Opuntia streptacantha

Opuntia streptacantha Lem.: A Comprehensive Reference

1. Identity and Botanical Classification

1.1 Accepted Name and Taxonomy

Opuntia streptacantha Lem. is the accepted scientific name for this species, first formally described by the French botanist Charles Lemaire in 1839 in his work Cactearum Genera Nova Speciesque Novae. In the NCBI taxonomy, Opuntia streptacantha Lem., 1839, is classified within the kingdom Plantae, phylum Streptophyta, class Magnoliopsida, order Caryophyllales, family Cactaceae, subfamily Opuntioideae, genus Opuntia. Within the subfamily, the species belongs to the tribe Opuntieae and the series Streptacanthae.

The genus name Opuntia encompasses a large and diverse group of cacti. The Cactaceae family includes about 200 genera and 2,000 species classified into three to six subfamilies; the Opuntioideae subfamily comprises between 15 and 18 genera, with Opuntia being the most diverse and widely distributed genus in the American continent. The species epithet streptacantha is derived from the Greek words streptos (twisted) and acantha (thorn), referring to the plant's characteristically twisted spines.

1.2 Synonyms

Recognized synonyms in taxonomic databases include Opuntia cardona F.A.C. Weber. Additional synonyms accepted by Plants of the World Online (Kew Science) include Opuntia coindetti F.A.C. Weber, Opuntia diplacantha A. Berger, Opuntia pachona Griffiths, and the subspecies Opuntia streptacantha subsp. aguirriana Scheinvar & A. Rodr. The species is recognized as having six synonyms in total by the Kew World Checklist of Selected Plant Families.

1.3 Common Names

Opuntia streptacantha is known by a wide range of common names. In Spanish these include: cardón, nopal cardón, nopal hartón, cenizo, chaveño, and tuna cardona. In English, it is called cardona pear, Gracemere pear, Westwood pear, and white-spine prickly pear. In older historical sources, the species was also called tecolonochtli or tecolonochnopalli in Nahuatl, and is referred to as the cardon nopal or cardona tuna. Among the most frequently used Opuntia species in traditional Mexican medicine, O. streptacantha is popularly known as "xoconoxtle" (xoconoste/xoconōchtli), meaning sour prickly pear.

1.4 Botanical Description and Natural Source

Opuntia is a diverse and widely distributed genus in Africa, Asia, Australia, and America, with Mexico having the largest number of wild species; the most representative of these are O. streptacantha, O. hyptiacantha, O. albicarpa, O. megacantha, and O. ficus-indica. In traditional regional farming classifications of Mexico, O. streptacantha was identified as a fruit species with broad pads. Its fruit (tuna) is described as intense red, aromatic, and refreshing, and the species holds great importance in semi-arid and desert zones of Mexico. O. streptacantha has a wide distribution, is locally abundant, and is classified as "Least Concern" on the IUCN Red List of Threatened Species (2017).

The plant grows predominantly in central and northern Mexico. The greatest opuntia populations, including O. streptacantha, are found in the states of San Luis Potosí, Tamaulipas, and Nuevo León. Its native distribution extends from central Mexico northward and into Guatemala. According to Plants of the World Online, the species is recorded from Guatemala, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Southwest, and has also been naturalized in Queensland (Australia) and Spain.

1.5 Plant Parts Used and Common Preparations

All major plant parts of O. streptacantha have documented uses. Most studies coincide in noting differences among the phytochemical composition of the various plant parts, including fruits, roots, cladodes (stem pads), flowers, seeds, and stems, as well as differences between wild and domesticated species.

The primary plant parts used as food and medicine are:

• Cladodes (stem pads / nopalitos): This species is a major source of "nopalitos," the edible stem sections that are very popular in Mexico. The plant is cultivated across its range, and its parts are also traded locally to elaborate products such as melcocha honey, red wine, colonche, and jelly.
• Fruit (tuna): The juice of the tuna (fruit) of O. streptacantha is used, among other species, for the preparation of "colonche," a traditional fermented beverage consumed by indigenous people from Chihuahua and Sonora (especially Tarahumaras and Yaquis) and by mestizo populations in Zacatecas, San Luis Potosí, Querétaro, Guanajuato, and Hidalgo, in season. The Aztecs called this drink "nochoctli" (from Nahuatl "nochtli," tuna and "octli," wine), while the word "colonche" derives from Nahuatl "coloa," meaning to stoop.
• Aqueous extracts and preparations: In clinical and pharmacological research, both broiled (cooked) stems and various extract forms (homogenate, dialysate, crude supernatant, precipitate) have been studied.
• Polysaccharide isolates: Purified polysaccharide fractions from cladode mucilage have been isolated and studied for their biological activity.

