Prickly Pear

Scientific Name(s): Opuntia tuna (L.) Mill. (tuna) and Opuntia ficus-indica (L.) Mill. (barbary fig, Indian fig). Other species include: Opuntia fragilis (Nutt.) Haw. (brittle prickly pear), Opuntia streptacantha Lem. Family: Cactacceae.

Common Name(s): Prickly pear , nopal (stem sections of plant), tuna (meaning fruit or seed). , , ,

Uses

Prickly pear is widely cultivated and commercially used in juices, jellies, candies, teas, and alcoholic drinks. American Indians used prickly pear juice to treat burns, and prickly pear has a long history in traditional Mexican folk medicine for treating diabetes. Its use in treating diabetes, lipid disorders, inflammation, and ulcers, as well as its other pharmacologic effects, have been documented. However, there is limited clinical information to support these uses.

Dosing

Prickly pear is commercially available in numerous doseforms, including capsules, tablets, powders, and juices, and as food. Follow manufacturers' suggested guidelines if using commercial products. Typical dosage regimens are two 250 mg capsules by mouth 3 times a day or every 8 hours.

Contraindications

Hypersensitivity to any components of prickly pear.

Pregnancy/Lactation

Avoid use during pregnancy and lactation because of the lack of clinical studies.

Interactions

None well documented.

Adverse Reactions

Dermatitis is the most common adverse reaction to prickly pear.

Toxicology

Little information is available.

Botany

Prickly pears are members of the Cactacceae or cactus family, which includes about 97 genera and 1,600 species. The species are found in Europe, Mediterranean countries, Africa, southwestern United States, and northern Mexico. Plants in the genus Opuntia prefer a dry, hot climate and consist of perennial shrubs, trees, and creeping plants. Prickly pear can grow 5 to 8 m in height; its roots are shallow, but the plant can spread up to 40 m in diameter over the ground. The stems are branched, leaves are cylindrical in shape, and the plant is covered with barb-tipped bristles (known as glochids) that are unique to Opuntia . Its flowers, petals, and sepals are numerous in quantity and color. The oval, pear-shaped, purplish fruit is pulpy and sweet but may be covered with spines or bristles. The seeds within the pulp are disk-shaped and have numerous colors. , , , , ,

Because information on this species as a whole is sparse, the following subspecies are also included in various aspects of the discussion: Opuntia fulginosa , Opuntia megacantha , Opuntia dillenii , Opuntia microdasys , Opuntia bieglovii , Opuntia acanthocarpa .

History

Prickly pear is widely cultivated and used in juices, jellies, candies, teas, and alcoholic drinks. The fruits and flowers of the plant are used as natural food colorants. Cactus gum is used to stiffen cloth. Essential oils from the flowers are used to make perfumes, and the seeds are a source of oil. Prickly pear has also been used as a source of animal feed and dye. ,

There are numerous medicinal uses of the plant. American Indians used prickly pear juice to treat burns. Often a cone of plant material would be burned on the skin to treat irritation or infection, a process known as moxabustion in Chinese medicine. The Lakota tribe used prickly pear in a tea to assist mothers during childbirth.

Prickly pear has a long history of traditional Mexican folk medicine use, particularly as a treatment for diabetes. Prickly pear pads have been used as a poultice for rheumatism. The fruit has been used for treating diarrhea, asthma, and gonorrhea. The fleshy stems or cladodes have been used to treat high cholesterol, blood pressure, gastric acidity, ulcers, fatigue, dyspnea, glaucoma, liver conditions, and wounds. , In South Korea the plant has been used to treat abdominal pain, bronchial asthma, burns, diabetes, and indigestion. In Sicily, a flower decoction of prickly pear has been used as a diuretic; the cladodes were valued for their anti-inflammatory activity in treating edema, arthrosis, and whooping cough, and for preventing wound infection.

Prickly pear has also been planted on steep slopes to control erosion.

Chemistry

The medicinal components of the plant are found in the flowers, leaves or pads, and fruit.

Isorhamnetin-glucoside, kaempferol, luteolin, penduletin, piscidic acids, quercetrin, rutin, and β-sitosterol have been found in the flowers of prickly pear. The leaves or pads are rich in mucilage and consist primarily of polysaccharides that contain galactose, arabinose, xylose, and rhamnose.

