Scientific Name(s): Citrus aurantium L.
Common Name(s): Bitter orange , bitter orange flower , bitter orange peel , green orange
Bitter orange tree grows up to 10 m in height and has long, leathery, dark green leaves and scented white flowers. It has with 5 to 8 petals with some thistles. The membranes and pulp of the orange fruit are bitter and sour. The tree is very resistant to plant diseases when compared with other citrus trees. It is the type of orange and The peel, flower, leaf, fruit, and fruit juice are used to make medicine. It grows in some parts of Iran such as Gilan , Mazandaran and Fars province. Also it is grown commercially in southern Europe, particularly in Spain and Portugal, as well as in Israel and various islands of the Caribbean. Bitter orange oil is made from the peel. In traditional medicine, bitter orange and extracts are made from the fruit which are used to treat digestive problems such as nausea, constipation and indigestion.
Bitter orange, both taken by mouth and applied to the skin, has many uses. But so far, science has shown only that the oil, when applied to the skin, might be effective for treatment of fungal skin infections. Bitter orange peel is also used to improve appetite. Also in surprising contrast, it is also used for weight loss. Other uses for the fruit and peel are upset stomach, nasal congestion, and chronic fatigue syndrome (CFS). The bitter orange flower and bitter orange oil are used for gastrointestinal (GI) disorders including ulcers in the intestine, constipation, diarrhea, blood in feces, drooping (prolapsed) anus or rectum, and intestinal gas. These parts of the bitter orange plant are also used for regulating fat levels in the blood, lowering blood sugar in people with diabetes, stimulating the heart and circulation, “blood purification,” disorders of liver and gallbladder, kidney and bladder diseases, and as a sedative for sleep disorders. Some people use bitter orange flower and its oil for general feebleness, “tired blood” (anemia), impurities of the skin, hair loss, cancer, frostbite, and as a tonic.
Bitter orange peel is applied to the skin for swelling (inflammation) of the eyelid and its lining, as well as the retina in the eye. It is also used for bleeding from the retina, exhaustion accompanying colds, headaches, nerve pain, muscular pain, joint pain, bruises, swelling of the veins (phlebitis), and bed sores. In aromatherapy, the essential oil of bitter orange is applied to the skin and also inhaled as a painkiller. In Asian medicine, the entire dried unripe fruit is used primarily for digestive disorders.
Bitter orange is frequently used in “ephedra-free” products since the FDA banned ephedra in 2004 for serious side effects on the heart. Bitter orange and caffeine, a frequent combination in weight loss and bodybuilding products, can cause high blood pressure and increased heart rate in healthy adults with otherwise normal blood pressure. There is no evidence to suggest that bitter orange is any safer than ephedra. Bitter orange (synephrine) is considered a banned substance by the National Collegiate Athletic Association (NCAA). Before taking bitter orange, talk with your healthcare professional if you take any medications. It can interact with many drugs.
Pharmacological actions for C. aurantium include the following: antispasmodic, sedative, tranquilizer, cholagogue, demulcent, eupeptic, tonic, and vascular stimulant; as an anti-inflammatory, antibacterial, and antifungal agent. Also it can be useful for reducing cholesterol; however, clinical data is limited. Most medical literature focuses on the safety and efficacy of its use in over-the-counter weight-loss supplement formulations. Studies examining this use have used small sample sizes and often focus on combination products.
Follow manufacturer’s dosage guidelines because synephrine content may vary in supplement formulation. There is evidence of effective weight loss at a synephrine dose of 32 mg/day in treating obesity.
Because of the potential for additive effects, synephrine use is best avoided in patients with hypertension, tachyarrhythmia, or narrow angle glaucoma.
Avoid use due to lack of clinical data regarding safety and efficacy during pregnancy and lactation.
Bitter orange may inhibit intestinal CYP3A4 and intestinal efflux and may interact with numerous drugs, including anxiolytics, antidepressants, antiviral agents, calcium channel blockers, dextromethorphan, GI prokinetic agents, vasoconstrictors, and weight-loss formulas.
Medical literature primarily documents cardiovascular toxicity, especially due to the stimulant amines synephrine, octopamine, and N-methyltyramine, which may cause vasoconstriction as well as increased heart rate and blood pressure.
The Spanish and Portuguese brought bitter oranges to the Americas in the 1500s. In Chinese folk medicine, bitter orange was used as a tonic and carminative to treat dyspepsia. Dried bitter orange was used to treat ptosis of the uterus and anus, to relieve abdominal distention and diarrhea, and for blood in feces.
In Europe, bitter orange flowers and oil have been used as a sedative and as a prophylactic for GI complaints, nervous conditions, gout, sore throat, and insomnia. The plant has been used to treat toxic and anaphylactic shock, heart conditions, cardiac exhaustion, and cancer. In Brazilian folk medicine it was used as an anticonvulsant and to treat anxiety and insomnia.
Bitter orange oil is used extensively to flavor many food products, alcoholic and nonalcoholic beverages, frozen dairy desserts, candy, baked goods, gelatins and puddings, meat and meat products, and condiments and relishes.
Its purported uses in the United States include prevention of skin, breast, and colon cancer. In Haiti the plant has been used as an antiseptic and purgative and in Turkey it has been used as a narcotic, sedative, and treatment for scurvy. The plant has been used as a remedy for treatment-resistant fungal skin diseases, and the tincture or extract has been used for treating heartburn.
Powdered extracts of the dried immature fruit or peel are used as an alternative to ephedra in many dietary supplements and herbal weight-loss products. Because FDA banned ephedra for safety concerns. Many manufacturers of weight-loss supplement formulations now offer ephedra-free products containing bitter orange extract. Because bitter orange extract contains a sympathomimetic, the safety and efficacy of these formulations is monitored closely.