2. Historical and Traditional Use

2.1 Pre-Columbian and Aztec Period

The utilization of Opuntia by humans was recorded in Mexico in pre-Hispanic times, where it played a major role in the agricultural economy of the Aztec empire; together with maize (Zea mays) and agave (Agave spp.), opuntias are among the oldest cultivated plants in Mexico. Some evidence indicates that Opuntia plants have been consumed by humans for more than 8,000 years, and due to their easy adaptation and spread in different types of soil, their domestication process favored the constant collection of cladodes and fruit by human populations.

Together with maize and agave, opuntia was a staple food instrumental in enabling human settlement and cultural development of the Chichimeca groups of the centre and north of Mexico; complementary to its importance as food were, among other uses, its uses as a beverage, medicine, source of dye, and as an object of magical-religious practices. In Mexico, these Opuntia cacti are known as "nopal," derived from the Nahuatl word "nochtli." The Aztecs used juice from this cactus to treat burns and other ailments, and they considered it sacred.

Pre-colonial medicinal records indicate that opuntia was used to cure burns: the burned part of the body was treated with the juice of the nopal.

2.2 Colonial and Post-Colonial Period

Friar Francisco de Ajofrín, who traveled through New Spain in the 18th century, reported that there were opuntia fruits (tunas) available almost year-round, some white, some yellow, and some more fleshy. Miguel Venegas also noted in the 18th century that in California the red tunas were less common, and in New Spain these were called "tunas taponas."

2.3 Ethnobotanical Use for Diabetes and Metabolic Conditions

Opuntia species have been used for centuries as food resources and in traditional folk medicine for their nutritional properties and their benefits in chronic diseases, particularly diabetes, obesity, cardiovascular diseases, and cancer; these plants are largely distributed in America, Africa, and the Mediterranean basin.

Nopal (Opuntia sp.) has been traditionally used by the Mexican population for the treatment of diabetes mellitus. O. streptacantha specifically was identified by indigenous and mestizo healers as particularly effective for this purpose; this traditional knowledge formed the basis for the first formal pharmacological and clinical investigations of the species conducted in Mexico from the 1980s onward.

2.4 Traditional Food Uses

The Opuntia species (also collectively called nopal cactus) has been used for food and medicinal purposes in Mexico since before the time of the Aztecs; the fruits (known as "tunas") and the cladodes (botanically known as cladodes) are eaten on a daily basis, with the cladodes being consumed as a nutritious green vegetable once the spines have been removed. Known as "nopales" in Mexico, where they are a common ingredient in numerous dishes, they can be eaten raw or cooked, used in marmalades, soups, stews, and salads.

3. Key Constituents and Active Compounds

3.1 Overview of Phytochemical Profile

The main bioactive compounds of Opuntia species include pigments (carotenoids, betalains, and betacyanins), vitamins, flavonoids (isorhamnetin, kaempferol, quercetin), and phenolic compounds. Other phytochemical components, including biopeptides and soluble fibers, have also been characterized and contribute to the medicinal properties of Opuntia spp.

Most studies note differences in phytochemical composition among various plant parts (fruits, roots, cladodes, flowers, seeds, and stems) as well as between wild and domesticated species; these variations can be attributed to environmental conditions (climate, humidity), soil type, cladode maturity, and harvest season.

3.2 Polysaccharides and Mucilage

The mucilage of Opuntia cladodes is a complex polysaccharide resulting from the polymerization of monosaccharides including arabinose, galactose, rhamnose, xylose, and uronic acids (e.g., galacturonic acid), and is present in the internal layer of the cladodes. This mucilage fraction is considered a principal bioactive component, particularly in relation to the hypoglycemic and lipid-modulating effects observed.

