Nephandus damage mitigation on Mambo

Mambo Jeanne
Cardtype: Vampire
Clan: Samedi
Group: 6
Capacity: 9
Discipline: FOR NEC OBF THN
Independent: Minions opposing Jeanne take 2 environmental damage each round during normal strike resolution at close range. +1 bleed.

Nephandus (Mage)
[Sabbat:R, Tenth:A, Third:R, SP:PwN8]
Cardtype: Ally
Clan: Tremere antitribu
Cost: 2 pool
Mage with 2 life. 0 strength, 1 bleed.
Nephandus can strike: 1R damage. Nephandus gets 1 optional press each combat. Nephandus can burn a vampire in torpor to gain 1 life as a action. Each strike or damaging effect made by the opposing minion against Nephandus in combat inflicts 1 less damage.

Can Nephandus receive 1 less damage from Mambo card text?

No. The damage from Mambo Jeanne's special text is "environmental" and not a "strike or damaging effect made by the opposing minion" because it is specifically called out as not being Mambo Jeanne damage, by card text.