Exploring Persicaria Glabra: A Comprehensive Review of Its Phytochemistry, Pharmacological Potential

Bhise Gorakhnath, Salve Aniket , Pokale Shraddha, Ghuge Tanuja, Vishakha Kolhe,

doi:10.5281/zenodo.17720171

Review Paper | Open Access
Volume 03 | Issue 11 | Article Id IJPS/250311704

Exploring Persicaria Glabra: A Comprehensive Review of Its Phytochemistry, Pharmacological Potential
Bhise Gorakhnath* Salve Aniket Pokale Shraddha Ghuge Tanuja Vishakha Kolhe
Vidya Niketan Institute of pharmacy and research center, Bota.

Abstract

Persicaria glabra (Willd.) M. Gómez, commonly known as dense flower knotweed, is a semi-aquatic medicinal herb belonging to the family Polygonaceae. The species is distributed widely across tropical and subtropical regions and is traditionally utilized for the treatment of colic pain, fever, skin infections, inflammatory disorders, dysentery, and snake bites. Phytochemical investigations reveal the presence of flavonoids, alkaloids, glycosides, phenolic compounds, tannins, saponins, steroids, and terpenoids, many of which contribute to its antioxidant, antimicrobial, analgesic, antidiabetic, hepatoprotective, and anticancer properties. Ecologically, P. glabra forms dense colonies in wetland habitats and plays an important role in nutrient cycling, soil stabilization, and supporting aquatic biodiversity. This review consolidates existing knowledge on its taxonomy, morphology, distribution, phytochemical profile, ecological roles, and pharmacological potentials, and highlights the need for further research into isolation and characterization of its bioactive constituents.

Keywords

Persicaria glabra, Polygonaceae, phytochemistry, pharmacology, wetland ecology, traditional medicine

Introduction

The genus Persicaria comprises several species of medicinal significance, many of which are widely used in traditional medicine across Asia, Africa, and the Americas. Among them, Persicaria glabra is recognized for its widespread therapeutic applications and ecological adaptability. Despite its traditional significance, scientific data on P. glabra remain comparatively limited, making comprehensive reviews valuable for guiding future pharmacological and phytochemical research.

Botanical Overview: -

According to the Integrated Taxonomic Information System Classification:

Kingdom: Plantae

Phylum: Tracheophyta

Class: Magnoliopsida

Order: Caryophyllales

Family: Polygonaceae

Genus: Persicaria

Species: Persicaria glabra

Common and Regional Names

Indian Name: Sheral (Marathi),

Atalari or Arralari (Tamil),

Nirusanne soppu or Neeru kanigalu (Kannada),

Chuvannamuthalamookku (Malayalam),

Bihagni (Bengali),

Rakta-rohidaa (Gujarati)

Common Name: Denseflower knotweed, smooth smartweed, Water Pepper

Morphology

The plant belongs to the genus Persicaria of the family Polygonaceae. The leaves are lanceolate, narrow, and tapering at both ends, arranged alternately along the stem. The leaf margins are entire and smooth, with pinnate venation, and the surface is glabrous (non-hairy). The stem is herbaceous, semi-aquatic, and erect to ascending in habit. It ranges in colour from green to reddish, and is cylindrical to slightly angular, with a smooth, glabrous surface. The nodes are distinct and slightly swollen, each bearing an ochrea—a papery, membranous sheath formed by the fusion of stipules, a characteristic feature of the Polygonaceae family. The plant typically reaches a height of 30–70 cm, with branching occurring mainly in the upper region, supporting the development of dense inflorescence spikes. The flowers are bisexual, small, and pale pink to whitish, arranged in dense terminal spikes at the tips of the stems. The root system is fibrous, consisting of slender and moderately branched roots adapted to moist soils. Adventitious roots often arise from the lower stem nodes when in contact with water or saturated soil, aiding in vegetative propagation and supporting growth in semi-aquatic environments.

Distribution:-

Persicaria glabra (Willd.) M. Gómez is widely distributed across tropical and subtropical regions of the world. The species occurs throughout South and Southeast Asia, including India, Sri Lanka, Bangladesh, Nepal, Myanmar, Thailand, Vietnam, Malaysia, and Indonesia. It is also reported from several parts of East Asia such as China and Japan. Beyond Asia, the plant is found in Africa, particularly in moist regions of Central and Eastern Africa. In the Americas, it occurs in localized areas of Central and South America, generally in wetland habitats.

Globally, P. glabra thrives in wetlands, riverbanks, marshes, paddy fields, lakeshores, irrigation canals, and seasonally flooded areas. Its ability to root from stem nodes and adapt to fluctuating water levels contributes to its broad ecological range and widespread naturalization in many regions.