Polysaccharides were isolated specifically from O. streptacantha cladodes in work cited by Alarcon-Aguilar et al. (2003). The polysaccharide from O. streptacantha (designated POLOS) was isolated by Zempoaltecatl (1999) under the direction of Dr. Manuel Jimenez Estrada at the Chemistry Institute of the Autonomous National University of Mexico. Fresh cladodes (2 kg) were ground and filtered, the filtrate was centrifuged and the supernatant precipitated with acetone (1:2), yielding 60 g of crude polysaccharide; these were then purified by dialysis using a 3,500 Da membrane for three days, yielding 824 mg of the purified polysaccharide POLOS.

3.3 Phenolic Compounds and Flavonoids

Numerous polyphenolic acids, including ferulic acid, p-coumaric acid, 4-hydroxybenzoic acid, caffeic acid, salicylic acid, and gallic acid, have been identified in Opuntia cladodes. The flavonoids isorhamnetin, kaempferol, and quercetin are among the most consistently reported flavonoid constituents across Opuntia species and are associated with antioxidant, anti-inflammatory, and metabolic effects documented in preclinical research.

3.4 Betalains and Pigments

Chemical characterization of O. streptacantha fruit extracts has documented the presence of 343 ng/L of phenolic compounds, 54 μg of flavonoids/mL, 66 mg of ascorbic acid/L, 124 mg of betalains/L, 187 mg of betacyanin/L, and 36 mg of betaxanthin/L. These pigment compounds are associated with antioxidant activity and hepatoprotective properties observed in experimental models.

3.5 Antiviral Protein Fraction

The active inhibitory component(s) of O. streptacantha extract identified in antiviral studies appeared to be protein in nature and resided mainly in the wall of the plant rather than in the cuticle or inner sap.

4. Established and Proposed Mechanisms of Action

4.1 Glucose Metabolism and Insulin Sensitivity

Several mechanisms have been proposed to explain the hypoglycemic effects of O. streptacantha. In the seminal clinical study by Frati-Munari et al. (1988), the mechanism of the hypoglycemic effect was acknowledged as unknown, but increased insulin sensitivity was suggested.

Alarcon-Aguilar et al. (2003) investigated the hypoglycemic activity of two polysaccharides isolated from O. ficus-indica and O. streptacantha, published in the Proceedings of the Western Pharmacology Society, 46, 139–142. The results suggest that the hypoglycemic effect produced by the polysaccharide can be explained by a mechanism that reduces the intestinal absorption of glucose due to some effect of the soluble dietary fiber present.

A further mechanism involves inhibition of the enzyme alpha-glucosidase. Becerra-Jiménez and Andrade-Cetto (2012) specifically examined the effect of Opuntia streptacantha Lem. on alpha-glucosidase activity, published in the Journal of Ethnopharmacology, 139(2), 493–496. Alpha-glucosidase inhibition delays the digestion and absorption of dietary carbohydrates in the small intestine, thereby reducing postprandial blood glucose peaks — a mechanism analogous to that of pharmaceutical alpha-glucosidase inhibitors such as acarbose.

The hypoglycemic efficacy of broiled (heated) O. streptacantha extracts was reported to be higher than that of raw preparations, as documented by Frati-Munari et al. in patients consuming broiled O. streptacantha extracts.

4.2 Antioxidant and Hepatoprotective Mechanisms

The hepatoprotective effect of some natural products is related to their antioxidant capacity to prevent liver cell damage or death; results from experimental studies suggest that the frequent consumption of O. streptacantha provides bioactive compounds with antioxidant activity that counteract cellular oxidative damage.

In a model of acute acetaminophen intoxication, O. streptacantha partially prevents depletion of glutathione (GSH), and treatment with Opuntia restored GSH concentration close to control levels.

4.3 Antiviral Mechanisms

An extract of Opuntia streptacantha inhibited intracellular virus replication and inactivated extracellular virus. Inhibition of virus replication also occurred following pre-infection treatment — a favorable finding in terms of in-vivo limitation of viral disease. There was inhibition of both DNA and RNA virus replication, including herpes simplex virus, equine herpes virus, pseudorabies virus, influenza virus, respiratory syncytial virus, and human immunodeficiency virus, with normal protein synthesis maintained in uninfected cells at extract concentrations 15-fold in excess of 50% viral inhibitory concentrations (1 mg/mL).

