Herb's Introduction
Psidium guineense Swartz, belonging to the family Myrtaceae, is a shrub or small tree native to the Americas. It is a close relative of the common Guava (Psidium guajava). This plant has a long history of traditional use across its native range, primarily for its edible fruit and various parts (bark, roots, leaves) used in traditional medicine. The species is characterized by its somewhat bristly or pubescent young branches and leaves, and its fragrant, small flowers that produce a small, globose, yellow, edible fruit. The plant is valued for its hardiness, ability to grow in a variety of conditions, and the potential pharmacological activities identified in its secondary metabolites.
Name in Different Countries
The plant is known by various common names across its native and introduced range, often referring to its origin or characteristics: English Names: Brazilian Guava, Castilian Guava, Guinea Guava, Güisara Guava, Guisaro Sour Guava, Wild Guava, Pineapple Guava (though this can be confused with Feijoa sellowiana). Chinese Name: 蒙自草胡椒 (Méngzì cǎo hújiāo) Local/Other Names: Araçai (Brazil), Guayabillo, Guayaba Agria.
Terminology
Scientific Name: Psidium guineense Swartz Family: Myrtaceae (The Myrtle family) Synonyms: This species has an extensive list of synonyms, reflecting historical classification changes and regional variations, including names like Guajava guineensis (Sw.) Kuntze, Psidium albidum Cambess., and Psidium polycarpon Lamb., among many others. These synonyms all refer to the same botanical entity, highlighting its wide geographical range and morphological variability. Chemical Constituents (Reported in extracts): Triterpenes: Ursolic acid (known for anti-inflammatory, cytotoxic, and anti-HIV properties), Oleanolic acid. Steroids: Sitosterol (a phytosterol with anti-inflammatory action and a precursor for Vitamin D). Flavonoids: Kaempferol, Rutin, Quercetin (known for multi-targeting action as antioxidants, anti-inflammatory, and antiviral agents), Avicularin, Guaijaverin. Volatile Oils/Terpenes: (Z)-nerolidol, β-caryophyllene, β-selinene, Limonene, α-pinene, epi-bisabolol, caryophyllene oxide. Other Metabolites: Tannins, aldehydes, dietary fiber, Vitamin C, minerals (Potassium, Magnesium, Iron, Phosphorus).
Availability
Native Range: Psidium guineense has a very wide natural distribution in the Americas, extending from Southern Mexico, through Central America, and down to Argentina and Peru, including parts of the Caribbean (Trinidad, Jamaica, Cuba, Martinique). Cultivation/Feral Populations: It is occasionally cultivated for its fruit in various regions, including parts of South America and Southern California. Feral or naturalized populations are also known to exist in parts of Asia, such as India. Habitat: It is a hardy plant that can grow in subtropical climates and arid zones, withstanding some drought. It grows best in sunny sites with moist, fertile soils but is tolerant of a wide range of conditions, including disturbed areas and poorer soils. It is found at medium elevations, ranging from about 80 to 2300 meters above sea level.
External Look
Plant Habit: The plant is typically a shrub 1 to 3 meters (3 to 10 feet) tall, but can sometimes grow into a small tree reaching up to 7 meters (23 feet) in height. It has a relatively slow growth rate. Branches/Bark: The branchlets are terete (cylindrical in section) and are covered in pubescence (fine, soft hairs). The trunk and older branches have grayish bark. Leaves: Leaves are subopposite or opposite, subcoriaceous (leathery), and broadly elliptic-oblong, measuring about 8-10 cm long. They are pellucid-dotted (having translucent oil glands) and have entire margins, often with a coating of pale or reddish hairs, especially on the glandular pubescent underside. Lateral nerves loop near the margin, typically 8-10 pairs. Flowers: Flowers are slightly fragrant and grow in the leaf axils, usually singly or in clusters of up to 3. They have a green, pubescent calyx tube imperfectly 5-lobed, and 5 caducous (falling off early) white, spathulate petals (about 1.5×1 cm). The center is dominated by approximately 200 long, white stamens. Fruit (Berry): The fruit is a globose (round) or pear-shaped berry, typically small, about 2-3 cm (up to 1 inch) in diameter. It is initially green, turning yellow when ripe, and retains a fine pubescence. The rind is yellow, enclosing a thick, pale-yellowish outer pulp and a whitish, creamy-yellow inner pulp that is acidic. It contains many small, hard seeds embedded in the central pulp. The taste is often described as tart, acidic, or sour, sometimes with a guava-strawberry or pineapple-like flavor.
