A 6-month, double-blind, placebo-controlled, randomized trial to evaluate the effect of Eurycoma longifolia (Tongkat Ali) and concurrent training on erectile function and testosterone levels in androgen deficiency of aging males (ADAM)

Do "testosterone boosters" really increase serum total testosterone? A systematic review

Testosterone boosters are heavily marketed on social media and marketplaces to men with claims to significantly increase testosterone. Lax industry regulation has allowed sales of supplements to thrive in the absence of verification of their purported benefits. Our primary objective was to systematically review all data published in the last two decades on testosterone boosters and determine their efficacy. Our outcome of interest was total testosterone increase versus placebo in four different populations: male athletes, men with late-onset hypogonadism infertile men and healthy men. Following search and screening, 52 studies were included in our review, relating to 27 proposed testosterone boosters: 10 studies of cholecalciferol; 5 zinc/magnesium; 4 Tribulus terrestris and creatine; 3 Eurycoma longifolia and Withania somnifera; 2 betaine, D-aspartic acid, Lepidium meyenii and isoflavones; while the remainder were single reports. Our findings indicate that most fail to increase total testosterone. The exceptions were β-hydroxy β-methylbutyrate and betaine, which can be considered effective for male athletes. Eurycoma longifolia, a blend of Punica granatum fruit rind and Theobroma cacao seed extracts (Tesnor™) and purified Shilajit extract (PrimaVie™) can be considered possibly effective for men with late-onset hypogonadism; Eurycoma longifolia and Withania somnifera possibly effective for healthy men; and a non-hormonal aromatase inhibitor (Novadex XT™) possibly effective for male athletes.

A narrative review on inflammaging and late-onset hypogonadism

The increasing life expectancy observed in recent years has resulted in a higher prevalence of late-onset hypogonadism (LOH) in older men. LOH is characterized by the decline in testosterone levels and can have significant impacts on physical and mental health. While the underlying causes of LOH are not fully understood, there is a growing interest in exploring the role of inflammaging in its development. Inflammaging is a concept that describes the chronic, low-grade, systemic inflammation that occurs as a result of aging. This inflammatory state has been implicated in the development of various age-related diseases. Several cellular and molecular mechanisms have been identified as contributors to inflammaging, including immune senescence, cellular senescence, autophagy defects, and mitochondrial dysfunction. Despite the extensive research on inflammaging, its relationship with LOH has not yet been thoroughly reviewed in the literature. To address this gap, we aim to review the latest findings related to inflammaging and its impact on the development of LOH. Additionally, we will explore interventions that target inflammaging as potential treatments for LOH.

Effect of aerobic exercise on erectile function: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The health benefits of regular aerobic exercise are well established, although there is limited high-quality evidence regarding its impact on erectile function.

AIM

To determine the effect of aerobic exercise on erectile function in men and to identify factors that may influence this effect.

METHODS

This systematic review and meta-analysis included randomized controlled trials that evaluated the effects of aerobic exercise on erectile function via the Erectile Function domain of the International Index of Erectile Function (IIEF-EF). The mean difference in IIEF-EF scores between the aerobic exercise and nonexercising control groups was estimated by a random-effects meta-analysis. Meta-regression was used to evaluate the association of moderator variables on meta-analysis results.

OUTCOMES

The IIEF-EF score is reported on a 6-30 scale, with higher values indicating better erectile function.

RESULTS

Among 11 randomized controlled trials included in the analysis, aerobic exercise resulted in statistically significant improvements in IIEF-EF scores as compared with controls, with a mean difference of 2.8 points (95% CI, 1.7-3.9; P < .001) and moderate heterogeneity among studies (I2 = 53%). The effect of aerobic exercise on erectile function was greater in men with lower baseline IIEF-EF scores, with improvements of 2.3, 3.3, and 4.9 points for mild, moderate, and severe erectile dysfunction, respectively (P = .02). The meta-analysis results were not influenced by publication bias or individual study effects.

CLINICAL IMPLICATIONS

Health care providers should consider recommending regular aerobic exercise as a low-risk nonpharmacologic therapy for men experiencing erectile difficulties.

