German chamomile is a low growing annual herbaceous plant native to southern and eastern Europe and Northern and West Asia, now common in wastelands and neglected field as well as cultivated ground throughout Europe. In Germany, chamomile is one of the most important medicinal plants obtained from cultivation. Chamomile has been described since ancient times and was an important drug in ancient Egyptian, Greek and Roman medicines. Its name is derived from the Greek “chamos” (ground) and “melos” (Apple), referring to its low growing habit and the apple scent of its fresh blooms.
Over 120 constituents have been identified in chamomile flowers. Amino acids, polysaccharides and fatty acids are present in the mucilage, which makes up approximately 10% of the flower head. Several flavonoids and other phenolic compounds have been identified in various parts of the chamomile flower head: Apigenin, quercetin, patuletin, luteolin and their glucosides (1). In Germany, the chamomile flower is licensed as a standard medicinal tea (infusion) for oral ingestion, and the German E Commission has also approved chamomile for internal use (2). Traditionally, chamomile preparations such as tea and essential oil aromatherapy have been used to treat insomnia and to induce sedation (calming effects) and is one of the most widely used types of CAM therapy for promoting sleep and treating insomnia (3), A study was conducted on a randomly selected sample of adults (n = 997; 60.9% women) from the province of Quebec, where a total of 18.5% of participants reported having used natural products as sleep aids in the past 12 months, with chamomile being the most popular prod¬uct (4).
Sedative Effects
Sedative effects may be due to the fla¬vonoid apigenin, which binds to benzodiazepine (BDZ) receptors in the brain. Studies in preclinical models have shown anticonvulsant and CNS-depressant effects (5). Investigations on the hypnotic activities of chamomile extracts using the sleep-disturbed preclinical model demonstrated a signif¬icant decrease in sleep latency observed with chamomile extract. No significant effects were observed on total times of wakeful¬ness, non-rapid eye movement (non-REM) sleep, and REM sleep. Flumazenil, a benzodiazepine receptor antagonist, at a dose of 3 mg/kg showed a significant antagonistic effect on the shortening in sleep latency induced by chamomile extract. In conclusion, chamomile extracts exhibit benzodiazepine-like hyp¬notic activity (6). According to Paladini et al. (7), the separation index (ratio between the maximal anxiolytic dose and the minimal sedative dose) for diazepam is 3 while for apigenin it is 10. Compounds other than api¬genin present in extracts of chamomile can also bind BDZ and gamma-aminobutyric acid (GABA) receptors in the brain, and are thought to be responsible for some of the sedative effect; however, many of these compounds are as yet unidentified.
Kupfersztain and colleagues (8) found that 12 weeks of an herbal extract for hot flashes that contained chamomile alleviated sleep disturbances and fatigue more than placebo. In another study, adults without sleep complaints who received chamomile jelly had higher peripheral skin temperature, higher ratings of relaxation, and, in men, lower sleep diary ratings of sleep onset latency, nighttime wakefulness, and morning sleepiness more than placebo (9). A study in 77 elderly residents in nursing homes examined the effects of administration of chamomile extract twice daily on quality of sleep using a Sleep Quality Questionnaire Index before and after intervention compared to placebo (10). The authors concluded oral administration of chamomile extract has sedative properties and can be effective in the improvement of the quality of sleep in older adults. In another randomized, double-blind, placebo-controlled pilot trial in 34 patients aged 18-65 years with DSM-IV primary insomnia for ≥ 6-months, patients were randomized to chamomile twice daily or placebo for 28-days (11). The primary outcomes were sleep diary measures. Secondary outcomes included daytime symptoms, safety assessments, and effect size of these measures. The authors concluded chamomile could provide modest benefits of daytime functioning and mixed benefits on sleep diary measures relative to placebo in adults with chronic primary insomnia.
Anxiety
Chamomile has been reported in the treatment of generalized anxiety disorder (GAD). But the reports seem contradictory as an earlier report suggests that German chamomile showed significant inhibition of GAD activity (12). The recent results from the controlled clinical trial on chamomile extract for GAD suggests that it may have modest anxiolytic activity in patients with mild to moderate GAD (13).
References
1 Mulinacci N, Romani A, Pinelli P, Vincieri FF, Prucher D. 2000.Chromatographia 51: 301–307.
2 Blumenthal M, Busse WR, Goldberg A et al. (eds). 1998. The Complete German Commission E Monographs – Therapeutic Guide to Herbal Medicines. American Botanical Council: Austin.
3 Wheatley D. Medicinal plants for insomnia: A review of their pharma¬cology, efficacy and tolerability. J Psychopharmacol. 2005;19(4):414- 421
4 Sanchez-Ortuno MM, Belanger L, Ivers H, et al: The use of natural products for sleep: A common practice? Sleep Med. 2009;10(9):982-987.)
5 Avallone , R. , Zanoli , P. , Corsi , L. , Cannazza , G. & Baraldi , M. ( 1996 ). Benzodiazepine compounds and GABA in fl ower heads of matricaria chamomilla . Phytother Res 10 , 177 – 179 .
6 Shinomiya, K. , Inoue, T. , Utsu, Y. , Tokunaga, S. , Masuoka, T. , Ohmori , A. & Kamei , C. ( 2005 ). Hypnotic activities of chamomile and passifl ora extracts in sleep-disturbed rats . B iol Pharm Bull 28 , 808 – 810 .
7 Paladini, A. C. , Marder , M. , Viola, H. , Wolfman, C. , Wasowski, C. & Medina, J. H. ( 1999 ). Flavonoids and the central nervous system: From forgotten factors to potent anxiolytic compounds . J Pharm Pharmacol. 51 , 519 – 526 .
8 Kupfersztain C, Rotem C, Fagot R, Kaplan B: The immediate effect of natural plant extract, Angelica sinensis and Matricaria chamomilla for the treatment of hot flushes during menopause. A preliminary report. Clin Exp Obstet Gynecol 2003, 30(4):203-206.
9 Kakuta H, Yano-Kakuta E, Moriya K: Psychological and Physiological Effects in Humans of Eating Chamomile Jelly. ISHS Acta Horticulture 749/ International Symposium on Chamomile Research, Development and Production 2007.
10 Abdullahzadeh M, Naji SA. Effect of Chamomile Extract on Sleep Quality of the Elderly. Evidence Based Care. 2014 Oct 1;4(3):47-56.
11 Zick SM et al. Preliminary examination of the efficacy and safety of a standardized chamomile extract for chronic primary insomnia: A randomized placebo controlled pilot study. BMC Complementary and Alternative Medicine 2011, 11:78
12 Awad R, Levac D, Cybulska P, Merali Z, Trudeau VL, Arnason JT. Effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (GABA) system. Can J Physiol Pharmacol 2007;85:933–942. [PubMed: 18066140]
13 Amsterdam JD, Li Y, Soeller I, Rockwell K, Mao JJ, Shults J. A randomized, double-blind, placebo-controlled trial of oral Matricaria recutita (Chamomile) extract therapy for generalized anxiety disorder. J Clin Psychopharmacol 2009;29:378–382. [PubMed: 19593179]
