A combination of cannabidiol (CBD) and beta-caryophyllene, a terpene found in marijuana, increased an electrical measure of intestinal barrier integrity by 125% compared with a control in laboratory-grown cells.
Researchers from the University of Kentucky and the U.S. Department of Agriculture’s Agricultural Research Service reported the findings in a conference abstract published recently in the Journal of Animal Science.
The team grew Caco-2 intestinal epithelial cells on semipermeable inserts for 14 days, then tested CBD, beta-caryophyllene and a combination over eight days.
Researchers measured transepithelial electrical resistance, an indicator of how tightly the cell layer restricts movement between cells.
The combination produced the highest readings across all sampling days. By day 22, electrical resistance was 125% higher than in the control group.
“These readings suggest increased barrier integrity and decreased barrier permeability,” the researchers wrote.
Treatments also affected glucose utilization and expression of SLC2A2, a gene involved in glucose transport.
The authors suggested beta-caryophyllene may be the main driver of changes in barrier integrity, permeability and glucose utilization.
Published in an annual meeting poster supplement, the research involved cultured cells. The authors identified potential applications involving intestinal health and glucose metabolism, while calling for studies in living animals to confirm the effects.
The abstract of the study can be found below:
Cannabidiol (CBD) and b-Caryophyllene (BCP) are plant-derived secondary compounds with potential beneficial properties for health and production of animals. These compounds may modulate cellular functions, including metabolism and barrier function; however, studies investigating these effects in intestinal epithelial cells (IECs) are limited. The objective of this study was to characterize modulatory effects of CBD and BCP on membrane permeability and glucose metabolism in cultured IECs using the Caco-2 cell model. Caco-2 cells were grown in replicates on semi-permeable membrane inserts (n = 4) for 14 days, allowing apical and basolateral sides of cells to form. Treatments included vehicle control (VC), 5mM CBD (C5), 10mM CBD (C10), 40mM BCP (B40), 80mM BCP (B80), and 10mM CBD plus 80mM BCP (BXC).
Treatments were added apically and supernatants were collected every 48h, over 8 days, from both sides of Caco-2 cells, followed by addition of fresh treatment. Glucose concentration was measured in supernatants to estimate disappearance, interpreted as utilization. Transepithelial electrical resistance (TEER; ohms/cm2) measurements were taken as an indicator of barrier integrity. On day 22, cells were lysed and collected for real time qPCR analysis to measure gene expression. Genes of interest included SI and SLC2A2 to investigate glucose digestion and transport, respectively. Statistical analyses were performed using lme and emmeans packages of R for TEER and glucose data. Gene expression data were analyzed using a Kruskal-Wallis and Wilcoxon rank-sum test. Treatment, time, and side were considered fixed effects. BXC resulted in the greatest TEER readings across all sampling days compared to other treatments (P < 0.05). On day 22, TEER readings of the BXC treatment group were 125% greater compared to VC (P < 0.001).
These readings suggest increased barrier integrity and decreased barrier permeability. Day 16 had no difference in glucose disappearance between treatments. On days 20 and 22, BXC and B80 had the lowest glucose disappearance compared to C5 and C10 (P < 0.05). The greatest difference in glucose disappearance was observed on day 22; BXC was 1.4±0.15 and 0.4±0.13 nmol/L compared to 3.2±0.15 and 1.9±0.13 nmol/L for VC on the apical and basolateral side, respectively (P < 0.001). Expression of SI was not affected by treatment. A 1.6-fold decrease in SLC2A2 expression was seen in B40 and BXC and a 3-fold decrease observed in B80 relative to VC (P < 0.05).
Together with glucose disappearance, these data suggest that while both compounds reduce glucose transport and utilization by cells, BCP may be the driving factor affecting barrier permeability, integrity, and cellular glucose utilization. Further implications include potential anti-diabetic properties in animals and humans in addition to barrier integrity improvement relative to intestinal conditions, including leaky gut in production animals. However, follow-up in vivo studies are needed to confirm these effects.
