Main Research Findings

1) Administration of 9-Me-BC resulted in improved cognitive functioning associated with increased dopamine levels in the hippocampus, as well as dendritic and synaptic proliferation.

2) 9-Me-BC has the potential to act as an anti-Parkinson’s Disease medication as the nootropic interferes with the pathogenic factors that facilitate degenerative processes in the substantia nigra.

 

Selected Data

1) The research team of Gruss et al. examined the underlying mechanisms of 9-Me-BC that are associated with improved cognitive functioning. For the purpose of the study female Wistar rats from a breeding colony were utilized. The animals were maintained under standard laboratory conditions and allowed ad libitum access to food and water. Six offspring were reared with the same litter up to 30 days postnatal, and were weaned at 31 days postnatal. After the animals were weaned they were individually housed in standard, translucent cages until experimental treatment began. At 7 weeks of age the rats were randomly assigned to one of four different treatment groups, including: non-injected animals that received no pharmacological treatment; vehicle-treated animals that were intraperitoneally injected with 1 mL once daily for 10 days; animals intraperitoneally injected with 2 umol of 9-Me-BC for 5 days; and animals intraperitoneally injected with 2 umol of 9-Me-BC for 10 days [1].

The animals were subjected to behavioral performance testing in order to assess the effects of 9-Me-BC. Spatial learning and memory was examined through the eight-arm radial maze. Each arm of the maze emerged from an octagonal platform that was marked as the start point of the test, and a food cup was placed at the end of each arm. The entire apparatus was painted gray and placed in a dark quiet room where the testing would be recorded. Computed coupled camera recording was used to monitor the rats behavior and activity during the radial arm maze test. Habituation to the radial arm maze test began 10 days after the animals were weaned; this included frequent exposure to the laboratory staff. 2 days after the rats were allowed to explore the radial arm maze test and received a food reward one a day for 10 minutes. After the adaptation procedure was complete the research team reduced the animals’ food intake to reduce the rat’s body weight by 10%.

At 7 weeks of age the first trial took place before the first dose of either 9-Me-BC or a vehicle was intraperitoneally administered, this was referred to as trial 0. Trials 1 through 11 occurred 3 hours after 9-Me-BC or a vehicle was administered to the test subjects. The trial began by placing the animal at the center of the radial arm maze, while the goal was for the rat to visit all eight arms and eat each piece of reward food. The animals were allowed to travel around the maze until they entered all eight arms, made 16 errors by entering into a previously visited arm, or ate all of the pellets that were placed on the arms. Training continued until all animals achieved the necessary criteria with a score of </=1 error [1].

After the last treatment administration the animals were euthanized while hippocampal sections were dissected and immediately frozen for further analysis using HPLC. HPLC was used to quantify levels of dopamine and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). Either the right or left hippocampal section was collected from the animals included in each treatment group. These sections were weighed and processed through homogenization via ultrasonic disruption, followed by centrifugation, filtering, and injection on an HPLC system. Reversed phase HPLC was used to separate dopamine, DOPAC, and HVA in order to electrochemically detect and quantify levels of these compounds. Additionally, a separate group of test subjects were euthanized following administration of the last treatment dose while their brains were dissected and transverse sections were sliced. Neuron tracing systems and three-dimensional analysis of the dendritic trees were used to quantify mean dendritic length, the number of spines, the frequency of spines, and the dendritic complexity [1].

2) The research team of Polanski et al. examined the inflammatory processes associated with the activation of microglia and degeneration in the substantia nigra. For the purpose of this study pregnant C57B1/6 mice between 3 and 6 months old were utilized. On the 14th gestation day the animals were euthanized while dopaminergic cell cultures were prepared and embryonic mesencephala were dissected. 2 mL of trypsin-solution, 3 mL of Hank’s balanced salt solution, and 100 ul DNase I was added to the samples that were then incubated in a water bath 2 mL of basic medium was added and the tissue sample was centrifuged and the supernatant was discarded. 3 mL of basic medium was supplemented with 60 uL of DNase 1 following trituration. ½ of the medium was changed on the first day in vitro while ⅔ of the medium was changed on day 3 in vitro. On the 5th day in vitro the medium was replaced with serum-free DMEM that was used for feeding starting at day 6 in vitro and replaced every other day [2].

