Developmental exposure to cannabidiol (CBD) alters longevity and health span of zebrafish (Danio rerio)

Abstract

Consumption of cannabinoid-containing products is on the rise, even during pregnancy. Unfortunately, the long-term, age-related consequences of developmental cannabidiol (CBD) exposure remain largely unknown. This is a critical gap given the established Developmental Origins of Health and Disease (DOHaD) paradigm which emphasizes that stressors, like drug exposure, early in life can instigate molecular and cellular changes that ultimately lead to adverse outcomes later in life. Thus, we exposed zebrafish (Danio rerio) to varying concentrations of CBD (0.02, 0.1, 0.5 μM) during larval development and assessed aging in both the F0 (exposed generation) and their F1 offspring 30 months later. F0 exposure to CBD significantly increased survival (~ 20%) and reduced size (wet weight and length) of female fish. While survival was increased, the age-related loss of locomotor function was unaffected and the effects on fecundity varied by sex and dose. Treatment with 0.5 μM CBD significantly reduced sperm concentration in males, but 0.1 μM increased egg production in females. Similar to other model systems, control aged zebrafish exhibited increased kyphosis as well as increased expression markers of senescence, and inflammation (p16^ink4ab, tnfα, il1b, il6, and pparγ) in the liver. Exposure to CBD significantly reduced the expression of several of these genes in a dose-dependent manner relative to the age-matched controls. The effects of CBD on size, gene expression, and reproduction were not reproduced in the F1 generation, suggesting the influence on aging was not cross-generational. Together, our results demonstrate that developmental exposure to CBD causes significant effects on the health and longevity of zebrafish.

Keywords: Aging; Cannabinoids; Danio rerio; Inflammaging; Senescence.

Fig. 1

Survival (%) measured at 30 months of age of adult F0 zebrafish developmentally exposed to CBD and enrolled into the study at 12 months old. a Male % survival from 12 to 30 months, n = 27–38. b Female % survival from 12 to 30 months, n = 7–13. The number displayed at the base of the bar is the total number of fish per treatment enrolled into the study at 12 months old. Number sign indicates a significant difference compared with aged controls (Fisher’s exact test p ≤ 0.05)

Fig. 2

Open-field behavior of adult F0 (young = 7 months old, aged = 30 months old) zebrafish developmentally exposed to CBD, n = 8. a, b Male and female zebrafish distance traveled (cm). c, d Male and female velocity (cm/s). e, f Male and female mobility (%). Asterisk indicates a significant difference between aged and young controls (t test, p ≤ 0.05). No significant difference between CBD treatment and aged controls (ANOVA, Dunnett’s post hoc, p > 0.05)

Fig. 3

Weight, length, and spinal curvature (kyphosis) of adult F0 (young = 7 months old, aged = 30 months old) male (n = 8–22) and female (n = 5–12) zebrafish developmentally exposed to CBD. a, b Male and female zebrafish total length (mm). c, d Male and female wet weight (g). e Male and female spinal curvature grading from healthy (1) to medium (3) to severe (5). f, g Male and female kyphosis (%). Asterisk indicates a significant difference between aged and young controls (t test, p ≤ 0.05). Number sign indicates a significant difference compared with aged controls (ANOVA, Dunnett’s post hoc, p ≤ 0.05 or Fisher’s exact test p ≤ 0.05)

Fig. 4

Correlation matrix of endpoints used in this CBD developmental exposure study. The values for each parameter were averaged by treatment and then plotted and analyzed by linear regression; the values presented in the table are the resulting r²

Fig. 5

Survival, distance traveled, length, weight, and incidence of kyphosis of male and female F1 zebrafish (parents exposed to CBD). a, b Male, n = 39–60, and female, n = 13–20, survival (%) from 12 to 30 months old. The number displayed at the base of each bar is the total number of fish per treatment enrolled into the study at 12 months old. c, d Male and female zebrafish distance traveled (cm), n = 6. e, f Weight; g, h length; and i, j spinal curvature (kyphosis) of adult F1 male (n = 11–60) and female (n = 6–19) zebrafish. No significant difference between F1 parentally exposed fish and aged controls (ANOVA, Dunnett’s post hoc, p > 0.05 or Fisher’s exact test p > 0.05)