Finger-Leaf Morning Glory (Ipomoea cairica): A Comprehensive Reference
1. Identity and Botanical Description
1.1 Botanical Name and Taxonomy
Ipomoea cairica (L.) Sweet is a species of flowering plant in the morning glory family, Convolvulaceae, commonly known as the five-fingered morning glory or mile-a-minute vine. The epithet cairica translates to "from Cairo," the city where the species was first collected. The plant carries a long list of accepted synonyms; notable synonyms include Convolvulus cairicus L., Convolvulus tuberculatus Desr., Ipomoea palmata Forssk., and Ipomoea pentaphylla Cav.
The family Convolvulaceae comprises about 59 genera and 1,880 species, and the genus Ipomoea is one of the largest within this family with more than 700 species mainly distributed in tropical and warm temperate regions of the world.
1.2 Common Names
Ipomoea cairica is a vining, herbaceous, perennial plant with palmate leaves and large, showy white to lavender flowers. Among its many common names are mile-a-minute vine, Messina creeper, Cairo morning glory, coast morning glory, and railroad creeper. Additional English names include coast morning glory, five-fingered morning glory, and Messina creeper. In Chinese, Ipomoea cairica is called "Five-Clawed Golden Dragon." In Hindi it is known as Giriya-val and Chatribel, and in isiZulu as ihlambe, ijalamu, intana, and umaholwana.
1.3 Morphology
The plant is a vigorous, perennial climber with a tuberous root that is brown outside and white inside. The stem grows up to about 5 m long and is smooth and twining. The leaves are green, palmate, and dissected into 5–7 leaflets, 30–100 mm in diameter. A hairless, slim climber with bulbous roots and a lignescent base, its leaf blade is ovate to circular in outline, 3 to 10 cm long and 6 to 9 cm wide, divided into five to seven segments that are lanceolate, ovate, or elliptic, entire, and pointed at the tip and base. The coast morning glory bears large, purple, trumpet-shaped flowers with a dark eye in the centre.
1.4 Geographic Distribution and Origin
Ipomoea cairica is an invasive climbing plant of probable origin from tropical Africa or Asia. It has been widely introduced as a garden ornamental across tropical, subtropical, and temperate regions. Currently, the species is listed as a weed in Thailand, Vietnam, the southern USA, and Central and South America, and as invasive and seriously harmful to the environment in southern China, Japan, Australia, Singapore, the Canary Islands, Cuba, and on many islands in the Pacific region.
1.5 Common Forms and Preparations
Most parts of the plant are edible. The roots are reportedly edible when cooked, and the leaves are eaten when young. In Nigeria, the plant is consumed as a vegetable in the south-south region. In research and traditional medicinal contexts, the plant is used as:
- Aqueous decoctions and concoctions prepared from leaves and roots, used in several traditional medicine systems.
- Ethanolic extracts of leaves, stems, and aerial parts, the most common form used in laboratory pharmacological studies.
- Methanolic extracts of leaves, aerial parts, and tubers, used in phytochemical and biological activity studies.
- Essential oil distilled from the plant, investigated primarily for larvicidal properties.
- The species is harvested from the wild in various regions for its nutritional, medicinal, and fibrous uses, and is cultivated both as a vegetable and as an ornamental plant.
2. Traditional and Historical Use
2.1 African Traditions
Zulu people use the plant medicinally, where they make a concoction with its crushed leaves and drink it to heal rashes and fever. The aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. Medicinally, it is used in Nigeria for treating jaundice, liver disorders, and as an aphrodisiac.
2.2 Brazilian and South American Folk Medicine
In Brazilian traditional medicine, I. cairica is used in the treatment of rheumatism and inflammations. Ethnobotanical records document the plant's use for treatment of rheumatism and inflammations. The treatment of inflammatory conditions using plant preparations is among the best-documented traditional uses in the South American context, and this claim was subsequently the basis for pharmacological investigation published in peer-reviewed literature.
2.3 Chinese Medicine
The plant is used in Chinese medicine for the treatment of tuberculosis, cough, asthma, acute and chronic viral hepatitis type B, liver cirrhosis, and jaundice.