5. Scientific Evidence by Area of Use

5.1 Blood Glucose Regulation and Type 2 Diabetes (NIDDM/T2DM)

This is the most extensively studied clinical application of O. streptacantha. The body of human evidence consists largely of small open-label trials conducted in Mexican hospital settings during the 1980s and early 1990s, primarily by the research group of Alberto C. Frati-Munari at the Hospital de Especialidades del Centro Médico La Raza, Instituto Mexicano del Seguro Social (IMSS), Mexico City.

Key Human/Clinical Studies

Frati-Munari et al. (1988) — Diabetes Care 11(1):63–66

This is the foundational clinical study of the species. To assess the hypoglycemic effect of O. streptacantha, three groups of patients with non-insulin-dependent diabetes mellitus (NIDDM) were studied: Group 1 (16 patients) ingested 500 g of broiled nopal stems; Group 2 (10 patients) received only 400 ml of water as a control; Group 3 (6 patients) underwent three tests — one with nopal, one with water, and one with 500 g broiled squash. Serum glucose and insulin levels were measured at 0, 60, 120, and 180 minutes. After intake of O. streptacantha, serum glucose and insulin levels decreased significantly in Groups 1 and 3, whereas no similar changes occurred in Group 2. The mean reduction of glucose reached 17.6 ± 2.2% of basal values at 180 minutes in Group 1 and 16.2 ± 1.8% in Group 3; the reduction of serum insulin at 180 minutes reached 50.2 ± 8.0% in Group 1 and 40.3 ± 12.4% in Group 3.

Frati-Munari et al. (1989) — Study of raw extracts

To determine the extent of the hypoglycemic effect of crude extracts of O. streptacantha, eight patients with Type II diabetes mellitus were studied. Five tests were performed per patient with: (A) supernatant, (B) precipitate, (C) complete homogenate of 500 g of crude stem, (D) 400 ml of water, and (E) 500 g of broiled Opuntia stems. Serum glucose levels were measured at 0, 30, 60, 120, and 180 minutes. Crude extracts did not cause a significant decrease of glycemia (P > 0.05) and results were similar to the water control. The intake of broiled Opuntia stems caused a significant decrease of serum glucose that reached 48.3 ± 16.2 mg/dL lower than basal values at 180 minutes (P < 0.01). This finding indicates that heat processing (broiling) is necessary for the hypoglycemic effect to manifest.

Frati-Munari et al. — Duration study (8 Type II diabetics)

To assess the duration of the hypoglycemic effect, two fasting tests — one with 500 g of broiled Opuntia stems and one with 400 ml of water as control — were performed in eight Type II diabetics, with serum glucose measured hourly over six hours. In the Opuntia test, the decrease in serum glucose levels was most pronounced at the fourth hour (P < 0.01 vs. control), with glucose levels remaining unchanged over the following two hours. No significant changes in glycemia occurred in the control test.

Frati-Munari et al. — Healthy subjects with induced hyperglycemia

The hypoglycemic effect of O. streptacantha that occurs in diabetic patients was not found in healthy subjects. To determine if this effect appears in healthy individuals when they are hyperglycemic, two tests were performed in 7 healthy volunteers who received intravenous dextrose infusion. This study demonstrated that the glucose-lowering effect appears to be conditional on an elevated blood glucose state.

Open-label studies — summary

One open-label study of 14 patients found that O. streptacantha decreased glucose and insulin levels in patients with non-insulin-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.

Dose-response relationship

Several reports confirm an important O. streptacantha hypoglycemic effect up to three hours after ingestion in different preparations, and there is a direct correlation between Opuntia dose and its hypoglycemic effect (Frati-Munari et al., 1989).

Evidence Strength Assessment (Blood Glucose)

The clinical evidence for blood glucose lowering in patients with NIDDM/T2DM is preliminary to moderate. All positive human trials are small, open-label, and unblinded, with no placebo control, and were conducted by a single research group in the 1980s–1990s. The absence of larger randomized controlled trials (RCTs) and the lack of independent replication in modern trial designs substantially limit the certainty of the evidence. Mechanistic data (alpha-glucosidase inhibition; soluble fiber effects on intestinal glucose absorption) are supportive but derive from in vitro or animal experiments rather than from human mechanistic studies.

