BDNF and sexually transmitted disease: Fructose Corni polysaccharide can induce the expression of brain-derived neurotrophic factor (BDNF) and B-cell lymphoma-2 (Bcl-2) genes in rats, exert its antiapoptotic effect, and promote the repair and self-protection of hippocampal neurons, thereby improving the learning and memory ability of VD rats (Li et al., 2016).