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.
This calls for serious conservation strategies of plant targets in drug development borrowing from the indigenous knowledge of the local people. For instance, medicinal plants documented in this study like Warburgia ugandensis and Cirtopsis articulata used in erectile dysfunction and sexual impotence and ED need to be conserved based on their demand and medicinal value to the people. In the event of increased biotechnology and the use of modified living organisms in agriculture, health and environment, most people will go for natural products18,26. Furthermore, research in natural products is on the increase in both developed and developing nations to show that there is renewed interest in medicines of natural origin.
Tribulus Terrestris is the fruit of the Zygophyllaceae plant and it grows primarily in North China. It is a well-known aphrodisiac with records that trace back to ancient times. There are plenty of animal experiments that verify the effectiveness of Tribulus for improving erectile function. These effects are mostly due to its androgen enhancing ability, namely increasing testosterone levels. Though testosterone doesn’t directly cause an erection, it does play a role. Erection is made possible by many factors, but mostly it's through receptors on cells lining our arteries that stimulate a chain reaction that relaxes the blood vessels that go to the penis, allowing blood flow to get in. Low testosterone is often associated with overall poor metabolic and cardiovascular health. When the test is low, estrogen is usually high, leading to oxidative stress and calcification of the arteries, including the penis, restricting blood flow to the penis. So, improving testosterone levels, and improving overall metabolic function, while reducing oxidative stress is a good plan for improving overall sexual function and erection.
Another important natural source of non-essential amino acid, L-Arginine is well studied to support many bodily functions even though its usually present in low quantities, especially as we started to age it is one of the most . One of the biggest benefits to our body is L-arginine or L Citruline (Our body converts L-citrulline to L-arginine, another type of amino acid) is converted into nitric oxide (proven), which causes blood vessels to open wider is its capability to improve blood flow and better circulation for Erectile Dysfunction.
Poor sleep patterns can be a contributing factor for erectile dysfunction, Mucher says. One review published in the journal Brain Research emphasized the intricate relationship between the level of sex hormones like testosterone, sexual function, and sleep, noting that testosterone levels increase with improved sleep, and lower levels are associated with sexual dysfunction. Hormone secretion is controlled by the body’s internal clock, and sleep patterns likely help the body determine when to release certain hormones.
The herb is particularly effective for those whose willy woes are based on other medications: An older study from the University of California found ginkgo biloba is 76% effective in treating sexual dysfunction caused by antidepressants. “Gingko helps counteract sexual dysfunction caused by certain antidepressants called SSRIs by blocking serotonin activity in the erectile centers of the brain, ultimately leading to better synthesis and bioavailability of nitric oxide,” Walker explains.
Experts feel that treating erectile dysfunction on your own, without consulting a doctor, is unsafe. "If you have ED, the first thing you need is a diagnosis," says impotence expert Steven Lamm, MD, a New York City internist and the author of The Hardness Factor (Harper Collins) and other books on male sexual health. He says men with severe erectile dysfunction probably need one of the prescription ED drugs, which include Levitra (vardenafil) and Cialis (tadalafil) as well as Viagra. But, he says, mild ED -- including the feeling that "you're not as hard as you could be" -- often responds to natural remedies.
Just because a product claims to be natural doesn't mean it's safe. Many herbal remedies and dietary supplements can cause side effects and dangerous interactions when taken with certain medications. Talk to your doctor before you try an alternative treatment for erectile dysfunction — especially if you're taking medications or you have a chronic health problem such as heart disease or diabetes.