Table 1.
Studies that have examined the effect of EGCG on neurogenesis and/or behavior in rodent models.
| Species/Strain | Treatment | Timing of treatment | Effect on neuroanatomy | Effect on behavior or LTP | Reference | |
|---|---|---|---|---|---|---|
| Transgenic Dyrk1a mice | YACtg152F7 mice | Daily green tea infusion (equivalent to administering 0.6–1 mg/day pure EGCG) or daily administration of polyphenon 60 solution (0.8 g/l, Sigma) containing a mixture of polyphenolic compounds. The dose is equivalent to 1.2 mg EGCG per day | From gestation to adulthood | Rescue of brain weight, brain volume and hypothalamus-thalamus volume | Rescue in the NOR test | 12 |
| TgDyrk1A mice | EGCG in drinking water (EGCG concentration: 90 mg/ml for a dose of 2–3 mg per day). EGCG solution was prepared from a green tea leaf extract (Mega Green Tea Extract, Decaffeinated, Life Extension®, USA) standardized to 98% polyphenols with 45% EGCG per capsule | 1 month in 21 day-old mice | Normalization of the density of Ki-67 positive cells and the proportion of cells exiting the cell cycle | N.D. | 9 | |
| mBACtgDyrk1a mice | Green tea extract solution in drinking water containing 0.25% green tea decaffeinated extract (0.8 mg/ml EGCG) and 0.25% glucose. Green tea extract contained 45% EGCG. Daily EGCG assumption ranged between 120 and 200 mg/kg | 4–6 weeks in 3–4 month-old mice | Rescue of spine density in prefrontal cortex pyramidal cells | Rescue of LTP in the prefrontal cortex | 13 | |
| TgDyrk1A mice | EGCG in drinking water (EGCG concentration: 90 mg/ml for a dose of 2–3 mg per day). EGCG solution was prepared from a green tea leaf extract [Mega Green Tea Extract, Lightly Caffeinated (0.8% caffeine), Life Extension®, USA] standardized to 98% polyphenols with 45% EGCG per capsule | 1 month in 3 month-old mice | N.D. | Rescue in the MWM and NOR tests | 17 | |
| mBACtgDyrk1a | Polyphenon 60 (POL60, Sigma) solution in drinking water (final concentration of POL60: 225 mg/kg/day) containing green tea polyphenols with 27% EGCG, 42% other catechins (EC, ECG, EGC, and GC) with no effect on DYRK1A activity, and 8% caffeine. 1% sucrose was added | 4 weeks in 3–4 month-old mice | Rescue of components in GABAergic and glutamatergic pathways in cortex and hippocampus | N.D. | 14 | |
| mBACtgDyrk1a | Administration of solid food pellets containing Decaffein-ated Mega Green Tea Extract, Life Extension® (contains 45% EGCG and 53% other catechins). Mega Green Tea Extract was produced at a dose corresponding to 60 mg/kg/day EGCG | 4 weeks in 3–4 month-old mice | N.D. | Improvement in the rate of spontaneous alternation in the Y-maze test | 14 | |
| Ts65Dn mice | Hippocampal slices from Ts65Dn mice | 10 μM pure EGCG (purity ≥95%) | 1h prior to the experiment | N.D. | Rescue of LTP in CA1 | 15 |
| NPCs from the dentate gyrus of 6–8 week-old Ts65Dn mice | 20 μM pure EGCG (purity ≥95%) | 24h | Proliferation enhancement and rescue of mitochondrial biogenesis | N.D. | 16 | |
| Ts65Dn mice | EGCG in drinking water (EGCG concentration: 90 mg/ml for a dose of 2–3 mg per day). EGCG solution was prepared from a green tea leaf extract [Mega Green Tea Extract, Lightly Caffeinated (0.8% caffeine), Life Extension®, USA] standardized to 98% polyphenols with 45% EGCG per capsule | 1 month in 3 month-old mice | N.D. | Rescue in the MWM and NOR tests | 17 | |
| Ts65Dn mice | Pure EGCG in drinking water (EGCG concentration: ∼100 mg/kg/day; purity ≥95%) | From postnatal day 24 to postnatal day 75 | N.D. | No improvement in the radial-arm maze, delayed non-matching-to-place pattern separation tests | 19 | |
| Ts65Dn mice | Pure EGCG in drinking water in a concentration of 0.124 mg/ml (∼20 mg/kg/day; purity ≥95%) | 3 or 7 weeks starting from 24 days of age | N.D. | No improvement in the OF, NOR, BB, DMNP or MWM tests | 18 | |
