Psychoactive Plant Database - Neuroactive Phytochemical Collection

1. Biochem J. 2024 Oct 16;481(20):1475-1495. doi: 10.1042/BCJ20240447.

Identification of inhibitors of human ChaC1, a cytoplasmic glutathione degrading 
enzyme through high throughput screens in yeast.

Suyal S(1), Choudhury C(1)(2), Kaur D(2), Bachhawat AK(1).

Author information:
(1)Department of Biological Sciences, Indian Institute of Science Education and 
Research, Mohali, S.A.S. Nagar, Punjab 140306, India.
(2)Department of Experimental Medicine and Biotechnology, Postgraduate Institute 
of Medical Education and Research, Sector-12, Chandigarh 160012, India.

The cytosolic glutathione-degrading enzyme, ChaC1, is highly up-regulated in 
several cancers, with the up-regulation correlating to poor prognosis. The 
ability to inhibit ChaC1 is therefore important in different pathophysiological 
situations, but is challenging owing to the high substrate Km of the enzyme. As 
no inhibitors of ChaC1 are known, in this study we have focussed on this goal. 
We have initially taken a computational approach where a systemic 
structure-based virtual screening was performed. However, none of the predicted 
hits proved to be effective inhibitors. Synthetic substrate analogs were also 
not inhibitory. As both these approaches targeted the active site, we shifted to 
developing two high-throughput, robust, yeast-based assays that were active site 
independent. A small molecule compound library was screened using an automated 
liquid handling system using these screens. The hits were further analyzed using 
in vitro assays. Among them, juglone, a naturally occurring naphthoquinone, 
completely inhibited ChaC1 activity with an IC50 of 8.7 µM. It was also 
effective against the ChaC2 enzyme. Kinetic studies indicated that the 
inhibition was not competitive with the substrate. Juglone is known to form 
adducts with glutathione and is also known to selectively inhibit enzymes by 
covalently binding to active site cysteine residues. However, juglone continued 
to inhibit a cysteine-free ChaC1 variant, indicating that it was acting through 
a novel mechanism. We evaluated different inhibitory mechanisms, and also 
analogues of juglone, and found plumbagin effective as an inhibitor. These 
compounds are the first inhibitor leads against the ChaC enzymes using a robust 
yeast screen.

© 2024 The Author(s). Published by Portland Press Limited on behalf of the 
Biochemical Society.

DOI: 10.1042/BCJ20240447
PMID: 39400295 [Indexed for MEDLINE]


2. RSC Med Chem. 2024 Sep 20. doi: 10.1039/d4md00519h. Online ahead of print.

Unveiling the anticancer potential of plumbagin: targeting pyruvate kinase M2 to 
induce oxidative stress and apoptosis in hepatoma cells.

Wu J(1), Ding Z(2), Tu J(1), Osama A(1), Nie Q(1), Cai W(3), Zhang B(1).

Author information:
(1)State Key Laboratory of Applied Organic Chemistry and College of Chemistry 
and Chemical Engineering, Lanzhou University Lanzhou 730000 China 
zhangbx@lzu.edu.cn.
(2)Beijing Key Laboratory of the Innovative Development of Functional Staple and 
Nutritional Intervention for Chronic Diseases, China National Research Institute 
of Food and Fermentation Industries Beijing 100015 China.
(3)Regor Therapeutics Inc 1206 Zhangjiang Road, Building C, Pu Dong New District 
Shanghai 201210 China wenqing.cai@qlregor.com.

Pyruvate kinase M2 (PKM2), a crucial enzyme in the glycolysis pathway, is 
commonly documented as being overexpressed in cancer cells. Inhibiting PKM2, a 
strategy to mitigate cancer cell-dependent glycolysis, has demonstrated efficacy 
in anticancer treatment. In this study, plumbagin, which was originally 
extracted from the plant Plumbago zeylanica L., was discovered as a novel PKM2 
inhibitor and it could bind to PKM2 to inhibit the enzymatic activity. Treatment 
with plumbagin in HepG2 cells resulted in the decrease of PKM2 expression, which 
in turn reduced the protein kinase function. The mRNA levels of its downstream 
genes, such as LDHA and MYC, were suppressed. Additionally, plumbagin 
downregulated the expression of intracellular antioxidant proteins, which 
induced oxidative stress and mitochondrial damage, ultimately triggering 
apoptosis. Moreover, plumbagin also reduced the migration and proliferation of 
HepG2 cells. This study offered valuable insights into the molecular mechanism 
of plumbagin and advocated for the exploration of PKM2 inhibitors as viable 
possibilities for anticancer therapeutics.

This journal is © The Royal Society of Chemistry.

DOI: 10.1039/d4md00519h
PMCID: PMC11446330
PMID: 39363929

Conflict of interest statement: The authors declare no competing financial 
interests.


3. Br J Pharmacol. 2024 Oct 3. doi: 10.1111/bph.17343. Online ahead of print.

Plumbagin, a novel TRPV2 inhibitor, ameliorates microglia activation and brain 
injury in a middle cerebral artery occlusion/reperfusion mouse model.

