Numerous adverse effects of cisplatin-based therapy are usually accompanied by enhanced oxidative damage and cell apoptosis in various tissues. Even neurotoxic manifestations of cisplatin administration, such as the anxiogenic effect, appear along with the increased oxidative stress and apoptotic indicators in certain brain regions. Thirty-five Wistar albino male rats were divided into seven groups: control, cisplatin (received a single dose of cisplatin: 7.5 mg/kg), three groups with oral administration of L. methanolic extract (SH) (low: 50 mg/kg, middle: 100 mg/kg, and high dose: 200 mg/kg) along with cisplatin application, a group with the extract in high dose alone, and a silymarin group (cisplatin and silymarin: 100 mg/kg), in order to evaluate the antioxidant effects of SH on cisplatin-induced increase in the anxiety level. After completing 10-day pretreatments, behavioral testing was performed in the open field and the elevated plus maze, followed by an investigation of oxidative stress and apoptosis parameters in hippocampal tissue samples. Cisplatin administration resulted in anxiogenic-like behavior, increased lipid peroxidation, and proapoptotic markers accompanied by the decline in antioxidant and antiapoptotic defense. The administration of extract alone did not significantly alter any of the estimated parameters. When applied along with cisplatin, SH in a dose of 100 mg/kg induced the significant anxiolytic effect with concomitant recovery of antioxidant and antiapoptotic activity indicators, while both lower and higher doses of the extract failed to improve the adverse effects of cisplatin administration. The beneficial effects of the middle dose of SH were equivalent to the same dose of silymarin, as a "golden standard." Our results indicate that the antioxidant supplementation with SH in an optimal dose significantly improved the oxidative status and it had antiapoptotic effect in the rat hippocampus disturbed by cisplatin administration, which was accompanied with attenuation of cisplatin-induced anxiogenic effect.