Seasonal Variations in Chemical Constituents of Some European Herbs

Thymus vulgaris L. in Torà (Segarra, Catalunya, Spain), 490 m altitude. Photo by Isidre blanc, from Wikipedia. Reproduced under Creative Commons CC BY-SA 4.0 licence.

This interesting paper presents an overview of the existing literature published since the year 2000, seeks to identify some repeatedly found seasonal trends and discusses some possible explanations for these trends.

Link to full text of article

Li, Y., Zidorn, C. Seasonal variations of natural products in European herbs. Phytochem Rev (2022). https://doi.org/10.1007/s11101-021-09797-7

Coriander: Traditional Uses, Phytochemistry, Cardiovascular Benefits

Coriandrum sativum L.: Image from Wikimedia Commons. Public domain. Original book source: Prof. Dr. Otto Wilhelm Thomé Flora von Deutschland, Österreich und der Schweiz 1885, Gera, Germany.

Simple Summary

The following is a simple summary of this recent review paper:

Mahleyuddin, N.N.; Moshawih, S.; Ming, L.C.; Zulkifly, H.H.; Kifli, N.; Loy, M.J.; Sarker, M.M.R.; Al-Worafi, Y.M.; Goh, B.H.; Thuraisingam, S.; et al. Coriandrum sativum L.: A Review on Ethnopharmacology, Phytochemistry, and Cardiovascular Benefits. Molecules 2022, 27, 209. https://doi.org/10.3390/molecules27010209.

1. Traditional Uses in Various Old-World Regions

Fruits (seeds)

  • Rheumatoid arthritis, inflammation, and joint pain.
  • Some liver diseases (roasted seeds).
  • Dyspeptic complaints, as a digestive.
  • Loss of appetite, as an appetiser.
  • Convulsions.
  • Anxiety, insomnia.
  • As a diuretic.
  • “Melancholia”.
  • To lower blood glucose levels.
  • Influenza.
  • Bad breath.
  • Bad odour from genitalia.

Leaves

  • Mouth ulcer.
  • Eye redness.
  • “Melancholia”.
  • Digestive complaints, poor digestion.
  • To lower blood glucose levels.

Aerial parts

  • Viral infection.
  • Neurasthenia.

Whole plant

  • Measles.
  • Diabetes.
  • Aerophagy.
  • Gastroenteritis.
  • As a diaphoretic.
  • As a diuretic.
  • As a carminative.
  • As a stimulant.

Essential oil

  • Aa an aphrodisiac.
  • As an analgesic.
  • As an antimicrobial, mouth infections.
  • As a digestive stimulant.
  • Gastric ulcers.

Unspecified part(s)

  • As a diuretic, some renal diseases.
  • Anxiety; as a sedative and muscle relaxant.

2. Main Phytochemical Constituents

Fruits (seeds)

  • Carotenoids including β-carotene.
  • Tocols: α-, β-, γ- δ- tocopherols, and α-, γ-tocotrienols.
  • Fatty acids: Petroselinic linoleic, palmitic and oleic acids.
  • Sterols: Stigmasterol, β-sitosterol, δ-stigmasterol.
  • Volatile constituents: Linalool, camphor, geraniol.

Aerial parts

  • Carotenoids including β-carotene.
  • Phenolic acids: Ferulic, gallic and caffeic acids.
  • Benzoic acid derivative: Salicylic acid.
  • Coumarins: Esculetin, esculin, scopoletin, 4-hydroxycoumarin, umbelliferone, dicoumarin.
  • Flavonoids: hyperoside, rutin, hesperidin, vicenin, diosmin, luteolin, apigenin, orientine, dihydroquercetin, catechin, arbutin.

Essential oil

  • Linalool.
  • γ-terpenine.
  • α-pinene.

3. Physiological Effects of Phytochemicals from C. sativum

Flavonoids: A flavonoid-rich fraction was found to have hypotensive activity.

Quercetin (a flavonoid): A quercetin-rich aqueous ethanolic extract inhibits α-amylase, α-glucosidase and lipase, and thus potentially has antidiabetic and anti-obesity effects.

Polyphenols: A polyphenol-rich extract inhibits angiotensin-converting enzyme thus potentially has a antihypertensive effect.

Isocoumarins: Isocoumarin aglycones and (to a lesser degree) isocoumarin glycosides (cilantroside A and B) have been found to have neurotrophic / neuroprotective effects by stimulation of nerve growth factor. The aglycones of isocoumarins also showed anti-inflammatory effects.

Phenolic glycosides: The phenolic glycosides daphnin and benzyl-O-β-d-glucoside have also been found to stimulate nerve growth factor.

Sterols: Plant sterols have hypocholesterolaemic effects.

Essential oil: Prominent activities against diabetes, microbial infections, and inhibitory to acetylcholinterase.

Other: A linalool, ascorbyl palmitate and petroselinic acid-rich petroleum ether extract of coriander seeds reduces oxidative stress, is hypolipidaemic, hypoglycaemic, and preventative against diabetic nephropathy.

4. Cardiovascular Benefits of C. sativum

A systematic review was carried out of studies investigating the potential cardiovascular benefits of C. sativum.

Studies have demonstrated the cardioprotective benefits of C. sativum. These include its effect as an antioxidant, antihypertensive, anti-atherogenic, antiarrhythmic, as well as the improvement of other factors that may lead to cardiovascular disease (CVD), such as altered lipid profile, hyperglycaemia and cardiac biomarkers or enzymes.

Most of the studies included in the review were in vivo studies carried out on laboratory animals. Only two were human studies. These latter demonstrated hypolipidaemic, hypocholesterolaemic, hypotensive and antioxidant effects of coriander seed powder. As to plant parts, the majority of the studies included investigated the effects of the seeds. The two studies on the leaves showed hypolipidaemic, hypotensive, normoglycaemic and antioxidant effects.

The authors comment that more in vitro studies are needed to elucidate mechanisms of action.