplantation, the implanted grafts were harvested. Endothelium dependent and independent vasorelaxations were investigated. TUNEL, CD-31, ICAM-1, VCAM-1, α-SMA, nitrotyrosine, dihydroethidium and cGMP immunochemistry were also performed. RESULTS: Compared with the control, the saline group showed significantly attenuated endothelium dependent maximal relaxation (Rmax) 2 h after reperfusion, which was significantly improved by vardenafil supplementation (Rmax control, 91 ± 2%; saline 22 ± 2% vs. vardenafil 39 ± 4%, p < .001). Vardenafil pre-treatment significantly reduced DNA fragmentation (control 9 ± 1%, saline 66 ± 8% vs. vardenafil 13 ± 1%, p < .001), nitro-oxidative stress (control 0.8 ± 0.3, saline 7.6 ± 1.3 vs. vardenafil 3.8 ± 1, p = .036), reactive oxygen species level (vardenafil 36 ± 4, control 34 ± 2 vs. saline 43 ± 2, p = .049), prevented vascular smooth muscle cell damage (control 8.5 ± 0.7, saline 4.3 ± 0.6 vs. vardenafil 6.7 ± 0.6, p = .013), decreased ICAM-1 (control 4.1 ± 0.5, saline 7.0 ± 0.9 vs. vardenafil 4.4 ± 0.6, p = .031), and VCAM-1 score (control 4.4 ± 0.4, saline 7.3 ± 1.0 vs. vardenafil 5.2 ± 0.4, p = .046) and increased cGMP score in the aortic wall (control 11.2 ± 0.8, saline 6.5 ± 0.8 vs. vardenafil 8.9 ± 0.6, p = .016). The marker for endothelial integrity (CD-31) was also higher in the vardenafil group (control 74 ± 4%, saline 22 ± 2% vs. vardenafil 40 ± 3%, p = .008). CONCLUSIONS: The results support the view that impairment of intracellular cGMP signalling plays a role in the pathogenesis of the endothelial dysfunction of an arterial graft after bypass surgery, which can effectively be prevented by vardenafil. Its clinical use as preconditioning drug could be a novel approach in vascular/cardiac surgery.

Preparation and characterization of intravaginal vardenafil suppositories targeting a complementary treatment to boost in vitro fertilization process.

Vaginal route has been recently considered as a potential route for systemic delivery of drugs with poor oral bioavailability. Vardenafil (VDF) is a relatively new phosphodiesterase-5 inhibitor that exhibits a limited oral bioavailability (≈15%) due to extensive first-pass metabolism. In this study, we attempted to enhance the systemic bioavailability of VDF via its formulation within vaginal suppositories. Witepsol H15 and Suppocire NA50 were adopted as lipophilic suppository bases while polyethylene glycol 4000/400 and glycerogelatin were used as hydrophilic suppository bases. The effect of different base types and/or the incorporation of bioadhesive polymer on in vitro release of VDF were evaluated. The in vivo fate and organ biodistribution of VDF following intravaginal (IVG) administration were also investigated. VDF release from water-soluble bases was higher than that from lipophilic bases. The incorporation of bioadhesive polymers, such as Na alginate, remarkably sustained drug release from suppository base. The organ biodistribution study showed a higher Cmax (32 times) and AUC0-4h (20 times) of VDF in uterus following IVG administration of conventional suppositories, compared to oral administration of VDF suspension. In addition, cyclic guanosine monophosphate (cGMP) serum levels, used as an indicator of the in vivo activity of VDF, in animals were higher following IVG administration rather than oral administration. This study suggests that IVG administration of VDF might represent a potential alternative to oral route with superior therapeutic benefits especially when targeting the uterus.

Apoptosis induction of poly-S-nitrosated human serum albumin in resistant solid tumor under hypoxia can be restored by phosphodiesterase 5 inhibition.