Prickly pear fruit is high in nutritional value. Ethanol-soluble carbohydrates are the most abundant components of prickly pear fruit pulp and skin, making up 50% of the pulp and 30% of the skin. The betalain compounds are responsible for the various colors of the fruit. The skin contains calcium, iron, potassium, magnesium, manganese, sodium, and selenium. , The edible pulp contains biothiols, taurine, flavonols, tocopherols, and carotenoids. , However, industrial processing of juice components results in some loss of vitamins A, E, and C. , The seeds are rich in phosphorus and zinc. The oils from the seeds and peel are a good source of polyunsaturated fatty acids. , ,

Several older chemical analyses of enzymes from Opuntia species are available. , , , One study documents the volatile constituents of prickly pear, while another identifies the constituents of O. fragilis . Other studies discuss the chemistry of prickly pear, including isolation of albumin, amino acid composition in the fruits, and fatty acids of the seeds.

Uses and Pharmacology

Diabetes

A mechanism of action remains to be discovered in diabetes; however, polysaccharides may be responsible for the plant's hypoglycemic activity.

Animal data

An extract of O. fulginosa prickly pear maintained normal blood glucose and glycated hemoglobin levels in streptozotocin-induced diabetic rats after insulin was withdrawn. Similar results were obtained with O. megacantha in reducing blood glucose in normal and streptozocin-induced diabetic rats. However, O. megacantha was nephrotoxic as shown by elevated plasma urea and creatinine concentrations and reduced plasma sodium concentrations. ,

Clinical data

The hypoglycemic effects of Opuntia species are documented in numerous studies. , , , , , , One open-label study of 14 patients found that O. streptacantha decreased glucose and insulin levels in patients with noninsulin-dependent diabetes mellitus; however, the plant had no effect on glucose or insulin levels in healthy volunteers. Another open-label study involving 32 patients with type 2 diabetes treated with O. streptacantha also resulted in decreased glucose and insulin levels.

Hyperlipidemia
Animal data

Two animal studies examined the effect of prickly pear seed oil on serum and lipid parameters in rats. , An increase in high-density lipoprotein cholesterol and a reduction in serum cholesterol was observed in rats treated with seed oil. Raw O. ficus-indica had beneficial effects on hypercholesterolemia in rats. A pectin isolate from Opuntia decreased low-density lipoprotein (LDL) metabolism in guinea pigs. , ,

Clinical data

In one small study of 29 patients, prickly pear significantly reduced cholesterol levels. Prickly pear may have antiplatelet activity, which may be useful in patients with prothrombotic conditions such as diabetes and hyperlipidemia. Eight healthy volunteers and 8 patients with familial heterozygous hypercholesterolemia were treated with prickly pear 250 mg for 2 months. Significant ( P > 0.01) decreases in total and LDL-cholesterol and reduced platelet proteins were found.

Opuntia capsules in a human trial had marginally beneficial effects on cholesterol and glucose levels.

Inflammation

The mechanism of action is associated with the anti-inflammatory principle β-sitosterol.

Animal data

Anti-inflammatory actions were demonstrated in Opuntia dillenii in an induced rat paw edema model. β-sitosterol from the fresh stems of prickly pear had potent anti-inflammatory activity in an adjuvant-induced chronic inflammation model in mice.

Clinical data

Prickly pear may inhibit the production of inflammatory mediators associated with the symptoms of alcohol hangover. In a double-blind, placebo-controlled, crossover trial, 55 healthy volunteers received placebo or 1,600 units of prickly pear 5 hours before consuming alcohol. Patients consumed 1.75 g alcohol/kg of body weight over 4 hours. C-reactive protein and symptoms such as nausea, dry mouth, and anorexia were reduced in patients treated with prickly pear.

Ulcers

A cytoprotective mechanism is associated with an interaction between the mucilage monosaccharides from prickly pear and membrane phospholipids. ,

Animal data

Histological evidence supports the efficacy of prickly pear cladodes against the formation of ethanol-induced ulcers.

Clinical data

No clinical trials could be found.

Other pharmacological effects
Antioxidant

Opuntia species have antioxidant activity that may be associated with their phenolic content. Short-term supplementation with 250 g of fresh fruit pulp in a comparative study and a study of patients with familial isolated hypercholesterolemia reduced oxidative damage to lipids and improved oxidative stress status of treated patients.

