Hua Jiao (Pericarpium Zanthoxyli or Sichuan Pepper)

What Is Hua Jiao

Hua Jiao commonly known as Pericarpium Zanthoxyli, Sichuan Pepper, Szechwan Pepper, Chinese Pepper, Mala Pepper, or Chuan Jiao is the dried ripe pericarp of Zanthoxylum schinifolium Sieb. et Zucc, or Zanthoxylum bungeanum Maxim, which is a deciduous shrub or small tree belonging to the family Rutaceae. The first one is also called Qing Hua Jiao, while the other one is called Hong Hua Jiao. It is a popular food additive and traditional 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 Zanthoxylum, which are mainly distributed in tropical and subtropical regions of Asia, Africa, Oceania, and America. Only a few species are distributed in temperate regions. Among them, some species have high economic and medicinal value.

Zanthoxylum schinifolium Sieb. et Zucc prefers warm and humid environments. They are suitable for planting in deep, fertile loam soil. They often grow in sparse forests, bushes, or next to rocks in mountainous areas below 800 meters above sea level. They are distributed in China, Japan, and Korea.

Zanthoxylum bungeanum Maxim is light-loving and drought-tolerant. They are common in plains to higher elevations in mountains. They are distributed in China, Nepal, and Uzbekistan.

Zanthoxylum bungeanum

In autumn, people gather the ripe pericarps of Zanthoxylum schinifolium Sieb. et Zucc, or Zanthoxylum bungeanum Maxim, dry them in the sun, remove their seeds and impurities, use them directly, or stir-fry them, and make them into Chinese herbal medicines.

Hua Jiao contains hydroxy-α-sanshool, α-sanshool, hydroxy-β-sanshool, β-Sanshool, hydroxy-γ-sanshool, γ-sanshool, (2E,4E)-2′-hydroxy-N-isobutyl-2,4-tetradecadienamide, (2E,4E, 8Z)-2′-hydroxy-N-isobutyl-2,4,8-tetradecatrienamide, N-[2-(3,4-Dimethoxyphenyl)ethyl]-3-phenyl-acrylamide, bugeanumamide A, skimmianine, haplopine, kokusaginine, linalool, limonene, geraniol, p-mentha-1,3,8-triene, citronellal, isopulegol, hotrienol, 4-terpinenyl acetate, cis-p-2-Menthen-1-ol, citronellyl acetate, cryptone, pinocarvone, Bornyl acetate, myrtenal, myrtenol, α-cubebene, α-bergamotene, germacrene B, γ-cadinene, α-calacorene, β-terpineol, α-terpineol, α-terpinene, β-thujone, caryophyllene oxide, β-pinene, γ-terpinene, terpinolene, α-pinene, rutin, syringetin-3-glucoside, quercetin 3-arabinoside, kaempferol 3-O-α-l-rhamnoside, kaempferol-7-rhamnoside, apigenin-8-C-glucoside, kaempferol-3-rutinoside, rosefuran, mycrene epoxide, perillene, vanillic acid-4-glucoside, β-sitosterol, daucosterol, isoimperatorin, methyl-4-hydroxyphenylacrylate, 7-methoxycoumarin, xanthoxylin and fatty acids.

Generally, the gray-green Qing Hua Jiao is preferred, and the purple-red Hong Hua Jiao is preferred.

According to the Chinese Pharmacopoeia, the medicinal nature of Hua Jiao is relatively warm, with a pungent taste. It has a therapeutic effect on pathological changes in the spleen, stomach, and kidney meridians.

In traditional Chinese medicine, it is often used to warm middle energizer to relieve pain, kill parasites to relieve itching, and treat cold pain in the stomach and abdomen, vomiting, poor appetite, indigestion, abdominal pain, diarrhea, dysentery, toothache, migraine, amnesia, fungal infection of the hand, pruritus vulvae, perianal pruritus, eczema, gastritis, bronchial asthma, ascariasis, pediatric pinworms, acute torsion contusion, and rheumatoid arthritis.

There are more than 100 kinds of traditional Chinese medicine prescriptions containing it, such as Da Zhong Jian Tang, Wu Mei Wan, and Zhuang Yuan Bu Xue Wan.


