UPDATE: The recent evidence I could see indicates the opposite. Curcumin and Ginger may help against COVID-19. But we need further research.
Original Question:
I understand that COVID-19 thrives and causes infection when ACE2 is expressed.
I found some papers indicating selenium, curcumin and ginger inhibits ACE, thus leading to increased expression of ACE2.
Should we conclude that taking ginger / turmeric extract (curcumin) supplements (liquid or powder) may increase the risk of COVID-19 infection? Paper 7 seems to be contradictory but I could not understand it well.
My understanding is they make us vulnerable for catching the infection but when we are infected, they can help with their anti-inflammatory mechanism to reduce cytokine storms, thus leading to survival.
- Paper 1 indicates: "ACE inhibitors actually INCREASE expression of ACE2"
- Paper 2 indicates "Among phytochemicals, curcumin treatment significantly inhibited the concentration and activity of ACE, concentration of AngII, and mRNA expression of ACE
- Paper 3 indicates "Curcumin is known to have no significant difference in inhibiting ACE compared to Captopril, but when it was incorporated in the self-nanoemulsifying carrier, it slightly increased the inhibitory effect on ACE."
- Paper 4 indicates "It is noteworthy that treatment with dietary curcumin inhibits oxidative stress and inflammation, as we have reported previously. Moreover, curcumin attenuates fibroblast proliferation and TGFβ1/Smads expression, as noted in the present study; this action may concomitantly attenuate reactive myocardial fibrosis via a pressure-dependent or -independent pathway. We found that dietary treatment with cur-cumin reduced expression of the AT1 receptor and enhanced expression of both the AT2 receptor and ACE2. These results suggest that curcumin modulates not only Ang II/AT1/AT2 receptor-dependent signaling pathways, but also activates an ACE2-mediated mechanism that modulates myocardial fibrosis. "
- Paper 5 indicates: "Treatment with curcumin suppressed ACE expression in TAA liver and reversed the toxicity produced"
- Paper 6 indicates: "Ginger and turmeric rhizomes are used in folk medicine for the treatment of hypertension but the mechanism remains unclear. Pre-treatment with both rhizomes respectively caused a significant decrease in ACE and arginase activities with a concomitant increase in nitric oxide (NO) level.Dietary supplementation of ginger and turmeric rhizomes inhibited ACE and arginase activities as well as increased NO production in L-NAME induced hypertensive rats. These activities could suggest possible mechanism of action for their antihypertensive benefits in traditional medicine"
- Paper 7 indicates: "we suggested that nelfinavir and lopinavir may represent potential treatment options, and kaempferol, quercetin, luteolin-7-glucoside, demethoxycurcumin, naringenin, apigenin-7-glucoside, oleuropein, curcumin, catechin, and epicatechin-gallate were the most recommended compounds found in medicinal plants that may act as potential inhibitors of COVID-19 Mpro".
[1] https://www.evolutamente.it/covid-19-pneumonia-inflammasomes-the-melatonin-connection/
[2] Article Effects of Phytochemicals on Blood Pressure and Neuroprotect...
[3] Article In Vitro Study on Antihypertensive and Antihypercholesterole...
[4] Article Attenuation of myocardial fibrosis with curcumin is mediated...
[5] Article Effects of curcumin on angiotensin-converting enzyme gene ex...
[6] Article Effect of dietary supplementation of ginger and turmeric rhi...
[7] https://www.preprints.org/manuscript/202003.0226/v1/download