Anti-Inflammatory and Antioxidant Activities of Medicinal Plants Used by Traditional Healers for Antiulcer Treatment
Division of Biochemistry, School of Medical Sciences, University of Phayao, Mueang, Phayao 56000, Thailand
Division of Nutrition, School of Medical Sciences, University of Phayao, Phayao Province 56000, Thailand
School of Traditional and Alternative Medicine, Chiangrai Rajabhat University, Mueang, Chiangrai 57100, Thailand
Division of Microbiology and Parasitology, School of Medical Sciences, University of Phayao, Phayao Province 56000, Thailand
Author to whom correspondence should be addressed.
Sci. Pharm. 2019, 87(3), 22; https://doi.org/10.3390/scipharm87030022
Received: 8 July 2019 / Revised: 6 August 2019 / Accepted: 8 August 2019 / Published: 2 September 2019
For centuries, many kinds of native plants and their products have been used for the treatment of gastric ulcers by traditional healers in Phayao province. The current study aimed to investigate the polyphenol content in some of these medicinal plants and to point out the relationship between their antioxidant capacity and anti-inflammatory activities. Six species were selected based on ethnopharmacologic considerations: Punica granatum L., Psidium guajava L., Careya arborea Roxb., Gochnatia decora (Kurz) Cabr., Shorea obtusa Wall. ex Blume, and Ficus hispida L.f. The leaves or bark of these plants were extracted with 70% ethanol and water. Anti-inflammatory and antioxidant activities of the extracts were analyzed based on nitric oxide (NO) and proinflammatory cytokine production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and through the determination of scavenging activity. The results demonstrated that the ethanol extract from P. granatum and P. guajava leaves significantly inhibited NO production by suppressing nitric oxide synthase. The extracts also inhibited tumor necrosis factor-α, interleukin-1, and interleukin-6 in terms of both mRNA and protein levels and possessed high antioxidants. These extracts were shown to contain the highest amount of polyphenols. Our study concluded that among the plants studied, P. granatum and P. guajava have the most significant anti-inflammatory and antioxidant activities and polyphenols. These plants may have the potential for use in gastric ulcer therapy due to their indicated properties. Future research should focus on the isolation of their active compounds and their in vivo biological activities. Their beneficial applications need to be warranted by such evidence.