Erectile dysfunction (ED) or male impotence is defined as inability of a man to achieve or maintain penile erection sufficient for sexual activity. It is primarily a neuronal and endothelial dysfunction of the corpus cavernosum of penile tissue, and is partly characterized by reduced production of nitric oxide (NO). Other factors that may contribute to the pathogenesis of ED include androgen deficiency in aging men, hypertension, high cholesterol levels, atherosclerosis, diabetes mellitus, diseases of the prostate and heart, and anatomical deformity of the penis. ED may also be caused by some medications, prostate surgery and spinal cord injury. Psychological and social conditions such as stress, depression and unhappy marital relationship may contribute to the problem. Chronic infections and inflammation can also contribute to the disease process. ED is linked to an increased risk for cardiovascular diseases and stroke. Several orally active drugs (sildenafil, vardenafil, tadalafil, avanafil) are currently prescribed for treating ED to improve the arterial blood flow to the penile tissue. Medicinal plants and their extracts have been used in traditional medicine in southwest Asia and other countries to treat ED. The current review focuses on four medicinal plants that have been used as aphrodisiacs for enhancing sexual performance and for the treatment of ED. These plants include Eurycoma longifolia Jack (tongkat ali); Chlorophytum borivilianum (safed musli); Withania somnifera (ashwagandha); and Pausinystalia johimbe (formerly known as Corynanthe johimbe). Suggested mechanisms of action for each of the plant extracts will be discussed.
In the East, many herbal tonics and preparations are used to assist the aging male improve his ability to have sexual drive or perform penetrative sex by increasing sexual stimulation, erectile, ejaculatory, orgasmic and other responses for sexual function and satisfaction. Currently available herbals, tonics and therapies range from Tongkat Ali, Ginseng, Tribulus etc. Those that act as testosterone releasers have some value especially if the male has andropause and those containing some pick-me-ups II and energizers like ginseng help the tired and fatigued male and possibly those with asthenia. Deer horn contains growth factors and taking these may help improve nocturnal erections in the male with somatopause. Popular in historic Singapore were remedies such as “Penis Soup II” (Figure 2) and Snake Meat, whilst Surabaya was known for Cobra meat (Figure 3) and Cobra Blood which had claims of improving erectogenic prowess-these myths including that of taking dog, cow, wild boar, bull and ostrich testicles (Figures 10,,11)11) are mainly Village doctor remedies still being practiced widely in the developing regions of Asia. In China, the horny goat weed (Figure 9) is currently still popular and may have some scientific merit (11) for enhancing sexual drive.
Ginseng, specifically “red ginseng,” is known as the “herbal Viagra” that helps puts to rest men’s bedroom woes. Red ginseng is when the root has been steamed and then dried. The ginseng root is the part of the plant that is mostly used as a natural remedy when in its supplement form. However, the plant must be grown for a minimum of five years before it can be used. In a 2008 review, seven studies on red ginseng and ED, ranging in dosages from 600 to 1,000 milligrams three times a day, were found to provide evidence for the effectiveness of the herb in ED treatment.
The semi-structured interviews and discussions were held with the specialist resource users and other knowledgeable people on particular ailments by use of interview schedules for each respondent. Interviewed people were mainly the herbalists (both men and women) and TBAs. In this selection to some extent, ethnic groups were recorded where possible because different people use the same plants differently. The time and place of interviews were arranged according to the schedules of the respondent. Depending on where the interviews and discussions were held, recording was done immediately or afterwards or appointments were made for more details in a more convenient place arranged with the respondent. Key informants were identified and later interviewed separately and even followed for further details. Some of the key questions asked included, name of the respondents, the village or parish or sub-county he or she was coming from, diseases treated, plant local names used, parts harvested, methods of preparation and administration. In addition, ingredients and incantations with which the plants are used for preparation and where the herbal medicines were harvested were documented.