Currently, there are four orally active drugs are available to treat ED. These include: sildenafil citrate (Viagra [Pfizer, USA]), vardenafil hydrochloride (Levitra [Bayer, Germany]), tadalafil (Cialis [Eli Lilly, USA]) and avanafil (Stendra, Spedra [Vivus Inc, USA]). These drugs inhibit the enzyme phosphodiesterase type 5 (PDE-5), which is responsible for the hydrolysis of cGMP. PDE-5 inhibitors and cGMP act as effectors of dilation of smooth muscle of cavernosal bodies. PDE-5 inhibitors are contraindicated in patients taking any kind of nitrate therapy for angina, and may not be appropriate for men with certain health conditions, such as severe heart disease, heart failure, history of stroke or heart attack, uncontrolled high blood pressure or diabetes, and patients with pigmental retinopathy. PDE-5 inhibitors are less effective in men with diabetes and men who have been treated for prostate cancer. PDE-5 inhibitors are also not effective in men with retinitis pigmentosa, a genetic disease involving PDE-5 deficiency. The common side effects of PDE-5 inhibitors include gastrointestinal upset, headache, nasal congestion, back pain and dizziness. The PDE-5 inhibitors may interact with other medications including antihypertension drugs. Nonetheless, the PDE-5 inhibitors are generally safe and effective for most men. The primary mechanism of action of these drugs is through the mediation of NO. NO is one of the key molecules involved in ED. It is a short-lived, highly permeable, pleiotropic, gaseous molecule, secreted from the postganglionic cavernosal parasympathetic nerves, endothelium of the cavernosal blood vessels, platelets in the cavernosal sinuses and phagocytic cells (monocytes, macrophages and neutrophils). NO acts on platelets to inhibit platelets adhesion and aggregation. NO causes relaxation of the smooth muscle of the cavernosal blood vessels of the penis, leading to vasodilation, tumescence and stimulation. Release of NO in the corpus cavernosum of the penis during stimulation activates the enzyme guanylate cyclase, which results in increased levels of cGMP, producing smooth muscle relaxation in the corpus cavernosum and resulting in increased blood flow (5). NO is mainly produced from cavernosal nerves, which are nonadrenergic, noncholinergic nerves within the penis, and acting via its second messenger cGMP. It has been suggested that maintaining normal body weight and mild exercise, as well as dietary supplementation of folic acid, zinc, calcium, vitamin C, vitamin E and L-arginine, a precursor of NO, can support the biochemical pathway leading to NO release . NO is an effector molecule that is involved in a number of intracellular functions such as vasorelaxation, endothelial regeneration, inhibition of leukocyte chemotaxis and platelet adhesion . A small proportion of autonomic nerves do not release either Ach or norepinephrine . For example, the cavernous nerves predominantly release NO in the penis. The exact mechanism is not known, but it is believed to be through increased intracellular calcium. Another gaseous molecule produced in the corpora cavernosa is hydrogen sulphide (H2S), which is also known to be involved in erectile function . H2S activates ATP-sensitive potassium channels in smooth muscle cells. Some reports indicate that NO acts in large vessels and H2S in small vessels. A high level of tumour necrosis factor-alpha has been shown in ED patients . Although current ED therapies using PDE-5 inhibitors are safe and effective, approximately 40% of ED patients do not respond to currently available treatment [11,12]. For these patients, herbal therapy may be useful.
ED can be caused by a handful of things, but one thing’s for sure: You need a healthy supply of the neurotransmitter nitric oxide (NO) to get and maintain an erection. NO is produced in nerve tissue and helps jolt your Johnson by relaxing the smooth muscle so blood can fill the penis. After the initial release of NO, your body releases a cascade of chemicals—including more of the neurotransmitter—to help keep you hard and happy, according to a study in the Proceedings of the National Academy of Sciences.
Yohimbe. Before Viagra and the other prescription erectile dysfunction drugs became available, doctors sometimes prescribed a derivative of the herb yohimbe (yohimbine hydrochloride) to their patients suffering from ED. But experts say the medication is not particularly effective, and it can cause jitteriness and other problems. "It's not a great drug," says McCullough. "And I suspect the herb is not as potent as the pharmaceutical version." What's more, evidence shows that yohimbe is associated with high blood pressure, anxiety, headache, and other health problems. Experts discourage its use.
Historically, it has been shown that herbal medicines may cure or prevent certain ailments. However, there are very little recorded data available to support the dose, efficacy, side effects and interactions. Because the safety and efficacy of herbal remedies have not been assessed, unlike synthetic drugs, well-controlled and randomized studies are warranted to establish the therapeutic efficy and safety of such products. Determination of side effects and interactions with prescription medicines are also needed. The amount of active ingredients in herbals may vary among preparations; thus, standardization of herbal medicines is required.
