Simple conceptual graphs can be seen as a very basic description logic, allowing however for answering conjunctive queries. In the first part of this paper, we translate some results obtained for conceptual graph rules of form ``if A then B'' into an equivalent DL-based formalism. Then we show that, our algorithms can automatically decide in some cases whether a given DL has the FOL-reducibility property, provided that the semantics of its constructors can be expressed by rules.