History and Traditional Use

     Native to Southwest China and Vietnam, Illicium Verum takes on the familiar star- shaped pericarp structure, which is found to grow on small evergreen trees of the Magnoliaceae family, see Figure 1 (Garden Action, 2000). 

       Figure 1- Star anise and tree of the Magnoliaceae family.
        Ref: http://davesgarden.com/guides/pf/showimage/211118/

Also known as Chinese Star Anise, it has been historically used by Ancient Greeks, Romans and East Asians both as a spice in cooking as well as a traditional pharmacopoeia, see Figure 2. However, it only became common in the 17^th century when it was widely sold at grocery and hardware stores. Traditionally, the French who imported Anise from India, incorporated it as a main ingredient in their infamous ‘liqueur d’Arabie’ as early as the 14^th century. The Greeks however prescribed it for coughs while the Romans used it to make cakes for special occasions as it has a licorice flavor (MDidea, 2010).

Figure 2- Szechuan Beef and Star Anise Noodle Soup
Ref: http://find.myrecipes.com/recipes/recipefinder.dyn?action=displayRecipe&recipe_id=10000001879901

The Chinese and Europeans had also used it as a warm stimulating herb mainly to facilitate digestion, combat stomachaches, as a breath freshener and as an anti- emetic. More specifically, the Chinese prescribed it as a carminative (flatulence) remedy, a stimulant, as well as a diuretic (Bottom Line Monograph, 2010). Early English populations however had utilized the herb for a broader range of biological processes and ailments such as hiccups, increase milk production for nursing mothers, treatment for water retention, headaches, asthma, Bronchitis, rheumatism, insomnia, lice, infant colic, cholera and even cancer (Agrisources, 2008). Anise seeds were typically crushed or bruised (Figure 3) and administered in the form of lozenges, placed in tea, mixed with wine, chewed after meals or smoked, where the latter was to induce coughing for phlegm removal. Anise-oil is also harvested from the pericarp for similar medicinal properties (MDidea, 2010).

Figure 3- Anise seeds being crushed and bruised with mortar and pestle.
Ref: http://www.kitchenexperiments.net/2009_05_01_archive.html

Active Components and Preparation

        Through experimentation, I.verum has proven to have a number of active components known to have varying medicinal properties. Evidence indicates 2 main components, starting with anethole (Figure 3), which is extracted from the oil of dried pericarp (Figure 4) and found in high concentrations of 72- 92% within I.verum species, has antimicrobial properties effective against bacteria, yeast and fungi (Katzer, 2004; Agrisources, 2008 and Ize-Ludlow, 2004). 

Figure 3- Chemical structure of anethole.
Ref: http://en.wikipedia.org/wiki/Anethole

Figure 4- Pericarp of Star anise.
Ref: http://www.ehow.com/how_7343124_use-star-anise.html

        
Anethole is also similar to estrogen hormone, which is why some mothers use it to promote breastmilk production. Anethole can be prepared as an ointment administered externally as well as ingested as an essential oil (Ize-Ludlow, 2004 and DigHerbs, 2008). Shikimic acid, on the other hand, is found in the pods and is a main constituent of the antiviral drug, Tamiflu® see Figure 5, administered in a standardized capsule (Bottom Line Monograph, 2010).

Figure 5- 75mg Tamiflu® (Oseltamivir) capsules.
Ref: http://commons.wikimedia.org/wiki/File:Tamiflu.JPG

It is known to reduce the duration and severity of flu symptoms (H5N1). Preparation involves a 10-step process, Figure 6, that takes 6-8 months to complete, starting with the extraction of shikimic acid and a series of complex chemical reactions (Watson, 2010).

Figure 6- Chemical reaction process to the production of Tamiflu®
Ref: http://en.wikipedia.org/wiki/Oseltamivir

Current Use and What the Science Says

        There are two current uses that dominate; consumption of star anise tea and the pharmaceutical drug, Tamiflu.

        It is important to note that large clinical trials have not yet been done to prove medicinal benefits of star anise tea or its efficacy. This is mainly because it has been consumed on a folklore basis and passed down through generations by verbal dissemination. Star anise tea is believed to have carminative and sedative properties used to treat infant colic and continues to be consumed based on traditional evidence rather than based on Western evidence.  

I have therefore chosen the study by Ize-Ludlow et al as it contradicts the validity of Star anise to be used as a traditional-based medicine. Seven cases of infants aged 2-12 weeks showed signs of acute star anise intoxication over a 2 -year period after consumption. Doses ranged from 1 to 6 stars boiled in water with consumption ranging from once per day to every 4 hours. These infants exhibited neurologic episodes including seizures, jitteriness, irritability, hyperexcitability, emesis, vertical nystagmus and myoclonic movements. See Table 1 of Appendix for findings. Results also showed contamination of the commercial Star anise with toxic Illicium anisatum (Figure 7), the Japanese star anise. With the recent rise in adulteration and an increase in the number of clinical toxicities, Ize-Ludlow and the FDA has warned against drinking star anise tea. 

Figure 7- Japanese star anise.
Ref: http://bakati.com/s~q-japanese%20star%20anise.aspx

The major limitation of the study is the small sample size and its lack of being a randomly- controlled trial, however their findings are supported by an agglomeration of similar studies (Biessels, 2002; Garzo, 2002; Okuyama, 1993; Johanns, 2002). The protocols were sound since patients had already been consuming star anise tea prior to the study, thereby the symptoms were naturally occurring not induced in a clinical study, which in itself is a limitation (Ize-Ludlow, 2004).

