“Neuroinflammation, which is mainly triggered by microglia, is a key contributor to multiple neurodegenerative diseases.

Natural products, and in particular Cannabis sativa L., due to its richness in phytochemical components, represent ideal candidates to counteract neuroinflammation.

We previously characterized different C. sativa commercial varieties which showed significantly different chemical profiles. On these bases, the aim of this study was to evaluate essential oils and aqueous distillation residues from the inflorescences of three different hemp varieties for their anti-neuroinflammatory activity in BV-2 microglial cells. Cells were pretreated with aqueous residues or essential oils and then activated with LPS. Unlike essential oils, aqueous residues showed negligible effects in terms of anti-inflammatory activity. Among the essential oils, the one obtained from ‘Gorilla Glue’ was the most effective in inhibiting pro-inflammatory mediators and in upregulating anti-inflammatory ones through the modulation of the p38 MAPK/NF-κB pathway. Moreover, the sesquiterpenes (E)-caryophyllene, α-humulene, and caryophyllene oxide were identified as the main contributors to the essential oils’ anti-inflammatory activity. To our knowledge, the anti-neuroinflammatory activity of α-humulene has not been previously described.

In conclusion, our work shows that C. sativa essential oils characterized by high levels of sesquiterpenes can be promising candidates in the prevention/counteraction of neuroinflammation.”

https://pubmed.ncbi.nlm.nih.gov/38068924/

https://www.mdpi.com/1422-0067/24/23/16601

Background: Cannabis Sativa L. (C. sativa) can efficiently synthesize of over 200 terpenes, including monoterpenes, sesquiterpenes and triterpenes that may contribute to the known biological activities of phytocannabinoids of relevance for the burgeoning access to medicinal cannabis formulations globally; however, to date have been uncharacterized. We assessed twelve predominant terpenes in C. sativa for neuroprotective and anti-aggregative properties in semi-differentiated PC12 neuronal cell line that is robust and validated as a cell model responsive to amyloid β (Aβ_1-42) protein exposure and oxidative stress.

Methods: Cell viability was assessed biochemically using the MTT assay in the presence of myrcene, β-caryophyllene, terpinolene, limonene, linalool, humulene, α-pinene, nerolidol, β-pinene, terpineol, citronellol and friedelin (1-200μM) for 24hr. Sub-toxic threshold test concentrations of each terpene were then applied to cells, alone or with concomitant incubation with the lipid peroxidant tert-butyl hyrdroperoxide (t-BHP; 0-250μM) or amyloid β (Aβ_1-42; 0-1μM) to assess neuroprotective effects. Direct effects of each terpene on Aβ fibril formation and aggregation were also evaluated using the Thioflavin T (ThT) fluorometric kinetic assay and transmission electron microscopy (TEM) to visualize fibril and aggregate morphology

Results: Terpenes were intrinsically benign to PC12 cells up to 50μM, with higher concentrations of β-caryophyllene, humulene and nerolidol inducing some loss of PC12 cell viability. No significant protective effects of terpenes were observed following t-BHP (0-200µM) administration, with some enhanced toxicity instead demonstrated from both β-caryophyllene and humulene treatment (each at 50µM). α-pinene and β-pinene demonstrated a significant neuroprotective effect against amyloid β exposure. α-pinene, β-pinene, terpineol, terpinolene and friedelin were associated with a variable inhibition of Aβ_1-42 fibril and aggregate density.

Conclusions: The outcomes of this study underline a neuroprotective role of α-pinene and β-pinene against Aβ-mediated neurotoxicity associated with an inhibition of Aβ_1-42 fibrilization and density. This demonstrates the bioactive potential of selected terpenes for consideration in the development of medicinal cannabis formulations targeting neurodegenerative diseases.”

https://pubmed.ncbi.nlm.nih.gov/38070653/

“In summary, the outcomes from this study reveal a novel and efficacious neuroprotective and anti-aggregatory effect of α-pinene and β-pinene against β amyloid-mediated toxicity. The modest inhibition of lipid peroxidation from α-pinene, β-pinene, and terpinolene may also contribute to the multifaceted neuroprotection of C. sativa-prevalent terpenes. In addition, limited anti-aggregatory effects were observed from terpineol, terpinolene, α-pinene, β-pinene and friedelin. The outcomes of this study contribute to an emerging body of knowledge towards the potential synergistic bioactivities of selected terpenes for consideration in the development of medicinal cannabis formulations targeting neurodegenerative diseases.”

https://www.sciencedirect.com/science/article/pii/S0161813X23001699?via%3Dihub