Significant aquaretic–antiseptic herbs Goldenrod

Probably the most effective and safest of these herbs is goldenrod. Although its value is scarcely recognized in the United States, the aboveground parts of several species of Solidago are widely used in Europe to treat inflam- mations of the urinary tract and to prevent the formation or facilitate the elimination of kidney stones. In Europe, S. virgaurea L., S. gigantea Ait., S. canadensis L., and their hybrids are all used more or less interchangeably.

The genus Solidago of the family Asteraceae is notorious for its ability to hybridize, much to the consternation of botanists who recognize about 130 species in the United States. 6 Deam collected twenty-seven species in Indiana alone. 7 Although there are some qualitative and quantitative differences in their anti-inflammatory and bacteriostatic properties, the aquaretic properties of all the goldenrods that have been investigated are

similar enough to permit them to be grouped together. 8 The information that follows is based largely on studies conducted on the European goldenrod (S. virgaurea).

Goldenrod contains a number of saponins based on polygalic acid; at least twelve diterpenes; phenolic glycosides, especially leiocarposide; and various miscellaneous flavonoids, tannins, polysaccharides, and the like. 9 The plant’s aquaretic action is sometimes attributed to the flavonoids, but an isolated flavonoid mixture proved relatively inactive in animal stud-

ies. 10 Saponins may enhance their effects. The glycoside leiocarposide has been shown to have both anti-inflammatory and analgesic properties in tests carried out in rats. 11 These effects are probably due to the fact that the glycoside is hydrolyzed in the intestinal tract—although very slowly and incompletely—to salicylic acid. 12

In spite of this relative metabolic stability of leiocarposide, Polish inves- tigators noted that it had significant diuretic activity in rats. 13 Interestingly, they also found that the diuretic effect of the glycoside was reduced by the

Chapter four: Kidney, urinary tract, and prostate problems

61 presence of flavonoids or saponins. The exact identity of the constituents

responsible for the aquaretic effects of goldenrod thus remains somewhat controversial, although most authors continue to ascribe it to the contained mixture of flavonoids and saponins. 14

More recently, a commercially available S. gigantea herb extract prepared using 60 percent ethanol as the extracting solvent revealed dose-related anti-inflammatory properties in the rat paw model. In high doses, these were almost as pronounced as the prescription drug diclofenac sodium. Further, a well-defined aquaretic and spasmolytic effect was observed. 15

As is the case with almost all herbs, preliminary studies of goldenrod have reported other activities, including antifungal properties in the triterpene saponin fraction 16 and antitumor activity in the polysaccharides. 17 These are merely initial indications and have, as yet, no therapeutic utility. In spite of some uncertainty regarding the nature of its active principles,

a decoction of goldenrod is an effective aquaretic. It is prepared by adding 1–2 teaspoonfuls of the dried herb to ½ pint of water, bringing the water to

a boil, and allowing it to stand for two minutes before straining and drink-

ing. 18 The usual dose ranges from 0.2 to 0.4 oz of the herb per day. 19

German Commission E has endorsed the herb to increase the amount of urine in inflammation of the kidney and bladder and as a preventive treatment in cases of kidney stones and gravel. Toxicity and contraindica- tions are not reported. In this regard, it is superior to most other aquaretics of plant origin.

Parsley All parts of the plant Petroselinum crispum (Mill.) A. W. Hill of the family Apiaceae contain varying amounts of a volatile oil with aquaretic activity; about 0.1 percent of the oil is found in the root, 0.3 percent in the leaf, and 2–7 percent in the fruit. 20,21 The aquaretic effect is attributed to the presence of two major components: myristicin and apiol. Concentrations of these constituents vary, depending on the variety of parsley from which the oil is obtained. However, some may contain 60–80 percent apiol and others 50–60 percent myristicin.

In addition to their aquaretic properties, both apiol and myristicin act as uterine stimulants, and the former was once widely used as an abortifa- cient drug. The oil also contains appreciable amounts of furanocoumarins or psoralens, compounds that cause photosensitivity on exposure to sun- light. Because of the presence in the volatile oil of these uterine-stimulant and photosensitizing constituents, use of the oil-rich seeds or the isolated

oil, with their greater potential for toxicity, is not recommended. 22 The German Commission E does recommend the leaves and roots of parsley as aquaretics for irrigation in disorders of the urinary tract and therapy for the prevention and treatment of kidney gravel. Average daily dose

62 Tyler's herbs of choice: The therapeutic use of phytomedicinals is 6 g. Many times, this amount is consumed by persons who enjoy the

Lebanese salad tabbouleh. Nevertheless, for pregnant women and light-skinned persons who may be subject to phototoxic effects, the consumption of parsley, either as

a nutrient or for therapeutic purposes, is best avoided. As is the case with other volatile-oil-containing aquaretics, parsley functions as an irritant to the epithelial tissues of the kidney, thus increasing the blood flow and glomerular filtration rate. For this reason, it should be used with consider- able caution by those suffering from kidney disease.

Juniper The most active but also the most potentially toxic of the volatile-oil-containing aquaretic–antiseptic herbs consists of the dried ripe fruits (berries) of Juniperus communis L. and its variety depressa Pursh of the family

Cupressaceae. Quality fruits normally yield 1–2 percent of a volatile oil containing various terpene hydrocarbons, especially α- and β-pinenes; sesquiterpenes, such as carophyllene and cadinene; and its principal aquaretic, the terpene alcohol terpinen-4-ol. 23

Both juniper berries and their steam-distilled oil have ancient reputa- tions as diuretics and genitourinary antiseptics and were official in the first edition of the USP in 1820. 24 However, it was gradually recognized that, as a result of its irritant action, the drug caused injurious effects to the kidneys. It was deleted from the official compendia in 1960. Although the herb is recommended by German Commission E for the treatment of indigestion, it is not approved as a single-ingredient aquaretic. 25

In traditional Swedish medicine, juniper has been used to treat wounds and inflammatory diseases. A recent study supports this therapeutic use by demonstrating that an aqueous extract of the berries has inhibitory activity in vitro on prostaglandin biosynthesis and platelet activating fac- tor (PAF)-induced exocytosis. 26

The exact composition of juniper oil is quite variable. Schilcher and colleagues have theorized that oils containing a low ratio (e.g., 3:1) of the irritating terpene hydrocarbons to the nonirritating, active aquaretic terpinen-4-ol do not exhibit nephrotoxicity. However, some oils have a hydrocarbon-to-alcohol ratio as high as 55:1 and are prone to cause kidney

damage characterized by albuminuria or renal hematuria. 10 This hypoth- esis requires additional pharmacological testing. More recently, Schilcher and Heil published a critical review of the literature from 1844 to 1993 and came to the conclusion that the nephrotoxic effects of juniper berries and oil have been confused with observa-

tions concerning the use of turpentine oil in veterinary medicine. 27 It is also possible that turpentine oil has been used to adulterate juniper oil, which would explain a high hydrocarbon-to-alcohol ratio. Further, they speculate that nephrotoxic effects have been erroneously suggested from

Chapter four: Kidney, urinary tract, and prostate problems

63 pathological protein values in urine, which in fact are due to acute kidney

infections rather than from the constituents of juniper. Because there is no simple way for the potential consumer to measure the terpene hydrocarbon-to-alcohol ratio in the oil contained in juniper berries, the only sensible alternative is not to use the herb or the oil as a therapeutic agent. The very small amounts of the oil used to flavor gin are certainly no more harmful than the beverage alcohol itself.

Significant aquaretic–antiseptic herbs Goldenrod