The present disclosure is in relation to a composition comprising nanosphere and histone acetyltransferase (HAT) activator. The disclosed nanosphere is carbon nanosphere (CSP) which is intrinsically fluorescent and the HAT activator is N-(4-Chloro-3-trifluoromethyl- phenyl)-2-n-propoxy-benzamide [COMPOUND 1]. The said N-(4-Chloro-3-trifluoromethyl- phenyl)-2-n-propoxy-benzamide is covalently conjugated with the carbon nanosphere. The present disclosure further relates to a process for obtaining a composition comprising carbon nanosphere and Histone acetyltransferase (HAT) activator [N-(4-Chloro-3-trifluoromethyl- phenyl)-2-n-propoxy-benzamide]. The composition is capable of crossing blood brain barrier and inducing histone acetylation in brain. Further, the composition is capable of increasing neurogenesis, as well as improving long-term memory formation. The said composition thus provides for managing pathological conditions to a subject in need thereof, such as aging- related, neurodegenerative diseases (Alzheimer's in particular), neurological disorders, depression or other kinds of diseases in which increased HAT activity, neurogenesis and/or memory improvement would benefit.L'invention concerne une composition comprenant une nanosphère et un activateur d'histone acétyltransférase (HAT). La nanosphère est une nanosphère de carbone (CSP) qui est intrinsèquement fluorescente et l'activateur HAT est un N-(4-Chloro-3-trifluoromethyl- phenyl)-2-n-propoxy-benzamide (composé 1). L'activateur N-(4-Chloro-3-trifluoromethyl- phenyl)-2-n-propoxy-benzamide est conjugué de manière covalente avec la nanosphère de carbone. L'invention concerne également un procédé pour obtenir une composition comprenant une nanosphère de carbone et un activateur N-(4-Chloro-3-trifluoromethyl-phenyl)-2-n-propoxy-benzamide] d'histone acétyltransférase (HAT). La composition est capable de traverser la barrière hématoencéphalique, d'induire une acétylation d'histone dans le cerveau et d'augmenter