9-Me-BC was prepared as a 1 mM stock solution that was diluted in a B27-supplemented medium. 1 hour before treatment with 9-Me-BC the solution was incubated with 100 uM of tyrphostin or 100 uM of genistein, and 15 minutes before treatment with 9-Me-BC incubation with 3 um GBR12909 began. The toxins used were prepared as 1 mM stock solutions that were diluted in a B27-supplemented medium. The cultures were treated with 2,9-dime-BC, MPP, LPS, or protein on the 10th day in vitro in order to induce acute injury. In order to induce chronic injury rotenone was added to the cultures from 6-12 days in vitro, every other day.

Immunocytochemical staining was used to identify microglia. The samples were then rinsed with DPBS followed by precooled with Accustain and washing with PBS. Cultures were then incubated to develop a reaction product. The resulting cells were counted using an inverted microscope in order to identify the average number of TH immunoreactive cells. After TH cell cultures were immunochemical stained, 10 of the cells were randomly allocated for additional monitoring in order to quantify neurite growth. Primary neurons were defined as every neurite that grew out of the soma while secondary neurites were defined as neurites originating from the first branching point of primary neurites [2].

Cell injury was determined by measuring the release of lactate dehydrogenase into the medium. Levels of LDH were determined through the use of the LDH CYtotoxicity Detection Kit. From there EdU was incorporated into the samples in order to quantify cell proliferation in the cultures. The cells were incubated for 4 hours with 10 uM of EdU, 12 hours with 5 uM of EdU, or 24 hours with 3 uM of EdU, followed by 48 hours of treatment with 9-Me-BC. From there the cell cultures were immunofluorescently stained for TH in order to determine if TH and EdU were co-localized. Protein concentrations were then determined using fluorescence technology after the cell cultures were rinsed with PBS and harvested in 100 uL of LDS and sample buffer [2].

The harvested protein samples were then incubated with 5 uL of NuPAGE LDS sample buffer in order to denature the cultures. The proteins were separated and the membranes were incubated with TH antibody in order to detect changes in the samples through the use of a chemiluminescent kit. The resulting images were stored for further analysis. Total RNA was also isolated in order to measure RNA concentration. The cells were rinsed with PBS and stabilized, followed by mixing with lysate buffer and homogenization using a spin column. Using an RNA assay kit, both concentration and purity of RNA in the samples was determined. Finally, inflammatory cytokines and receptors were measured, purified, and hybridized. Chemiluminescent images were obtained for further analysis [2].

 

Discussion

1) When assessing the ability of 9-Me-BC, the research team found that treatment with the nootropic was able to improve spatial learning, increase levels of dopamine, and stimulate growth of the synapses and dendrites in the brain. In order to determine whether 5 days or 10 days of treatment with the nootropic was better, the number of errors was analyzed to see which group achieved the necessary criteria first as a measure of performance on the radial arm maze test and overall spatial learning. After only seven training trials, the rats that were administered 9-Me-BC for 10 days reached the necessary criteria to enter all eight arms of the maze with </= 1 error. There was no difference in the error scores between the 5 day 9-Me-BC treatment group and the vehicle group of test subjects [1].

Figure 1: Number of errors made by each treatment group over the course of 11 training trials on the radial arm maze test.

The hippocampal tissues were dissected from the test subjects in order to analyze levels of dopamine, DOPAC, and HVA through the samples. There were no significant differences noted between samples collected from the right side of the brain versus the left side of the brain. Statistical analysis revealed that in comparison to the non-injected animals that received no pharmacological treatment and the animals treated with a vehicle, there was a significant increase in levels of dopamine in the group of animals treated with 9-Me-BC for 10 days. These results were not observed in the group of animals treated with 9-Me-BC for 5 days in comparison to the non-injected group and the vehicle group of animals. These findings suggest that intraperitoneal administration of 9-Me-BC has the potential to improve levels of dopamine, DOPAC, and HVA in the hippocampus [1].

Figure 2: Dopamine levels in hippocampal tissue sections collected from test subjects in each experimental treatment group.

