Rekha R. Shenoy

Doxorubicin (DOX) is the most widely used broad-spectrum anticancer agent, either alone or in combination, for most cancers including breast cancer. Long-term use of chemotherapeutic agents to treat breast cancer patients results in cognitive complications with a negative impact on survivors' quality of life. The study objective was to evaluate rutin (RUT) for its neuroprotective effect against DOX in human neuroblastoma (IMR32) cells in vitro and study its potential to ameliorate DOX-induced cognitive dysfunction in Wistar rats. Cell viability assay (3-[4,5 dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide), neurite growth assay, detection of apoptosis by (acridine orange/ethidium bromide) staining, intracellular reactive oxygen species (ROS) assay, and flowcytometric analysis were carried out to assess neuroprotective potential against DOX. An in vivo study was conducted for assessing protective effect of RUT against memory deficit associated with DOX-induced chemobrain using object recognition task (ORT). Locomotion was assessed using open field test. Serum biochemistry, acetylcholinesterase, oxidative stress markers in hippocampus, and frontal cortex were assessed. Histopathological analysis of major organ systems was also carried out. Prior exposure to RUT at 100 µM protected IMR32 cells from DOX (1 µM) neurotoxicity. DOX exposure resulted in increased cellular death, apoptosis, and intracellular ROS generation with inhibition of neurite growth in differentiated IMR32 cells, which was significantly ameliorated by RUT. Cognitive dysfunction was induced in Wistar rats by administering ten cycles of DOX (2.5 mg/kg, intra-peritoneal, once in 5 days), as we observed significant impairment of episodic memory in ORT. Coadministration with RUT (50 mg/kg, per os) significantly prevented memory deficits in vivo without any confounding influence on locomotor activity. RUT also offered protection against DOX-induced myelosuppression, cardiotoxicity, and nephrotoxicity. In conclusion, RUT may be a possible adjuvant therapeutic intervention to alleviate cognitive and other complications associated with DOX chemotherapy.

Abstract Objective Literature favours the in vitro neuroprotective role of caffeic acid, a naturally derived polyphenolic compound. This study was aimed to investigate the role of caffeic acid in experimental model of Alzheimer's disease. Methods Firstly, caffeic acid was tested for in vitro anticholinesterase potential using rat brain homogenate. Later, in vivo antidementia activity of caffeic acid was assessed against aluminium chloride (AlCl3)-induced dementia in rats. Behavioural (Morris water maze test) and brain biochemical parameters (acetylcholinesterase (AChE), catalase, glutathione-S-transferase (GST) activity, glutathione (GSH) and nitrite levels) were assessed to correlate the cognitive function with cholinergic transmission and oxidative stress. Key findings Rats administered with caffeic acid showed improved cognitive function in Morris water maze test. The antidementia activity of caffeic acid was confirmed by the reduction in brain AChE activity and nitrite levels. Further, caffeic acid corrected the diminished level of antioxidant enzymes such as catalase, GSH and GST in brain. Conclusion These findings suggest the antidementia activity of caffeic acid against AlCl3-induced dementia in rats. The outcome of present study offers a wider scope to screen caffeic acid against neurodegeneration associated disorders.

BACKGROUND: Diabetic foot ulcer is an intractable complication of diabetes, characterized by the disturbed inflammatory and proliferative phases of wound healing. Sesamol, a phenolic compound, has been known for its powerful antioxidant, anti-inflammatory, anti-hyperglycaemic and wound healing properties. The aim of the present study was to develop a sesamol nano formulation and to study its effect on the various phases of the wound healing process in diabetic foot condition. METHODS: Sesamol-PLGA (SM-PLGA) nanosuspension was developed using nanoprecipitation method. TEM, in vitro drug release assay and in vivo pharmacokinetic studies were performed for the optimised formulation. Diabetic foot ulcer (DFU) in high fat diet (HFD)-fed streptozotocin-induced type-II diabetic animal model was used to assess the SM-PLGA nanosuspension efficacy. SM-PLGA nanosuspension was administered by oral route. TNF-α levels were estimated using ELISA and Western blot analysis was performed to assess the effect on the expression of HSP-27, ERK, PDGF-B and VEGF in wound tissue. Wound re-epithelization, fibroblast migration, collagen deposition and inflammatory cell infiltration were assessed by H&E and Masson's trichrome staining. Effect on angiogenesis was assessed by CD-31 IHC staining in wound sections. RESULTS: The optimized SM-PLGA nanosuspension had an average particle size of <300 nm, PDI<0.200 with spherical shaped particles. Approximately 80% of the drug was released over a period of 60 h in in vitro assay. Half-life of the formulation was found to be 13.947 ± 0.596 h. SM-PLGA nanosuspension treatment decreased TNF-α levels in wound tissue and accelerated the collagen deposition. Whereas, HSP-27, ERK, PDGF-B and VEGF expression increased and improved new blood vessels' development. Rapid re-epithelization, fibroblast migration, collagen deposition and reduced inflammatory cell infiltration at the wound site were also observed. CONCLUSION: Results indicate that sesamol-PLGA nanosuspension significantly promotes the acceleration of wound healing in diabetic foot ulcers by restoring the altered wound healing process in diabetic condition.