5.2 Lipid Metabolism

Broader Opuntia genus research, including some work with O. streptacantha, has examined effects on serum lipids. Extracts of these cacti have been described as important sources of bioactive substances with beneficial properties for the prevention and treatment of certain metabolic disorders; current data show that Opuntia products used in preclinical studies have a significant capacity to prevent, at least partially, obesity and certain derived co-morbidities. However, robust clinical evidence specific to O. streptacantha for lipid outcomes is limited. The available evidence for lipid-lowering effects is primarily animal-derived and cannot be extrapolated directly to human populations without further clinical study.

5.3 Antiviral Activity

Ahmad, Davies, Randall & Skinner (1996) — Antiviral Research 30:75–85

An extract of Opuntia streptacantha inhibited intracellular virus replication and inactivated extracellular virus. Inhibition of virus replication also occurred following pre-infection treatment. Inhibition of both DNA and RNA virus replication was demonstrated for herpes simplex virus, equine herpes virus, pseudorabies virus, influenza virus, respiratory syncytial virus, and HIV, with normal protein synthesis in uninfected cells at extract concentrations 15-fold in excess of 50% viral inhibitory concentrations (1 mg/mL). The extract was non-toxic on oral administration to mice, horses, and human patients; non-toxicity of intravenous administration of 70 mg to a mouse represented at least a fifty-fold safety margin.

This antiviral study of O. streptacantha Lem. against viruses in cell culture represents the only report on antiviral activity of the Opuntia genus.

Evidence Strength Assessment (Antiviral)

The antiviral evidence is very preliminary — consisting of a single in vitro and animal study with limited human data. No controlled clinical trials of antiviral efficacy in human patients have been conducted for O. streptacantha extracts.

5.4 Hepatoprotective Effects

González-Ponce et al. (2016) — Nutrients 8:607

This study evaluated the hepatoprotective effect of Opuntia robusta and Opuntia streptacantha fruit extracts against acetaminophen (APAP)-induced acute liver failure. Fruit extracts (800 mg/kg/day, orally) were given prophylactically to male Wistar rats before intoxication with APAP (500 mg/kg, intraperitoneally). Opuntia robusta had significantly higher levels of antioxidants than Opuntia streptacantha. Both extracts significantly attenuated APAP-induced injury markers AST, ALT, and ALP and improved liver histology. The Opuntia extracts reversed APAP-induced depletion of liver GSH and glycogen stores. In cultured hepatocytes, Opuntia extracts significantly reduced leakage of LDH and cell necrosis, both prophylactically and therapeutically. Both extracts appeared to be superior to NAC when used therapeutically. The authors concluded that Opuntia extracts are hepatoprotective and can be used as a nutraceutical to prevent acute liver failure.

Evidence Strength Assessment (Hepatoprotective)

Hepatoprotective evidence for O. streptacantha is preclinical only (animal model and cell culture). No human clinical data are available for this indication.

5.5 Antioxidant Activity

The main bioactive compounds of Opuntia spp. — pigments (carotenoids, betalains, betacyanins), vitamins, flavonoids (isorhamnetin, kaempferol, quercetin), and phenolic compounds — are considered phytochemically important and are associated with control, progression, and prevention of some chronic and infectious diseases.

The biological properties of Opuntia spp. have been investigated on cellular and animal models and in clinical trials in humans, allowing characterization and clarification of the protective effect of Opuntia-enriched diets in chronic diseases. For O. streptacantha specifically, antioxidant capacity has been quantified in fruit extracts and compared to related species, though most mechanistic antioxidant data remain preclinical.

6. Body Systems and Health Areas Associated with O. streptacantha

• Endocrine/Metabolic system: Blood glucose modulation (multiple human open-label studies in T2DM patients); insulin sensitivity (proposed mechanism); alpha-glucosidase inhibition (in vitro).
• Hepatic system: Hepatoprotective effects against oxidative liver damage, GSH restoration, attenuation of liver injury markers AST, ALT, and ALP (animal and cell culture studies).
• Immune and antiviral: Broad-spectrum inhibition of DNA and RNA virus replication in cell culture; active component protein-based (single in vitro/animal study).
• Cardiovascular and lipid metabolism: Preliminary and genus-wide evidence for lipid modulation; no species-specific clinical trials for O. streptacantha on lipids available from reviewed sources.
• Gastrointestinal system: Mucilage and soluble fiber content proposed to reduce intestinal glucose absorption; potential prebiotic effects from mucilage polysaccharides (studied in related species).

