Heat Shock Proteins play a crucial role in maintaining cellular integrity during thermal stress conditions, acting as chaperones and participating in the regulation of cellular responses. The focus was to contribute valuable insights into the potential role of hypericin in modulating these heat shock proteins and its implications for anti-tumoral properties. This study employs computational methods, specifically molecular docking, to investigate the potential biological interactions between the chaperone proteins HSP90 and HSC70 and Hypericin, a natural compound recognized for its anti-tumor properties. Despite the limited existing studies in this domain, this research aims to uncover structural insights into the binding mechanisms between Hypericin and these heat shock proteins. In the docking assessments, hypericin demonstrated notable binding energy results, exhibiting a binding energy of -10.5 kcal/mol with Heat Shock Cognate 71 kDa protein and -11.2 kcal/mol with Heat Shock Protein HSP90-alpha.

The HSP70 and HSP90 family members belong to molecular chaperones that exhibit protective functions during the cellular response to stressful agents. We investigated whether the exposure of rats to chronic mild stress (CMS), a validated model of depression, affects the expression of HSP70 and HSP90 in the prefrontal cortex (PFC), hippocampus (HIP) and thalamus (Thal). Male Wistar rats were exposed to CMS for 3 or 8 weeks. The antidepressant imipramine (IMI, 10 mg/kg, i.p., daily) was introduced in the last five weeks of the long-term CMS procedure. Depressive-like behavior was verified by the sucrose consumption test. The expression of mRNA and protein was quantified by real-time PCR and Western blot, respectively. In the 8-week CMS model, stress alone elevated HSP72 and HSP90B mRNA expression in the HIP. HSP72 mRNA was increased in the PFC and HIP of rats not responding to IMI treatment vs. IMI responders. The CMS exposure increased HSP72 protein expression in the cytosolic fraction of the PFC and HIP, and this effect was diminished by IMI treatment. Our results suggest that elevated levels of HSP72 may serve as an important indicator of neuronal stress reactions accompanying depression pathology and could be a potential target for antidepressant strategy.