2.4 Indian Traditional Use
Ipomoea cairica is used by different communities in Northeast India for various medicinal purposes. The species is harvested from the wild in various regions for its nutritional, medicinal, and fibrous uses. Medicinally, it is used as an antioxidant, anti-inflammatory, antiviral, and highly potent against malaria. It is used in rheumatism and inflammations, and as a carminative agent. It is considered useful in fever, jaundice, biliousness, bronchitis, liver complaints, and as an anti-cancerous agent.
2.5 Other Ethnobotanical Records
Traditional records from parts of Asia document the plant's use as an antidote to snake poison. Preparations of the plant may be used as a carminative agent and to lessen inflammation, and are described in traditional contexts as useful in fever, jaundice, biliousness, bronchitis, and liver complaints. The plant has been traditionally used to treat a variety of ailments, including diabetes, hypertension, liver diseases, cancer, and heart disease.
3. Key Phytochemical Constituents
3.1 Overview of Secondary Metabolite Classes
Phytochemical investigations have displayed that I. cairica contains a wide range of secondary metabolites, including flavonoids, phenolic acids, alkaloids, coumarins, tannins, and saponins, which contribute to its pharmacological potential. Phytochemical investigations have revealed the presence of diverse bioactive constituents such as coumarins, flavonoids, lignans, resin glycosides, and anthocyanins.
The detected phytochemicals in leaf extract include alkaloids, flavonoids, steroids, triterpenoids, reducing sugars, tannins, gums, and saponins. In the stem extract, flavonoids, steroids, triterpenoids, reducing sugars, tannins, and saponins are present.
3.2 Coumarins
From the aerial parts of Ipomoea cairica, the coumarins umbelliferone and scopoletin, and the dibenzyl-γ-butyrolactone lignans arctigenin, matairesinol, and trachelogenin, were isolated along with β-sitosterol and fatty acids. In a bioguided fractionation study of the ethanolic extract of I. cairica stems, coumarins, specifically 7-hydroxy-6-methoxychromen-2-one (scopoletin) and 7-hydroxychromen-2-one (umbelliferone), were identified as major compounds.
3.3 Lignans
Chemical studies of Ipomoea cairica led to isolation of arctiin, arctigenin, trachelogenin, matairesinol, umbelliferone, β-sitosterol, scopoletin, fatty acids, 4′,7-dimethylquercetin, 7-O-β-glucopyranosyl-4′-methylapigenin, friedelinol, and cyanidin-3-(p-coumaryl-caffeoyl)-sophoroside. Additional compounds obtained from the methanolic extract include (+)-(8R,8′S)-thujaplicatin methyl ether, arctigenin, matairesinol, trans-2,3-dibenzylbutyrolactone, vanillic acid, p-hydroxybenzoic acid, methoxybenzoic acid, methylparaben, stearic acid, palmitic acid, oleic acid, friedelinol, and a mixture of β-sitosterol and stigmasterol.
3.4 Resin Glycosides (Cairicosides)
Six partially acylated pentasaccharide resin glycosides, cairicosides A–F, were isolated from the aerial parts of Ipomoea cairica. These compounds were characterized as a group of macrolactones of simonic acid A, partially acylated with different organic acids. The lactonization site of 11S-hydroxyhexadecanoic acid (jalapinolic acid) was bound to the second saccharide moiety at C-3 in cairicosides A–E and at C-2 in cairicoside F. This species is also rich in pentasaccharide resin glycosides (cairicosides A–F), mainly in its aerial parts.
3.5 Flavonoids and Anthocyanins
Phytochemically, I. cairica is rich in phenolic compounds, flavonoids, tannins, anthocyanins, and carotenoids, which are known for their antioxidant and therapeutic properties. Recent studies have identified rare sulphated flavonoids such as ombuin-3-sulphate and rhamnetin-3-sulphate, along with quercetin and kaempferol glycosides, which exhibit significant antidiabetic activity through inhibition of α-glucosidase and α-amylase enzymes. Four new acylated anthocyanins have also been isolated from the flowers of Ipomoea cairica (L.) Sweet.