STRENGTHS AND LIMITATIONS

The primary strength of this review was the generation of level 1 evidence on a topic of general interest regarding sexual health in men. However, the included studies evaluated diverse groups, which may complicate data interpretation for specific segments of the population.

CONCLUSION

Regular aerobic exercise can improve the erectile function of men, particularly those with lower baseline IIEF-EF scores.

Dietary Supplements for Erectile Dysfunction: Analysis of Marketed Products, Systematic Review, Meta-Analysis and Rational Use

The use of nutraceutical products to enhance male sexual performance has a long history, especially with regard to the treatment of erectile dysfunction (ED). Alternative treatments for ED are becoming increasingly popular, with growing interest from consumers, as well as increased revenue for manufacturers. Dietary supplements (DSs), which are a mixture of active ingredients, are mainly sold online. In randomized controlled trials, the molecules contained in DSs have demonstrated varying degrees of effectiveness, or even have no evidence to support their use. However, none of the studies carried out provided sufficient evidence to consider these products a first-line therapy. Therefore, the combination of the various active ingredients, especially in relation to the daily dose, leaves doubts about the real effectiveness. In order to evaluate the potential efficacy of DS formulations, we analyzed the products marketed in Italy using a scoring approach. A systematic review of the literature was performed to evaluate the effect of DS and to detect the active ingredients able to improve erectile function-called effective ingredients (EIs)-and their minimal effective daily dose (mED). A metanalysis identified some nutraceuticals, such as Panax ginseng, Tribulus terrestris and L-arginine, that are able to improve male sexual function. Based on the scoring system, 2 (8%) supplements matched with the cluster of higher expected efficacy, 3 (12%) with the lower efficacy cluster and 20 (80%) matched with the criterion of no expected efficacy. DSs marketed in Italy are usually blends of many substances that are frequently employed at a negligible dose or without any evidence.

Botanical drugs for treating erectile dysfunction: clinical evidence

Phosphodiesterase-5 inhibitors (PDE5-i) have been widely used in clinical practice for the treatment of erectile dysfunction (ED). However, due to its suboptimal therapeutic effects and side effects, it is necessary to develop new medicines for ED treatment. Botanical drugs have been widely investigated as potential ED treatment drugs and have shown promising therapeutic effects. This review summarized 34 studies, including five botanical drugs with PDE5 inhibitory activity, seven botanical drugs without PDE5 inhibitory activity, and six mixed botanical drugs. The results of clinical studies regarding the aforementioned botanical drugs and relevant mechanisms are summarized in this study. It is necessary to conduct high-quality clinical trials to verify the dosage, targeted patients and therapeutic effects, and further pharmacology experiments are also needed to identify the active compounds.

Botanicals in health and disease of the testis and male fertility: A scoping review

BACKGROUND

Male factor infertility often results from testicular disorders leading to inadequate sperm quantity and quality. Both beneficial and detrimental effects of botanical products, especially herbal medicines, on testicular functions and male fertility have been reported in the literature.

PURPOSE

This scoping review aims to map the main clinical evidence on different impacts of botanical entities on the testis and to critically appraise relevant randomized controlled trials (RCTs) published in the recent 5 years, so as to inform the future.

METHODS

Systematic reviews, meta-analyses and RCT reports on botanical impacts on testicular functions and male fertility were retrieved and synthesized from Pubmed, Web of Science, Scopus, Embase, ProQuest, Cochrane Library and Google Scholar up to 10th May 2022. RCTs published since 2018 were critically appraised against good practice guidelines for RCT and for reporting herbal studies.

