Sexual function can be divided into three stages which represent the cycle of sexual response: 1- libido or sexual desire, 2- arousal, which comprises erectile function in men and lubrication in women, 3- release, comprising orgasm in women and ejaculation in men. The prevalence of sexual dysfunction has been reported among middle-aged and elderly men and women to be 10-25%.
Drugs can affect either one or several of the stages of sexual response cycle. The mechanisms involved in sexual response are not entirely known, but there is evidence of involvement of dopaminergic, adrenergic, muscarinic and serotonergic mechanisms. In practice, dopamine increases sexual activity and serotonin decreases it.
Libido is affected by reproductive hormones and the overall emotional and physical health of the individual. Presence of testosterone is necessary for a natural sexual arousal in men and women. Deficiency in testosterone is accompanied by impotence (inability in erection) in men.
The sexual function of men depends on the harmony of neurogenic, hormonal and psychologic mechanisms, a disturbance in either of them can result in Erectile Dysfunction (ED). The smooth muscles and the vessels of the penis receive sympathetic and parasympathetic innervation, and erection is mainly a parasympathetic function.
In the flaccid state, the smooth muscles are in contracted state and prevent blood flow. The stimulation of the parasympathetic nerves, which is mediated by Nitric Oxide, relaxes the smooth muscles of arterioles in the corpus cavernosa and allows the blood to rush into the penis. At the same time, the outflow of venous blood from the penis is reduced from the penis, the blood is trapped in the corpus cavernosa and rigid erection occurs.
Oxytocin is an important neurotransmitter in men and has strong pro-erectile effects, as it activates stimulating neural paths from the spinal erection-generating center to the penis.
ED is not a natural consequence of aging. Nowadays, millions of men, young and old, suffer from ED, which can have several causes, including the presence a large amount of synthetic hormones of xenoesterogens in the diet and environment, lack of balance in the diet due to low-quality products, and low levels of testosterone. Around 25 percent of ED cases are due to medications, the most common of which are antihypertensive and anticonvulsant drugs. Among blood pressure reducing drugs, thiazide diuretics and betablockers are the main culprits for ED, while calcium channel blockers and ACEIs play a smaller role.
The prevalence of ED is higher in individuals with diabetes, obesity, those suffering cardiovascular conditions and hypertension, in a way that ED occurs in 35-75 percent of diabetic men. Also, it can be a consequence of damage to the spinal cord and surgery or radiotherapy of the hip or perineal area. Smoking and alcohol are also important factors causing ED.
ED is highly prevalent and around 50% of men aged 40 to 70 years -around 150 million men globally- suffer from it. ED is a manifestation of a functional and/or structural disturbance of penis blood flow. Any man suffering primary or secondary ED for more than 3-6 months should consult a physician. Although balancing lifestyle risk factors can be helpful, in the majority of cases patients need medication to improve or cure ED. The common treatment of this disorder is the use of Phosphodieserase-5 (PDE-5) inhibitors like sildenafil, vardenafil, tadalafil and avanafil. Apart from drug interactions with nitrates, protease inhibitors and erythromycin, cimetidine and ketoconazole, sight impairment, headache, muscle pain, and hot flashes are among the side effects of these drugs, which make the use of these drugs difficult for many patients. Also, diabetic patients with neuronal damage show weak responses to PDE-5, or are resistant to their effects. Therefore, attempts to find alternative drugs, including drugs containing herbal compounds like ginseng and bindii continue. L-arginine is the semi-essential amino acid present in the diet protein and is made from L-citrulline in the body. In in vitro, it causes expansion of the isolated tissue of corpus cavernosa. In a placebo-controlled, double-blind clinical trial, the improvement in erectile function in men using L-arginine was 31% and in the placebo group 12%. In this study, no adverse effect was reported. L-arginine improves vessel expansion caused by Nitric Oxide and endothelium function. NO is the necessary physiological signal for erection, as it both acts as the neurotransmitter of transmitter of non-adrenergic and non-cholinergic nerve fibers of the penis, and is a vasodilator of the vessels of the smooth muscle cells of the arteries, sinusoids and trabeculars of the penis. The main use of ginseng is the control of glucose metabolism, psychomotor function and lung diseases.
In a multi-centered, randomized, parallel, double-blind, placebo-controlled, 119 patients with mild to moderate ED were studied, to receive daily 4 tablets (350mg) containing ginseng seed extract or placebo for 8 weeks. The determination of the efficacy was carried out using International Index for Erectile Function (IIEF)-15, and premature ejaculation was determined using the Premature Ejaculation Determination Tool (PEDT) in the 4th and the 8th week. Based on the results of this study, in week 8, in the group receiving ginseng, the score of each section and the total score of (IIEF)-15 significantly rose from 40.95±7.05 to 46.19±12.69 (p<0.05). Also, the score of the IIEF section rose slightly from 17.17±2.57 to 18.59±5.99 (p<0.05). Furthermore, after 4 and 8 weeks the PEDT score improved from 9.14±5.57 to 7.97±4.4 and 7.53±4.26, respectively (p<0.05). Compared to the beginning of the study, at the end of weeks 4 and 8, the index of safety of use, including hormone test results and lipid profile showed no change. The researchers concluded that the use of ginseng extract improves all aspects of sexual function and can be used as a suitable alternative medication to improve the sex life of men suffering ED.
To study the safety and efficacy of the product containing bindii, ginseng and L-arginine, in a parallel, double-blind, placebo-controlled clinical trial, 50 men aged 25-50 with mild to moderate ED were randomly divided into two groups, to use for 12 weeks, 2 times a day either the drug or placebo. The evaluation of the efficacy was done using IIEF, Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), serum testosterone, ejaculate analysis, Investigator Global Assessment (IGA) and the opinion of the patient. The results were as follows:
In comparison with the group receiving placebo, in patients using the product containing bindii, ginseng and L-arginine, the score for erectile function in IIEF significantly improved. After 3 months of treatment, the mean score of erectile function went from 16.07(2.86) to 25.07(4.55) in the test group and from 15.85(3.23) to 16.46(4.24) in the placebo group. In the test group, the results of the four other aspects of IIEF, including orgasm, sexual desire, satisfaction and general gratification was better than the placebo group. Also, compared to the placebo group, in the test group there was significant difference regarding EDITS score for the patients and their partners; 82.31(20.23) in comparison with 36.78(22.53) and 82.75(9.8) to 18.50(9.44), respectively (p<0.001). 92% of the patients in the text group, and only 8% of the patients in the placebo group requested to continue with the product of their group.
The overall evaluation of the researchers in the test group was very good to excellent in 77% of the cases and relatively good to good in 21% of the cases in the placebo group. In comparison with the placebo group, the effect of the product containing bindii, ginseng and L-arginine was statistically significant (p<0.05). The occurrence of side effects and the degree of patient compliance was identical in both groups. The researchers concluded that in improving sexual function in men, in comparison with placebo, the product containing bindii, ginseng and L-arginine is well tolerated, is more effective, and this drug is a suitable choice for the treatment of erectile dysfunction, and can be used, with a dose of 2 tablets per day over a 3-month period, as a first health supplement.