By Samuel Odoom
Antimicrobial activity of Guava leaves is through the mechanism of Oxidative phosphorylation and substratum inhibitions by tannins and saponins
For the treatment of various diseases like pneumonia, diarrhea, ulcers, bronchitis, colds, and diseases of the respiratory tract, the World Health Organization (WHO) has cataloged more than 20,000 plant species with medicinal properties (Gonçalves et al., 2008).
This suggests that plants can be used to inhibit the growth of pathogens since they manifest compounds with relatively high levels of antimicrobial action (Kim and Fung, 2004).
The results of the phytochemical analysis of guava leaf extract carried out by Das and Goswami (2019), showed that phenols, flavonoids, and tannins are present in large amounts whereas components like triterpenes, alkaloids, and saponins are present in comparatively lesser amounts in guava leaf extract (Das and Goswami., 2019)
Flavonoids are active compounds showing antibacterial properties. Terpenoids have also been found to be potential antibacterial agents against inhibiting bacteria in spite of being mostly used for their aromatic properties (Biswas et al., 2013). Phenols inhibit ergosterol which is a component of the fungal cell membrane.
Glucosamine; a growth indicator present only in the fungal cells, indicating the presence of anti-fungal activity.
Tannins which are water-soluble compounds, act as an antimicrobial agent with the help of different mechanisms like deprivation of substratum, inhibition of oxidative phosphorylation, extracellular enzyme inhibition, etc.
Hence it can be concluded that the most probable cause of the antimicrobial activity of guava leaves extract is the wide range of polyphenolic compounds (Das and Goswami., 2019)