Ding M(1), Han R(1), Xie Y(1), Wei Z(1), Xue S(1), Zhang F(1), Cao Z(1).

Author information:
(1)State Key Laboratory of Natural Medicines and Jiangsu Provincial Key 
Laboratory for TCM Evaluation and Translational Research, School of Traditional 
Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.

BACKGROUND AND PURPOSE: Transient receptor potential vanilloid 2 (TRPV2) is a 
Ca2+-permeable non-selective cation channel. Despite the significant roles of 
TRPV2 in immunological response, cancer progression and cardiac development, 
pharmacological probes of TRPV2 remain to be identified. We aimed to discover 
TRPV2 inhibitors and to elucidate their molecular mechanism of action.
EXPERIMENTAL APPROACH: Fluorescence-based Ca2+ assay in HEK-293 cells expressing 
murine TRPV2 was used to identify plumbagin as a novel TRPV2 inhibitor. 
Patch-clamp, in silico docking and site-directed mutagenesis were applied to 
investigate the molecular mechanisms critical for plumbagin interaction. ELISA 
and qPCR were used to assess nitric oxide release and mRNA levels of 
inflammatory mediators, respectively. si-RNA interference was used to knock down 
TRPV2 expression, which was validated by western blotting. Neurological and 
histological analyses were used to examine brain injury of mice following middle 
cerebral artery occlusion/reperfusion (MCAO/R).
KEY RESULTS: Plumbagin is a potent TRPV2 negative allosteric modulator with an 
IC50 value of 0.85 μM, exhibiting >14-fold selectivity over TRPV1, TRPV3 and 
TRPV4. Plumbagin suppresses TRPV2 activity by decreasing the channel open 
probability without affecting the unitary conductance. Moreover, plumbagin binds 
to an extracellular pocket formed by the pore helix and flexible loop between 
transmembrane helices S5 and S6 of TRPV2. Plumbagin effectively suppresses 
LPS-induced inflammation of BV-2 microglia and ameliorates brain injury of 
MCAO/R mice.
CONCLUSION AND IMPLICATIONS: Plumbagin is a novel pharmacological probe to study 
TRPV2 pathophysiology. TRPV2 is a novel molecular target for the treatment of 
neuroinflammation and ischemic stroke.

© 2024 British Pharmacological Society.

DOI: 10.1111/bph.17343
PMID: 39363399


4. Biomolecules. 2024 Sep 7;14(9):1132. doi: 10.3390/biom14091132.

Effect of Agitation and Temporary Immersion on Growth and Synthesis of 
Antibacterial Phenolic Compounds in Genus Drosera.

Makowski W(1), Mrzygłód K(1), Szopa A(2), Kubica P(2), Krychowiak-Maśnicka M(3), 
Tokarz KM(1), Tokarz B(1), Ryngwelska I(1), Paluszkiewicz E(4), Królicka A(3).

Author information:
(1)Department of Botany, Physiology and Plant Protection, Faculty of 
Biotechnology and Horticulture, University of Agriculture in Krakow, 29 
Listopada 54, 31-425 Krakow, Poland.
(2)Department of Pharmaceutical Botany, Collegium Medicum, Jagiellonian 
University, Medyczna 9, 30-688 Krakow, Poland.
(3)Laboratory of Biologically Active Compounds, Intercollegiate Faculty of 
Biotechnology UG and MUG, University of Gdansk, Abrahama 58, 80-307 Gdansk, 
Poland.
(4)Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 
80-233 Gdansk, Poland.

Sundews (Drosera sp.) are the source of biologically active secondary 
metabolites: phenolic acids, flavonoids, and 1,4-naphtoquinones. Because 
obtaining them from the natural environment is impossible (rare and endangered 
species), in this study modifications of traditional tissue cultures grown in 
solid medium (SM), such as agitated cultures (ACs) (cultures in liquid medium 
with rotary shaking) and temporary immersion bioreactors PlantformTM (TIB), were 
used for multiplication of four sundew species: Drosera peltata, Drosera indica, 
Drosera regia, and Drosera binata, with simultaneously effective synthesis of 
biologically active phenolic compounds. Each species cultivated on SM, AC, and 
TIB was tested for biomass accumulation, the content of total phenols and 
selected phenolic derivative concentrations (DAD-HPLC), the productivity on of 
phenolic compounds, as well as its antibacterial activity against two human 
pathogens: Staphylococcus aureus and Escherichia coli. The results showed that 
the type of culture should be selected for each species separately. 
Phytochemical analyses showed that the synthesis of secondary metabolites from 
the groups of phenolic acids, flavonoids, and 1,4-naphthoquinones can be 
increased by modifying the cultivation conditions. D. regia turned out to be the 
richest in phenolic compounds, including 1,4-naphtoquinones: plumbagin and 
ramentaceone. Extracts from D. indica and D. regia tissue showed strong 
antibacterial activity against both pathogens. It has also been shown that the 
growth conditions of sundews can modify the level of secondary metabolites, and 
thus, their biological activity.

