does saliva contain sodium hdroxide?

no                             

Saliva does contain sodium ions and hydroxide ions, but the concentration of OH- is very low since saliva is pretty much neutral. So technically, yes it does, but effectively it doesn't since other anions are present at much higher concentrations.

Saying that saliva contains sodium hydroxide is comparable to saying that if I dissolve sodium chloride in a glass of water, the solution contains sodium hydroxide.