Combination of Vinpocetine and Dexamethasone Alleviates Cognitive Impairment in Nasopharyngeal Carcinoma Patients following Radiation Injury

Abstract

<b><i>Background:</i></b> Nasopharyngeal carcinoma (NPC) originates in the nasopharyngeal epithelium. The most common treatments for NPC rT1–4 are radiotherapy and surgery. The pathogenesis of radiation-induced cognitive impairment is complex and includes oxidative stress, mitochondrial dysfunction, neuro-inflammation, and even apoptosis and cell death. Principally, toll-like receptors (TLRs) could regulate the inflammatory/anti-inflammatory balance in patients with radiation-induced brain injury. Vinpocetine has an anti-inflammatory effect as shown in both animal and in vitro studies. Also, dexamethasone is a widely used anti-inflammatory drug. Thus, it is important to test whether addition of vinpocetine could improve the anti-inflammatory properties of dexamethasone for the treatment of NPC patients with radiation-induced brain injuries. <b><i>Methods:</i></b> A total of 60 NPC patients with radiation-related brain injury were recruited for this study. All subjects were randomly and blindly assigned to the following groups: the dexamethasone group (D group, <i>n</i> = 30) and the vinpocetine and dexamethasone group (VD group, <i>n</i> = 30). Both medicine treatments were uninterrupted for 14 days of administration. <b><i>Results:</i></b> Combined administration of vinpocetine and dexamethasone lowered the expression levels of serum inflammatory cytokines, including TLR2, TLR4, interleukin (IL)-20, IL-8, tumor necrosis factor-α, interferon-γ, monocyte chemoattractant protein 2, and interferon-induced protein 20, when compared to dexamethasone monotherapy. Notably, combination therapy increased antioxidants (superoxide dismutase, glutathione, glutathione peroxidase, and glutathione reductase) and decreased oxidants (thiobarbituric acid reactive substances). Furthermore, combination therapy significantly increased the Mini Mental State Examination score, when compared to dexamethasone monotherapy. <b><i>Conclusion:</i></b> Administration of a combination of vinpocetine and dexamethasone may enhance the anti-inflammatory and anti-oxidative effects when compared to dexamethasone monotherapy, which leads to alleviated cognitive impairment in NPC patients with radiation injury.