Observed Impact of Long-Term Consumption of Oral Cannabidiol on Liver Function in Healthy Adults

The Role of Cannabidiol in Liver Disease: A Systemic Review

Cannabidiol (CBD), a non-psychoactive phytocannabinoid abundant in Cannabis sativa, has gained considerable attention for its anti-inflammatory, antioxidant, analgesic, and neuroprotective properties. It exhibits the potential to prevent or slow the progression of various diseases, ranging from malignant tumors and viral infections to neurodegenerative disorders and ischemic diseases. Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, and viral hepatitis stand as prominent causes of morbidity and mortality in chronic liver diseases globally. The literature has substantiated CBD's potential therapeutic effects across diverse liver diseases in in vivo and in vitro models. However, the precise mechanism of action remains elusive, and an absence of evidence hinders its translation into clinical practice. This comprehensive review emphasizes the wealth of data linking CBD to liver diseases. Importantly, we delve into a detailed discussion of the receptors through which CBD might exert its effects, including cannabinoid receptors, CB1 and CB2, peroxisome proliferator-activated receptors (PPARs), G protein-coupled receptor 55 (GPR55), transient receptor potential channels (TRPs), and their intricate connections with liver diseases. In conclusion, we address new questions that warrant further investigation in this evolving field.

Comparative role of acetaminophen, carbon tetrachloride and thioacetamide in development of fibrosis in rats

Background

Several hepatotoxicants such as acetaminophen, carbon tetrachloride, and thioacetamide are repeatedly used to develop hepatic fibrosis to mimic the histological and hemodynamic characteristics of human illness. It may be a good idea to establish a better model among these hepatotoxicants to develop hepatic fibrosis.

Aim

The present study evaluated comparative toxic effects of three model hepatotoxicants for experimental progression of fibrosis or cirrhosis.

Materials and methods

Acetaminophen (200 mg/kg), carbon tetrachloride (200 µl/kg) and thioacetamide (200 mg/kg) were administered orally, thrice in a week for 8 weeks in different groups. After 8 weeks of exposure, animals were euthanized, blood and tissues were collected for various hematological, serological, tissue biochemical analysis and histological observations for comparative assessment of toxic consequences.

Results

Significant deviation was noted in liver function tests, lipid peroxidation, glutathione, activities of superoxide dismutase, catalase, and GSH cycle enzymes; aniline hydroxylase, amidopyrine-N-demethylase, DNA fragmentation and level of hydroxyproline when compared with control group. Histology also depicted damage in liver histoarchitecture with exposure to acetaminophen, carbon tetrachloride and thioacetamide. Tukey's HSD post hoc test confirmed that thioacetamide produced severe toxic effects in comparison to carbon tetrachloride and acetaminophen.

Conclusion

In conclusion, toxic effects were noted in ascending order as acetaminophen.

Cannabidiol safety considerations: Development of a potential acceptable daily intake value and recommended upper intake limits for dietary supplement use

Consumer use of hemp-derived products continues to rise, underscoring the need to establish evidence-based safety guidance. The present study sought to develop recommendations for oral upper intake limits of cannabidiol (CBD) isolate. Sufficiently robust and reliable data for this purpose were identified from published human clinical trials and guideline-compliant toxicity studies in animal models. Based on the metrics used in this assessment, a potential Acceptable Daily Intake (ADI) value of 0.43 mg/kg-bw/d (e.g., 30 mg/d for 70-kg adult) was determined for the general population based on liver effects in human studies. This value applies to the most sensitive subpopulations, including children, over a lifetime of exposure and from all sources, including food. For dietary supplements with adequate product labeling intended for use by healthy adults only, a potential Upper Intake Limit (UL) of 70 mg/d was determined based on reproductive effects in animals. For healthy adults, except those trying to conceive, or currently pregnant or lactating, a conservative dietary supplement UL of 100 mg/d was identified based on liver effects; however, as the target population excludes individuals at risk for liver injury, an alternative dietary supplement UL of 160 mg/d for this population can also be considered.