Importance:-

The Persicaria glabra plant use as astringent diuretic, vermifuge, antidepressant, antipyretic, antioxidant, anticancer, anxiolytic, analgesic, antibacterial, anti-inflammatory, antiviral. Traditionally use an infusion made from pounded whole plant was used by Hawaiians as a blood medicine. In India, the leaves are used for treatment of colic pains and fever while in Sudan they are used to treat round and tape worm infestations .The tribes of Chhattisgarh use the root paste as a medicine for snake bites .In Sudan, the leaves are used as an antimalarial agent while in South India, the leaves are used in dysentery. Decoctions of the leaves are seeds are used as cardiotonic, astringent and anthelmintic. Whole plant decoction is used as a remedy for colic pain, pneumonia and the boiled paste is applied on cuts and wounds. The stem peels are used for treating rheumatism.

ersicaria glabra commonly forms dense colonies in aquatic and semi-aquatic habitats, where it plays an important ecological role. The species is highly adaptable and capable of growing under a wide range of environmental conditions. It is primarily associated with freshwater ecosystems, occurring in slow-flowing streams, riverbanks, marshes, swamps, lakeshores, paddy fields, irrigation channels, wet thickets, and water-saturated soils. Its worldwide distribution includes India, tropical and subtropical Asia, Africa, and parts of North and South America.

Ecology and Environmental Significance of Persicaria glabra

The plant spreads efficiently in wetlands because adventitious roots emerge from stem nodes when these nodes come into contact with water or moist soil. This capacity allows the plant to extend horizontally, forming large colonies and contributing to long-distance vegetative propagation. Ecologically, P. glabra provides food, shelter, and nutrient-cycling services within wetland ecosystems. Its rapid growth and high biomass production make it an active component of the wetland food web. Like other aquatic macrophytes, it absorbs nutrients—such as nitrogen, phosphorus, and micronutrients—from both water and substrate. After senescence, its decaying biomass returns these nutrients to the ecosystem, supporting microbial decomposition and nutrient recycling.Large colonies of P. glabra create microhabitats for microorganisms, aquatic insects, and small invertebrates. Its flowers attract pollinating insects including bees, butterflies, wasps, and various dipterans, thereby supporting pollinator diversity. The root zone (rhizosphere) of the plant hosts beneficial microorganisms such as sulfate-reducing bacteria, which contribute to biochemical processes in wetland soils. The species exhibits considerable phenotypic flexibility, adjusting its growth pattern according to fluctuations in water level, soil moisture, and aquatic conditions. This ecological plasticity contributes to high genetic variability and enables the species to thrive in diverse habitats across its global range.

Figure 1:- Persicaria Glabra Plant

Medicinal Benefits of Persicaria glabra

The genus Persicaria (family Polygonaceae) includes several species of recognised medicinal value, many of which are commonly used in traditional and alternative healthcare systems. Within this genus, Persicaria glabra is known for its notable therapeutic properties and long-standing ethnomedicinal relevance. Traditionally, different parts of the plant—particularly the leaves and aerial portions—have been used to manage colic pain, skin infections such as scabies and ringworm, boils, abscesses, and inflammatory conditions including rheumatic pain, joint discomfort, and gout. Preparations from the plant are also employed in the treatment of diarrhoea, dyspepsia, haemorrhoids, and pruritic skin disorders. Phytochemical investigations of P. glabra have shown the presence of a diverse range of secondary metabolites, including flavonoids, terpenoids, phenolic compounds, tannins, anthraquinones, saponins, glycosides, and sesquiterpenes. These biologically active constituents are associated with the plant’s broad pharmacological profile. Scientific studies indicate that extracts of P. glabra exhibit significant antioxidant, antimicrobial, anti-inflammatory, analgesic, hepatoprotective, antidiabetic, and cytotoxic activities. The strong antioxidant potential is largely attributed to its flavonoid-rich composition, which enables effective scavenging of reactive oxygen species. Antimicrobial action has been demonstrated against several bacterial and fungal pathogens, supporting its traditional use in treating skin infections and wounds.

The plant’s anti-inflammatory and analgesic properties help reduce tissue inflammation and pain mediators, while its hepatoprotective effects contribute to the restoration of liver function under chemically induced oxidative stress. Additionally, its antidiabetic potential is linked to improved glucose regulation and inhibition of carbohydrate-digesting enzymes. Preliminary cytotoxic studies suggest possible anticancer activity, though more advanced research is needed to validate these effects. Although P. hydropiper, a related species, is frequently cited for strong pharmacological potency, P. glabra also possesses considerable therapeutic promise due to its phytochemical richness and wide range of biological activities. Continued phytochemical and pharmacological investigation could support the development of medicinal formulations based on P. glabra.