Diuretic

Prickly pear cladode, fruit, and flower infusions increased diuresis in a rat model.

Neuroprotective effects

Animal models in rats demonstrated that the flavonoids isolated from O. ficus-indica var. saboten species had neuroprotective activity against oxidative injury induced in cortical cell cultures and neuronal damage induced by global ischemia. , ,

Nutrition

Prickly pear fruit liquid has been studied as a natural sweetener. Opuntia has been studied as a source of dietary fiber.

Viral activity

One study reports O. streptacantha antiviral action in animals and humans.

Wound healing

Histological evidence documents that topical application of polysaccharide extracts from prickly pear cladodes enhanced cutaneous repair and healing of large, full-thickness wounds in a rat model. , The polysaccharides from prickly pear cladodes have been studied for their chondroprotective effects in treating joint diseases.

Dosage

Prickly pear is commercially available in numerous doseforms, including capsules, tablets, powders, and juices, and as food. Follow manufacturers' suggested guidelines if using commercial products. Typical dosage regimens are two 250 mg capsules by mouth 3 times a day or every 8 hours.

Pregnancy/Lactation

Avoid use during pregnancy and lactation because of the lack of clinical studies.

Interactions

Prickly pear may theoretically exacerbate hypoglycemia in patients being treated with hypoglycemic agents (eg, metformin, glyburide, rosiglitazone, acarbose). Prickly pear may also exacerbate diuresis in patients being treated with diuretic agents (eg, furosemide, hydrochlorothiazide). However, these interactions are not well documented.

Adverse Reactions

Dermatitis from prickly pear is the most common adverse reaction. A case report of cactus dermatitis in a 2-year-old child was described after contact with O. microdasys . Two other patients were also affected by this species, both experiencing dermatitis and one developing severe keratoconjunctivitis in the right eye. A case of cactus granuloma in a 24-year-old man is described from contact with O. bieglovii thorns. Granuloma formation has also been seen from O. acanthocarpa spines embedded in the dermis, with onset occurring within several days and lasting several months. Treatment with topical corticosteroids has been recommended. ,

Toxicology

Patients hypersensitive to any components of prickly pear should avoid use. O. streptacantha is nontoxic in mice, horses, and humans in oral and intravenous preparations. O. megacantha is nephrotoxic in rats. ,

Bibliography

1. DeFelice MS . Prickly pear cactus, Opuntia spp. A spine-tingling tale . Weed Technol . 2004 ; 18 ( 3 ): 869-877 .
2. Hou rou HN . The role of cacti ( Opuntia spp.) in erosion control, land reclamation, rehabilitation and agricultural development in the Mediterranean Basin . J Arid Environ . 1996 ; 33 ( 2 ): 135-159 .
3. Synman HA . A greenhouse study on root dynamics of cactus pears, Opuntia ficus-indica and O. robusta . J Arid Environ . 2006 ; 65 ( 4 ): 529-542 .
4. Saleem M , Kim HJ , Han CK , Jin C , Lee YS . Secondary metabolites from Opuntia ficus-indica var. saboten . Phytochemistry . 2006 ; 67 ( 13 ): 1390-1394 .
5. van Sittert L . Our irrepressible fellow-colonist: the biological invasion of prickly pear ( Opuntia ficus-indica ) in the Eastern Cape c.1890-c.1910 . J Hist Geogr . 2002 ; 28 ( 3 ): 397-419 .
6. Hocking GM . A Dictionary of Natural Products . Medford, NJ: Plexis Publishing, Inc; 1997 : 546-547 .
7. Chevallier A . The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing; 1996 : 240 .
8. Gurrieri S , Miceli L , Lanza CM , Tomaselli F , Bonomo RP , Rizzarelli E . Chemical characterization of Sicilian prickly pear ( Opuntia ficus indica ) and perspectives for the storage of its juice . J Agric Food Chem . 2000 ; 48 ( 11 ): 5424-5431 .
9. Kim JH , Park SM , Ha HJ , et al. Opuntia ficus-indica attenuates neuronal injury in in vitro and in vivo models of cerebral ischemia . J Ethnopharmacol . 2006 ; 104 ( 1-2 ): 257-262 .
10. D'Amelio FS . Botanicals: A Phytocosmetic Desk R