THC and CBD: Similarities and differences between siblings

Δ9-tetrahydrocannabinol (THC) and its sibling, cannabidiol (CBD), are produced by the same Cannabis plant and have similar chemical structures but differ dramatically in their mechanisms of action and effects on brain functions. Both THC and CBD exhibit promising therapeutic properties; however, impairments and increased incidence of mental health diseases are associated with acute and chronic THC use, respectively, and significant side effects are associated with chronic use of high-dose CBD. This review covers recent molecular and preclinical discoveries concerning the distinct mechanisms of action and bioactivities of THC and CBD and their impact on human behavior and diseases. These discoveries provide a foundation for the development of cannabinoid-based therapeutics for multiple devastating diseases and to assure their safe use in the growing legal market of Cannabis-based products.

Long-Term, Self-Dosing CBD Users: Indications, Dosage, and Self-Perceptions on General Health/Symptoms and Drug Use

Introduction

Self-dosing of off-the-shelf cannabidiol (CBD) for a myriad of health conditions is common in the USA. These CBD products are often mislabeled, suggesting that much less or much more CBD is being consumed than indicated on the label. This study examined the relationship between long-term self-dosing of CBD and (a) indications and, when a verified concentration of CBD is being consumed, (b) the daily CBD dosage, (c) the impact on general health and symptoms, and (d) over-the-counter (OTC) and prescription (Rx) drug usage.

Methods

US adults 18-75 years of age who had used unverified CBD products for >1 month were recruited to participate in this decentralized, observational, IRB-approved study and provided a concentration-verified CBD product of their choice from 15 different vendors for 4 weeks. Prior to receiving product, they were queried on their primary reason for use (PRfU), primary symptom for use (PSfU), general health score (GHS), symptom score (SS), OTC and Rx drug use, and daily CBD dose. Individuals were queried daily on OTC and Rx drug use and CBD dose and weekly on SS and GHS prior to (pre-CBD) and after (post-CBD) ingestion of CBD on that day.

Results

The PRfU included chronic pain, mental health, general health and wellness, sleep disorders, the central nervous system, digestive health, and others, while the PSfU included anxiety, back and/or joint pain, sleep, inflammation, and others. The mean daily dose was normally distributed, with a mean, median, and range of 53.1, 40.8, 8-390 mg/day, respectively. For both GHS and SS, the post-CBD was significantly higher than the pre-CBD score for each category of PRfU. The GHS scores did not change over the study, but pre- and post-CBD SS improved over time, with pre-improving more than post-CBD SS. The percentage of individuals decreasing or completely stopping OTC drugs or Rx drugs over the 4 weeks was 31.2% and 19.2%, respectively, with those taking CBD for chronic pain, decreasing drug use the most. OTC and Rx drug usage decreased when the CBD dose was changed and when GHS and SS improved.

Conclusion

Pain, mental health (primarily anxiety/stress), and sleep are the most common reasons for CBD use. Self-administration of CBD reduced OTC and Rx drug usage at daily doses less than those reported in controlled studies. CBD self-administration significantly improves self-perception of general health and decreases symptom severity, and as these improve, fewer OTC and Rx drugs are used.

The Effects of Long-Term Self-Dosing of Cannabidiol on Drowsiness, Testosterone Levels, and Liver Function

Introduction

Previous research indicated that cannabidiol (CBD) may result in low levels of male total testosterone (TT), elevations in liver tests (LTs), and daytime drowsiness (DD). We investigated the prevalences of TT and LT in a large adult sample self-administering CBD and determined the effect self-dosing of CBD has on the severity of DD.

Methods

Adult participants (18-75 years of age) who self-dose CBD orally for a minimum of 30 days were recruited for this decentralized observational study from companies that offer CBD products. Participants were sent their usual CBD regimen. A clinical study platform was used on a phone app to obtain consent and collect study data. Data included demographic information, reasons for self-dosing, dosage, current medications and dosage, medical history, adverse effects, effects on DD, and efficacy. After 30 days, LT and TT were obtained and follow-up LT was offered to participants who demonstrated elevated values of alanine transaminase (ALT).

