Synergistic Neuroprotective Effect of Schisandra chinensis and Ribes fasciculatum on Neuronal Cell Death and Scopolamine-Induced Cognitive Impairment in Rats.

Mild cognitive impairment (MCI) is considered as a transitional stage between aging and Alzheimer's disease. In the present study, we examined the protective effect of Schisandra chinensis (SC) and Ribes fasciculatum (RF) on neuronal cell death in vitro and scopolamine-induced cognitive impairment in Sprague Dawley® rats in vivo. A mixture of SC and RF extracts (SC+RF) significantly protected against hydrogen peroxide-induced PC12 neuronal cell death. The neuroprotective effect of SC+RF on scopolamine-induced memory impairment in rats was evaluated using the passive avoidance test and the Morris water maze test. In the passive avoidance test, SC+RF-treated rats showed an increased latency to escape, compared to the scopolamine-treated rats. Moreover, SC+RF treatment significantly reduced escape latency in water maze test, compared to treatment with scopolamine alone. To verify the long-term memory, we performed probe test of water maze test. As a result, rat treated with SC+RF spent more time in the target quadrant. Consistent with enhancement of memory function, the brain derived neurotrophic factor (BDNF) and its downstream molecules (pERK, pATK, and pCREB) are increased in SC+RF treatment in hippocampal area compared with scopolamine treated group. These results suggest that a mixture of SC and RF extracts may be a good therapeutic candidate for preventing mild cognitive impairment.

Effect of some commonly used pesticides on seed germination, biomass production and photosynthetic pigments in tomato (Lycopersicon esculentum).

Pesticides are highly toxic substances. Their toxicity may not be absolutely specific to the target organisms but can adversely affect different processes in the non-target host plants. In the present study, the effect of over application of four commonly used pesticides (emamectin benzoate, alpha-cypermethrin, lambda-cyhalothrin and imidacloprid) was evaluated on the germination, seedling vigor and photosynthetic pigments in tomato. The obtained results revealed that seed germination was decreased by the pesticides and this effect was more prominent at early stages of exposure. All the tested pesticides reduced the growth of tomato when applied in higher concentration than the recommended dose, but at lower doses the pesticides had some stimulatory effects on growth as compared to the control. A similar effect of pesticides was observed on the photosynthetic pigments, i.e. a decrease in pigments concentrations was caused at higher doses but an increase was observed at lower doses of pesticides. The calculation of EC50 values for different parameters revealed the lowest EC50 values for emamectin (ranged as 51-181 mg/L) followed by alpha-cypermethrin (191.74-374.39), lambda-cyhalothrin (102.43-354.28) and imidacloprid (430.29-1979.66 mg/L). A comparison of the obtained EC50 values for different parameters of tomato with the recommended doses revealed that over application of these pesticides can be harmful to tomato crop. In a few cases these pesticides were found toxic even at the recommended doses. However, a field based study in this regard should be conducted to further verify these results.

Phytotoxicity evaluation of some commonly used shampoos using Brassica napus L.

Hair shampoos are among the most commonly used chemicals in everyday life. Since shampoos are a major component of domestic and municipal wastewater, they may affect plants when irrigated with wastewater. However, their effects on plants have never been investigated in detail. The present study was aimed to evaluate the effect of some commonly used hair shampoos on seed germination and seedling vigor of Brassica napus. Seeds of Brassica napus were exposed to different concentrations of hair shampoos, i.e., 0 (control), 0.001, 0.01, 0.1, 1.0, and 10 %. The obtained results revealed that germination was not very sensitive to shampoo stress and was significantly inhibited only at the highest tested concentration (10 %) of shampoo except in the case of one shampoo where it was inhibited at concentration of 1 % or above. The other tested parameters of Brassica napus were comparatively more sensitive than germination to shampoo stress. However, at lower concentrations of shampoos, stimulatory effects were also observed in some cases. Although no exact data is available on shampoo concentration in wastewater used for irrigation, it is unlikely that shampoo concentration in irrigation water reach so high and pose adversity to plants.