Phytochemical composition

The phytochemical investigation of Persicaria glabra provides strong evidence of its medicinal value, reflecting a rich diversity of secondary metabolites and essential mineral constituents. Physicochemical parameters—including total ash, acid-insoluble ash, water-soluble ash, and methanol- and water-extractive values—were analysed to assess the quality, purity, and standardization of the crude drug. These parameters serve as important indicators in the identification and authentication of plant materials used in herbal formulations.Preliminary phytochemical screening of methanolic extracts from the leaves and stems revealed the presence of a wide array of bioactive secondary metabolites, such as alkaloids, flavonoids, tannins, glycosides, steroids, terpenoids, saponins, proteins, amino acids, reducing sugars, phenolic compounds, emodins, and phlobatannins. While most constituents were present in both organs, terpenoids and saponins were absent in the stem, suggesting organ-specific metabolic variation within the species.

In addition to organic constituents, the plant demonstrated a significant inorganic nutrient profile. Qualitative mineral analysis identified carbonates and sulfates in leaf tissue, whereas nitrates, phosphates, and sulfates were detected in the stem. Important basic radicals—including arsenic, sodium, calcium, iron, and ammonium ions—were observed in both the leaves and stems, while zinc was exclusively detected in the leaves. These mineral elements contribute to the plant’s therapeutic relevance by supporting metabolic, antioxidant, and structural functions. Overall, the phytochemical and mineral richness of Persicaria glabra reinforces its traditional medicinal applications and highlights its potential as a valuable natural source for pharmacologically active compounds. The findings warrant further investigation focused on the isolation, quantification, and structural characterization of individual phytoconstituents to enable advanced pharmacological evaluation and potential drug development.

Phytochemical Tests Table for Persicaria glabra

Test Name	Key Ingredient/Reagent Used	Expected Result	Constituent Detected
Mayer’s Test	Mayer’s reagent (Potassium mercuric iodide)	Cream-colored precipitate	Alkaloids
Wagner’s Test	Wagner’s reagent (Iodine in KI)	Reddish-brown precipitate	Alkaloids
Dragendorff’s Test	Dragendorff’s reagent + dilute HCl	Orange precipitate	Alkaloids
Hager’s Test	Saturated picric acid	Bright yellow precipitate	Alkaloids
Tannic Acid Test	Tannic acid	Yellow-brown precipitate	Alkaloids
Ferric Chloride Test (for alkaloids)	Neutral FeCl?	Cream-yellow precipitate	Alkaloids
Legal’s Test	Sodium nitroprusside + pyridine	Cherry-red color	Glycosides
Keller–Killiani Test	Glacial acetic acid, FeCl?, conc. H?SO?	Reddish-brown ring at interface	Cardiac glycosides
Conc. H?SO? Test	Concentrated H?SO?	Reddish precipitate	Glycosides
Molisch’s Test	Molisch’s reagent + conc. H?SO?	Reddish-purple ring	Glycosides / Carbohydrates
Phlobatannin Test	10% HCl (boiling)	Red precipitate	Phlobatannins
Resin Test	CuSO? solution	Green precipitate	Resins
Quinone Test	Alcoholic KOH	Red to blue coloration	Quinones
Saponin Foam Test	Water + olive oil	Stable emulsion	Saponins
Ellagic Acid Test	Glacial acetic acid + NaNO?	Muddy brown color	Phenols
Phenol Test (Ferric chloride)	FeCl?	Intense coloration	Phenols
Ferric Chloride Test (for tannins)	FeCl?	Blackish precipitate	Tannins
Lead Acetate Test (for tannins)	Basic lead acetate	Bulky red precipitate	Tannins
Alkaline Reagent Test (for tannins)	NaOH	Red coloration	Tannins
Lead Acetate Test (for flavonoids)	Basic lead acetate	Reddish-brown precipitate	Flavonoids
FeCl? Test (for flavonoids)	Ferric chloride	Blackish-red precipitate	Flavonoids
Alkaline Reagent Test (for flavonoids)	NaOH	Yellowish-red color	Flavonoids
Libermann–Burchard Test	Acetic anhydride + conc. H?SO?	Reddish-brown ring	Sterols
Salkowski Test	Chloroform + conc. H?SO?	Red color in lower layer	Sterols

Pharmacological activities of Persicaria glabra

Persicaria glabra possesses a diverse profile of bioactive secondary metabolites—including alkaloids, flavonoids (such as quercetin and kaempferol derivatives), phenolic acids, tannins, saponins, terpenoids, and essential oils—which collectively contribute to its broad spectrum of pharmacological properties.

1. Anti-inflammatory Activity

Flavonoids, terpenoids, and phenolic acids present in the plant exhibit strong anti-inflammatory effects. These compounds are known to suppress cyclooxygenase (COX-1 and COX-2) pathways, downregulate nitric oxide (NO) production, and inhibit pro-inflammatory cytokines. Such mechanisms help reduce tissue inflammation and edema.

