Chinese Name : 枳实
Latin Name : Fructus aurantii immaturus
This herb is the dried, unripe or immature, and sour (bitter) fruit of Citrus aurantium L. or its sweet variety C. sinensis Osbeck of the family Rutaceae. The plant is grown in the Sichuan, Jiangxi, Fujian, and Zhejiang provinces of China. It is collected in the early summer, dried, sliced, and used unprocessed.
The unripe fruit is cooling, deobstruent (removing food stagnation), and carminative. It was used as an excellent stomachic, and for coughs and dyspnea. Today, immature bitter orange is used as a carminative, stomachic, and Qi-regulating stomachic herb. The ripe fruits of C. aurantium L. and C. wilsonii Tanaka, called zhi qiao (ripe bitter orange), have the same effects as immature bitter orange (zhi shi) but are less potent in action and mostly used to promote the flow of Qi and to relieve epigastric distension.
Use of Immature Bitter Orange in TCM
Bitter and pungent in taste, and cold, it acts on the spleen, stomach, and large intestine meridians.
Effects, Medicinal Uses, and Combinations
- Relieves stagnation of Qi and food: for abdominal distension and pain, constipation , or evacuation with foul odor, immature bitter orange is often used with hawthorn fruit, germinated barley, and medicated Also, it may be prescribed with magnolia bark and rhubarb, as in Da Cheng Qi Tang (R-73), for constipation, abdominal distension, and pain due to Heat accumulation in the bowels.
- Reduces phlegm and removes feelings of stiffness and fullness in the chest and upper abdomen: for chest pain and shortness of breath due to obstruction of Qi by phlegm, immature bitter orange is combined with macrostem onion, cinnamon twig, and trichosanthes fruit. It is also dispensed with astragalus root, cimicifuga, and other herbs for gastroptosis, gastric dilation, and prolapse of the rectum or of the uterus.
- To treat gastroptosis, gastric dilation, prolapse of the rectum, and hysteroptosis, immature bitter orange is mixed with codonopsis, astragalus root, and cimicifuga or with white atractylodes as in Zhi Zhu Wan.
In a decoction of 3 to 10 g.
People suffering from hypofunction of the spleen and stomach, and pregnant women should not use immature bitter orange or use with caution.
Side Effects and Toxicity
No undesirable side effects or toxicity were reported at the theraupetic dose in classical Chinese materia medica. Toxicological tests show that this herb has low toxicity. The intravenous LD50 of the injection solution in mice was 71.8 ± 5 g/kg. Intravenous injection to anesthetized dogs at 21 g/kg did not result in any serious reactions.
Immature bitter orange contains essential oil, bitter principles, flavones, and alkaloids. The major components in the oil of the fruit are alpha-limonene and linanool. The flavones include hesperidine, neohespiridine, tangeretin, auranetin, 5-hydroxyauranetin, and others. The alkaloids synephrine and N-methyltyramine have been isolated. Other components include organic acids and vitamins A, B, and E.
- The herb’s decoction inhibited the movement of the intestinal tract in mice and rabbits. This effect was antagonized by acetylcholine. In contrast, oral administration of 10 ml of 100 percent of the decoction to conscious dogs was stimulating, increasing the contraction rhythm of gastrointestinal movement, which indicates the herb’s value as a gastrointestinal therapeutic remedy.
- Intravenous administration of the decoction or the alcoholic extract of the herb markedly increased blood pressure in anesthetized dogs and rabbits and the result was similar to norepinephrine.
- The decoction of the herb’s synephrine and N-methyltyramine increased cardiac contractibility, contraction magnitude, and cardiac output.
- The herb’s decoction or its ingredient of N-methyltyramine increased urine output in dogs, which was accompanied by an increase in blood pressure. Diuresis is probably a result of the inhibition of renal reabsorption.
- The flavonoid contents of immature bitter orange are antibacterial, anti-inflammatory, antifungal, and stimulating to the uterine muscles and alimentary tract muscles with force and rhythm.