Zhi Zi (Fructus Gardeniae or Cape Jasmine Fruit)

What Is Zhi Zi

Zhi Zi also known as Fructus Gardeniae or Cape Jasmine Fruit is the ripe fruit of Gardenia Jasminoides, which is an evergreen shrub of the family Rubiaceae. It is a relatively practical and common Chinese herbal medicine, which first appeared in <Shennong Ben Cao Jing> in the late Western Han Dynasty (around 100 BCE).

There are about 250 species of Gardenias, which are distributed in tropical and subtropical regions of the Eastern Hemisphere. Among them, some species are used as garden ornamental plants. Only a few species of them have medicinal value.

Gardenia Jasminoides likes a warm and humid climate. They grow well in loose, fertile, well-drained, lightly sticky acid soil.

They often grow in the wilderness, hills, valleys, mountain slopes, shrubs, or forests at an altitude of 10-1,500 meters. They can be found in China, Japan, North Korea, Vietnam, Laos, Cambodia, India, Nepal, Pakistan, Pacific Islands, and Northern America.

Gardenia Jasminoides

During the Qin and Han Dynasties, the fruit of this plant was the most widely used yellow dye. Archaeology has confirmed that the yellow color of the dyed fabrics unearthed at Hanmawangdui was dyed with Gardenia Jasminoides. Because the fabrics dyed with it have poor sun resistance, people used Sophora japonica instead of it to dye yellow fabrics after the Song Dynasty.

From September to November each year, people gather reddish yellow and ripe fruits of Gardenia Jasminoides, remove impurities, use them directly, or stir-fry them, or carbonize them, to make them into Chinese herbal medicines.

Zhi Zi contains gardenoside, gardoside, caryptoside, genipin-1-β-gentian glycoside, deacetylasperulosidic acid methyl ester, jasminoside A-H, croceic acid, crocin, ursolic acid, rotundic acid, isotaraxeral, barbinervic acid, clethric acid, myrianthic acid, β-sitosterol, stigmasterol, daucosterol, flavonoids, organic acids, volatile oils, and some trace elements.

Generally, the red-yellow and plump Zhi Zi with thin-skinned is preferred.

According to the Chinese Pharmacopoeia, the medicinal nature of Zhi Zi is relatively cold, with a bitter taste. It has a certain therapeutic effect on the pathological changes of the heart, lung, and tri-jiao meridians.

In traditional Chinese medicine, it is often used to purge fire and relieve restlessness, clear heat and promote diuresis, cool blood and remove toxins, treat closed soft tissue injuries, acute edematous pancreatitis, acute catarrhal conjunctivitis, icteric hepatitis, hypertension, diabetes, Gallstones, chronic cholecystitis, toothache, hematemesis, uterine bleeding, hematuria, and cerebral hemorrhage caused by blood heat.

About 300 kinds of traditional Chinese medicine prescriptions contain it, such as Angong Niuhuang Wan, Huang Lian Shang Qing Wan, Long Dan Xie Gan Wan, and Ba Zheng San.


  • Anti-inflammation and inhibiting the swelling of the toes of mice caused by formaldehyde and the swelling of the ears of mice caused by xylene.
  • Anti-oxidation, scavenging active reactive oxygen species and DPPH free radicals and enhancing superoxide dismutase activity.
  • Inducing apoptosis of gastric cancer AGS cells, human prostate cancer PC3 cells, and HeLa cells.
  • Raising the pain threshold and inhibiting the pain caused by the hot plate experiment and glacial acetic acid experiment in mice.
  • Reducing liver damage induced by CCL4, Concanavalin A, or D-galactosamine, and protecting the liver.
  • Inhibiting platelet aggregation induced by adenosine diphosphate, reducing the incidence of thrombosis and atherosclerosis.
  • Inhibiting α-glycosidase activity, promoting insulin secretion, and lowering blood sugar levels.
  • Promoting the secretion and excretion of bile and reducing the cholesterol content in the bile.
  • Reducing the content of total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol in the serum and liver tissue of experimental hyperlipidemia rats, and increasing the content of high-density lipoprotein cholesterol.
  • Purging heart fire, treating upset and restlessness caused by febrile diseases.
  • Treating high fever, irritability, and delirium caused by the excessiveness of fire toxins.
  • Treating jaundice caused by damp-heat in the liver and gallbladder.
  • Clearing damp-heat in the lower jiao, treating stranguria with hematuria, and heat strangury.
  • Cooling blood, treating vomiting blood, nose bleeding, and metrorrhagia caused by blood heat.
  • Clearing heat in the tri-jiao, treating redness, swelling, and pain of eyes caused by fire heat attacking the upper.
  • Removing heat toxins, relieving skin redness, swelling, and pain.
  • It can cooperate with pentobarbital sodium to extend the sleep time of experimental mice.
  • Crocenic acid can reduce the activity of creatine kinase (CK) and lactate dehydrogenase (LDH) in serum, increase the amount of ATP in myocardial tissue, relieve myocardial stunning, and improve myocardial ischemia.
  • Inhibiting Staphylococcus aureus, Streptococcus hemolyticus, Catalococcus, Bacillus cholera, Bacillus diphtheria, Mycobacterium tuberculosis, Escherichia coli, Proteus, and Leptospira.
  • Studies have found that gardenia yellow pigment can extend the exhaustive swimming time of mice under low pressure and low oxygen environment. It has an anti-fatigue effect.


Side Effects

  • Modern research shows that overdose of it may cause toxic reactions.
  • Overdose of it may cause dizziness, palpitations, abdominal pain, nausea, vomiting, heavy urination, general weakness, cold sweats, and coma in severe cases.
  • A small proportion of patients taking it may cause allergic reactions, such as urticaria or miliary papules.

Precautions and Warnings

  • The dosage of Zhi Zi should be controlled at 5-10g.
  • It can be made into decoctions, tea, pills, or ground into powder for external use.
  • People who are allergic to Zhi Zi should not take it.
  • Patients with loose stools due to deficiency in the spleen should not take it.
  • Patients with stomach cold should not take it.
  • Pregnant and breastfeeding women should not take it.
  • The unprocessed Zhi Zi is often used to purge fire, and the carbonized Zhi Zi is often used to cool blood to stop bleeding.