Due to its common name, it is often confused with the species Plectranthus ornatus, known as falso boldo ("fake boldo"), boldo paraguayo or boldo rastrero, which has led to confusion about the uses, properties and toxicity of both species.
Description
Boldo, together with litre, quillay, peumo, bollén and other indigenous plants, is a characteristic component of the sclerophyllous forests endemic to central Chile. Its leaves, which have a strong, woody and slightly bitter flavor and camphor-like aroma, are used for culinary purposes, primarily in Latin America. The leaves are used in a similar manner to bay leaves and are also prepared as a herbal tea, primarily in Chile and Argentina.
The edible fruits are small drupes about 2 centimeters in diameter, green in color and having a pleasant flavor. Though not well known outside their native range, boldo fruits, which appear between December and February, are very tasty, nutritious, small, green, edible spheres. Boldo's assertive flavor comes primarily from the presence of the chemical ascaridole, which is also present in the epazote plant.
Uses
In Brazil, Argentina, Chile, Uruguay, and Paraguay, boldo is mixed with yerba mate or other teas to moderate its flavor. Some families keep a boldo plant at home for this purpose, although boldo teabags are readily available in nearly all supermarkets.
Boldo leaves have a slightly bitter, soft flavor and a bit of a rough, coniferous taste when brewed in tea. They are used as a culinary herb to spice many savory dishes including fish, mushrooms, and vegetables and as a component in sauces. In some local South American kitchens boldo leaves are also popular for wrapping frying fish and meat. Boldo fruits, when dried, are used to make spicy condiments.[4]
Abortifacient and teratogenic effects in rats were observed with very high doses (800 mg/kg) of a dry ethanolic extract of boldine in the first days of pregnancy, not present at lower doses.[6]
Most investigations have been carried out using boldine.[citation needed]
Limited information is available on herbal preparations of boldo leaf and where studies have been reported, details of the preparations are usually lacking. There are no reported genotoxicity or carcinogenicity studies with herbal preparations of boldo leaf.
Boldo oil should not be used internally or externally. Where boldo leaf is used, the total exposure to ascaridole should be considered from a safety standpoint. The levels of ascaridole in herbal medicinal products should be quantified. In view of the low solubility of ascaridole in water, the use of aqueous extracts including herbal teas could be accepted.[medical citation needed] The use of ethanolic extracts of boldo leaf is not considered acceptable for traditional herbal medicinal products, in view of the potentially higher levels of the toxic ascaridole constituent.[6]