RESULTS

We identified 24 systematic reviews and meta-analyses published since 2005, by authors from Iran (25%), China (21%), USA (12.5%) and 9 other countries. All but two were published in English. Only 3 systematic review protocols were identified, all published in English from China in the recent 3 years. We identified 125 RCTs published in six languages, mainly English (55%) and Chinese (42%). They were published since 1994 from 23 countries on all the six inhabitable continents, with China (46%), Australia (8%), USA (8%), India (7%) and Iran (5%) being the leading contributors. 72% and 28% RCTs published in English were on efficacy (botanicals vs placebo) and comparative effectiveness (a botanical vs other treatments), respectively. In contrast, 98% RCT reports in Chinese were on comparative effectiveness, with merely 2% on efficacy. Among all the 125 RCTs, 57% were studies in patients with semen abnormality and/or male infertility, 22% investigated herbal effects in healthy men, 14% were on patients with male sexual dysfunction and hypogonadism, and 7% were conducted in men with non-sexual disorders. Since 2018, 32 RCTs have been published, in English (69%) or Chinese (31%). Nineteen RCT reports from China, India, Japan and Korea all studied herbal formulae while the 13 RCT reports from Australia, Brazil, Czech and Italy, Iran, Malaysia, Spain, the UK and the USA all exclusively studied extracts of a single species. Putting geo-cultural differences aside, gossypol and extracts of Tripterygium wilfordii Hook. f. were found to be detrimental to the testis and male fertility, while the extracts of Withania somnifera (L.) Dunal and traditional Chinese medicine Qilin Pill, etc., might improve testosterone levels and semen parameters, thus could be therapeutic for male sexual dysfunction and infertility. However, all still require further evaluation in view of recurring weaknesses in quality control of herbal materials, RCT design and reporting. For example, only 9%-23% of the RCTs published since 2018 provided information on voucher samples, chemical profiling, herbal authentication and herbal extraction.

CONCLUSION

Research on botanicals and the testis has been reported worldwide, demonstrating clear geo-cultural differences in studied plant species, botanical types, study objectives and quality of research design, implementation and reporting. Due to a few recurring weaknesses in the literature, this study is unable to recommend the use of any specific botanicals, however, current evidence does indicate that botanicals can be double-edged swords to the testis and male fertility. To secure better clinical evidence, future studies must faithfully implement existing and emerging good practice guidelines.

How Internet Websites Portray Herbal Vitality Products Containing Eurycoma longifolia Jack: An Evaluation of the Quality and Risks of Online Information

BACKGROUND

Tongkat Ali (TA) or Eurycoma longifolia is a herbal medicine (HM) plant traditionally used to treat sexual dysfunction and enhance libido in men. Websites containing information about HM are abundant. However, studies have shown that in general the quality of websites containing information on HM is low. The present study aims to assess the quality and risks of websites containing information about TA supplements and to identify the health claims for TA.

METHODOLOGY

A cross-sectional study to evaluate the quality and risks of websites discussing TA supplements was conducted. Online marketing websites, research articles, news articles, personal opinions, and those restricted by password were excluded. The quality and risks of websites were assessed using a modified DISCERN tool and a set of risk assessment criteria, respectively. The health claims for TA were identified and analyzed using content analysis.

RESULTS

Overall, 321 websites met the inclusion criteria and were further evaluated. The overall rating of the quality of the websites was low, with a mean score ± standard deviation of 1.07 ± 0.51. Most websites lacked information that there may be more than one possible treatment choice and did not discuss areas of uncertainty. However, 67.9% (218/321) of the websites received a risk score of zero. A minority of websites (5/321, 1.6%) discouraged the use of conventional medicines. The most common health claims for TA included in the websites related to the enhancement of testosterone level (121/321, 37.7%), treatment of malaria (112/321, 34.9%), and improvement in libido (108/321, 33.6%).

CONCLUSIONS

Websites containing information about TA supplements generally have a low-quality rating based on a modified DISCERN tool despite having a low-risk score. Government agencies and healthcare professionals (HCPs) must be more proactive in the critique and dissemination of information relating to HM, and in ensuring the safe use of HM among the public and patients.

Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials

Background and Objectives: Male hypogonadism is a clinical disorder characterized by reduced serum testosterone in men. Although treatment using herbal medicines, including Eurycoma longifolia, has been investigated, the benefits remain unclear. This study aims to investigate the efficacy of E. longifolia as a sole intervention to increase testosterone levels in males. Materials and Methods: We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) according to the PRISMA guidelines. Relevant articles were retrieved from the databases PubMed, Scopus, Web of Science, Cochrane, Ovid/Embase, and Google Scholar. Results: After literature screening, a total of nine studies was included in the systematic review. Five RCTs were included in the meta-analysis. A significant improvement in total testosterone levels after E. longifolia treatment was mostly reported in both healthy volunteers and hypogonadal men. The random model effect revealed a significant increase (SMD = 1.352, 95% CI 0.565 to 2.138, p = 0.001) in the total testosterone levels in men receiving E. longifolia supplementation, which was confirmed in the hypogonadism subgroup. Conclusions: This systematic review and meta-analysis of the literature supports the possible use of E. longifolia supplementation for enhancing testosterone production. Although more research is required before its use in clinical practice, this may represent a safe and promising therapeutic option, particularly in hypogonadal men.

Phosphodiesterase-5 Inhibitory Activity of Canthin-6-One Alkaloids and the Roots of Eurycoma longifolia and Eurycoma harmandiana

Eurycoma longifolia (EL) and Eurycoma harmandiana (EH) are natural medicinal plants belonging to the Simaroubaceae family, and are well-known for their ability to enhance male sexual performance. The present study investigated the phosphodiesterase-5 (PDE-5) inhibitory activity of intact roots of EL and EH. Additionally, canthin-6-one alkaloids, β-carboline alkaloids, and quassinoids were also screened for PDE-5 inhibitory activity. We developed in vitro root and callus cultures of EL and EH to determine their PDE-5 inhibitory activity. Our results indicated that canthin-6-one alkaloids, which include canthin-6-one-9-O-β-D-glucopyranoside, 9-methoxycanthin-6-one, canthin-6-one, and 9-hydroxycanthin-6-one, exhibited PDE-5 enzymatic inhibitory activity, with IC₅₀ values of 2.86±0.23, 3.30±1.03, 4.31±0.52, and 4.66±1.13 μM, respectively. The ethanolic extract of the intact roots of EL and EH, and the in vitro root culture of EH had large amounts of canthin-6-one alkaloids (1.50±0.04, 2.12±0.03, and 3.48±0.08 mg/g dry weight, respectively), and showed potent PDE-5 inhibition. Our findings indicate that in vitro root cultures of EH may be used to replace intact plants, and canthin-6-one-9-O-β-D-glucopyranoside should be further investigated for development as a health supplement.

Testosterone Boosters Intake in Athletes: Current Evidence and Further Directions

“Testosterone boosters” (TB)—are supplements that are claimed to increase testosterone levels in the human body. While the consumption of TB may be popular among athletes, there is insufficient evidence both about the safety and the real efficacy of TB. In our review, we searched MEDLINE/PubMed and Cochrane Library for studies on the effects of 15 substances that are claimed to increase testosterone levels Anacyclus pyrethrum; Bulbine natalensis; Epimedium (horny goat weed); L-arginine; L-carnitine; magnesium; Mucuna pruriens; pantothenic acid; selenium; shilajit Eurycoma longifolia (Tongkat Ali); Serenoa repens (saw palmetto); boron; Withania somnifera (ashwagandha); and Trigonella foenum-graecum (fenugreek) in athletes and healthy adults under 55 years of age. We found such studies regarding 10 out of 15 substances: L-arginine (3 studies); L-carnitine (2); magnesium (1); selenium (2); shilajit (1); Tongkat Ali (2); Serenoa repens (1); boron (3); ashwagandha root (2); and fenugreek (7). Many of them fail to prove the efficacy of these substances to increase testosterone levels. Tongkat Ali, ashwagandha, and fenugreek were the substances with the strongest evidence. The positive effect of magnesium and shilajit on testosterone concentration was shown in single studies. Conflicting data found that L-arginine, L-carnitine, Serenoa repens, selenium and boron do not appear to increase testosterone levels. There are almost no data on the safety profile of various TB components; however, certain TB components may be linked to coagulation, and pancreatic and hepatic disorders. Based on the review, the authors conclude that at present TB cannot be recommended for use by athletes due to insufficient data on their efficacy and safety.