CHEMICAL CONSTITUENTS OF SECONDARY METABOLITES OF MEDICINAL IMPORTANCE IN GUAVA PLANT (PSIDIUM GUAJAVA L.)
Background of the Study
The guava plant (Psidium guajava L.), a member of the Myrtaceae family, is a tropical evergreen shrub valued for its rich content of bioactive secondary metabolites. These compounds are primarily concentrated in the leaves, fruit peel, bark, and roots (Kumar et al., 2021). The major classes of secondary metabolites in guava include flavonoids, phenolic acids, tannins, saponins, terpenoids, and essential oils, all of which contribute significantly to its therapeutic potential.
Key bioactive compounds found in guava include:
- Flavonoids such as quercetin, guaijaverin, kaempferol, and avicularin, which act as powerful antioxidants. They help scavenge free radicals, reduce oxidative stress, and play protective roles against chronic diseases including diabetes and cardiovascular disorders (Huynh et al., 2025).
- Phenolic acids including gallic acid, ellagic acid, caffeic acid, and ferulic acid, which exhibit strong anti-inflammatory properties by inhibiting enzymes such as COX-2 and modulating cytokine production. These compounds support traditional uses of guava in treating gastrointestinal disorders, arthritis, and wound healing (Sahal, 2025).
- Tannins and saponins, known for their potent antimicrobial activities. They disrupt bacterial cell membranes and inhibit the growth of pathogens such as Staphylococcus aureus and Escherichia coli, justifying the plant’s traditional application in managing infections and diarrhea (Al-Rimawi, 2025).
- Terpenoids (e.g., β-caryophyllene, limonene, and caryophyllene oxide) and essential oils, which demonstrate analgesic, anticancer, and antidiabetic properties. These effects are mediated through mechanisms such as induction of apoptosis in cancer cells, modulation of pain pathways, and improvement of insulin sensitivity (Zou, 2023).
Additionally, guava is rich in ascorbic acid (Vitamin C), which enhances immune function and supports collagen synthesis. The synergistic interactions among these various metabolites are believed to enhance the plant’s overall medicinal efficacy (Butt, 2025).
Despite substantial in vitro and preclinical evidence supporting the antioxidant, antimicrobial, anti-inflammatory, antidiabetic, and anticancer potentials of guava, several research gaps still hinder its full clinical application (Ugbogu et al., 2022). There is a notable shortage of large-scale, randomized controlled clinical trials in humans to confirm efficacy, determine optimal dosage, assess long-term safety, and evaluate therapeutic outcomes. Most current evidence relies heavily on animal models and observational studies (Tousif et al., 2022).
Other important gaps include limited understanding of regional and cultivar-specific variations in metabolite profiles due to differences in environment, soil, and agronomic practices. Furthermore, the impact of extraction methods, processing techniques, and bioavailability enhancement on compound stability and absorption remains inadequately studied. Synergistic mechanisms between compounds, potential drug-herb interactions, toxicity profiles across diverse populations, and metabolomics-based valorization of processing byproducts also require more comprehensive investigation (Emam, 2025; Huynh et al., 2025; Sahal, 2025).
Addressing these gaps through advanced clinical research, metabolomics, and interdisciplinary studies is essential to bridge traditional knowledge with modern evidence-based medicine. This will help unlock the full potential of guava as a sustainable and valuable medicinal resource.
References
- Al-Rimawi, F. (2025). Evaluation of antimicrobial efficacy of Psidium guajava L. leaf extract. Scientific Reports.
- Butt, E. (2025). Guava (Psidium guajava): A brief overview of its therapeutic and health benefits. Journal of Medicinal Plants Research. (In press)
- Emam, Y. (2025). Metabolomics in guava: quality, traits, composition, applications. Phytochemistry Reviews.
- Huynh, H. D. (2025). Bioactive compounds from guava leaves (Psidium guajava L.). Molecules, 30(6), 1278.
- Kumar, M. et al. (2021). Guava (Psidium guajava L.) leaves: Nutritional composition, phytochemical profile, and health-promoting bioactivities. Foods, 10(4), 752.
- Sahal, A. (2025). A comprehensive review on the nutritional composition, bioactive compounds, and encapsulation of guava leaves. Food Chemistry Advances.
- Tousif, M. I. et al. (2022). Psidium guajava L.: An incalculable but underexplored food crop—its phytochemistry, ethnopharmacology, and industrial applications. Molecules, 27(20), 7016.
- Ugbogu, E. A. et al. (2022). The ethnobotanical, phytochemistry and pharmacological activities of Psidium guajava L. Arabian Journal of Chemistry, 15(5), 103753.
- Zou, X. (2023). Meroterpenoids bioactivity from guava (Psidium guajava L.) review. Advances in Traditional Medicine.
