Concocted by a don, it fights harmful substances (8)

I believe the answer is:

antibody

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'concocted by a don it fights harmful substances' is the definition.
I can't tell whether this defines the answer.

'concocted by a don it' is the wordplay.
'concocted' indicates an anagram.
'by'+'a'+'don'+'it'='byadonit'
'byadonit' is an anagram of 'ANTIBODY'.

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(Other definitions for antibody that I've seen before include "Antigen attacker" , "Fighter in blood" , "protection against disease" , "Pathogen fighter" , "Immune system protein" .)

I've seen this clue in The Irish News.

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