Efficacy of Psidii Guava's Extract For COVID-19

This study was an experimental, randomized clinical trial, with a parallel design, with aims were seeing the effectiveness of extracted Psidii guava on white blood cells (WBCs) count, neutrophil, lymphocyte, monocyte, neutrophil-lymphocyte ratio (NLR), high sensitive C reactive protein (hs-CRP), proportion and duration COVID-19 seroconversion subjects compared to controls.

One of the herbs standardized that was commonly used in Indonesia is extracted Psidii guava, which is known as a guava leaf extract. Extract Psidii guava contains chemical substances saponins, oleanolic acid, xylopyranoside, flavonoids, quercetin, arabinopyranoside, and Guaijavarin. The Previous study on Psidii guava stated that guava leaves contain lots of flavonoids, especially quercetin. An in vitro study of dengue virus type 2 found that quercetin significantly inhibited the activity of the DEN-2 virus, while other flavonoids looked weaker. On the other hand, in an in vitro test of glycosylated flavonoids from Psidium Geunesse, which is a guava leaf from Brazil, received the use of flavonoids in Psidium Geunesse to inhibit HIV-1 virus activity with a 50% inhibition concentration of about 8.5 μg / ml compared to single active substances. Quercetin with a 50% inhibitory concentration of about 53μg / ml. These flavonoids also inhibited the enzyme reverse transcriptase HIV-1(RT)with an inhibition concentration of 7.2 μM compared to quercetin 0.6 μM single. Another study found that quercetin in Psidii guava inhibits RNA polymerase, which is important in dengue virus replication. In addition, quercetin can inhibit protease enzyme, helicase domain, and viral ATPase enzyme.

There is an antiviral effect based on limited in vitro studies but with quite a lot of literature studies, and considering that there are no effective antiviral drugs against COVID-19, especially mild and moderate cases, also considering the length of healing time for patients COVID-19 with the risk of isolation. For a long time with various consequences, researchers tried to examine the effectiveness of extract Psidii guava inpatients COVID-19 at the quarantine location of the West Sumatra Provincial Government. Extract Psidii guava is hypothesized to improve WBCs, neutrophil, lymphocyte, monocyte, NLR, hs-CRP level, to increase proportion and shorten the duration of COVID-19 seroconversion in mild and symptomless cases.