Healing Properties
The healing properties of Psidium guineense are primarily attributed to its rich content of secondary metabolites such as tannins, flavonoids (like quercetin and rutin), and various terpenes. These compounds confer the following activities, largely supported by traditional use and preliminary scientific studies: Anti-Diarrheal and Anti-Dysenteric: The most prominent traditional use. Extracts from the bark, roots, leaves, and young fruit are used to treat diarrhea and dysentery, likely due to the astringent action of tannins and antimicrobial effects of other compounds against gut microbes. Antimicrobial/Antibacterial/Antifungal: Extracts (aqueous and ethanol) from the fruit, peel, and pulp have demonstrated inhibitory activity against various pathogens, including Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Streptococcus mutans. This supports its use in treating intestinal issues. Anti-inflammatory: The presence of phytosteroids (like sitosterol) and terpenes (β-caryophyllene, limonene) contributes to its anti-inflammatory effects, making the leaf essential oil useful for this purpose. Antioxidant: The fruit and its extracts, rich in flavonoids and other phenolics, exhibit significant free radical scavenging and antioxidant activity. Diuretic: Decoctions of the bark or roots are traditionally employed in the interior of Brazil as a diuretic, aiding in the treatment of urinary diseases. Antispasmodic: Extracts are also used traditionally for "bad-belly" and might help reduce intestinal spasms related to diarrhea.
Advantages
Traditional Medicine Efficacy: It has a long and strong tradition of use in Central and South America for common ailments, particularly gastrointestinal problems like diarrhea and dysentery. Rich in Bioactive Compounds: Contains significant levels of pharmaceutically important compounds like flavonoids (quercetin, rutin), triterpenes (ursolic acid), and phytosteroids (sitosterol), providing justification for its medicinal uses. High Nutritional Value: The fruit pulp is rich in Vitamin C, fiber (about 8.4 g per 100g), and essential minerals (Potassium, Magnesium, Iron, Phosphorus). Hardiness: The plant is relatively easy to grow in subtropical and semi-arid conditions and is drought-tolerant, making it a sustainable local resource. Culinary Versatility: The acidic, aromatic fruit is not just eaten raw but is highly suitable for processing into jams, jellies, preserves, cakes, and juices, which is sometimes preferred over the common guava for certain preserves.
Uses
The plant parts are used for both medicinal and non-medicinal purposes: Medicinal Uses: Diarrhea/Dysentery/Stomach Ache: Decoction of the bark, roots, or leaves is taken internally. The juice of the young fruit is also used as an anti-dysenteric. Colds and Bronchitis: A decoction of the leaf is taken to relieve respiratory symptoms. Urinary Diseases: Decoction of the bark or roots is used as a diuretic. Varicose Veins and Leg Ulcers: A decoction is said to be used to reduce these conditions in Costa Rica. Culinary Uses (Fruit): Eaten raw, especially the sweeter varieties. Processed into jams, jellies, preserves, cakes, and juices. The high pectin content is excellent for setting jellies. Other Uses: Wood: The wood is strong and sturdy, used for tool handles, beams, planks, and agricultural instruments. Tanning: The bark is rich in tannin and is used for curing hides.
Using way
The preparation and method of using Psidium guineense in traditional medicine generally involve decoctions or infusions: Decoction (Bark/Roots/Leaves): Method: The bark, roots, or leaves are typically boiled in water for a period (e.g., 10-15 minutes). Application: The resulting liquid is then strained and drunk as a treatment for diarrhea, dysentery, urinary issues, colds, or bronchitis. Example (Traditional Brazilian use): A decoction of the bark or roots is drunk to treat urinary diseases, diarrhea, and dysentery. Infusion (Leaves): Method: Leaves are steeped in hot water. Application: Used for general ailments like coughing or as a milder anti-diarrheal. Fresh Juice (Young Fruit): Method: The juice of the young, unripe fruit is squeezed. Application: Used specifically as a remedy for "bad-belly" or anti-dysenteric action, likely due to higher astringency. External Application (Leaves): While not explicitly mentioned for P. guineense in the provided text, related species and general guava leaf use often involves applying cooked or mashed leaves topically for wounds or skin issues, capitalizing on its antimicrobial and anti-inflammatory properties. Dietary Intake (Ripe Fruit): The ripe fruit is consumed raw or incorporated into cooked foods (jams, jellies, etc.) for its nutritional and fiber content. Note on Usage: As with all herbal remedies, the precise dosages and preparation methods vary greatly by tradition and region. Scientific studies often use concentrated extracts (aqueous, ethanol, or essential oils) under controlled conditions, which may not directly correlate with traditional preparations. Consultation with a healthcare professional or qualified herbalist is always recommended.
Conclusion
Psidium guineense, the Brazilian Guava, is a significant member of the Myrtaceae family, valued across its extensive native range from Mexico to Argentina. It stands out not only as a source of an edible, albeit acidic, fruit used in preserves and raw consumption, but also as a potent traditional medicinal plant. The plant's strength lies in its diverse array of phytochemicals, particularly tannins, triterpenes, and flavonoids, which collectively support its established uses as an effective anti-diarrheal, anti-dysenteric, anti-inflammatory, and antimicrobial agent. Its hardiness and wide distribution ensure its continued availability as a local resource. Further scientific research is warranted to fully explore and validate the therapeutic potential of its isolated compounds and various plant parts against modern health challenges, building upon its strong foundation of traditional usage.
