Guava leaf, like many other herbs, has an amazing array of qualities, and it seems to be able to do amazing things. It can stop diarrhea and has saved many lives across the world. Especially in impoverished countries, and in regions where modern health care is either not accessible, or it is not affordable (or both). There are constituents in guava leaf that attack pathogens. It’s antibacterial. Guava leaf can regulate blood glucose levels. It can help make you thin! It can even allow you to drink as much as you want and not have (many) repercussions the next day!
Aqueous extract of Psidium guajava L. budding leaves (PE) has been shown to possess anti-prostate cancer activity in a cell line model. We examined whether its bioactivity could be conserved either in the presence or the absence of synthetic androgen R1881. In both cases, PE was shown to inhibit LNCaP cell proliferation and down-regulate expressions of androgen receptor (AR) and prostate specific antigen (PSA). The cytotoxicity of PE was shown by enhanced LDH release in LNCaP cells. The flow cytometry analysis revealed cell cycle arrests at G0/G1 phase with huge amount of apoptotic LNCaP cells after treatment with PEfor 48 h in a dose-responsive manner, which was also confirmed by TUNEL assay. From the results of decreased Bcl-2/Bax ratio, inactivation of phosphor-Akt, activation of phosphor-p38, phospho-Erk1/phospho-Erk2, the molecular action mechanism of PE to induce apoptosis in LNCaP cells was elucidated. Compatible with the in vitro study findings, treatment with PE (1.5 mg/mouse/day) significantly diminished both the PSA serum levels and tumor size in a xenograft mouse tumor model. Conclusively, PE is a promising anti-androgen-sensitive prostate cancer agent.
Some of the earliest mentions of guava leaf in the Western world appear in the medical journal The Lancet, dating to the early 1800’s, as doctors chronicled their experiences in tropical locales, reporting on indigenous customs they discovered during their travels. “For my own part,” writes Dr. J Hancock, “I think there is no method better adapted for the successful treatment of fevers in general, than that which is followed by certain tribes of Guiana, which consists of very little besides the use of aromatic vapour-baths and frictions; they take for this purpose the leaves of the guava, lime-tree… bruise and throw them into the bath. A similar practice is pursued by the Creoles of Martinique [for] fever, and with a success much greater than that attending the European practice” (Lancet 1830). This early example of Western medicine borrowing knowledge from traditional or indigenous medicine is a practice recurring throughout history, and still continues today. Read more