3.6 Caffeoylquinic Acids
From the bio-active fraction of the ethanolic extract used in an antinociceptive study, 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid were obtained. These compounds have been previously reported to have analgesic and antioxidative effects.
3.7 Tuber Composition
Phytochemical analyses of the Ipomoea cairica tuber revealed the presence of alkaloids, flavonoids, cyanogenic glycosides, tannins, phytate, and saponins. Quantitatively, the tuber contained flavonoid (1.52 ± 0.03%), alkaloid (2.10 ± 0.28%), tannin (0.05%), saponin (1.24 ± 0.04%), cyanogenic glycoside (0.05%), and phytate (0.02%).
4. Mechanisms of Action
4.1 Anti-inflammatory Mechanisms
Pharmacological effects are largely attributed to the plant's ability to modulate oxidative stress, inflammation, and enzymatic activity in various experimental models. The lignan arctigenin, one of the plant's principal isolates, has been found to inhibit MAP kinases and AP-1 activation via potent MKK inhibition, with a consequent role in TNF-alpha inhibition — a key mechanistic pathway for anti-inflammatory activity. Arctigenin presents antioxidant and anti-inflammatory activities.
4.2 Antinociceptive Mechanism
Ethanolic extract (100–3,000 mg/kg; per os) induced dose-dependent reduction of response in the formalin test inflammatory phase in mice. I. cairica is used in Brazilian folk medicine for the treatment of rheumatism and inflammations. The same dose range did not modify neurogenic pain in the formalin test, tail-flick reflex latency, carrageenan-induced paw edema, or Rota-Rod test motor performance, indicating a peripheral rather than central mechanism of action operating through the inflammatory pathway.
4.3 Antiviral / Anti-HIV Mechanism
Naturally occurring lignanolides isolated from Ipomoea cairica — (−)-arctigenin and (−)-trachelogenin — were found to inhibit strongly the replication of human immunodeficiency virus type 1 (HIV-1; strain HTLV-III B) in vitro. At a concentration of 0.5 µM, (−)-arctigenin and (−)-trachelogenin inhibited the expression of HIV-1 proteins p17 and p24 by 80–90% and 60–70%, respectively. The reverse transcriptase activity in culture fluids was reduced by 80–90% when cells were cultivated in the presence of 0.5 µM (−)-arctigenin or 1 µM (−)-trachelogenin.
These compounds were found to suppress the integration of proviral DNA into the cellular genome. More detailed experiments with purified HIV-1 integrase, however, showed (−)-arctigenin to be inactive in the cleavage (3′-processing) and integration (strand transfer) assays, suggesting the mechanism may be more complex or upstream of integrase activity.
4.4 Alpha-Glucosidase Inhibition (Antidiabetic Mechanism)
Six pentasaccharide resin glycosides from Ipomoea cairica, including four new acylated pentasaccharide resin glycosides (cairicosides I–IV) and two known compounds (cairicosides A and C), were isolated from the aerial parts. Their structures were established by spectroscopic and chemical methods. The core of the six compounds was simonic acid A. Compounds 1 and 5, and 4 and 6, were two pairs of isomers. Compounds 1–4 were evaluated for inhibitory activity against α-glucosidase, and all showed inhibitory activities.
4.5 Larvicidal Mechanism
Ipomoea cairica contains alkaloids with natural larvicidal properties effective against mosquitoes. Saponins in I. cairica leaves weaken insect cuticle membranes, causing developmental delays, reduced food intake, and increased mortality. A bioguided fractionation study found that coumarins such as scopoletin and umbelliferone were identified as major compounds from the stem extract but were not shown to be directly responsible for larvicidal activity; rather, this activity might be attributed to a synergistic effect of all the compounds present in the most active secondary fraction.
5. Scientific Evidence by Area of Use
5.1 Pain and Inflammation (Antinociceptive and Anti-inflammatory)
Evidence type: Animal study (in vivo)
The most rigorously conducted pharmacological study on I. cairica in this domain is a 2006 publication in the Journal of Ethnopharmacology. Ipomoea cairica ethanolic extract (100, 300, 1,000, and 3,000 mg/kg; per os) induced dose-dependent reduction of response in the formalin test inflammatory phase in mice. I. cairica L. Sweet (Convolvulaceae) is used in Brazilian folk medicine for the treatment of rheumatism and inflammations. The same dose range did not modify neurogenic pain in the formalin test, tail-flick reflex latency, carrageenan-induced paw edema, or Rota-Rod test motor performance.