Poly-S-nitrosated human serum albumin (Poly-SNO-HSA) delivered and accumulated nitric oxide (NO) in tumors and induces apoptosis. Tumor hypoxia is strongly associated with malignant progression and tumor resistance to therapy. In this study, we examined the cytotoxic effect of Poly-SNO-HSA under hypoxia on the murine colon 26 adenocarcinoma (C26) cells in vitro and in vivo. Under hypoxia, at about 4 times LD50 dose of Poly-SNO-HSA in vitro, the reactive oxygen species production was hindered but apoptotic cells were induced via cGMP pathway as the effect was suppressed by a soluble guanylate cyclase inhibitor, NS2028. The apoptosis induction effect of low dose Poly-SNO-HSA on C26 cells in vitro under hypoxia can be restored by a phosphodiesterase 5 (PDE5) inhibitor, vardenafil. In C26-bearing mice, Poly-SNO-HSA/vardenafil combination treatment significantly suppressed the tumor volume compared with Poly-SNO-HSA or vardenafil treatment alone. Furthermore, the core tumor tissues showed increased expression of caspase-3 than the non-core tissue. The expression of caspase-3 appeared to overlap with the hypoxic zone of tumor tissues. Similar results were also obtained when the experiments were repeated using Epimedium extract, a natural herbal supplement with PDE5 inhibition activity. In conclusion, Poly-SNO-HSA/PDE5 inhibitors combination therapy is a promising approach for enhancing the anticancer therapeutic effects of Poly-SNO-HSA against not only anti-cancer drug resistance but also hypoxic stress related solid tumor resistance.

Vardenafil reduces macrophage pro-inflammatory overresponses in cystic fibrosis through PDE5- and CFTR-dependent mechanisms.

Chronic inflammation that progressively disrupts the lung tissue is a hallmark of cystic fibrosis (CF). In mice, vardenafil, an inhibitor of phosphodiesterase type 5 (PDE5), restores transepithelial ion transport and corrects mislocalization of the most common CF mutation, F508del-CFTR. It also reduces lung pro-inflammatory responses in mice and in patients with CF. To test the hypothesis that macrophages are target effector cells of the immunomo-dulatory effect of vardenafil, we isolated lung macrophages from mice homozygous for the F508del mutation or invalidated for the cftr gene and from their corresponding wild-type (WT) littermates. We then evaluated the effect of vardenafil on the classical M1 polarization, mirroring release of pro-inflammatory cytokines. We confirmed that macrophages from different body compartments express CF transmembrane conductance regulator (CFTR) and showed that vardenafil targets the cells through PDE5- and CFTR-dependent mechanisms. In the presence of the F508del mutation, vardenafil down-regulated overresponses of the M1 markers, tumour necrosis factor (TNF)-α and inducible nitric oxide synthase (NOS)-2. Our study identifies lung macrophages as target cells of the anti-inflammatory effect of vardenafil in CF and supports the view that the drug is potentially beneficial for treating CF as it combines rescue of CFTR protein and anti-inflammatory properties.

Determination of Common Adulterants in Herbal Medicine and Food Samples using Core-shell Column Coupled to Tandem Mass Spectrometry.

High-performance liquid chromatography coupled to tandem mass spectrometry was used to develop and validate a rapid method to qualitatively and quantitatively analyse 18 common adulterants in herbal medicine and food samples. Initially, the mobile phase composition was optimized in three different columns: core-shell, monolithic and standard 3.5-µm-particle-size columns. The results show that the core-shell column provides the best separation. Moreover, the tandem mass spectrometry was optimized. The linear range for all adulterants was 0.5-500 µg mL-1. Finally, the samples that were supplied by the Public Authority of Customer Protection, Ministry of Health, and those collected from the local market were analysed. The results indicate that 7 of 33 analysed samples contained adulterants. The adulterated samples mainly contain sildenafil, tadalafil or vardenafil. The concentrations of these three adulterants in the samples were 0.18-39 wt%. This study is the first report in the Sultanate of Oman about adulteration in herbal medicine and food samples. The results clearly raise some concern and require proper plan of action to increase public awareness about this serious issue.

Additive effects of the Rho kinase inhibitor Y-27632 and vardenafil on relaxation of the corpus cavernosum tissue of patients with erectile dysfunction and clinical phosphodiesterase type 5 inhibitor failure.