7. Dosage Forms and Doses Reported in Studies

The following doses are reported directly from published sources:

• Broiled nopal stems (clinical, human): 500 g of broiled nopal stems, consumed as a single dose. This was the dose used in the foundational Frati-Munari et al. (1988) clinical trial and repeated in several subsequent studies by the same group.
• Water control (clinical, human): 400 ml of water, used as the control comparator.
• Crude stem preparations (clinical, human): 500 g of crude O. streptacantha stem in various forms (supernatant, precipitate, complete homogenate) compared to broiled stems.
• Duration study dose (clinical, human): 500 g of broiled Opuntia stems consumed as a single dose, with glycemia measured hourly for six hours.
• Fruit extract (animal study): 800 mg/kg/day of fruit extract, administered orally to male Wistar rats for hepatoprotection studies.
• Antiviral concentration (in vitro): Concentrations 15-fold in excess of the 50% viral inhibitory concentration (1 mg/mL) did not affect normal protein synthesis in uninfected cells.

No standardized supplemental dosage for O. streptacantha has been established by any pharmacopeia, regulatory health body, or systematic review. The doses described in the literature are those used in specific experimental contexts and should not be interpreted as recommended supplemental doses.

8. Safety Considerations and Interactions

8.1 Oral Safety in Humans and Animals

In the antiviral study by Ahmad et al. (1996), the plant extract was non-toxic on oral administration to mice, horses, and human patients; intravenous administration of 70 mg to a mouse was also non-toxic, representing at least a fifty-fold safety margin over the effective antiviral concentration.

In the repeated clinical studies by Frati-Munari et al. involving Type 2 diabetic patients consuming 500 g of broiled stems, no serious adverse events were reported in the published literature. However, these studies were short-term (up to six hours per session) and small in scale; long-term safety data in humans specific to O. streptacantha are not available from the sources reviewed.

8.2 Potential for Additive Hypoglycemic Effects

A clinically relevant safety consideration follows from the documented glucose-lowering effect: patients with T2DM taking antidiabetic medications (including insulin, sulfonylureas, or metformin) who also consume significant quantities of O. streptacantha may theoretically be at increased risk of hypoglycemia due to an additive effect. The stems of O. streptacantha Lem. cause a hypoglycemic effect in patients with NIDDM; the mechanism of this effect remains unknown, but increased insulin sensitivity is suggested. This pharmacodynamic interaction has not been evaluated in formal drug-interaction studies, and the magnitude of any additive effect is uncertain from the published record.

8.3 Effect Specific to Diabetic State

The hypoglycemic effect of O. streptacantha that occurs in diabetic patients has not been found in healthy subjects. This suggests that the mechanism of action is conditional on an elevated blood glucose environment, which has implications for both efficacy and safety prediction.

8.4 Comparative Antioxidant Profile and Liver Safety

In comparative studies, Opuntia robusta had significantly higher levels of antioxidants than Opuntia streptacantha; both extracts significantly attenuated APAP-induced liver injury markers AST, ALT, and ALP and reversed APAP-induced depletion of liver GSH and glycogen stores. This hepatoprotective characterization was conducted in animal models only and does not demonstrate direct liver safety in humans consuming O. streptacantha.

8.5 Processing-Dependent Activity

A practically important finding concerns the necessity of heat treatment for glycemic activity: crude extracts of O. streptacantha did not cause a significant decrease of glycemia (results similar to water control, P > 0.05); the intake of broiled Opuntia stems caused a significant decrease of serum glucose reaching 48.3 ± 16.2 mg/dL lower than basal values at 180 minutes (P < 0.01). This implies that raw or unheated preparations may lack the hypoglycemic activity documented in cooked forms, a consideration relevant both for efficacy and for safety when extrapolating results to supplement products.