Evidence strength: Preliminary. Evidence is animal-only (mice) with no human clinical trials reported. The selective action in the inflammatory phase of the formalin test supports a peripheral, inflammation-related mechanism, but translation to humans has not been studied.
5.2 Liver Protection (Hepatoprotective Activity)
Evidence type: Animal study (in vivo, rats)
Two separate animal studies have investigated hepatoprotective effects. In the first, a study investigated the hepatoprotective effect of Ipomoea cairica against cadmium-induced liver injury. Male Wistar rats were orally pretreated with 100 and 250 mg/kg of I. cairica leaf extract (ICE) before administration of 3.5 mg/kg of cadmium chloride intraperitoneally. Animals were sacrificed 24 h later and evaluated for hematological parameters, markers of hepatotoxicity, oxidative stress, and antioxidant status.
In the second, a study evaluated the hepatoprotective effect of I. cairica leaf extract against the hepatotoxic effect of acetaminophen in rats. Thirty-five male Wistar rats were randomly divided into five groups of seven rats each: normal control; 2,000 mg/kg of acetaminophen (ACET); 100 mg/kg of methanolic extract of I. cairica (MEIC) for 14 days before a single dose of ACET; 250 mg/kg MEIC for 14 consecutive days before ACET; and 250 mg/kg MEIC.
Evidence strength: Preliminary. Both studies are animal-based with no human clinical data. The results support a hepatoprotective action consistent with the plant's antioxidant constituents, but clinical validation is entirely lacking.
5.3 Neuroprotection
Evidence type: Animal study (in vivo, rats) and in vitro
Several reports have confirmed antioxidant, anti-inflammatory, cardioprotective, and neuroprotective activities of the plant. Exposure to cadmium is implicated in the etiology of some neurodegenerative diseases. Compounds isolated from Ipomoea cairica extract are reported to be neuroprotective. Pretreatment with I. cairica extract (ICE) was able to prevent the oxidative effect of cadmium in the rat brain.
The plant has been described as having potential as a treatment for Japanese encephalitis due to its neuroprotective effects, based on findings with arctigenin, one of its primary lignans. This is referenced in relation to the constituent arctigenin studied in the context of Japanese encephalitis, not directly clinical testing of the plant itself.
Evidence strength: Very preliminary. Entirely preclinical (animal and in vitro). No human studies exist.
5.4 Antidiabetic Activity
Evidence type: In vitro and in silico
Antidiabetic activity of methanolic extract, petroleum ether, ethyl acetate, and n-butanol fractions of Ipomoea cairica (L.) Sweet leaves was performed in vitro using α-glucosidase and α-amylase inhibition methods. Studies identified rare sulphated flavonoids such as ombuin-3-sulphate and rhamnetin-3-sulphate, along with quercetin and kaempferol glycosides, which exhibited significant antidiabetic activity through inhibition of α-glucosidase and α-amylase enzymes. The resin glycoside cairicosides I–IV also showed α-glucosidase inhibitory activities in vitro.
Evidence strength: Very preliminary. Entirely in vitro and in silico; no animal or human clinical data on antidiabetic outcomes have been published for this plant as a whole.
5.5 Antimicrobial and Antibacterial Activity
Evidence type: In vitro
The crude extract from the aerial parts of I. cairica showed good antimicrobial activities against all the selected microbial strains for both bacteria and fungi. Phytochemical analysis revealed the presence of key secondary metabolites, including phenolics, flavonoids, terpenoids, tannins, saponins, and alkaloids, which may contribute to the observed biological effects.
The aerial parts of Ipomoea cairica are used for treatment of microbial infections among other ailments in African traditional medicine. A study aimed to investigate the antimicrobial phytochemicals in Ipomoea cairica aerial parts to validate their traditional use in Ugandan herbal medicine. Chromatographic fractionation of the extract yielded friedelin from I. cairica.