Results

A total of 28,121 individuals were contacted, 1,475 met the criteria and were enrolled, and 1,061 (female: 65.2%, male: 34.8%) completed the study. Most of the participants used full-spectrum CBD oil or CBD isolate with the mean ± SD daily dose of CBD for all users of 55.4 ± 37.8 mg. CBD use was associated with a significant decrease in DD and a decrease in the prevalence of low TT in males >40 years of age. The prevalences of elevations in ALT and aspartate aminotransferase were not significantly different from those of the general adult population, and the prevalences of elevated levels of alkaline phosphatase and bilirubin were less than those of a healthy adult population. There was no relationship between LT and CBD dose.

Conclusions

In this large-sample study, self-dosing CBD was not associated with an increased prevalence of elevation of LT or low levels of TT in men. Furthermore, CBD administration decreased DD and was associated with a lower prevalence of low testosterone levels in older men as compared to age-adjusted population norms.

Safety and Tolerability of Oral Cannabinoids in People Living with HIV on Long-Term ART: A Randomized, Open-Label, Interventional Pilot Clinical Trial (CTNPT 028)

BACKGROUND

With anti-inflammatory properties, cannabinoids may be a potential strategy to reduce immune activation in people living with HIV (PLWH) but more information on their safety and tolerability is needed.

METHODS

We conducted an open-label interventional pilot study at the McGill University Health Centre in Montreal, Canada. PLWH were randomized to oral Δ9-tetrahydrocannabinol (THC): cannabidiol (CBD) combination (THC 2.5 mg/CBD 2.5 mg) or CBD-only capsules (CBD 200 mg). Individuals titrated doses as tolerated to a maximum daily dose THC 15 mg/CBD 15 mg or 800 mg CBD, respectively, for 12 weeks. The primary outcome was the percentage of participants without any significant toxicity based on the WHO toxicity scale (Grades 0-2 scores).

RESULTS

Out of ten individuals, eight completed the study. Two from the CBD-only arm were withdrawn for safety concerns: phlebotomy aggravating pre-existing anemia and severe hepatitis on 800 mg CBD with newly discovered pancreatic adenocarcinoma, respectively. Seven did not have any significant toxicity. Cannabinoids did not alter hematology/biochemistry profiles. CD4 count, CD4/CD8 ratio, and HIV suppression remained stable. Most adverse effects were mild-moderate.

CONCLUSIONS

In PLWH, cannabinoids seem generally safe and well-tolerated, though larger studies are needed. Screening for occult liver pathology should be performed and hepatic enzymes monitored, especially with high CBD doses.

The effects of subacute exposure to a water-soluble cannabinol compound in male mice

Background

Cannabinol (CBN) is one of the many cannabinoids present in Cannabis sativa and has been explored as a potential treatment for sleeplessness. The purpose of this study was to determine the physiological and behavioral effects of subacute exposure to therapeutic and low pharmacological levels of a mechanically formed, stabilized water-soluble cannabinol nano-emulsion (CBNight™).

Methods

Sixty-two male mice were randomly assigned to one of six treatment groups given CBNight™ at dosages designed to deliver 0mg (control) to 4 mg/kg of CBN daily via oral gavage for 14 days. In-cage behavior was observed at 30 minutes and at 2, 4, 8, and 16 hours after each dose. After 14 days, the mice were sacrificed and necropsied. Organs were weighed and inspected for gross abnormalities, and blood was collected via cardiac puncture for clinical chemistry.

Results

No dosage-dependent adverse effects on behavior, body mass, or blood chemistry were observed, except that the highest doses of CBNight™ were associated with significantly lower eosinophil counts.

Conclusions

The commercially available, water-soluble CBN compound employed in this study does not appear to cause adverse effects in mice; rather, it appears to be well tolerated at pharmacological levels. The findings of eosinopenia at higher doses of CBN and lack of hepatotoxicity at any dosage employed in this study have not been reported to date.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00153-w.

