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

Abstract

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.

Ginkgo biloba Seeds—An Environmental Pollutant or a Functional Food

“…Our data from chromatographic analysis, as well as data from other authors, confirm that the terpene trilactones in seed extract are in greater quantities than flavonoids, and it could have healing properties similar to leaf extract. In a recent study, we confirmed that this extract enhances learning and memory functions in rats and has an effect comparable to that of the nootropic medication Piracetam [28].…”

Chromatographic Profile and Redox-Modulating Capacity of Methanol Extract from Seeds of Ginkgo biloba L. Originating from Plovdiv Region in Bulgaria

“…The extract was centrifuged at 6000× g for 10 min, and the supernatant was separated. The extraction was carried out two more times, using 70% methanol as an extractant [4]. Thereafter, the combined extracts were evaporated at 30 • C under a vacuum [4].…”

“…The extraction was carried out two more times, using 70% methanol as an extractant [4]. Thereafter, the combined extracts were evaporated at 30 • C under a vacuum [4]. The amount of dry matter obtained was determined gravimetrically.…”

“…The GBSE composition was determined as 12 batches with an average dry matter content of 6-8% and was quantified by liquid chromatography-mass spectrometry (LC-MS) as described by Tomova et al [4]. The chromatographic system Thermo Dionex Ultimate 3000 with a triple quadrupole mass detector, Thermo TSQ Quantum Access MAX and HESI-ionizator (Heated Electrospray Ionization) was used.…”

“…One of the reasons for avoiding seeds is the unpleasant odor emitted by ripened fleshy seed coats. Nevertheless, the seeds are rich in secondary metabolites, which are considered responsible for the beneficial properties of ginkgo leaves [4]. The study of the pharmacological properties of seed extracts may offer new perspectives for the use of these neglected sources of biologically active substances.…”