An aqueous extract from I. cairica showed anti-RSV (respiratory syncytial virus) activity in vitro.
Evidence strength: Preliminary. All antimicrobial data are in vitro. No human clinical trials for infections have been conducted. Minimum inhibitory concentration (MIC) and mechanistic data are limited.
5.6 Antiviral Activity (HIV-1)
Evidence type: In vitro
The lignans (−)-arctigenin and (−)-trachelogenin were found to inhibit replication of human immunodeficiency virus type I (HIV-1; strain HTLV-III B) in vitro, and significant anti-tumor and Ca²⁺-antagonist activities have been reported. This finding was based on the isolation of these compounds from I. cairica and testing in infected human cell systems. However, more detailed experiments with purified HIV-1 integrase showed (−)-arctigenin to be inactive in the cleavage (3′-processing) and integration (strand transfer) assays, highlighting the complexity and limitations of the mechanism.
Evidence strength: Very preliminary. All data are from cell-based in vitro studies. The mechanistic findings are partially contradictory. No animal or clinical data exist for this application.
5.7 Anticancer / Cytotoxic Activity
Evidence type: In vitro
Six partially acylated pentasaccharide resin glycosides, cairicosides A–F, were isolated from the aerial parts of Ipomoea cairica. These compounds were characterized as macrolactones of simonic acid A, partially acylated with different organic acids. The lactonization site was bound at C-3 in cairicosides A–E and at C-2 in cairicoside F. Compounds cairicosides A–E exhibited moderate cytotoxicity against a small panel of human tumor cell lines with IC₅₀ values in the range of 4.28–14.31 µM.
Phytochemical constituents include lignans like arctigenin, which show cytotoxicity against cancer cell lines.
Evidence strength: Preliminary, in vitro only. No animal or clinical oncology studies have been conducted specifically with I. cairica preparations. IC₅₀ values for isolated compounds in cell lines do not translate directly to clinical efficacy.
5.8 Larvicidal Activity
Evidence type: In vitro / laboratory bioassay
This is one of the areas with the most detailed published laboratory data for I. cairica. A preliminary study determined that, of a set of 14 plants found in Costa Rica, 5 showed larvicidal activity against A. aegypti, with the ethanolic extract of I. cairica stems representing the most lethal extract toward A. aegypti, with a 50% lethal concentration (LC₅₀) of 0.0341 mg/mL and a 95% confidence interval of 0.0293–0.0393 mg/mL.
The ethanolic extract of I. cairica stems produced 71.3% mortality, and that of leaves produced 40.0% mortality. The essential oil of this species presented larvicidal properties against larvae of Culex tritaeniorhynchus, Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus. The essential oil of Ipomoea cairica achieved 100% mortality in mosquito larvae at concentrations of 100–170 ppm.
Evidence strength: Moderate for laboratory bioassay conditions. Multiple laboratory studies consistently demonstrate larvicidal activity. No field efficacy or safety data exist for use in integrated vector management.
6. Body Systems and Health Areas Associated with the Plant
- Musculoskeletal system: Traditional use in rheumatism and joint inflammation; supported by animal antinociceptive studies (inflammatory phase).
- Hepatic (liver) system: Experimental studies have demonstrated hepatoprotective properties. Traditional use in jaundice and liver complaints is documented across multiple cultures.
- Nervous system: Neuroprotective properties have been demonstrated in experimental studies. In vitro data on arctigenin suggests potential relevance to neuroinflammation.
- Immune / infectious disease: In vitro antiviral (HIV-1, RSV) and antimicrobial activity; traditional use for fevers and infections in Africa and South Asia.
- Metabolic / endocrine (diabetes): In vitro α-glucosidase and α-amylase inhibition from sulphated flavonoids and resin glycosides.
- Dermatological: Traditional Zulu concoction of crushed leaves used for rashes.
- Respiratory: Traditional use for bronchitis, cough, asthma, and tuberculosis documented in Chinese and Indian medicine.
- Renal (kidney): Nephroprotective effect of Ipomoea cairica leaf extract against cadmium-induced renal damage has been reported in preclinical research.