2. Antioxidant Activity

The high content of polyphenols and flavonoids contributes to potent antioxidant effects. Extracts of P. glabra demonstrate significant free-radical scavenging activity (DPPH assay), ferric-reducing capability, and protection against oxidative stress-induced cellular damage, thereby preventing lipid peroxidation and oxidative injury.

3. Antimicrobial and Antifungal Activity

Methanolic and aqueous extracts exhibit inhibitory effects on several pathogenic microorganisms. The plant shows notable activity against Gram-positive bacteria (e.g., Staphylococcus aureus), Gram-negative bacteria (e.g., Escherichia coli), and fungi such as Candida albicans. These effects are primarily attributed to essential oils, flavonoids, and phenolic compounds that disrupt microbial cell walls and interfere with metabolic processes.

4. Analgesic and Antipyretic Activity

Extracts of P. glabra demonstrate significant analgesic action by inhibiting prostaglandin synthesis and modulating nociceptive signaling pathways. Antipyretic effects are associated with cyclooxygenase inhibition and suppression of pyrogen-induced cytokines such as IL-1β and TNF-α.

5. Hepatoprotective Activity

The plant exhibits protective effects against chemically induced liver damage. Its antioxidant constituents help reduce lipid peroxidation, stabilize hepatocellular membranes, enhance endogenous antioxidants, and restore hepatic enzyme levels, indicating strong hepatoprotective potential.

6. Antidiabetic Activity

Preliminary studies indicate that P. glabra extracts may help regulate blood glucose levels. The plant contributes to reduced fasting blood glucose, improved glucose tolerance, and potential α-glucosidase inhibitory action, suggesting a role in controlling post-prandial hyperglycemia.

7. Anticancer and Cytotoxic Activity

Flavonoids, tannins, and certain phenolic derivatives exhibit cytotoxic and antiproliferative properties. These compounds may alter cell cycle progression, promote apoptotic pathways, and inhibit tumor cell proliferation. Such effects make P. glabra a promising candidate for anticancer drug research.

8. Diuretic and Gastroprotective Activity

Traditional usage and preliminary studies suggest diuretic effects, likely due to modulation of electrolyte balance and kidney function. Gastroprotective properties are attributed to the plant’s antioxidant, anti-inflammatory, and cytoprotective compounds, which may help protect gastric mucosa.

Growth Habitat

Persicaria glabra thrives predominantly in moist, water-rich, and semi-aquatic environments, making it a characteristic species of tropical and subtropical regions. It commonly occurs along riverbanks, lake margins, ponds, marshes, irrigation channels, wetlands, and periodically flooded lowlands. The plant prefers soft, nutrient-rich, alluvial soils that retain moisture for extended periods, allowing it to form dense and stable populations. As a semi-aquatic herb, P. glabra is capable of rooting both in water-saturated soil and in shallow aquatic zones. Adventitious roots develop from the swollen nodes of the stem whenever they come in contact with water or moist substrates, facilitating rapid vegetative propagation and colony expansion. This rooting behaviour enables the plant to spread efficiently across wet landscapes and maintain ecological dominance.

The species exhibits remarkable adaptability to fluctuating water levels, enabling it to survive in fully submerged, partially submerged, and intermittently dry conditions. In natural ecosystems, P. glabra often forms dense colonies that stabilize soil along water bodies, reduce erosion, and provide microhabitats for aquatic insects, small invertebrates, and microbial communities. By contributing to nutrient cycling, habitat structure, and shoreline integrity, the species plays a vital ecological role in wetland and riparian ecosystems.

CONCLUSION

Persicaria glabra is a semi-aquatic herb that predominantly thrives in water-rich tropical and subtropical regions. The species is widely distributed across India, North and South America, Africa, and several parts of Asia. Its extensive medicinal value is attributed to its rich phytochemical profile, which includes alkaloids, glycosides, resins, quinones, saponins, phenols, tannins, flavonoids, and sterols. These bioactive constituents contribute to a broad spectrum of pharmacological activities such as anti-inflammatory, antioxidant, antimicrobial, analgesic, antidiabetic, anticancer, hepatoprotective, wound-healing, antipyretic, antiviral, anxiolytic, and diuretic effects. Ecologically, P. glabra plays an important role in wetland environments by supporting nutrient cycling, providing habitat for aquatic organisms, and contributing to the stability of riparian ecosystems. Traditionally, the plant has been used in the treatment of snakebite and various ailments, reflecting its long-standing ethnomedicinal significance.

Overall, Persicaria glabra represents a valuable medicinal and ecological resource. Its diverse phytochemical composition and wide-ranging therapeutic potential highlight the need for further scientific exploration, particularly in the development of novel formulations and pharmaceutical applications.

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