The common opinion about the absolute safety of herbal drugs is undoubtedly wrong. It is obvious that biologically active compounds causing a therapeutic effect may be dangerous in certain situations and doses. As far as caraway is concerned, most authors agree that it shows no toxic effect towards people, and is well tolerated in medicinal doses and as a spice. However Lewis (1977) discussing the problem of allergy, mentioned carvone as sensitising substance, and classified Carum carvi among plants causing contact dermatitis.
The Umbelliferae in general is the family of plants rich in furocoumarins, which occur especially in fruits. Furocoumarins such as 5-methoxypsoralen (5-MOP) and 8-methoxypsoralen (8-MOP) are potent photosensitising, phototoxic, mutagenic and photocarcinogenic substances (Ceska et al. 1987). The consumption of some Umbelliferae fruits may be hazardous for health. It may result in severe dermatitis in the presence of sunlight. Fruits of Carum carvi have, among others, been tested for the content of 5-MOP and 8-MOP by Ceska et al. (1987). Using an ultrasensitive bioassay they detected just traces of these furocoumarins and concluded that the content of 5-methoxypsoralen and 8-methoxypsoralen in the fruits of Carum carvi is negligible.
Potentially hazardous for human health may be residues of nitrate, nitrite and pesticides in plants. Nitrate residues in herbs and vegetables can be transformed by bacteria to toxic nitrites which can cause blood circulation disorder and methemoglobinaemia. Generally nitrite and especially nitrate residues are present in herbs. Gajewska et al. (1995) examined samples of 24 herbs and reported the content of NaNO2 and KNO3 in most of them. There were no exclusive data concerning fruits of Carum carvi, but fruits of fennel (Fructus foeniculi), although did not show the content of nitrites, did show relatively small but significant content of nitrates.
The analysis of pesticide residues in certain plants of medical importance (including Carum carvi) was performed by Dogheim et al. (1986). Gas liquid and thin layer chromatography tests showed that HCH was the main compound found in the tested samples. In the case of Carum carvi the residue did not exceed the maximum limit of 0.2mg/kg.
The contamination of foods and herbs by fungi is a problem of great importance. This is mainly because of toxic and carcinogenic mycotoxins produced by numerous species. For example Aspergillus flavus, a very popular mildew fungus, produces aflatoxins which are the strongest known natural carcinogenic substances. They can be consumed with contaminated food and herbs, cumulated in liver and result in cancer. Pande and Bangale (1994) analysing the mycoflora associated with umbelliferous plants used in Ayurvedic medicines (Foeniculum vulgare, Peucedanum graveolens and Carum carvi) recorded a total of 50 species of fungi belonging to 30 genera. The most hazardous fungus being present on Fructus carvi was Aspergillus spp. responsible for aflatoxins and sterigmatocystin production. El Kady et al. (1995) using thin layer chromatography analysed 24 spices extracts. Aflatoxins and sterigmatocystin were discovered in some of them, including caraway. It means that caraway fruits and preparations made from fruits stored in favourable conditions for fungi, may be hazardous for human health.
As it was reported by Regina et al. (1992) fungi like Aspergillus flavus, Aspergillus niger and Fusarium moniliforme can cause biochemical changes in caraway fruits—reduce protein, carbohydrates and total oil, and increase fatty acids.
Was this article helpful?
Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.