A Systemic Review on Antioxidant and Hepatoprotective Effect of Psidium Guajava Leaf and Fruit Extract

Abstract

Background: Plant derived natural products such as flavonoids, terpenoids, carbohydrates, tannins, saponins, steroids, proteins, amino acids and Vitamin C  have received considerable attention in recent years due to their diverse pharmacological properties including antioxidant and hepatoprotective activity. Psidium guajava (Myrtaceae) is one of such plants in folk medicine that has been used for the management of various disease conditions. Various parts of the plant has been used in traditional medicine .Antioxidants from medicinal plants play an important role in inhibiting and scavenging radicals, thus providing protection to human against infection and degeneration diseases.

Objective: To review the antioxidant and hepatoprotective activity of psidium guajava.

Methods: Computerised literature search was conducted using PubMed, Medline and Google search engine using different key words for studies investigating the antioxidant and hepatoprotective activities of Psidium guajava using the following as heading terms, psidium guajava, antioxidant, hepatoprotectie, Liver injury, oxidative stress. In addition, the reference lists of the retrieved articles helped me to find further articles, relevant to the present review that was not revealed through the searching procedure.

Result: Out of a total of 152 articles on guava resulted 19 studies which were related to antioxidant and hepatoprotective activity of leaf and fruit extract were included in this review.

These were then categorized into six groups; 1) Six studies on in vitro antioxidant studies with leaf extracts, 2) four studies on in vitro antioxidant studies with fruit extract, 3) one in vivo study on antioxidant with leaf extract in rat, 4) one in vivo study on antioxidant with fruit extract in rat, 5) one study antioxidant fruit extract in human and 6) six in vivo studies on hepatoprotective with leaf extract in rat.

Conclusion: The antioxidant activity of Psidium guajava may be due to inhibition of the formation of radicals, scavenging of the formed free radicals, reducing of oxidized intermediates and the presence of the phenolic compounds. It also acts as promising hepato protective which is correlated directly with its ability to reduce activity of serum enzymes and enhance antioxidant defense status. The phenolic content in Psidium guajava extract played a significant role on the antioxidant and hepatoprotective activity.

Keywords: guava, Psidium guajava, Antioxidant activity; Radical scavenging; Phenolic compound; Hepatoprotective activity; Carbon tetra chloride; Paracetamol.