Author(s): Md. Sahab Uddin, Md. Asaduzzaman, Abdullah Al Mamun, Mohammed Ashraful Iqbal, Ferdous Wahid and Ram Kamol Rony
Background: Medicinal plants are superior gift of nature to human lives to support disease free healthy life. Neurodegenerative diseases especially Alzheimer’s disease (AD) affects the central nervous system causing progressive degeneration of neurons, which affect cognitive function. The plant Asparagus racemosus (AR) Linn. has been used traditionally by Ayurvedic practitioners for nervous disorders. In this consequence, the intention of this study was to evaluate the neuroprotective effects of ethanolic extract of Asparagus racemosus (EEAR) Linn. roots in ethanol-induced cognitive impairment and oxidative stress in rats brain. Methods: The learning and memory enhancing activity of EEAR roots extract were investigated in Swiss albino male rats for 21 days and its effects on learning and memory were examined using various behavioral studies such as elevated plus maze (EPM) test, passive avoidance (PA) test, morris water maze (MWM) test, novel object recognition (NOR) test and biochemical studies such as lipid peroxidation (TBARS) contents and acetylcholinesterase (AChE) activity. Results: In the EPM test, administration of EEAR (i.e., 100 and 200 mg/kg b.w.) significantly (P<0.05, P<0.01) decreased retention transfer latency (RTL) on 21st day with respect to the disease control group. EEAR at 200 mg/kg b.w. markedly (P<0.05, P<0.01) increased the retention latency (RL) on 11th and 21st day compared to disease control group for PA test. In the NOR test administration of EEAR (i.e., 200 mg/kg b.w.) considerably (P<0.05) increased DI of rats on 21st day with respect to disease control group. Both doses of EEAR (i.e., 100 and 200 mg/kg b.w.) markedly (P<0.05, P<0.01) decreased escape latency (EL) and highest dose of EEAR (i.e., 200 mg/kg b.w.) noticeably (P<0.05, P<0.001) increased time spent in the target quadrant (TSTQ) on successive days for acquisition trial of MWM test. In case of probe trial administration of EEAR (i.e., 200 mg/kg b.w.) considerably (P<0.05, P<0.01) increased TSTQ and TSA (time spent in the annuli) of rats as compared to that of disease control group. EEAR administration (i.e., 100 and 200 mg/kg b.w.) significantly (P<0.01) decreased the TBARS level in the brain tissue of rats with respect to disease control group. The lowest and highest dose of EEAR (i.e., 100 and 200 mg/kg b.w.) significantly (P<0.05, P<0.01) decreases the AChE activity in the brain tissue of rats as compared to disease control group. Conclusion: The existing study displays that EEAR roots possesses an outstanding source for natural nootropic and confirming the traditional uses of this plant which could be industrialized for enhancing learning and memory impairment associated with neurodegenerative disorders particularly AD.