| Ts65Dn mice | Polyphenon 60 (POL60, Sigma) solution in drinking water (final concentration of POL60: 225 mg/kg/day) containing green tea polyphenols with 27% EGCG, 42% other catechins (EC, ECG, EGC, and GC) with no effect on DYRK1A activity, and 8% caffeine. 1% sucrose was added | 6 weeks in 3–4 month-old mice | Rescue of levels in GABAergic and glutaminergic markers in cortex and hippocampus | Rescue in the Y-maze test | 14 | |
| Ts65Dn mice | Daily injection of pure EGCG (25 mg/kg; purity: ≥95%) | From postnatal day 3 to postnatal day 15 | Rescue of proliferation, and cellularity in the dentate gyrus and rescue of connectivity in hippocampus and neocortex at P15. Disappearance of these effects at P45 | No improvement in the Y-maze and MWM tests at P45 | 20 | |
| Transgenic APP mice | APP/PS1 transgenic mice | Daily intragastric administration (pure EGCG concentration: 2 mg/kg; purity ≥95%) | 1 month in 9 month-old mice | Attenuation of neuronal apoptosis in the hippocampus; deceleration of Aβ(1–40) plaque formation | Improvement in the PA and MWM tests | 29 |
| Normosomic mice | C57BL/6J mice | Green tea catechins (purity: 93%; EGCG: 71%; caffeine: 0.3%; Orient Tea Development Co., Ltd) in drinking water at different concentrations: 0.25, 0.5 and 1 g/l | 6 months in 14 month-old mice | Prevention of age-related reductions of PSD-95 in the hippocampus. No effect on granule cell density | Improvement in the MWM test at the concentration of green tea catechins of 0.5 and 1g/l; no effect on OF | 27 |
| C57BL/6J mice | Daily administration of pure EGCG (25 mg/kg; purity ≥95%) through oral gavage | 1 month in 8 week-old mice | Proliferation enhancement in the dentate gyrus | N.D. | 24 | |
| C57BL/6J mice | Daily intraperitoneal injection of pure EGCG (20 mg/kg; purity ≥95%) | 2 months in 2 month-old mice | Proliferation enhancement in the dentate gyrus | Improvement in the MWM test | 26 | |
| NPCs from the hippocampus of 8–10 week-old C57BL/6J mice | 5, 10, 20, 40 μM of pure EGCG (purity ≥95%) | 24h | Proliferation enhancement of adult NPCs (10, 20, 40 μM) | N.D. | 26 | |
| BALB/cJ mice | Food pellets made with Teavigo® (>90% EGCG, DSM Nutritional Products, Basel, Switzerland). Estimated EGCG dose ∼250 mg/kg/day | 39 days in 10 week-old mice | No effect on proliferation in the dentate gyrus | No improvement in the CFC test | 31 | |
| Rats | Wistar rats | Green tea in drinking water (EGCG concentration: 299.56 μg/ml) and exercise | 3 months and 7 days in 9 month-old rats | N.D. | No improvement in the OF, NOR, IA tests in rats treated with EGCG; improvement in these tests in rats treated with EGCG and exercise | 32 |
| Sprague–Dawley rats | Daily injection of pure EGCG (100 mg/kg; purity ≥95%) in stressed rats | 21 days in 8 week-old rats | N.D. | Rescue in the OF and MWM tests | 28 | |
| Wistar rats | Green tea catechins, Polyphenon E (63% (-)-epigallocat-echin gallate, 11% (-)- epicatechins, 6% (-)-epigallocatechin and 6% (-)-epicatechin gallate) in drinking water | 26 weeks in adult rats | Proliferation enhancement in the dentate gyrus | N.D. | 25 | |
| SH rats | Daily intraperitoneal injection of pure EGCG (100 mg/kg; purity ≥95%) | 28 days in 8 week-old rats | N.D. | Rescue in the OF and MWM tests | 30 | |
Abbreviations: BB: Balance Beam; CFC: Contextual Fear Conditioning; DMNP: T-maze delayed non-matching-to-place; EC: epicatechin; ECG: epicatechin gallate; EGC: epigallocatechin; EGCG: epigallocatechin gallate; GC: gallocatechin; GTC: green tea catechins; IA: inhibitory avoidance/aversive memory; MWM: Morris Water Maze; OF: Open Field; N.D.: not done; NOR: Novel Object Recognition; NPCs: neural progenitor cells; PA: Passive Avoidance; SH: spontaneously hypertensive.