  • Anti-inflammation, inhibiting xylene-induced ear swelling and carrageenan-induced paw swelling in mice [1].
  • Increasing the pain threshold and decreasing the number of writhing responses in mice induced by acetic acid and the licking foot time of mice in phase Ⅱ induced by formalin [1].
  • Anti-oxidation, scavenging hydroxyl free radicals and DPPH radicals, reducing ferric ion (Fe3+) to the ferrous ion (Fe2+) [2].
  • Decreasing platelet aggregation, prolonging the hemorrhage and coagulation time as well as enhancing the survival rate of mice subjected to collagen-adrenaline induced thrombosis [3].
  • Warming middle energizer to relieve pain, treating stomach cold, cold in the stomach, and vomiting caused by pathogenic cold invading the interior.
  • Treating cold pain in the stomach and abdomen, vomiting, and poor appetite caused by deficiency-cold in the spleen and stomach.
  • Treating chronic diarrhea caused by dampness and cold in summer.
  • Expelling and killing ascarid, treating abdominal pain and vomiting caused by parasitic malnutrition, and infantile oxyuriasis.
  • Treating pruritus vulvae, perianal pruritus, and eczema.
  • Its flavonoids ameliorate dextran sulfate sodium-induced experimental colitis in mice via the regulation of TLR4 and TLR4-related signaling pathways [4].
  • Its water extracts showed significant inhibiting effects on experimental gastric ulcers in mice, including the pylorus ligation ulcer, water immersion stress ulcer, indomethacin-ethanol ulcer, and hydrochloric acid ulcer. Additionally, its petroleum ether extracts can inhibit diarrhea induced by castor oil, and its water extracts can inhibit diarrhea caused by senna leaf.
  • Its water extracts and volatile oil improve cognitive dysfunction and neurological deficits in D-galactose-induced aging mice via activating PI3K/Akt/Nrf2 signaling pathway [5].
  • Its volatile oil has ameliorative effects on chronic unpredictable stress-induced anxiety behavior. This anxiolytic effect is potentially involved in inhibiting activation of the HPA axis and restoring the dysbiosis of gut microbiota, thus improving the stress-induced abnormality of the microbiota-gut-brain axis and brain homeostasis [6].
  • Its essential oil can inhibit the proliferation of HaCaT cells, PC-3 cells, HEp-2 cells, Hela cells, and MFC-7 cells.
  • Its essential oil has a certain inhibitory effect on Bacillus subtilis, Salmonella, Staphylococcus aureus, Bacillus cereus, E. coli, Proteus vulgaris, Pentcillum Crtinum Thom, Aspergillus flavus, Aspergillus niger, Ruinous orgzae, and Saccharomyces cerevisiae [7].
  • Hydroxy-α-sanshool can reduce the levels of total cholesterol, triglyceride, and low-density lipoprotein cholesterol in hyperlipidemic rats, and increase the level of high-density lipoprotein cholesterol. In addition, it can reduce the amount of abdominal adipose tissues and the adipocyte ratio in the liver tissues of HFD rats [8].
  • Sanshool treatment can protect human dermal fibroblasts against the effects of UVB irradiation by increasing cell viability, inhibiting MMP expression, and inducing autophagy. In addition, sanshool alleviates UVB-induced skin photodamage in nude mouse skin [9].
  • Studies have found that its extract promoted the cell viability of arachidonic acid plus iron-stimulated HepG2 cells. In addition, its extracts reduced CCL4-induced plasma ALT and AST levels in mice. This suggests that its extracts have protective effects against hepatotoxicity both in vitro and in vivo [10].


  • It can be used in combination with Sheng Jiang (Rhizoma Zingiberis Recens), Bai Dou Kou (Fructus Amomi Rotundus), etc. to treat stomach cold, cold in the stomach, and vomiting caused by pathogenic cold invading the interior.
  • It can be used in combination with Gan Jiang (Dried Ginger), Ren Shen (Radix et Rhizoma Ginseng), etc. to treat cold pain in the stomach and abdomen, vomiting, and poor appetite caused by deficiency-cold in the spleen and stomach.
  • It can be used in combination with Sha Ren (Fructus Amomi), Rou Dou Kou (Semen Myristicae), etc. to treat chronic diarrhea caused by dampness and cold in summer.
  • It can be used in combination with Wu Mei (Fructus Mume), Gan Jiang (Dried Ginger), Huang Bai (Cortex Phellodendri), etc. to treat abdominal pain, vomiting, and deadly cold hand and foot caused by parasitic malnutrition.
  • It can be used in combination with Wu Zhu Yu (Evodiae Fructus), She Chuang Zi (Fructus Cnidii), etc. to treat intense pruritus vulvae.
  • It can be combined with Fu Ling (Poria) to treat humid asthma, low back pain, and cold feet caused by a deficiency of the kidney.

Side Effects

  • Animal studies have shown that an overdose of its volatile oil can cause retardation, diarrhea, drowsiness, cardiac arrhythmia, twitching of limbs, slowing of respiration and heart rate, or even death.
  • Overdose of it may cause toxic reactions such as nausea, vomiting, dizziness, twitching of limbs, difficulty in breathing, or coma.
  • It may cause allergic reactions such as vomiting, diarrhea, tingling of the extremities, hives, or anaphylaxis in a small percentage of patients.

Precautions and Warnings

  • The dosage of Hua Jiao should be controlled between 3-6g.
  • It can be made into decoctions, pills, dispersions, sprays, or lotions.
  • People who are allergic to Hua Jiao should not take it.
  • Patients with internal heat due to yin deficiency should not take it.
  • Pregnant women should not take it.
  • Lactating women, children, and the elderly and infirm should be taken under the guidance of a physician.