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THEROSCLEROSISAtherosclerosis is the result of a chronic inflammatory condition in the circu-latory system that is manifested by the laying down of lipids (triglycerides and cholesterol), proteins, and calcium on the internal wall surface of arterial blood vessels. The process of atherosclerosis is activated by interleukin-6, when an acute phase of a localized inflammatory process in the arterial wall begins.
A prominent presence of inflammatory biomarkers (cytokines and proteins) is seen in the arterial wall, and various proteins (such as C-reactive protein) increase in concentration in the circulation. As a result, atherosclerotic plaques develop and may lead to blockading blood flow through the vessel and/or the development of blood clots.1Atherosclerosis is an extremely serious condition and requires medical attention. Reactive oxygen species (ROS) are thought to be a contributing factor to the development of atherosclerotic plaques. Thus, suppression of the inflammatory reactions as well as scavenging of ROS can re-duce plaque formation on the blood vessels. Moreover, lowering of total serum lipids, in particular total cholesterol, triglycerides, LDL and VLDL (very-low-density lipoprotein) cholesterol, and increasing HDL (high-(very-low-density lipoprotein) level can collectively yield to a protection against atherosclerosis development.
Botanicals such as garlic (Allium sativum) and turmeric (Curcuma longa) have been shown to exert a protective effect against atherosclerosis by reducing the cholesterol level in the circulation as well as by imparting a vasorelax-ant effect to blood vessels and improving various cardiovascular parameters (heart rate, arterial blood pressure, etc.).2 A survey was conducted to evalu-ate the use of garlic with respect to blood pressure in 101 adults with mild hypertension receiving medical care at the Family Practice Center, Aga Khan University Hospital in Karachi, Pakistan. With an average intake of 134 g per person per month, the extent of hypertension’s severity (systolic blood pressure only) was inversely related to the garlic consumed in the diet. Interestingly, 59% of patients reported that garlic was good for their health, and two-thirds
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of them added it as an ingredient to meals.3 Collectively, human clinical in-vestigations with garlic products are inconclusive with respect to garlic’s ef-fect on blood pressure, with some showing no changes and others reporting lowering in both diastolic and systolic blood pressure. In vitro studies have shown that certain substances in garlic, namely the gamma-glutamylcysteines, as angiotensin-converting enzyme inhibitors could result in a vasorelaxant action and a subsequent reduction in blood pressure.4 Organosulfur com-pounds in garlic, namely N-acetylcysteine, S-ethylcysteine, S-methylcysteine, S-propylcysteine, diallyl disulfide, and diallyl sulfide, were shown to exhibit a protective action against LDL (low-density lipoprotein) cholesterol oxidation, a major risk factor in cardiovascular health. Diallyl disulfide and diallyl sulfide showed a greater activity on LDL oxidation than the other organosulfur garlic components.5,6
Mammals, including humans, are incapable of biosynthesizing certain types of fatty acids. These fatty acids must be supplied in the diet and are termed
“essential fatty acids.” Two types of essential fatty acids exist: omega-3 and omega-6. The source for omega-6 in diet is fatty fish. Vegetable oils (e.g., flaxseed oil) are good sources for omega-3 fatty acids. Flaxseed oil contains approximately 57% of alpha-linolenic acid, the principal component of omega-3 fatty acids.7 Flaxseed is also rich in phytoestrogens known as lignans that possess antioxidant activity. ROS are produced by the polymorphonuclear leukocytes upon stimulation by certain immune system mediators (leukotriene B4, interleukin-1, and tumor necrosis factor) and platelet-activating factor.
The omega-3 fatty acids inhibit immune system mediator production, and lignans have an antiplatelet-activating factor effect.8 Rabbits maintained on high cholesterol diet rich in flaxseed (7.5 g/kg of body weight per day) showed a 46% reduction in atherosclerotic plaques in the aorta as compared to control (the same high cholesterol diet but without added flaxseed). Interestingly, this protection against atherosclerosis was seen without a decrease in serum cholesterol level. Moreover, flaxseed ingestion in rabbits with normal serum cholesterol concentration resulted in an increase in the serum cholesterol level without altering total serum triglycerides.8
People who are accustomed to fatty foods may find it helpful to drink tea with their meal. In certain areas in the country (southern part of the United States) the “regional” drink with meals is iced tea. This tradition was developed over generations as people realized the benefits of tea in helping them with digestion and perhaps overcoming the effect of fat in developing circulatory system–related problems. In fact, traditional Chinese medicine recommends tea drinking to decrease the plaque buildup associ-ated with atherosclerosis.9 This effect is partly related to the ability of tea to improve the blood lipid profile and in particular to lower serum cholesterol concentration. Healthy volunteers consuming two cups of green tea per day (250 mg of total catechins) for forty-two consecutive days had significant re-duction in serum LDL cholesterol by 13.3 mg/dL, on average; an increase in the total plasma antioxidant action; and a decrease in peroxides level. A
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reduced oxidative damage on the DNA was also noted.10These combined ef-fects of tea help to eliminate the ROS and, as consequence, lower the incidence of atherosclerotic plaques formation. The antioxidant activity of green tea was enhanced by another powerful natural antioxidant known as ubiquinone.