As it was previously mentioned the following parameters were measured to track changes in dendritic and synaptic growth: dendritic length, number of dendritic spines, spine frequency, and dendritic complexity. First, the length of the dendrites was found to be significantly increased in the animals treated with 9-Me-BC for 10 days. Next, the total number of dendritic spines per dendritic tree was also found to significantly increase in the animals treated with 9-Me-BC for 10 days. This is compared to spine frequency, defined as the number of spines per um dendritic length where there were no statistically significant differences in the animals treated with a vehicle versus those treated with the nootropic for either time period. Finally, dendritic complexity, defined as the total number of dendritic intersections along the length of the dendrite, was shown to increase in the animals treated with 9-Me-BC for 10 days. The most significant difference was observed at 110 um away from the soma, while a strong positive trend was seen at 160 um away from the soma [1].

Figure 3: Changes in (a) dendritic length, (b) number of dendritic spines, and (c) dendritic complexity in male rats treated with a vehicle compound or 9-Me-BC for 10 days.

2) The results of the study conducted by the research team of Polanski et al found that when primary dopaminergic cultures were treated with 9-Me-BC for 48 hours, there was a significant increase in the number of THir neurons in a concentration-dependent manner. The number of neurons increased by 48% when the compound was administered in concentrations of 90 uM. These results were confirmed by the completion of western blot analysis of TH expression. As it was previously mentioned, primary neurons were defined as every neurite that grew out of the soma while secondary neurites were defined as neurites originating from the first branching point of primary neurites. The number of primary neurites from THir neurons increased from 4.75 to 6.7 and the number of secondary neurites increased from 3.99 to 5.51. Additionally, when the cell cultures were co-treated with DAT-inhibitor GBR12909 there was a diminishing effect elicited on the 9-Me-BC-induced stimulation of THir neurons. However, there was still a significant increase in the number of primary and secondary neurites from 4.74 to 6.23 and 3.85 to 5.03, respectively, indicating that the DAT-inhibitor did not affect neurite outgrowth [2].

Figure 4: Changes in concentration-dependent stimulation of THir neurons and (a) primary and secondary neurites; (b) after treatment with 9-Me-BC; (c) after co-treatment with GBR12909, and d) the relative protein expression of TH after treatment with 9-Me-BC.

After identifying the effects of 9-Me-BC on stimulation of THir neurons, the research investigated additional THir neuronal cultures derived from proliferative cells and treated with nucleoside analog, EdU, for either 4 hours, 12 hours, or 24 hours. It was revealed that even after 24 hours of incubation none of the THir neurons tested as EdU-positive. In a similar manner, neurons treated with 90 uM of 9-Me-BC for 48 hours did not result in the incorporation of EdU in THir neuronal cultures. These findings support the hypothesis proposed by the research team that administration of 9-Me-BC only affects pre-existing dopaminergic neurons.

In order to further examine whether 9-Me-BC affects pre-existing and “silent” dopaminergic neurons that do not express TH, cultures were stained for dopa decarboxylase immunoreactive neurons following 48 hours of incubation with 90 uM 9-Me-BC. There was a significant increase in the number of THir neurons, and each neuron was shown to be dopa decarboxylase immunoreactive. In the control groups that were not treated with 9-Me-BC, levels of dopa decarboxylase immunoreactive neurons were 50% more than THir neurons. Compared to the groups treated with 90 uM of 9-Me-BC, were levels of dopa decarboxylase immunoreactive neurons were 23% more than THir neurons. Furthermore, when treatment with 9-Me-BC was stopped, the number of THir neurons decreased to 8-10% above baseline values. Similar results were seen with the number of primary and secondary neurites [2].

9-Me-BC was also assessed for its neuroprotective and anti-inflammatory effects against various dopaminergic neurotoxins. The cultures were pretreated for 48 hours with 90 uM of 9-Me-BC followed by incubation with mitochondrial inhibitors Mpp+, 2,9-dime-BC+, rotenone, or inflammation-inducing LPS for 48 hours. Lipopolysaccharide was shown to decrease the number of THir neurons by 37% while the number of microglia increased by 300% and the release of LDH increased by 84%. When the cell cultures were co=treated with LPS and 9-Me-BC the number of THir neurons increased by 16%. This was compared to the untreated controls that experienced a significant reduction in microglia and LDH release compared to LPS controls. These results indicate that reduction of a pro-inflammatory environment caused by the proliferation of microglia may contribute to the neuroprotective effects elicited by 9-Me-BC [2].

