OPEN Foundation

C. Wang

Plasma BDNF concentrations and the antidepressant effects of six ketamine infusions in unipolar and bipolar depression


Objectives: Accumulating evidence has implicated that brain derived neurotrophic factor (BDNF) is thought to be involved in the pathophysiology of depression, but its correlation with ketamine’s antidepressant efficacy focusing on Chinese individuals with depression is not known. This study was aim to determine the correlation of plasma BDNF (pBDNF) concentrations and ketamine’s antidepressant efficacy.

Methods: Ninety-four individuals with depression received six intravenous infusions ketamine (0.5 mg/kg). Remission and response were defined as Montgomery-Asberg Depression Rating Scale (MADRS) scores less than 10 and a reduction of 50% or more in MADRS scores, respectively. Plasma was collected at baseline and at 24 h and 2 weeks after completing six ketamine infusions (baseline, 13 d and 26 d).

Results: A significant improvement in MADRS scores and pBDNF concentrations was found after completing six ketamine infusions compared to baseline (all ps < 0.05). Higher baseline pBDNF concentrations were found in ketamine responders/remitters (11.0 ± 6.2/10.1 ± 5.8 ng/ml) than nonresponders/nonremitters (8.0 ± 5.5/9.2 ± 6.4 ng/ml) (all ps < 0.05). Baseline pBDNF concentrations were correlated with MADRS scores at 13 d (t = – 2.011, p = 0.047) or 26 d (t = – 2.398, p = 0.019) in depressed patients (all ps < 0.05). Subgroup analyses found similar results in individuals suffering from treatment refractory depression.

Conclusion: This preliminary study suggests that baseline pBDNF concentrations appeared to be correlated with ketamine’s antidepressant efficacy in Chinese patients with depression.

Zheng, W., Zhou, Y. L., Wang, C. Y., Lan, X. F., Zhang, B., Zhou, S. M., Yan, S., & Ning, Y. P. (2021). Plasma BDNF concentrations and the antidepressant effects of six ketamine infusions in unipolar and bipolar depression. PeerJ, 9, e10989.

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Investigation of medical effect of multiple ketamine infusions on patients with major depressive disorder



Single-dose intravenous ketamine has rapid but time-limited antidepressant effects. We aimed to examine the sustained effects of six consecutive ketamine infusions in Chinese patients with major depressive disorder.


Seventy-seven patients with major depressive disorder were eligible to receive augmentation with six ketamine infusions (0.5 mg/kg over 40 min) administered over the course of 12 days (Monday-Wednesday-Friday). The coprimary outcome measures were the rates of response and remission as measured on the 10-item Montgomery-Asberg Depression Rating Scale. Psychotomimetic and dissociative symptoms were measured with the Brief Psychiatric Rating Scale-positive symptoms and the Clinician Administered Dissociative States Scale, respectively.


After the first ketamine infusion, only 10 (13.0%) and 6 (7.8%) patients responded and remitted, respectively; after six ketamine infusions, 52 (67.5%) patients responded and 37 (48.1%) remitted. There was a significant mean decrease in Montgomery-Asberg Depression Rating Scale score at four hours after the first ketamine infusion (7.0±7.5, p<0.001), and this decrease was maintained for the duration of the infusion period. The response to ketamine treatment was positively associated with no history of psychiatric hospitalization (odds ratio=3.56, p=0.009). Suicidal ideation rapidly decreased across the entire study sample, even among the nonresponder group. No significant differences were found regarding Brief Psychiatric Rating Scale and Clinician Administered Dissociative States Scale scores from the first infusion at baseline to four hours post-infusion.


Six ketamine infusions increased rates of response and remission when compared to a single-dose ketamine infusion in patients with major depressive disorder. Future controlled studies are warranted to confirm and expand these findings.

