An experimental study on phytochemical composition and memory enhancing effect of Ginkgo biloba seed extract.

INTRODUCTION: The Ginkgo biloba L. tree is considered as one of the oldest species on Earth. It is known as a "living fossil" dating back approximately 200 million years. Both the leaves and seeds of this tree have been used for millennia in traditional Chinese medicine. AIM: To study the phytochemical profile of Gingko biloba seed extract (GBSE) and its memory enhancing effects. MATERIALS AND METHODS: Liquid chromatography with mass detection (LC-MS) was performed for phytochemical analyses of the extracts. For the in vivo experiments, male Wistar rats were divided randomly into 5 groups (n=8): saline; piracetam;  GBSE 50; 100, and 200 mg/kg b.w. Y-maze, T-maze, step-down passive avoidance and novel object recognition test (NORT) were performed. The observed parameters were: percentage of spontaneous alternations (% SA), working memory index, latency of reaction and recognition index, respectively. Statistical analysis was done using SPSS 19. RESULTS: LC-MS analysis showed the presence of the flavonoids quercetin, kaempferol and isorhamnetin (as aglycones), the ginkgolides A, B, C, J, and bilobalide. In Y-maze task, the groups treated with 50 and 100 mg/kg of GBSE significantly increased the % SA during the memory test compared to saline (p<0.05). In T-maze test, the three experimental groups with GBSE significantly increased the working memory index in comparison with that of the control group (p<0.05). In step-down test, the animals receiving 100 mg/kg b.w. GBSE, notably increased the latency during both retention tests (p<0.05 and p<0.01, respectively). In NORT, only the animals with the middle dose of GBSE ameliorated the recognition index when compared to saline (p<0.05). CONCLUSIONS: GBSE enhances spatial working memory, recognition memory, and short- and long-term recall in naïve rats due to the synergic effects of detected flavonoids and terpene lactones on brain functions. The brain structures involved are probably the hippocampus and prefrontal cortex.

Antinociceptive and anti-inflammatory effects of Rhodiola rosea L. extract in rats.

BACKGROUND: Rhodiola rosea (golden root) is a unique phytoadaptagen with immunomodulatory, antioxidant, anti-inflammatory and antinociceptive activity. AIM: The aim of this study was to evaluate the antinociceptive and anti-inflammatory effects of the alcohol/water extract of Rhodiola rosea roots in rats. MATERIALS AND METHODS: Thirty male Wistar rats were used in the study. They were divided in 3 groups (n = 10), treated respectively with saline (controls), Rhodiola rosea extract 50 mg/kg bw and 100 mg/kg bw orally. The antinociceptive effect was evaluated using the hot-plate test, Randall-Sellito test and the formalin test. The hot-plate test evaluates the reaction time of rats which are dropped on a heated surface. The analgesy-meter test exerts a force increased at constant rate. In the formalin test we measured the total time spent in licking the injected paw during the early (0-10 min) and late phase (20-30 min) of test. To study anti-inflammatory effect the carrageenan-induced paw edema was used. The paw volume was measured plethysmometrically at 2, 3 and 4 hours. RESULTS: In the hot-plate test Rhodiola rosea increased in both doses the latency reaction compared with that in the controls. In analgesy-meter test Rhodiola rosea in a dose of 50 mg/kg showed a significant increase of pressure reaction compared with the controls. In the formalin test Rhodiola rosea in a dose of 100 mg/kg significantly decreased the paw licking time during the first phase. In the plethysmometer test Rhodiola rosea extract significantly reduced carrageenan-induced paw edema when compared with the saline-induced edema. CONCLUSION: The studied extract of Rhodiola rosea exhibited significant analgesic activity in all the pain models used--inhibition of thermal pain, mechanical hyperalgesia and formalin-induced pain behavior. Significant anti-inflammatory activity was observed from Rhodiola rosea extract in carrageenan induced paw edema in rats.