The dopaminergic model toxin MPP+ was shown to decrease the number of THir neurons by 72% while increasing the number of microglia cells by 193% and LDH release by 100%. Co-treatment and pre-treatment with 9-Me-BC was shown to reduce microglia proliferation and release of LDH. These findings suggest that the inhibitory effects of MPP+ on the mitochondrial respiratory chain outweighs the potential protective effects caused by reducing microglia proliferation. Furthermore, rotenone was found to decrease the number of THir neurons by 68% while increasing microglia proliferation by 209% and LDH release by 103%. Co-treatment and pretreatment with 9-Me-BC resulted in further deterioration of THir neurons but also reduced proliferation of microglia.

Finally, 2,9-dime-BC+ was shown to decrease the number of THir neurons by 51% while microglia proliferation and LDH release was increased by 298% and 130%, respectively. Co-treatment with 9-Me-BC resulted in THir neurons being protected from deterioration while less protection was provided to the cell cultures when they were pre-treated with 9-Me-BC. Both co-treatment and pre-treatment with 9-Me-BC resulted in a significant decrease in microglia proliferation and LDH release. These findings suggest that co-treatment with the nootropic was more effective at combating neurotoxicity elicited by 2,9-dime-BC+ [2].

Figure 5: Changes in (a) % of THir neurons, (b) % of microglia, and (c) LDH release after LPS administration. Changes in (d) % of THir neurons, (e) % of microglia, and (f) LDH release after MPP+ administration. Changes in (g) % of THir neurons, (h) % of microglia, and (i) LDH release after rotenone administration. Changes in (j) % of THir neurons, (k) % of microglia, and (l) LDH release after 2,9-dime-BC+ administration.

 

Disclaimer

**LAB USE ONLY**
*This information is for educational purposes only and does not constitute medical advice. THE PRODUCTS DESCRIBED HEREIN ARE FOR RESEARCH USE ONLY. All clinical research must be conducted with oversight from the appropriate Institutional Review Board (IRB). All preclinical research must be conducted with oversight from the appropriate Institutional Animal Care and Use Committee (IACUC) following the guidelines of the Animal Welfare Act (AWA).

 

Citations

[1] Gruss M, Appenroth D, Flubacher A, Enzensperger C, Bock J, Fleck C, Gille G, Braun K. 9-Methyl-β-carboline-induced cognitive enhancement is associated with elevated hippocampal dopamine levels and dendritic and synaptic proliferation. J Neurochem. 2012 Jun;121(6):924-31. doi: 10.1111/j.1471-4159.2012.07713.x. PMID: 22380576.

[2] Polanski W, Reichmann H, Gille G. Stimulation, protection and regeneration of dopaminergic neurons by 9-methyl-β-carboline: a new anti-Parkinson drug? Expert Rev Neurother. 2011 Jun;11(6):845-60. doi: 10.1586/ern.11.1. PMID: 21651332.

 

What is 9-ME-BC?

9-Methyl-𝛃-Carboline (9-Me-BC) is a potent nootropic that has shown promise in improving wakefulness, alertness, cognition, and mood. 9-Me-BC works by regulating the serotonergic and dopaminergic centers of the brain to decrease the reuptake of the two compounds. Evidence has shown that the increased levels of dopamine and serotonin help to greatly improve cognition and energy levels.

The primary active compound of 9-Me-BC is the 𝛃-Carboline. 𝛃-Carboline are alkaloids found in various insects, plants, mammals, and marine animals, and are known for its beneficial biochemical and pharmacological effects. 𝛃-Carboline compounds have been shown to insert themselves into DNA, interact with 5-hydroxy serotonin and benzodiazepine receptors, and inhibit the actions of CDK, topoisomerase, and monoamine oxidase. These properties indicate that the compounds have strong antioxidant and anti-inflammatory effects [1].

 

Main Research Findings

1. 9-Me-BC has been shown to enhance cognition by regulation of the dopaminergic system. The increased dopamine levels are strongly correlated to proliferation of dendrites and synapses

2. Additional research conducted on this compound has found that due the regulation of dopamine that occurs, 9-Me-BC could potentially be considered as a treatment for Parkinson’s Disease.

 

Selected Data

1. 7-week-old female Wistar rats were split into 4 experimental groups: non-injected animals, vehicle-injected animals, animals treated with 9-Me-BC for 5 days, and animals treated with 9-Me-BC for 10 days. The radial maze (RAM) test was used in order to measure changes in spatial learning. The first RAM test was conducted on day 0 before any treatment began while all following tests took place everyday approximately 3 hours after treatment [2].