- Vector-borne disease prevention: Larvicidal activity against multiple mosquito species documented in laboratory bioassays.
7. Dosage Forms and Dosages Reported in Studies
No standardized human clinical dosages have been established for Ipomoea cairica, as no approved human clinical trials have been completed. The following dosages were used exclusively in preclinical (animal) studies:
- Antinociceptive study (mice): Ethanolic extract administered at 100, 300, 1,000, and 3,000 mg/kg body weight, per os, in a dose-response design.
- Hepatoprotective study vs. acetaminophen (rats): Methanolic extract of I. cairica (MEIC) was administered at 100 mg/kg or 250 mg/kg for 14 days before a single toxic dose of acetaminophen (2,000 mg/kg).
- Hepatoprotective study vs. cadmium (rats): Oral pretreatment with 100 and 250 mg/kg of I. cairica leaf extract (ICE) before intraperitoneal administration of 3.5 mg/kg cadmium chloride.
- Larvicidal studies: LC₅₀ of 0.0341 mg/mL for the ethanolic stem extract against A. aegypti. Essential oil achieved 100% mortality at 100–170 ppm.
- Cytotoxicity (in vitro): Cairicosides A–E exhibited moderate cytotoxicity against human tumor cell lines with IC₅₀ values in the range of 4.28–14.31 µM.
8. Safety Considerations
8.1 Current Safety Data Status
Despite significant progress in characterizing this plant's biological activities, further studies are required to isolate and characterize the specific active compounds responsible for these effects, elucidate their mechanisms of action, and assess their safety and therapeutic potential through preclinical and clinical evaluations. No formal human clinical safety trials for Ipomoea cairica preparations have been published in the peer-reviewed literature identified during this review.
8.2 Cyanogenic Glycoside Content
Phytochemical analysis of the Ipomoea cairica tuber detected cyanogenic glycosides at a level of 0.05%. Cyanogenic glycosides are compounds that can release hydrogen cyanide upon hydrolysis; their presence in the tuber is a notable safety consideration, particularly in the context of raw food consumption.
8.3 Phytate and Anti-nutrient Content
Phytate was detected in the tuber at 0.02%. Phytates are known anti-nutritional factors that can impair mineral absorption.
8.4 Psychotomimetic and Anticholinergic Reports
I. cairica has been reported in the pharmacological literature to have antimicrobial, spasmolytic, anti-rheumatic, anti-inflammatory, anti-HIV, antipyretic, anti-tumor, analgesic, spasmogenic, hypotensive, and psychotomimetic activities. The psychotomimetic designation appears in pharmacological characterizations but no specific human case reports or toxicological studies directly examining this effect for I. cairica were identified in the peer-reviewed literature reviewed here.
8.5 Resin Glycoside Class Considerations
Resin glycosides are a class of compounds characteristic of the Convolvulaceae family and are known for purgative and cytotoxic properties across the genus Ipomoea. Cairicosides A–E exhibited moderate cytotoxicity against human tumor cell lines with IC₅₀ values in the range of 4.28–14.31 µM, indicating potential for cellular toxicity that would need to be carefully evaluated in the context of medicinal use at relevant doses.
8.6 Research Gaps and Limitations
Research into the chemical composition and biological activities of compounds from I. cairica is still inadequate to understand the compounds associated with their uses claimed in traditional medicine. Such studies are crucial for understanding the pharmacological basis of traditional uses and for potentially developing novel plant-derived agents. The absence of standardized human dosage, formal toxicology studies in humans, and clinical trials means that all pharmacological findings remain at the preclinical or in vitro stage. The overall safety profile in humans is currently unknown from a formal evidence-based standpoint.
8.7 No Recognized Regulatory Status
At the time of writing, Ipomoea cairica does not appear in major regulatory monographs, including the WHO Monographs on Selected Medicinal Plants, ESCOP monographs, German Commission E monographs, or EMA Community herbal monographs. It is therefore not a recognized medicinal ingredient within any major Western regulatory system. Reviews on the plant emphasize the need for further pharmacological studies to explore its unexploited therapeutic potential.
References
Go back