By Rob McCaleb
European phytotherapy has taken advantage of plants in North and South America, and millions of people in Europe benefit from drugs that our own medical system considers too useless to investigate, because they are not patentable. In this issue, we focus on American plants that are among the most intensively studied medicinal agents in the world.
Plants from the "New World" have played a prominent role as food, fiber and medicine throughout the world. Many of the plants that are now the focus of interest for researchers around the world are native to the Western Hemisphere.
THE CHILLIES OR GARLIC, EACH TIME MORE SPICY
Most people are surprised to learn that Capsicum (the genus that includes chillies: small, red pepper, very hot) and, especially, its active ingredient, capsaicin, are involved in more scientific research than any other gender separately. In the last two years alone, more than 650 studies have been done on capsaicin, including 114 clinical studies in humans. Most of these studies take advantage of the unique mechanism by which capsaicin produces pain, either to investigate pain mechanisms or to relieve chronic pain. Nothing is more fascinating than using topical applications of capsaicin cream for arthritis pain relief. Chronic pain forces arthritics to use anti-inflammatory and analgesic medications, with serious side effects. Most of these drugs are toxic to the liver, kidneys, or both. But chilli cream has no appreciable toxicity.
The irritation and heat that we experience when eating chili peppers is due to the fact that they stimulate certain nerve cells to release a chemical called substance P ("Pani Substance"), responsible for the transmission of painful signals within our nervous system . Capsaicin triggers the release of this neurotransmitter and inhibits the production of more of it in the body. With long-term use of capsaicin, substance P in nerve cells is partly used up, thus relieving chronic pain (a condition that requires substance P).
Investigators (Deal et al.) From Case Western Reserve University in Cleveland evaluated the effects of capsaicin in both rheumatoid arthritis and osteoarthritis patients (1). They found significant pain relief when capsaicin cream was applied topically to painful knees, four times a day. In rheumatoid arthritis, the treatment reduced pain to about half, while in osteoarthritis it decreased to about a third. The authors conclude that "capsaicin cream is a safe and effective treatment for arthritis."
Capsaicin produces additional benefits in patients with rheumatoid arthritis, according to a study by Matucci Cerinic et al., At the Italian Institute of Clinical Medicine (2). In addition to reducing the transmission of pain, capsaicin also increases the production of the collagenase enzyme and prostaglandins, reducing both pain and inflammation. An Austrian study, reported by O. Partsch et al. in the Scandinavian Journal of Rheumatology, confirms this result (3).
One of the most surprising results is that our sensory nerves produce their own anti-inflammatory response. The activation of pain signals carried out by capsaicin produces the release of a powerful natural anti-inflammatory. This is confirmed by the authors of a Swedish study, noting that "the result provides new information on the possible impact of sensory nerve activation during inflammatory processes, indicating that sensory nerves may fulfill an anti-inflammatory function" (4). Far from being limited to arthritis research, topical use of capsaicin may be helpful in more than a dozen chronic pain syndromes, including postherpetic neuralgia, postmastectomy neuroma, reflex sympathetic dystrophy, diabetic neuropathy, rheumatoid arthritis, psoriasis, associated itch to hemodialysis and vulvar vestibulitis (5).
LATIN AMERICAN ANTIBIOTICS
The natives of Central America have developed an extensive materia medica from local plants to treat common medical problems, a situation common to all indigenous peoples. Modern research continues to find utility in these plants. Traditional Mexican medicine has received surprisingly little attention in the US, considering its large and growing Hispanic population. A study from the Autonomous University of Baja California Sur reported on a study made with 72 plants used in the Baja Area. All the plants have been used to treat conditions including constipation, infected wounds, pimples, kidney pain, cold sinusitis, toothache, fever, bronchitis, cystitis, venereal diseases and others "that could be caused by pathogenic microorganisms." The extracts were tested on five microbes, five bacteria, and the pathogenic yeast, Candida albicans. Of the plants evaluated, only three (4% of those studied) were active against E. coli, a common bacterium in the intestine. However, 18% were active against Candida, 129% against Streptococcus faecalis, 60% against Bacillus subtilis, and 76% against Staphylococcus aureus. The only active plant against all five microbes was Lippia palmeri, a relative of the herb Luisa. Larrea tridentata, known in the USA as chapote or creosote, was very active against streptococcus, bacillus and staphylococcus (6).