Ginseng. Korean red ginseng has long been used to stimulate male sexual function, but few studies have tried systematically to confirm its benefits. In one 2002 study involving 45 men with significant ED, the herb helped alleviate symptoms of erectile dysfunction and brought "enhanced penile tip rigidity." Experts aren't sure how ginseng might work, though it's thought to promote nitric oxide synthesis. "I would recommend ginseng [for men with ED]," says Espinosa. Discuss with your doctor before taking it since ginseng can interact with drugs you may already be taking and cause allergic reactions.
The study was conducted between April 2000 and March 2003 in western Uganda. To collect this data indirect asking of questions and investigations that do not refer or offend anyone were used since nobody especially men can say openly that they have this problem. These methods are explained in the textbook of ethnobotany and others have been used in the field for this kind of studies in Uganda and elsewhere in the world10,12,13,14,21. These methods included visiting the traditional healers to document the indigenous knowledge (IK), regarding medicinal plants used, gender and socio-cultural aspects and where the plants are harvested. Informal and formal conversations, discussions and interviews, market surveys and field visits were conducted.
The Science: Chemicals inside these plants called ginsenosides are thought to ramp up the physiological pathway that makes nitric oxide, the neurotransmitter that gets the blood flowing during penile erection. Some studies support that idea: one found that ginsenoside-rich ginseng berry extracts relaxed smooth muscle inside rabbit erectile tissue. But so far there haven’t been high-quality double-blind and randomized trials of the chemicals’ effect on humans. The jury’s still out on whether ginsenosides have any effect on people at all, or (if they do) whether they work as well as medications like Viagra.
Ginkgo biloba. Known primarily as a treatment for cognitive decline, ginkgo has also been used to treat erectile dysfunction -- especially cases caused by the use of certain antidepressant medications. But the evidence isn't very convincing. One 1998 study published in the Journal of Sex & Marital Therapy found that it did work. But a more rigorous study, published in Human Pharmacology in 2002, failed to replicate this finding. "Ginkgo has come out of fashion in the past few years," says Ronald Tamler, MD, assistant professor of medicine and codirector of the men's health program at Mount Sinai Medical Center in New York City. "That's because it doesn't do much. I can say that in my practice, I have not seen ginkgo work -- ever."
Despite the name, horny goat weed actually helps improve your erection, not libido. Botanically known as epimedium, this herb has been used by the Chinese for centuries to treat, among other things, low libido and erectile dysfunction. “A growing body of research shows that isolated icariin—the extract of epimedium—inhibits the enzyme phosphodiesterase-5 (PDE-5) and significantly increases nitric oxide synthase, helping to improve erectile function,” says Fisch. In fact, this is the same mechanism that Viagra works through (but the herb comes with a way better name).
Reproductive Health care is the second most prevalent health care problem on African continent4. Reproductive health care did not appear on the health agenda until recent after the Cairo conference on population and the Peking conference on women that it indeed became a live issue4. In some instances RH certainly includes the RH needs of the youth or adolescents.
The Plant: It’s true, the name’s hilarious. But as it turns out, it’s not just one plant: supplement manufacturers might put any one of 15 different species from this genus of shade-loving perennials inside that pill. That’s important to keep in mind, because the types and amounts of biologically active molecules the plant contains can differ from species to species.
Some natural viagra supplements have been shown to increase nitric oxide levels and increase blood flow to the penis. But there are no true natural alternatives to prescription ED medication, like Viagra. But healthy food and (some) vitamins and supplements can improve your overall health and blood flow. And anything that improves blood flow can treat some of the causes of erectile dysfunction (as well as making you healthier).
It doesn’t look good for the herbs. So far, there’s no data from controlled human trials that support the erection-promoting claims for any 5 of the most frequently used herbs. The icariin in the horny goat weed can help get it up, but since you’re getting the herb rather than a purified molecule, the concentration probably isn’t high enough to have much of an effect. Worse, it turns out that Viagra is much better at blocking that erection-killing enzyme than icariin is.
Reiter, W. J., Pycha, A., Schatzl, G., Pokorny, A., Gruber, D. M., Huber, J. C., & Marberger, M. (1999, March). Dehydroepiandrostone in the treatment of erectile dysfunction: A prospective, double-blind, randomized, placebo-controlled study [Abstract]. Urology, 53(3), 590-594. Retrieved from http://www.sciencedirect.com/science/article/pii/S0090429598005718