TEHRAN – Bioactive compounds of medicinal herbs have possible health benefits with antioxidative, anticarcinogenic, antihypertensive, antimutagenic, and antimicrobial activities. Iranian traditional medicine is rich in various herbs which have been used to treat various diseases and disorders since ancient times.

Recently researchers and food manufacturers have become increasingly interested in plant extracts as natural sources of antioxidants. The antioxidant and antimicrobial properties of various extracts from medicinal plants have been of great interest because of their potential use as natural additives for the prevention of oxidation, and controlling pathogens, and/or toxin-producing microorganisms in foods.

Medicinal plants have been used as traditional medicines all over the world for thousands of years. A report by Gen8 showed that out of the 104 compounds that are used globally as drugs over 37 years, 60 of them originated from Chinese traditional medicinal plants.

This review introduces 8 endemic medicinal plants of Iran that have antioxidant, antimicrobial, and therapeutic activities.

Anethum graveolens “Shevid”

Anethum graveolens L. (Dill), a member of the Apiaceae family, is an herbal plant characterized by a single stem and a terminal or primary umbellate flower. Dill has been used in various foods such as cans, soups, sauces and also flavoring salads. It is traditionally used in Iran as a treatment for some gastrointestinal ailments such as flatulence, indigestion, stomachache, and colic and has also an antispasmodic effect on the smooth muscles of the gastrointestinal tract.

Different experiments showed dill's excellent antioxidant activity and the effects of dill extracts on the female reproductive system.

Coriandrum sativum “Geshniz”

Coriandrum sativum L. (Coriander) is a culinary and medicinal plant from the Umbelliferae family which is used as a flavoring agent in food products, perfumes, and cosmetics. It is generally cultivated for its seeds. The seeds contain essential oil and the linalool (monoterpenoid compound), as the main components. Coriander is traditionally used in Iran to treat some ailments including dyspeptic complaints, loss of appetite, convulsion, insomnia, and anxiety.

Studies showed that Ethyl acetate extracts of both seeds and leaves had the highest amounts of phenolic compounds and the strongest radical-scavenging activity. In addition, leaf extracts were more effective antioxidants than seeds. The results of the study indicated that the compounds with medium polarity were the most potential antioxidants.

Cuminum cyminum “Zireye sabz”

Cuminum cyminum is an annual herbaceous plant, that belongs to the Apiaceae family. Each fruit of this plant contains a green seed with aromatic characteristics. It is used in Iranian folk medicine since more than 200 years ago.41 The fruits have been extensively used as an Iranian traditional medicine for the treatment of toothache, diarrhea, and epilepsy.

Dhandapani et al. evaluated the effect of C. cyminum seed powder supplementation on the plasma and tissue lipids in alloxan diabetic rats. Results showed that oral administration of cumin extract to diabetic rats significantly reduced blood glucose levels and increased levels of plasma cholesterol, phospholipids, free fatty acids, and triglycerides.

And other research has shown antioxidant and antibacterial activities, bioactive compounds, and health effects of some herbs of Apiaceae family grown in Iran.

Cichorium intybus “Kasni”

Cichorium intybus (Chicory) belongs to the Compositae family and is called “Kasni” in Iran. It is used for the treatment of acne, inflammation of the throat, enlargement of the spleen, diarrhea, and vomiting. Chicory has also been used as an herbal medicine due to its tonic effects on the liver and digestive tract. Fresh chicory consists of 68% inulin, 14% sucrose, 5% cellulose, 6% protein, 4% ash, and 3% other compounds, whereas dried chicory contains about 98% inulin and 2% other compounds.

Experiments investigated the protective effects of C. intybus in short and long-term diabetes in albino rat models. Feeding with dried powder of Chicory leaves lowered the blood glucose level to near normal level (85-100mg/dl). Other papers compared conventionally and biodynamically-grown chicory for its polyphenol content and antiradical activity. Results indicated that total polyphenol content was higher in plants exposed to water stress.