Guatemalan researchers have also studied plants traditionally used against bacteria. 68 plants for the treatment of respiratory infections were added to cultures of important respiratory infectious agents. This article includes a list of plants by family, local name, parts used, and bibliographical references on the use of each one. The authors began with a list of 234 plants, derived from ethnobotanical research, 149 of which were native to the American continent. Unfortunately, only 37 plants were tested with the three microorganisms, but the overall results were encouraging. 40% of the plants were active against at least one bacteria. One plant, the fruit of Physalis philadelphica, used for bronchitis, colds and sore throats, was active against all three bacteria. Other promising plant extracts showed high activity against two bacteria, including Eucalyptus globulus, Salvia officinalis, Lippia alba, and L. dulcis. "So there is now preliminary scientific evidence for the popular use of some of the plants that are supposed to have antibacterial activity." The authors note that additional studies "will allow the scientific community to recommend its use as an accessible and safe alternative to synthetic antibiotics" (7).
Utah scientists reported this year on the promising antiviral activity of plants used in traditional medicine in Panama. The plants tested are little-known names in the US, but the study confirms the rational justification for their use in indigenous medicine. The most encouraging results occurred with Ouratea lucens and Trichilia cipo. Another species of the first genus, O. angustifolia, has been used as a tonic and stomachic, while T. havanensis was used for the treatment of malaria. Ouratea lucens and Trichilia cipo demonstrated the highest activity against herpes simplex viruses 1 and 2 (HSV 1 and HSV2) and vesicular stomatitis (VSV). The findings are especially relevant because they go beyond providing indications for antivirals of potentially important use in modern medicine. They also point out plants related to the species used in traditional medicine that may be better alternatives to those used. These plants have exceeded the levels that are usually considered significant for antivirals, reducing VSV infection by up to 99.9%. The doses used in the in vitro tests were far below the levels that could harm normal cells (human diploid cells). Furthermore, as they were more toxic to human tumor cells than normal cells, the authors emphasize that "their potential roles as antitumor agents should be further investigated."
"Taken together, these data suggest that the extracts from the examined Panamanian plants contain components that can be used effectively as antiviral or antitumor agents."
MORE TESTS OF GARLIC ANTI-CANCER EFFECTIVENESS
Much has been written about the anticancer efficacy of garlic (seemingly unknown to the medical community and the FDA) (In the journal we have published articles on this subject in issues 24 (p. 90) and 31 (p. 92)) . The Journal of the National Cancer Institute reported, in 1988, some of the clearest evidence known to date, as we mentioned in HerbalOram issue 18. This study, carefully controlled for other factors, found a direct correlation between increased consumption of garlic and other vegetables of the Allium genus (onions, shallots, and chives) and a decrease in the incidence of stomach cancer. In simple words, the NCI found that, in humans, the more these foods are consumed, the less stomach cancer is suffered. The study included 1,695 people, 564 of whom suffered from stomach cancer. Most stomach cancers occurred in people who ate little or no garlic. Chinese residents who did not eat garlic suffered from a thousand times more stomach cancer than those who drank large amounts of garlic regularly (9).
More evidence has recently appeared in another prestigious journal, Cancer Research. The Rutgers State University study showed that diallyl sulfide (DAS), taken by mouth, reduces the carcinogenicity of nitrosamines, one of the most powerful known chemical carcinogens. Nitrosamines, which can be formed in the stomach from nitrate-rich foods, including vegetables, are activated during metabolism into more harmful compounds. The garlic compound inhibits this metabolism, suggesting that it may be effective in inhibiting tumor formation (11).