Zheng, W., Zhou, Y. L., Liu, W. J., Wang, C. Y., Zhan, Y. N., Li, H. Q., … & Ning, Y. P. (2019). Investigation of medical effect of multiple ketamine infusions on patients with major depressive disorder. Journal of Psychopharmacology, 0269881119827811., 10.1177/0269881119827811
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Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression



Ketamine has proven to have rapid, robust antidepressant effects on treatment-resistant depression. However, whether repeated ketamine infusions would cause short-and long-term neurocognitive impairments was not clear. Our aims were to investigate the neurocognitive effects of six ketamine infusions and to examine the association between these infusions and the antidepressant response in patients with unipolar and bipolar depression.


Six intravenous infusions of ketamine (0.5 mg/kg) over a 12-day period were administered to 84 patients with unipolar and bipolar depression. Severity of depressive symptoms and four domains of neurocognition, including speed of processing, working memory, visual learning and verbal learning, were assessed at baseline, one day following the last infusion and again two weeks post-infusion.


Significant improvements were found on speed of processing ( F=9.344, p<0.001) and verbal learning ( F=5.647, p=0.004) in a linear mixed model. The Sobel test showed significant indirect effects between time and improvement in speed of processing (Sobel test=3.573, p<0.001) as well as improvement in verbal learning (Sobel test=6.649, p<0.001), which were both significantly mediated by change in depressive symptoms. Logistic regression analysis showed ketamine responders had better visual learning at baseline than non-responders (B=0.118, p<0.001).


Our findings suggest that neurocognitive function would not deteriorate after six ketamine infusions, while verbal learning and speed of processing improved over 13 days and 26 days of observation, respectively. However, this change was mainly accounted for by improvements in severity of depressive symptoms over time. Greater baseline visual learning predicted an antidepressant response over six ketamine infusions.

Zhou, Y., Zheng, W., Liu, W., Wang, C., Zhan, Y., Li, H., … & Ning, Y. (2018). Neurocognitive effects of six ketamine infusions and the association with antidepressant response in patients with unipolar and bipolar depression. Journal of Psychopharmacology32(10), 1118-1126, 10.1177/0269881118798614
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Harmine is an inflammatory inhibitor through the suppression of NF-κB signaling


Harmine is a major constituent in a hallucinogenic botanical mixture ayahuasca and medical plant Peganum harmala L. The plant is used for various illnesses and exhibits anti-inflammatory activity. However, the active constituents remain unclear. Here, we screened the seven alkaloids in P. harmala for their anti-inflammatory activity using an nuclear factor-κB (NF-κB) reporter assay. We found that harmine and harmol could inhibit NF-κB transactivity. As the most abundant compound, harmine inhibited tumor necrosis factor-α (TNF-α)- and lipopolysaccharides (LPS)-induced NF-κB transactivity and nuclear translocation in mouse macrophage RAW 264.7 cells. The mRNA and protein levels of NF-κB downstream inflammatory cytokines also reduced. In an LPS-challenged mouse model, harmine markedly averted inflammatory damage of the lung, and decreased serum TNF-α, interleukin-1β (IL-1β) and IL-6 levels. Our data indicate that harmine may exert the anti-inflammatory effect by inhibition of the NF-κB signaling pathway and harmine is probably responsible for the anti-inflammatory effects of P. harmala.

Liu, X., Li, M., Tan, S., Wang, C., Fan, S., & Huang, C. (2017). Harmine is an inflammatory inhibitor through the suppression of NF-κB signaling. Biochemical and Biophysical Research Communications. 10.1016/j.bbrc.2017.05.126
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A review on traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology of the genus Peganum


Ethnopharmacological relevance

The plants of the genus Peganum have a long history as a Chinese traditional medicine for the treatment of cough, hypertension, diabetes, asthma, jaundice, colic, lumbago, and many other human ailments. Additionally, the plants can be used as an amulet against evil-eye, dye and so on, which have become increasingly popular in Asia, Iran, Northwest India, and North Africa.

Aim of the review

The present paper reviewed the ethnopharmacology, phytochemistry, analytical methods, biological activities, metabolism, pharmacokinetics, toxicology, and drug interaction of the genus Peganum in order to assess the ethnopharmacological use and to explore therapeutic potentials and future opportunities for research.

