IL1B and Parkinson disease: In addition, piperine with quercetin significantly enhanced neurotransmitter levels (e.g., DA, norepinephrine, serotonin, GABA, and glutamate), improved mitochondrial complex I and IV activities, and attenuated levels of proinflammatory cytokines TNF-α, IL-6, and IL-1β in rotenone-induced PD rats [127].