2. Researchers Polanski et. Al have determined that 9-Me-BC has different beneficial properties that could support the claim that the compound is an effective treatment for Parkinson’s. This theory is based on the observed activity between 9-Me-BC and variables such as tyrosine hydroxylase and various immunoreactive neurons [3]

 

Discussion

1. By decreasing the uptake of dopamine, which is known to be an important neurotransmitter, the compound is able to “relay its message” but is not reabsorbed by the synapse. This indicates that dopamine is active and present in the neuronal receptors for a longer period of time, thus leading to cognitive benefits. Results of the study conducted by found that after 7 days of treatment, rats given 9-Me-B for 10 days were already successful in completing the RAM test. However, there was no difference in the amount of errors made by the rats treated with a vehicle and the rats treated with 9-Me-BC for 5 days.

Figure 1: Decrease in errors on RAM test with administration of 9-Me-BC

The hippocampal tissue of the rats were examined further in order to measure changes in hippocampal dopamine levels and proliferation of synapses and dendrites. Again, there was no difference in the hippocampal dopamine levels of the rats administered 9-Me-BC for 5 days and to those given the vehicle. However, the rats given 9-Me-BC for 10 days saw a significant increase in hippocampal dopamine levels, almost double the levels of the non-injected animals.

Figure 2: Changes in dopamine levels based on the different experimental variables

It is important to note that when observing synaptic and dendritic proliferation, the only data compared was from the rats injected with a vehicle and those receiving 9-Me-BC for 10 days. That being said, there was drastic growth found in the synapses and dendrites of the rats receiving 9-Me-BC. The most significant changes were seen at 60 μm, 110 μm, and 160 μm [2].

Figure 3: Changes in the dendrites after administration of 9-Me-BC

2. 9-Me-BC is capable of increasing the release of tyrosine hydroxylase and its various transcription factors in immunoreactive neurons. This ultimately has a stimulatory effect on neurons of the dopaminergic system. Furthermore, 9-Me-BC has been shown to induce gene expression of different neurotrophic factors while also decreasing the rate of apoptosis cell signaling. This indicates that the compound has both protective and regenerative properties towards the dopaminergic neurons. 9-Me-BC can combat inflammation by inhibiting monoamine oxidase and the proliferation of microglia through the reduction of chemotactic cytokines.

Both the protection of the dopaminergic neurons and the overall anti-inflammatory properties the compound promotes is what leads researchers to believe 9-Me-BC could be used as a treatment for Parkinson’s Disease, considering dopamine and inflammation play a key role in the disease. However, further research is currently being conducted to hone in on the properties of the nootropic compound [3]

 

Conclusions

**LAB USE ONLY**
*This information is for educational purposes only and does not constitute medical advice. THE PRODUCTS DESCRIBED HEREIN ARE FOR RESEARCH USE ONLY. All clinical research must be conducted with oversight from the appropriate Institutional Review Board (IRB). All preclinical research must be conducted with oversight from the appropriate Institutional Animal Care and Use Committee (IACUC) following the guidelines of the Animal Welfare Act (AWA).

Citations

[1] Cao R, Peng W, Wang Z, Xu A. beta-Carboline alkaloids: biochemical and pharmacological functions. Curr Med Chem. 2007;14(4):479-500. doi: 10.2174/092986707779940998. PMID: 17305548.

[2] Gruss M, Appenroth D, Flubacher A, Enzensperger C, Bock J, Fleck C, Gille G, Braun K. 9-Methyl-β-carboline-induced cognitive enhancement is associated with elevated hippocampal dopamine levels and dendritic and synaptic proliferation. J Neurochem. 2012 Jun;121(6):924-31. doi: 10.1111/j.1471-4159.2012.07713.x. PMID: 22380576.

[3] Polanski W, Reichmann H, Gille G. Stimulation, protection and regeneration of dopaminergic neurons by 9-methyl-β-carboline: a new anti-Parkinson drug? Expert Rev Neurother. 2011 Jun;11(6):845-60. doi: 10.1586/ern.11.1. PMID: 21651332.

9-Methyl-β-carboline (9-Me-BC) is sold for laboratory research use only. Terms of sale apply. Not for human consumption, nor medical, veterinary, or household uses. Please familiarize yourself with our Terms & Conditions prior to ordering.