Translation: María Jesus Baldonedo
1- Deal, C.L., Schnitzer, T.J., Lipstein, E., Seibold, J.R., Stevens, R.M., Levy, M.D., Albert, D., Renold F. Treatment of arthritis with tropical capsaicin: a double-blind trial. Case Western Reserve University, Cleveland, Ohio. Clin Ther 1991 May-Jun; 13 (3): 38395.
2- Matucci-Cerinic, M., Marabini, S., Jantsch, S., Cagnoni, M., Partsch, G. Effects of capsaicin on the metebolism of rheumatoid arthritis synoviocytes in vitro. (See comrnents) Comment in: Ann Rheum Dis 1990 Aug; 49 (8): 653 Institute for Clinical Medicine IV, University of F1orence, Italy. :
3- Partsch, G., Matucci-Cerinic, M., Marabini, S., Jantsch, S., Pignone, A., Cagnoni: M. Collagenase synthesis of rheumatoid arthritis synoviocytes: dosedependent stimulation by substance P and capsaicin. Ludwig Boltzmann Institute of Rheumatology and Balneology, Vienna-Oberlaa, Austria. Scand J Rheumato11991; 20 (2): 98-103.
4- Raud, J., Lundeberg, T., Brodda-Jansen, G., Theodorsson, E., Hedqvist, P. Potent anti-inflammatory action of ca1citonin gene-related peptide. Department of Physiology, Karolinska Institutet, Stockholm, Sweden. Biochem Biophys Res Commun 1991 Nov 14; 180 (3): 1429-35.
5- Rumsfield, J.A., West, D.P. Topical capsaicin in dermatologic and peripheral pain disorders. Department of Pharmacy Practice, Colleges of Pharmacy, University of Minois, Chicago 60612. DICP 1991 Apr; 25 (4): 381-7.
6-Dimayuga, R.E. and García, S.K. Antimicrobial screening of Medicina1 plants from Baja Califomia Sur, Mexico. Autonomous University of Baja California Sur, Department of Marine Biology, Apartado Posta119-B, La Paz, Baja California Sur 23080 (Mexico). Journal of Ethnopharmacology 1991 Feb; 31 (2): 181192.
7 -Caceres, A., Alvarez, A. V., Ovando, A.E. and Samayoa, B; E. Plants used in Guatema1a for the treatment of respiratory disease. L. Screening of 68 plants against gram-positive bacteria. Center for Mesoamerican Studies on Appropiate Technology (CEMAT), P.O. Box 1160, Guatema1a and Faculty of Chemical Sciences and Pharmacy, University of San Carlos (USAC), Guatemala City (Guatema1a). Jouma1 of Ethnopharmaco1ogy 1991 Feb; 31 (2): 193-208.
8- Roming T.L., et al. Antiviral activity of Panamanian plant extracts. Department of Botany and Range Science, Brigham Young University, Provo, UT 84602. Phytotherapy Research 1992 Jan / Feb; 6 (1): 38-43.
9- Yu, W.C. et a1. Allium Vegetables and Reduced Risk of Stomach Cancer. Jouma1 of the National Cancer Institute 1989; 81: 162-4.
10- Hodges, L.C., Robinson, G.W., and Green, K. Extract of tobacco callus with antiglaucoma activity. Phytotherapy Research 1991 Feb; 5 (1): 15-18.
11- Hong, J. Y. Metabolism of carcinogenic nitrosamines by rat nasal mucosa and the effect of diallyl sulfide. College of Pharmacy, Rutgers State University, Piscataway, NJ 08855-0789. Cancer Research 1991; 51 (5): 1509-14.
The Herb Research Foundation 1007 Pearl St., Suite 200. Boulder, CO 80302. USA.
Extracted from the journal Complementary Medicines N ° 32 -AMC-
* By Rob McCaleb
Director of the Herb Research Foundation