Curcumin in Combination with Other Adjunct Therapies for Brain Tumor Treatment: Existing Knowledge and Blueprint for Future Research

Malignant brain tumors proliferate aggressively and have a debilitating outcome. Surgery followed by chemoradiotherapy has been the standard procedure of care since 2005 but issues of therapeutic toxicity and relapsestill remain unaddressed. Repurposing of drugs to develop novel combinations that can augment existingtreatment regimens for brain tumors is the need of the hour. Herein, we discuss studies documenting the use ofcurcumin as an adjuvant to conventional and alternative therapies for brain tumors. Comprehensive analysis ofdata suggests that curcumin together with available therapies can generate a synergistic action achieved throughmultiple molecular targeting, which results in simultaneous inhibition of tumor growth, and reduced treatmentinducedtoxicity as well as resistance. The review also highlights approaches to increase bioavailability andbioaccumulation of drugs when co-delivered with curcumin using nano-cargos. Despite substantial preclinicalwork on radio-chemo sensitizing effects of curcumin, to date, there is only a single clinical report on braintumors. Based on available lab evidence, it is proposed that antibody-conjugated nano-curcumin in combinationwith sub-toxic doses of conventional or repurposed therapeutics should be designed and tested in clinical studies.This will increase tumor targeting, the bioavailability of the drug combination, reduce therapy resistance, andtumor recurrence through modulation of aberrant signaling cascades; thus improving clinical outcomes in brainmalignancies