Cannabidiol-enriched cannabis extraction product in Parkinson's disease: A randomized, double-blind, and placebo-controlled trial in Buriram Hospital

Objectives

The objective of this study was to assess cannabidiol-enriched cannabis extraction product (CBDEP) efficacy in patients with Parkinson's disease (PD).

Materials and Methods

Forty patients with PD were randomly assigned to the sublingual CBDEP (n = 20) or placebo (n = 20) group. All patients were prescribed a low initial dose with gradual titration within 2 weeks based on individual response - including side effects - followed by 6 weeks of stable dosing. The primary outcome was the Unified Parkinson's Disease Rating Scale (UPDRS) score. The secondary outcomes were as follows: Quality of life (QOL) evaluated by the EQ-5D-5L, timed up and go (TUG) test, 5 times sit to stand (FTSTS) test, gait velocity, hospital anxiety and depression scale (HADS), renal and liver function indices, and adverse events. All outcomes were measured at baseline and at 8 weeks. The generalized estimating equation adjusted for baseline scores was used to compare the values at baseline and at 8 weeks, and between the groups.

Results

Four patients were lost to follow-up (CBDEP group, n = 1; placebo group, n = 3) and 36 were included in the analysis (CBDEP group, n = 19; placebo group, n = 17). The CBDEP group received mean cannabidiol and tetrahydrocannabinol dosages of 15.59 ± 5.04 mg/day and 0.61 ± 0.19 mg/day, respectively. No significant differences were found between the groups in terms of the UPDRS, TUG test, FTSTS test, gait velocity, HADS-anxiety, and HADS-depression. The placebo group had significantly improved EQ-5D-5L scores for QOL (P = 0.004). The CBDEP group showed significantly improved blood urea nitrogen (BUN), serum albumin, serum globulin levels, and albumin/globulin ratio (P = 0.037, P < 0.001, P = 0.011, and P = 0.002, respectively) compared with the placebo group. Neither group had serious side effects.

Conclusion

No evidence was found that CBDEP can reduce disease severity or improve functional performance, anxiety, or depression in PD. However, CBDEP is safe and can improve the levels of BUN, serum albumin, serum globulin, and albumin/globulin ratio in patients with PD.

Trial Registration

Thai Clinical Trials Registry (registration number: TCTR 20210303005).

Cannabidiol and Cannabidiol Metabolites: Pharmacokinetics, Interaction with Food, and Influence on Liver Function

Cannabidiol (CBD) is widely available and marketed as having therapeutic properties. Over-the-counter CBD is unregulated, many of the therapeutic claims lack scientific support, and controversy exists as to the safety of CBD-liver interaction. The study aims were to compare the pharmacokinetics of commercial CBD and CBD metabolites following the ingestion of five different CBD formulations, determine the influence of CBD on food induced thermogenesis, determine the influence of food on CBD pharmacokinetics, and determine the influence of CBD on markers of liver function. Fourteen males (body mass index ≥ 25 kg/m²) were studied in a placebo-controlled, randomized, crossover design. On five occasions, different CBD formulations were ingested (one per visit). On two additional occasions, CBD or placebo was ingested following a meal. CBD servings were standardized to 30 mg. Considerable pharmacokinetic variability existed between formulations; this pharmacokinetic variability transferred to several of the metabolites. CBD did not influence food induced thermogenesis but did favorably modify early insulin and triglyceride responses. Food appreciably altered the pharmacokinetics of CBD. Finally, CBD did not evoke physiologically relevant changes in markers of liver function. Collectively, these data suggest that consumers should be aware of the appreciable pharmacokinetic differences between commercial CBD formulations, CBD is unlikely to influence the caloric cost of eating but may prove to be of some benefit to initial metabolic responses, consuming CBD with food alters the dynamics of CBD metabolism and increases systemic availability, and low-dose CBD probably does not represent a risk to normal liver function.