Melissa officinalis “Badranjbooye”

Melissa officinalis L. is an Iranian medicinal plant locally named Badranjbooye, Varangboo, and Faranjmoshk and grows in the north, northwest, and western parts of the country.55 It is traditionally used as a treatment for headaches, flatulence, indigestion, colic, nausea, nervousness, anemia, vertigo, syncope, malaise, asthma, bronchitis, amenorrhea, cardiac failure, arrhythmias, insomnia, epilepsy, depression, psychosis, hysteria, ulcers, and wounds. The leaves of M. officinalis L. are also utilized in Iranian traditional medicine as digestive, carminative, antispasmodic, sedative, analgesic, tonic, and diuretic as well as for functional gastrointestinal disorders.

Mentha piperita (Na’na)

Mentha piperita (Peppermint) belongs to the Lamiaceae family and probably originated in Eastern Asia. This medicinal plant is particularly beneficial in building the immune system and fighting secondary infections. M. piperita is rich in polyphenolic compounds and therefore has strong antioxidant activity. Menthol is the most abundant constituent of the essential oil which has antibacterial effects.

Studies evaluated the antimicrobial activity and chemical composition of M. piperita oil against food spoilage microorganisms.

Mentha pulegium “Pooneh”

Mentha pulegium L. commonly known as pennyroyal is a medicinal plant of Labiatae (Lamiaceae) family. The flowering aerial parts of the plant have been conventionally used for their antiseptic properties to treat cold, sinusitis, cholera, food poisoning, bronchitis, and tuberculosis and are also used as antiflatulent, carminative, expectorant, diuretic, antitussive and menstruate.64 Kamkar et al., investigated the antioxidative activities of the essential oil, methanol, and water extracts of Iranian pennyroyal in vegetable oil during storage.

The antioxidant activity of the essential oil and extracts was evaluated and proved.

Urtica dioica “Gazaneh”

Urtica dioica L. (nettle) is an herbaceous perennial flowering plant, that belongs to the Urticaceae family. Herbal infusion of leaves is used to treat diarrhea, vaginal discharge, and internal/external bleeding.67 In addition leaves have been shown to have hypotensive and anti-inflammatory effects, diuretic and immunomodulatory activity, and to alleviate rheumatic pain.

Steroids, terpenoids, phenylpropanoids, coumarins, polysaccharides, lectins; and seven flavonol glycosides (kaempherol-3-O-glucoside and -3-O-rutinoside; quercetin-3-Oglucoside and -3-O-rutinoside, isorhamnetin-3-O-glucoside, -3-O-rutinoside and -3-Oneohesperidoside) have been identified as major components of root and flowers of U. dioica respectively.

The antioxidant activity of hydroalcoholic solution extracts of U. dioica and M. neglecta Wallr plants and their mixture were investigated. Hydroalcoholic extracts of both plants had strong antioxidant activity, reducing power, superoxide anion radical scavenging, hydrogen peroxide scavenging, free radical scavenging, and metal chelating activities in comparison to natural and synthetic standard antioxidants such as BHA, BHT, and tocopherol. The total antioxidant activity of these two plants was nearly the least while that of the mixture extract was higher than estimated.

Iranian traditional medicine strongly focuses on prioritizing health maintenance and disease prevention over treatment.

It is one of the most ancient forms of traditional medicine. It is grounded in the concept of four senses of humor: phlegm (Balgham), blood (Dam), yellow bile (Safra'), and black bile (Sauda'). The concept of the four senses of humor is based on the teachings of Rhazes and Avicenna in an elaborate medical system.

So far, about 30,000 plant species have been identified in the world, with Iran's share of about 8,000 species which is more than the whole of species found in Europe.

The per capita consumption of medicinal plants in Iran is about one kilogram of dried plants, in other words, 83,000 tons of medicinal plants worth 1.2 trillion rials (around $4 million) are consumed in the country, while in Europe this amount is 900 grams and in the United States is 2.5 kilograms.