06 Lug 2020

New article published on Drug and Chemical Toxicology

The presence on the market of new psychoactive substances raises the need for an in vitro screening of possible effects on the central nervous system. In this context University of Genova, University of Eastern Piedmont, Italian National Police and São Paulo State University and ATS (ETT&IBF-CNR Joint Lab) showed evidence of neuroactive effect of Zornia latifolia Sm., a perennial herbal legume native to South America, also known as ‘maconha brava’ (false marijuana), and ‘white marijuana’ and commonly abused especially by young people as a legal substitute of cannabis.
The results of this multidisciplinary study was collected in the article “Cannabis like activity of Zornia latifolia Sm. detected in vitro on rat cortical neurons: major role of the flavone syzalterin”.

Zornia latifolia is a plant suspected to possess psychoactive properties and marketed as a marijuana substitute under the name 'maconha brava'. In this study, the effects of fractions obtained from a 2-propanol extract of aerial portions of the plant were determined by multielectrode array (MEA) analyses on cultured networks of rat cortical neurons. Lipophilic (ZL_lipo, mainly containing flavonoid aglycones), and hydrophilic (ZL_hydro, mainly containing flavonoid glycosides) fractions were initially obtained from the raw extract. ZL_lipo significantly inhibited mean firing rate (MFR) and mean bursting rate (MBR) of MEA recordings, while ZL_hydro induced no inhibition. Column chromatography separation of ZL_lipo yielded five fractions (ZL1- ZL5), among which ZL1 induced the strongest MFR and MBR inhibition. NMR and HPLC-MS analyses of ZL1 revealed the prevalence of the common flavonoids genistein (1) and apigenin (2) (in about a 1:1 ratio), and the presence of the rare flavone syzalterin (6,8-dimethylapigenin) (3) as a minor compound. Exposures of MEA to apigenin and genistein standards did not induce the MFR and MBR inhibition observed with ZL1, whereas exposure to syzalterin standard or to a 1:9 mixture syzalterin-genistein induced effects similar to ZL1. These inhibitory effects were comparable to that observed with high-THC hashish, possibly accounting for the plant psychoactive properties. Data indicate that Z. latifolia, currently marketed as a free herbal product, should be subjected to measures of control. In addition, syzalterin showed distinctive pharmacological properties, opening the way to its possible exploitation as a neuroactive drug.

For further information see:
Alloisio S, Clericuzio M, Nobile M, Salis A, Damonte G, Canali C, Fortuna-Perez AP, Cornara L, Burlando B. Cannabis-like activity of Zornia latifolia Sm. detected in vitro on rat cortical neurons: major role of the flavone syzalterin. Drug Chem Toxicol. 2020 Jul 6:1-13. doi: 10.1080/01480545.2020.1788057. Epub ahead of print. PMID: 32628037.