OBJECTIVES: To evaluate the expression of the Rho/Rho-associated protein kinase (ROCK) pathway in the corpus cavernosum of patients with severe erectile dysfunction (ED) compared with healthy human corpus cavernosum, and to test the functional effects of two Rho kinase inhibitors (RKIs) on erectile tissue of patients with severe ED, which did not respond to phosphodiesterase type 5 inhibitors (PDE5Is). PATIENTS AND METHODS: Human corpus cavernosum samples were obtained after consent from men undergoing penile prosthesis implantation (n = 7 for organ bath experiments, n = 17 for quantitative PCR [qPCR]). Potent control subjects (n = 5) underwent penile needle biopsy. qPCR was performed for the expression of RhoA and ROCK subtypes 1 and 2. Immunohistochemistry staining against ROCK and α smooth muscle actin (αSMA) was performed on the corpus cavernosum of patients with ED. Tissue strips were precontracted with phenylephrine and incubated with 1 µm of the PDE5I vardenafil or with DMSO (control). Subsequently, increasing concentrations of the RKIs azaindole or Y-27632 were added, and relaxation of tissue was quantified. RESULTS: The expression of ROCK1 was unchanged (P > 0.05), while ROCK2 (P < 0.05) was significantly upregulated in patients with ED compared with controls. ROCK1 and ROCK2 protein colocalized with αSMA, confirming the presence of this kinase in cavernous smooth muscle cells and/or myofibroblasts. After incubation with DMSO, 10 µm azaindole and 10 µm Y-27632 relaxed precontracted tissues with 49.5 ± 7.42% (P = 0.1470 when compared with vehicle) and 85.9 ± 10.3% (P = 0.0016 when compared with vehicle), respectively. Additive effects on relaxation of human corpus cavernosum were seen after preincubation with 1 µm vardenafil. CONCLUSION: The RKI Y-27632 causes a significant relaxation of corpus cavernosum in tissue strips of patients with severe ED. The additive effect of vardenafil and Y-27632 shows that a combined inhibition of Rho-kinase and phosphodiesterase type 5 could be a promising orally administered treatment for severe ED.

Patient diagnosed with chronic erectile dysfunction refractory to PDE 5 Inhibitor therapy reports improvement in function after hyperbaric oxygen therapy.

Erectile dysfunction (ED), defined as the inability to achieve or sustain an erection firm enough for sexual intercourse, is common in men older than 50 years of age whose medical history includes diabetes mellitus. This case report describes a male patient treated with hyperbaric oxygen (HBO2) therapy as part of a comprehensive wound treatment plan for an open right foot wound. The patient's medical history included Type 1 diabetes mellitus and chronic ED refractory to previous trials of phosphodiesterase type 5 inhibitors. The patient completed a total of 60 HBO2 treatments over a 15-week period. He reported an improvement in his ED symptoms after the first 20 hyperbaric treatments, with morning tumescence being the first sign of a change. Patient continued to report morning tumescence 24 weeks after final HBO2 treatment.

Simultaneous Detection of Three Phosphodiesterase Type 5 Inhibitors and Eight of Their Analogs in Lifestyle Products and Screening for Adulterants by High-Performance Thin-Layer Chromatography.

An HPTLC method is proposed to permit effective screening for the presence of three phosphodiesterase type 5 inhibitors (PDE5-Is; sildenafil, vardenafil, and tadalafil) and eight of their analogs (hydroxyacetildenafil, homosildenafil, thiohomosildenafil, acetildenafil, acetaminotadalafil, propoxyphenyl hydroxyhomosildenafil, hydroxyhomosildenafil, and hydroxythiohomosildenafil) in finished products, including tablets, capsules, chocolate, instant coffee, syrup, and chewing gum. For all the finished products, the same simple sample preparation may be applied: ultrasound-assisted extraction in 10 mL methanol for 30 min followed by centrifugation. The Rf values of individual HPTLC bands afford preliminary identification of potential PDE5-Is. Scanning densitometry capabilities enable comparison of the unknown UV spectra with those of known standard compounds and allow further structural insight. Mass spectrometric analysis of the material derived from individual zones supplies an additional degree of confidence. Significantly, the proposed screening technique allows focus on the already known PDE5 Is and provides a platform for isolation and chemical categorization of the newly-synthesized analogs. Furthermore, the scope could be expanded to other therapeutic categories (e.g., analgesics, antidiabetics, and anorexiants) that are occasionally coadulterated along with the PDE5-Is. The method was successfully applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl hydroxyhomosildenafil, or dimethylsildenafil).

Male enhancement Nutraceuticals in the Middle East market: Claim, pharmaceutical quality and safety assessments.

The global market is invaded by male enhancement nutraceuticals claimed to be of natural origin sold with a major therapeutic claim. Most of these products have been reported by international systems like the Food and Drug Administration (FDA). We hypothesize that these products could represent a major threat to the health of the consumers. In this paper, pharmaceutical evaluation of some of these nutraceutical products sold in Egypt under the therapeutic claim of treating erectile dysfunction, are discussed along with pharmacological evaluation to investigate their safety and efficacy parameters. Samples were analyzed utterly using conventional methods, i.e.: HPLC, HPTLC, NIR, content uniformity and weight variation and friability. The SeDeM system was used for quality assessment. On the basis of the results of this research, the sampled products are adulterated and totally heterogeneous in their adulterant drug content and pharmaceutical quality. These products represent a major safety threat for the consumers in Egypt and the Middle East, especially; the target audience is mostly affected with heart and blood pressure problems seeking natural and safe alternatives to the well-established Phosphodiesterase 5 Inhibitors (PDE-5Is).