Administrating both antioxidants to rats significantly counteracted the oxida-tive stress imposed on the animals by reserpine (an agent capable of causing liver damage and oxidative stress). The inhibitory effect on oxidative stress of the two agents was greater than that by green tea alone. The liver damage caused by reserpine was also partially halted by the coadministration of both agents.11
Red yeast rice (Monascus purpureus) contains naturally occurring statin (lo-vastatin) that lowers serum cholesterol level. Animal experimentations with rabbits that were fed a high-fat diet for three months resulted in the devel-opment of atherosclerosis. However, when an extract of red yeast rice was given to the rabbits along with the high-fat diet, total serum cholesterol, LDL cholesterol, and malondialdehyde (a marker for lipid peroxidation by ROS) were significantly reduced compared to control.12When the botanical extract (0.4 g/kg per day or 1.35 g/kg per day) was given to rabbits for 200 days in a diet containing 0.25% cholesterol, the animals showed a remarkable reduction in atherosclerotic plaque (50.5 and 63.4 percentage point reduction with the low dose and the high dose, respectively) as compared to control.13 After a six-week regimen, red yeast rice extract (1,200 mg per day, given in two equal doses) administered to coronary heart disease patients resulted in lowering total serum cholesterol by 20%, LDL cholesterol by 34%, and triglycerides by 32%. The same treatment raised serum HDL level by 18%. In addition, total serum triglyceride level was significantly decreased by 32%, 38%, and 43% at two, four, and six hours in after-meal measurements, respectively.14 In another study from China, the effect of red yeast rice extract on serum lipoprotein(a) and high-sensitivity C-reactive protein (both considered to be independent risk parameters for coronary heart disease) was investigated in sixty coronary heart disease patients. Patients were randomized to receive ei-ther the botanical extract (1,200 mg per day) or a placebo, administered for six consecutive weeks. Blood samples were collected at the beginning and end of the study both before (fasting state) and after receiving a meal (800 calo-ries) rich in fat (50 g). At the six-week point, both the fasting and after-meal sample concentrations for lipoprotein(a) and high-sensitivity C-reactive pro-tein were significantly reduced.15It should be noted that the level of serum C-protein serves as a general indicator of cardiovascular health and is nor-mally elevated in people who are obese, do not exercise regularly, or smoke.
Population studies have also revealed differences in C-protein level between Asians and Westerners; on average, C-protein serum concentration in Asians is about one-tenth of that in Westerners. In addition, since Asian diet includes red yeast rice as a common component, it may contribute in part to lower values of C-protein in Asians.16C-protein concentration was shown to corre-late well with the triglycerides level in coronary heart disease patients.1,15 A
meta-analysis published in 2006 summarizing results obtained from ninety-three clinical studies involving 9,625 subjects reported that red yeast rice was effective in increasing serum HDL cholesterol level and decreasing total cholesterol and LDL cholesterol levels; the botanical was similar in its effect on the lipid profile to the various statin prescription drugs and more effective than nicotinate and fish oil. However, the meta-analysis found that red yeast rice was not as effective as the non-statin lipid-lowering agents gemfibrozil and fenofibrate.17 The positive effect of red yeast rice in protecting against the development of atherosclerotic lesions is obvious from animal and human studies. This effectiveness is related to the presence to lovastatin, an effective cholesterol-lowering compound. However, in the United States, the FDA in 2001 banned the sales of red yeast rice products containing lovastatin.
Essential (volatile) oils are common components in the plant kingdom. These oils are obtained from plants in their concentrated forms and should never be used unless diluted. Normally, essential oils are diluted with fixed oils (e.g., olive oil), so that they do not cause damage to the tissues with which they come in di-rect contact. Examples include oils obtained from lavender, fir, basil (Photo 13), eucalyptus, pine (Pinus pinaster), and rosemary. When administered, these oils can cause a reduction in lipid peroxidation, indicative of their effect as antioxidants.18 For example, rosemary oil was shown to protect against lipid peroxidation and increase the level of natural antioxidant compounds (e.g., glutathione) in mice exposed to radiation.19Pine seed oil was found to reduce the level of plasma total cholesterol and VLDL in mice; however, it does not alter the status of atherosclerotic plaques.20
Photo 13. Sweet basil (Ocimum basili-cum). Photographer Karen Bergeron, www.altnature.com.
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Photo 14. Horse chestnut (Aesculus hippocastanum).
Photographer Karen Bergeron, www.altnature.com.
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EMORRHOIDSHemorrhoids are a common complaint and can be severe enough to require surgical intervention. For mild cases botanicals may be used to alleviate symp-toms and pain. Bioflavones (from fruits and herbs) and several herbs may be recommended for this condition including Butcher’s broom (Ruscus aculeatus), gotu kola (Centella asiatica), horse chestnut (Aesculus hippocastanum) (Photo 14), and witch hazel (Hamamelis virginiana) (Photo 15).21