There is a research behind it, published online 2014 Jan 12.
The Study : The effects of Nigella sativa (Ns), Anthemis hyalina (Ah) and Citrus sinensis (Cs) extracts on the replication of coronavirus and the expression of TRP genes family
Evaluation of the effects
To evaluate the effect of extracts of Ah, Ns and Cs on the replication of coronavirus (CoV) and on the expression of TRP genes during coronavirus infection
Lowering Virus Load
The virus load decreased when any of the Ah, Ns or Cs extracts was added to the CoV infected cells with extract treatment leading to very low virus load
PRIOR USAGE OF BLACK SEED OIL IS EFFECTIVE AGAINST COV
The results presented here suggest that treatment of cells with Ns, Ah or Cs extracts prior to infection with CoV decreases the replication of the virus.
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