8.6 IUCN and Conservation Status

O. streptacantha has a wide distribution, is locally abundant, and is classified as "Least Concern" on the IUCN Red List of Threatened Species (2017). Wild harvesting of cladodes and fruit for food and supplement use therefore does not present an immediate conservation concern at the species level.

References

• del Socorro Santos Díaz M. et al. — Opuntia genus in Human Health: A Comprehensive Summary on Its Pharmacological, Therapeutic and Preventive Properties. Part 1. Horticulturae 2022; 8(2):88.
• Del Socorro Santos Díaz M. et al. — Opuntia spp. in Human Health: A Comprehensive Summary on Its Pharmacological, Therapeutic and Preventive Properties. Part 2. Plants 2022; 11(18):2333. PMC9505094.
• Ahmad A., Davies J., Randall S., Skinner G.R.B. — Antiviral properties of extract of Opuntia streptacantha. Antiviral Research 1996; 30:75–85. PubMed PMID 8783800.
• Frati-Munari A.C., Gordillo B.E., Altamirano P., Ariza C.R. — Hypoglycemic effect of Opuntia streptacantha Lemaire in NIDDM. Diabetes Care 1988; 11(1):63–66. PubMed PMID 3276479.
• Frati-Munari A.C. et al. — Hypoglycemic action of Opuntia streptacantha Lemaire: study using raw extracts. Arch Invest Med (Mex) 1989. PubMed PMID 2488772.
• Frati-Munari A.C. et al. — Duration of the hypoglycemic action of Opuntia streptacantha Lem. Arch Invest Med (Mex) 1989. PubMed PMID 2488768.
• Frati-Munari A.C. et al. — Activity of Opuntia streptacantha in healthy individuals with induced hyperglycemia. PubMed PMID 2103713.
• del Socorro Santos Díaz M. et al. — Opuntia spp.: Characterization and Benefits in Chronic Diseases. Oxidative Medicine and Cellular Longevity 2017; 2017:8634249. PubMed PMID 28491239.
• del Socorro Santos Díaz M. et al. — Opuntia spp.: Characterization and Benefits in Chronic Diseases. PMC5401751.
• González-Ponce H.A. et al. — Hepatoprotective Effect of Opuntia robusta and Opuntia streptacantha Fruits against Acetaminophen-Induced Acute Liver Damage. Nutrients 2016; 8:607. PMC5083995.
• Alarcon-Aguilar F.J. et al. — Hypoglycemic activity of two polysaccharides isolated from Opuntia ficus-indica and O. streptacantha. Proc West Pharmacol Soc 2003; 46:139–142. PubMed PMID 14699912.
• Usefulness of Opuntia spp. on the Management of Obesity and Its Metabolic Co-Morbidities. PMC11085070.
• Gouws C.A. et al. — Effects of the Consumption of Prickly Pear Cacti (Opuntia spp.) and its Products on Blood Glucose Levels and Insulin: A Systematic Review. Medicina 2019; 55(5):138. PMC6572313.
• GBIF — Opuntia streptacantha Lem. Taxon entry.
• Plants of the World Online (Kew Science) — Opuntia streptacantha Lem.
• NCBI Taxonomy Browser — Opuntia streptacantha.
• FAO — Introduction: Cactus (Opuntia spp.) as Forage.
• FAO — History of the Use of Opuntia as Forage in Mexico.
• ScienceDirect Topics — Opuntia streptacantha overview (including colonche traditional use).
• Opuntia spp.: An Overview of the Bioactive Profile and Food Applications of This Versatile Crop Adapted to Arid Lands. PMC10094368.
• Beneficial Effects of Opuntia spp. on Liver Health. PMC10294873.
• Castaneda-Andrade I., Gonzalez-Sanchez J., Frati-Munari A.C. — Hypoglycemic Effect of an Opuntia streptacantha Lemaire Dialysate. Journal of the Professional Association for Cactus Development 1997; 2:73–75.
• Hepatoprotective Effect of Opuntia robusta Fruit Biocomponents in a Rat Model of Thioacetamide-Induced Liver Fibrosis. PMC9370284.
• Beneficial Effects of Opuntia humifusa on Human Health: Systematic Review and Meta-Analysis. PMC9854510.