VERBENA OFFICINALIS

Experiments conducted at the University of Hong Kong (China) have demonstrated the neuroprotective effect of Verbena Officinalis extracts. The studies were performed in vitro on neurons in the cerebral cortex of mice. In vitro cultured neurons were treated with an aqueous extract of the plant, followed by treatment with various toxins such as β-amyloid 25–35 (25 μM for 24 hours), tunicamycin (1 μg/mL for 16 hours), dithiothreitol (0.5 and 1.0 mM for 16 hours), hydrogen peroxide (50 μM for 16 hours), and UV radiation (32 kJ/cm2 for 2 hours). The cells were then washed with a fresh medium. Cell lysates were subjected to a caspase activity assay. Cytotoxic activity was determined based on the level of lactate dehydrogenase (LD) in the harvested medium. Measurements of LD50 levels showed that a Verbena plant extract at a concentration of 100 μg/mL reduced the mortality of nerve cells exposed to β-amyloid (Aβ) by 9.1% and dithiothreitole by 9.8% (0.5 mM DTT) and 29.6% (1.0 mM DTT). However, the lack of protection against the effects of tunicamycin, H2O2, and UV radiation may indicate that the extract has a weaker effect against agents that directly damage DNA. Colorimetric caspase-3-like and caspase-2-like activity analyses were used to measure the effect of a Verbena plant extract at doses of 25 to 150 μg/mL. Verbena Officinalis extract significantly reduced Aβ-triggered activity by 1.4-fold at a dose of 75 mg/mL compared to control conditions. This activity was dose-dependent. The results obtained demonstrate that extracts from Verbena Officinalis can potentially be used in the prevention of neurodegenerative diseases, particularly Alzheimer's disease. Verbenalin, hastatoside, aucubin, swertiamarin, acetoside, isoacteoside, jionoside D, cistanoside F, acacetin-7-O-rutinoside, apigenin-7-O-glucoside, glucosyl-6-pedalin, and acacetin were used for molecular docking. Verbenalin, swertiamarin, and jionoside D have a good binding effect with NLRP3, which may play a role in Alzheimer's treatment by reducing inflammation. Phenylethanoid glycosides, including acetoside and isoacteoside, have good docking effects with NLRP3 and BACE1, which may reduce the inflammatory response and prevent Aβ accumulation. Apigenin-7-O-glucoside and glucosyl-6-pedalitine showed higher molecular coupling with NLRP3, BACE1, and AChE than positive drugs. Acacetin-7-O-rutinoside has a good binding effect on all four protein targets, better than apigenin-7-O-glucoside and glucosyl-6-pedalitine. Acacetin also has multi-target effects.

Verbenalin, a natural product found in Verbena Officinalis, is classified as an iridoid glucoside and possesses a wide range of biological activities, including sleep-inducing, antioxidant, and hepatoprotective properties. Specifically, aqueous extracts from Verbena Officinalis have been reported to reduce Aβ-induced neurotoxicity, such as neurite shortening and DNA condensation in primary cortical neurons. In a recent study, human neuroblastoma SH-SY5Y cells treated with verbenalin showed neuroprotective properties against Aβ-induced cytotoxicity. Verbenalin has been shown to reduce both intracellular and extracellular expression of APP, a precursor of Aβ. Furthermore, Verbenalin significantly reduced Aβ42 in SweAPP/N2a cells. Numerous studies have shown that the hippocampus and amygdala, as well as other structures of the medial temporal lobe, undergo significant atrophy as Alzheimer's disease progresses. Verbenalin reduced Aβ and tau expression in the hippocampus of animal models of Alzheimer's disease; this was consistent with the results of in vitro assays. Taken together, these findings suggest that verbenalin could be used as a supportive element in adjuvant therapy for Alzheimer's disease due to its ability to improve Aβ and tau-related Alzheimer's pathology.

PUBLICATIONS ON THE SUBJECT:

** BMC Pharmacol Toxicol. 2022 Oct 24;23(1):82. doi: 10.1186/s40360-022-00620-3.

Cornin protects against cerebral ischemia/reperfusion injury by preventing autophagy via the PI3K/Akt/mTOR pathway

** Basic Clin Neurosci. 2020 Jan-Feb;11(1):91-98.doi: 10.32598/bcn.11.1.3. Epub 2020 Jan 1.

Evaluating the Antidepressant Effect of Verbena officinalis L. (Vervain) Aqueous Extract in Adult Rats

** Front Plant Sci. 2022 Aug 4;13:955075.doi: 10.3389/fpls.2022.955075. eCollection 2022.

Integrating transcriptome and chemical analyzes to reveal the anti-Alzheimer's disease components in Verbena officinalis Linn

** Saudi J Biol Sci. 2018 Sep;25(6):1170-1177.doi: 10.1016/j.sjbs.2017.10.005. Epub 2017 Oct 13.

The protective role of verbenalin in rat model of focal cerebral ischemia reperfusion

** Molecules. 2022 Dec 8;27(24):8678.doi: 10.3390/molecules27248678.

Verbenalin Reduces Amyloid-Beta Peptide Generation in Cellular and Animal Models of Alzheimer's Disease