DOI: 10.3390/biom14091132
PMCID: PMC11430277
PMID: 39334898 [Indexed for MEDLINE]

Conflict of interest statement: The authors declare no conflicts of interest.


5. Free Radic Biol Med. 2024 Sep 24;225:193-207. doi: 
10.1016/j.freeradbiomed.2024.09.037. Online ahead of print.

Oral administration of plumbagin is beneficial in in vivo models of Duchenne 
muscular dystrophy through control of redox signaling.

Cervia D(1), Zecchini S(2), Pincigher L(3), Roux-Biejat P(2), Zalambani C(3), 
Catalani E(1), Arcari A(2), Del Quondam S(1), Brunetti K(1), Ottria R(2), Casati 
S(4), Vanetti C(5), Barbalace MC(6), Prata C(3), Malaguti M(6), Casati SR(7), 
Lociuro L(6), Giovarelli M(2), Mocciaro E(8), Falcone S(9), Fenizia C(5), 
Moscheni C(2), Hrelia S(6), De Palma C(7), Clementi E(10), Perrotta C(11).

Author information:
(1)Department for Innovation in Biological, Agro-Food and Forest Systems 
(DIBAF), Università Degli Studi Della Tuscia, Viterbo, 01100, Italy.
(2)Department of Biomedical and Clinical Sciences (DIBIC), Università Degli 
Studi di Milano, Milano, 20157, Italy.
(3)Department of Pharmacy and Biotechnology (FABIT), Alma Mater 
Studiorum-Università di Bologna, Bologna, 40126, Italy.
(4)Department of Biomedical, Surgical, and Dental Science (DISBIOC), Università 
Degli Studi di Milano, Milano, 20133, Italy.
(5)Department of Biomedical and Clinical Sciences (DIBIC), Università Degli 
Studi di Milano, Milano, 20157, Italy; Department of Pathophysiology and 
Transplantation (DEPT), Università Degli Studi di Milano, Milano, 20122, Italy.
(6)Department for Life Quality Studies, Alma Mater Studiorum-Università di 
Bologna, Rimini, 47921, Italy.
(7)Department of Medical Biotechnology and Translational Medicine (BIOMETRA), 
Università Degli Studi di Milano, 20054, Segrate, Italy.
(8)Department of Biomedical and Clinical Sciences (DIBIC), Università Degli 
Studi di Milano, Milano, 20157, Italy; Gene Expression and Muscular Dystrophy 
Unit, Division of Genetics and Cell Biology, IRCCS Ospedale San Raffaele, 
Milano, 20132, Italy.
(9)Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en 
Myologie, Paris, F-75013, France.
(10)Department of Biomedical and Clinical Sciences (DIBIC), Università Degli 
Studi di Milano, Milano, 20157, Italy; IRCCS Eugenio Medea, Bosisio Parini, 
23842, Italy.
(11)Department of Biomedical and Clinical Sciences (DIBIC), Università Degli 
Studi di Milano, Milano, 20157, Italy. Electronic address: 
cristiana.perrotta@unimi.it.

Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease. 
Recently approved molecular/gene treatments do not solve the downstream 
inflammation-linked pathophysiological issues such that supportive therapies are 
required to improve therapeutic efficacy and patients' quality of life. Over the 
years, a plethora of bioactive natural compounds have been used for human 
healthcare. Among them, plumbagin, a plant-derived analog of vitamin K3, has 
shown interesting potential to counteract chronic inflammation with potential 
therapeutic significance. In this work we evaluated the effects of plumbagin on 
DMD by delivering it as an oral supplement within food to dystrophic mutant of 
the fruit fly Drosophila melanogaster and mdx mice. In both DMD models, 
plumbagin show no relevant adverse effect. In terms of efficacy plumbagin 
improved the climbing ability of the dystrophic flies and their muscle 
morphology also reducing oxidative stress in muscles. In mdx mice, plumbagin 
enhanced the running performance on the treadmill and the muscle strength along 
with muscle morphology. The molecular mechanism underpinning these actions was 
found to be the activation of nuclear factor erythroid 2-related factor 2 
pathway, the re-establishment of redox homeostasis and the reduction of 
inflammation thus generating a more favorable environment for skeletal muscles 
regeneration after damage. Our data provide evidence that food supplementation 
with plumbagin modulates the main, evolutionary conserved, mechanistic 
pathophysiological hallmarks of dystrophy, thus improving muscle function in 
vivo; the use of plumbagin as a therapeutic in humans should thus be explored 
further.

Copyright © 2024 Elsevier Inc. All rights reserved.

DOI: 10.1016/j.freeradbiomed.2024.09.037
PMID: 39326684

Conflict of interest statement: Declaration of competing interest The authors 
declare that they have no known competing financial interests or personal 
relationships that could have appeared to influence the work reported in this 
paper.