Materials and methods

Information on studies of the genus Peganum was gathered via the Internet (using Google Scholar, Baidu Scholar, Elsevier, ACS, Pudmed, Web of Science, CNKI and EMBASE) and libraries. Additionally, information was also obtained from some local books, PhD and MS’s dissertations.


The genus Peganum has played an important role in traditional Chinese medicine. The main bioactive metabolites of the genus include alkaloids, flavonoids, volatile oils, etc. Scientific studies on extracts and formulations revealed a wide range of pharmacological activities, such as cholinesterase and monoamine oxidase inhibitory activities, antitumor, anti-hypertension, anticoagulant, antidiabetic, antimicrobial, insecticidal, antiparasidal, anti-leishmaniasis, antioxidant, and anti-inflammatory.


Based on this review, there is some evidence for extracts’ pharmacological effects on Alzheimer’s and Parkinson’s diseases, cancer, diabetes, hypertension. Some indications from ethnomedicine have been confirmed by pharmacological effects, such as the cholinesterase, monoamine oxidase and DNA topoisomerase inhibitory activities, hypoglycemic and vasodilation effects of this genus. The available literature showed that most of the activities of the genus Peganum can be attributed to the active alkaloids. Data regarding many aspects of the genus such as mechanisms of actions, metabolism, pharmacokinetics, toxicology, potential drug interactions with standard-of-care medications is still limited which call for additional studies particularly in humans. Further assessments and clinical trials should be performed before it can be integrated into medicinal practices.

Li, S., Cheng, X., & Wang, C. (2017). A review on traditional uses, phytochemistry, pharmacology, pharmacokinetics and toxicology of the genus Peganum. Journal of Ethnopharmacology. 10.1016/j.jep.2017.03.049
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Anticancer activities of harmine by inducing a pro-death autophagy and apoptosis in human gastric cancer cells


Harmine, a β-carboline alkaloid from Peganum harmala, has multiple anti-tumor activities, especially for its folk therapy for digestive system neoplasm. However, the underlying mechanism of harmine on gastric cancer remains unclear.
To illuminate the potential anti-tumor activity and mechanism of harmine against gastric cancer cells.
The anti-proliferative activity of harmine in vitro was evaluated by MTT assay. The autophagic activity induced by harmine was assessed using GFP-LC3 transfection. FITC/PI double staining was applied for the apoptosis inspection. The mitochondrial membrane potential was detected by JC-1 fluorescence probe. The potential mechanisms for proteins level in autophagy and apoptosis were analyzed by Western blot.
Harmine exhibited potent effects on both autophagy and apoptosis. Treatment with harmine could enhance dots of GFP-LC3 in cells. Meanwhile, the process had connection with Beclin-1, LC3-II, and p62 by the inhibition of Akt/mTOR/p70S6K signaling. However, high concentration of harmine led to apoptosis characterized by the propidium/Annexin V-positive cell pollution, cell shrunk and the collapse of mitochondrial membrane potential. The regulation of Bcl-2, Bax and the gathering of cleaved-PARP, cleaved-caspase 3 and cleaved-caspase 9 contributed to the induction of apoptosis. In addition, 10μM LY294002 (a specific inhibitor of PI3K/Akt) combination with 40μM harmine significantly increased the cytotoxicity to the gastric cancer cells and up-regulated both the apoptosis-related protein (cleaved-PARP, cleaved-caspase-3) and autophagy-related protein (Beclin-1, LC3-II, and p62). Adding the inhibitor of autophagy, 3-MA or BafA1, increased the viability of harmine-exposured gastric cancer cells, which confirmed the role of autophagy played in the gastric cancer cell death induced by harmine.
Harmine might be a potent inducer of apoptosis and autophagy, which offered evidences to therapy of harmine in gastric carcinoma in the folk medicine.
Li, C., Wang, Y., Wang, C., Yi, X., Li, M., & He, X. (2017). Anticancer activities of harmine by inducing a pro-death autophagy and apoptosis in human gastric cancer cells. Phytomedicine28, 10-18. 10.1016/j.phymed.2017.02.008
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30 April - Q&A with Rick Strassman