        Shikimic acid found within the pericarp of Star anise is a main component of Tamiflu (oseltamivir), a pharmaceutical drug used to combat various strains of influenza (Figure 8). With the recent 2009 H1N1 pandemic, Tamiflu has become the only recommended antiviral drug for treating children of <5yrs. 

Figure 8- Chemical structure of oseltamivir phosphate.
Ref: http://en.wikipedia.org/wiki/Oseltamivir

According to Heinonen et al., results indicate that treating influenza with orally administered oseltamivir within 12 hours of symptom onset decreases the development of acute otitis media, a bacteria infection caused by influenza, by 85% (95% CI, P=0.2), see Figure 9. Treatment also shortened the child’s median time for recovery from influenza symptoms by 1.4 days and reduced parental absence from work by 2 days. No significant efficacy was found when oseltamivir was started within 24 hours, therefore it has been concluded to administer Tamiflu as early as possible after symptom onset. See Table 2 and 3 in Appendix for findings. 

Figure 9- Example of otitis media, which is inflammation and fluid, within middle ear caused by influenza.
Ref: http://www.nlm.nih.gov/medlineplus/ency/imagepages/19324.htm

These results show statistical significance, where its overall efficacy is supported by previous studies done on adults and maintained by the high rate of adherence to oseltamivir. Their study was a good example of a Western evidence-based clinical study where they performed randomized, double- blind, placebo- controlled trials on a fairly large sample of 408 children within 1-3 years old. Study procedures were thorough, logical and unbiased as they made certain that symptoms were caused by influenza nothing else and protocols were sound ensuring the health of the children as their priority (Heinonen, 2010).

Adverse Effects, Cautions, Cross Drug and Herb Interactions

        I.verum is often mistaken with other Illicium species, as their structural appearances are similar to one another. More pertinent however is its confusion with Japanese star anise, I.anisatum, which is toxic (Figure 10). Recently, a rise in adulteration with I.anisatum has caused more cases of neurotoxicity within younger individuals and consequently, the U.S. Food and Drug Administration advises against its use in teas. 

Figure 10- Comparison of Japanese star anise (left) with Chinese star anise (right).
Ref: http://www.wellsphere.com/wellpage/star-anise

Therefore, caution should be taken when purchasing Chinese Star anise. Also, although I.verum is considered safe to consume and has been historically used for culinary purposes, it does contain toxic compounds veranisatin A, B and C as found in I.anisatum but only in low concentrations. Therefore, high doses or an overdose of I.verum can produce adverse neurological and gastrointestinal harm, especially in regards to young children. Symptoms of toxicity include irritability, vomiting and seizures. As previously mentioned, studies have shown that treatment of influenza with Tamiflu have caused vomiting, its only adverse effect. No cross drugs or herb interactions have been reported or found to date (Ize-Ludlow, 2004 and Philip, 2004).

Sources and Additional Links

Agrisources. (2008). Star Anise (Chinese Anise)- Illicium Verum (Illiciaceae). Retrieved November 20, 2010 from http://www.agrisources.com/herbs/illiciumverum.html.

Biessels, G., Vermeij, F. and F, Leijten. (2002). Epileptic seizure after a cup of tea: intoxication with Japanese star anise. Ned Tijdschr Geneeskd, 146, 808- 811.

Bottom Line Monograph. (2010). Natural Standard- The Authority on Integrative Medicine. Star Anise (Illicium Verum). Retrieved November 20, 2010 from http://naturalstandard.com/index-abstract.asp?create-abstract=patient-staranise.asp&title=Star%20anise.

DigHerbs. (2008). Star Anise- (Illicium verum or Chinese Anise). Retrieved from November 20, 2010 from http://www.digherbs.com/star-anise.html.

Garden Action. (2000). The Herb Star Anise. Retrieved November 20, 2010 from http://www.gardenaction.co.uk/fruit_veg_diary/star_anise.asp.

Garzo, C., et al. (2002). Cases of neurological symptoms associated with star anis consumption used as a carminative. An Esp Pediatr, 57, 290- 294.

Heinonen, S., et al. (2010). Early oseltamivir treatment of influenza in children 1-3 years of age: a randomized controlled trial. Clincal Infectious Diseases, 51(8), 887- 894.

Ize- Ludlow, D., Ragone, S., and I., Bruck. (2004). Chemical Composition of Chinese Star Anise (Illicium verum) and Neurotoxicity in Infants. JAMA, 291(5), 562- 563.

Ize-Ludlow, D., et al. (2004). Neurotoxicities in infants seen with the consumption of Star anise tea. Pediatrics, 114(5).

Johanns, E., et al. (2002). An epidemic of epileptic seizures after consumption of herbal tea. Ned Tijdschr Geneeskd, 146, 813- 816.

Katzer, G. (2004). Star Anise (Illicium verum Hook fil.) Retrieved from November 20, 2010 from http://www.uni-graz.at/~katzer/engl/Illi_ver.html.

MDidea Brand. (2010). The Star Anise or Anise Seed, Good Remedy and Useful Seed Step from Ancient World. Extracts Professionals. Retrieved November 20, 2010 from http://www.mdidea.com/products/new/new04303.html.

Okuyama, E., et al. (1993). Convulsants from star anise (Illicium verum Hook. F.).  Chem Pharm Bull (Tokyo), 41, 1670- 1671.

Philip, R. (2004). Herbal-drug interactions and adverse effects: An evidence- based quick reference guide. New Jersey: McGraw-Hill Professional.

Watson, S. (2010). How Tamiflu works. Retrieved November 20, 2010 from http://health.howstuffworks.com/medicine/medication/tamiflu1.htm.