Subchronic oral toxicity assessment of a cannabis extract

Cannabidiol (CBD) is present in Cannabis Sativa L. and has been used in medicines and foods to deliver beneficial health effects. Despite this, research on CBD safety utilising modern testing methods is lacking. Therefore three separate safety experiments were performed on a CBD isolate. Sprague-Dawley rats were used to investigate prenatal development, a 14-day toxicity sighting study, and an OECD compliant 90-day subchronic oral toxicity trial, with 35-day off-dose recovery. The prenatal screening study demonstrated reduced body weights and food consumption in the highest dose group, but no substance-related changes in pregnancy rate, maternal or placental gross abnormalities, or premature deliveries. The 14-day study indicated tolerance up to 460 mg/kg bw/d of CBD isolate. Based on these findings, a 90-day repeated dose oral toxicity study was performed at doses of 0, 30, 115, 230, and 460 mg/kg bw/d of CBD, followed by a 35-day off-dose recovery period. In the 90-day study, some non-adverse organ and tissue changes were observed. With the exception of the high dose group, these fully reversed during the recovery period. Based on these findings, sub-chronic consumption of highly purified isolate results in a CBD NOAEL of 460 mg/kg bw/d for males and 230 mg/kg bw/d for females.

The effects of cannabidiol on male reproductive system: A literature review

Cannabidiol (CBD) is one of the most abundant phytocannabinoids present in the plant Cannabis sativa (marijuana). There have been several studies of CBD in the last few decades, mainly focused on its neuroprotective properties, particularly after the identification of the endocannabinoid system and its participation in the central nervous system. On the other hand, the peripheral effects of CBD, particularly on reproductive physiology, were also evidenced. A narrative review was conducted using the PubMed database to identify studies that analyzed the pharmacological effects of CBD on the male reproductive system of vertebrates and invertebrates. Thirty-two citations (in vivo and in vitro) were identified. Among the vertebrates, the studies were carried out with men, monkeys, rats and mice. Studies with invertebrates are centered exclusively on the sea urchin. The CBD treatment periods include mostly acute and subacute evaluations. Exposure to CBD is associated with a reduction in mammalian testis size, the number of germ and Sertoli cells in spermatogenesis, fertilization rates, and plasma concentrations of hypothalamic, pituitary and gonadal hormones. Moreover, chronic doses of CBD have impaired sexual behavior in mice. From the studies identified in this review, it is possible to conclude that CBD has negative effects on the reproductive system of males. However, knowledge is still limited, and additional research is required to elucidate fully the mechanisms of action, as well as the reversibility of CBD effects on the reproductive system.

Cannabidiol for neurodegenerative disorders: important new clinical applications for this phytocannabinoid?

Cannabidiol (CBD) is a phytocannabinoid with therapeutic properties for numerous disorders exerted through molecular mechanisms that are yet to be completely identified. CBD acts in some experimental models as an anti-inflammatory, anticonvulsant, anti-oxidant, anti-emetic, anxiolytic and antipsychotic agent, and is therefore a potential medicine for the treatment of neuroinflammation, epilepsy, oxidative injury, vomiting and nausea, anxiety and schizophrenia, respectively. The neuroprotective potential of CBD, based on the combination of its anti-inflammatory and anti-oxidant properties, is of particular interest and is presently under intense preclinical research in numerous neurodegenerative disorders. In fact, CBD combined with Δ(9)-tetrahydrocannabinol is already under clinical evaluation in patients with Huntington's disease to determine its potential as a disease-modifying therapy. The neuroprotective properties of CBD do not appear to be exerted by the activation of key targets within the endocannabinoid system for plant-derived cannabinoids like Δ(9)-tetrahydrocannabinol, i.e. CB(1) and CB(2) receptors, as CBD has negligible activity at these cannabinoid receptors, although certain activity at the CB(2) receptor has been documented in specific pathological conditions (i.e. damage of immature brain). Within the endocannabinoid system, CBD has been shown to have an inhibitory effect on the inactivation of endocannabinoids (i.e. inhibition of FAAH enzyme), thereby enhancing the action of these endogenous molecules on cannabinoid receptors, which is also noted in certain pathological conditions. CBD acts not only through the endocannabinoid system, but also causes direct or indirect activation of metabotropic receptors for serotonin or adenosine, and can target nuclear receptors of the PPAR family and also ion channels.