“Objective: To compare the pharmacokinetics of cannabidiol (CBD) and cannabidiolic acid (CBDA) in horses and to evaluate the safety of their chronic administration.

Methods: CBD- and CBDA-rich oil (1 mg/kg) were administered orally twice daily to 7 adult horses over 6 weeks in a randomized, crossover design with a 2-week washout period. A 12-hour pharmacokinetic analysis was conducted on day 1 of each 6-week trial, followed by the measurement of peak and trough concentrations at weeks 1, 2, 4, and 6. The cannabinoids safety was assessed via daily physical examination, periodic bloodwork, and liver biopsy at the beginning and end of the study.

Results: 12-hour pharmacokinetics revealed a higher maximum serum concentration (103 vs 12 ng/mL) and greater area under the curve (259 vs 62 ng·h/mL) for CBDA when compared to CBD. Cannabidiolic acid nadir and peak serum levels over time ranged from 46 to 122 ng/mL, which was higher than CBD (12 to 38 ng/mL). Complete blood count and serum chemistry revealed no clinically relevant changes with either CBD or CBDA. No significant abnormalities were detected on liver ultrasonographic and histopathologic evaluation on day 0 and after both phases of the study.

Conclusions: A dose of either 1 mg/kg of CBD or CBDA administered long term appears safe; however, CBDA serum concentrations suggest superior absorption/retention.

Clinical relevance: Chronic cannabinoid supplementation in horses is safe. Considering the higher absorption of CBDA, its use is recommended to evaluate the therapeutic efficacy of this common hemp derived cannabinoid.”

https://pubmed.ncbi.nlm.nih.gov/39787699/

https://avmajournals.avma.org/view/journals/ajvr/aop/ajvr.24.08.0235/ajvr.24.08.0235.xml

“The growing awareness and need to protect public health, including food safety, require a thorough study of the mechanism of action of veterinary drugs in consumers to reduce their negative impact on humans. Inappropriate use of veterinary drugs in animal husbandry, such as tiamulin, leads to the appearance of residues in edible animal tissues.

The use of natural substances of plant origin, extracted from hemp (Cannabis sativa L.), such as cannabidiol (CBD), is one of the solutions to minimize the negative effects of tiamulin.

This study aimed to determine the effect of CBD on the cytotoxicity of tiamulin in humans.

The cytotoxic activity of tiamulin and the effect of its mixtures with CBD were tested after 72 h exposure to three human cell lines: SH-SY5Y, HepG2 and HEK-293. Cytotoxic concentrations (IC₅₀) of the tested drug and in combination with CBD were assessed using five biochemical endpoints: mitochondrial and lysosomal activity, proliferation, cell membrane integrity and effects on DNA synthesis. Oxidative stress, cell death and cellular morphology were also assessed. The nature of the interaction between the veterinary drug and CBD was assessed using the combination index. The long-term effect of tiamulin inhibited lysosomal (SH-SY5SY) and mitochondrial (HepG2) activity and DNA synthesis (HEK-293). IC₅₀ values for tiamulin ranged from 2.1 to >200 µg/mL (SH-SY5SY), 13.9 to 39.5 µg/mL (HepG2) and 8.5 to 76.9 µg/mL (HEK-293). IC₅₀ values for the drug/CBD mixtures were higher.

Reduced levels of oxidative stress, apoptosis and changes in cell morphology were demonstrated after exposure to the mixtures. Interactions between the veterinary drug and CBD showed a concentration-dependent nature of tiamulin in cell culture, ranging from antagonistic (low concentrations) to synergistic effects at high drug concentrations.

The increased risk to human health associated with the presence of the veterinary drug in food products and the protective nature of CBD use underline the importance of these studies in food toxicology and require further investigation.”

https://pubmed.ncbi.nlm.nih.gov/39769305/

https://www.mdpi.com/1422-0067/25/24/13542

“Pests and diseases have caused significant problems since the domestication of crops, resulting in economic loss and hunger. To overcome these problems, synthetic pesticides were developed to control pests; however, there are significant detrimental side effects of synthetic pesticides on the environment and human health. There is an urgent need to develop safer and more sustainable pesticides.

Industrial hemp is a reservoir of compounds that could potentially replace some synthetic bactericides, fungicides, and insecticides.

We determined the efficacy of industrial hemp extracts against Pseudomonas syringae pv. tabaci (PSTA), Pseudomonas syringae pv. tomato (PSTO), and Erwinia carotovora (EC).

The study revealed a minimum inhibitory concentration (MIC) of 2.05 mg/mL and a non-inhibitory concentration (NIC) of 1.2 mg/mL for PSTA, an MIC of 5.7 mg/mL and NIC of 0.66 mg/mL for PSTO, and an MIC of 12.04 mg/mL and NIC of 5.4 mg/mL for EC. Time-kill assays indicated the regrowth of E. carotovora at 4 × MIC after 15 h and P. syringae pv. tomato at 2 × MIC after 20 h; however, P. syringae pv. tabaci had no regrowth. The susceptibility of test bacteria to hemp extract can be ordered from the most susceptible to the least susceptible, as follows: P. syringae pv. tabaci > P. syringae pv. tomato > E. carotovora.

Overall, the data indicate hemp extract is a potential source of sustainable and safe biopesticides against these major plant pathogens.”

https://pubmed.ncbi.nlm.nih.gov/39769990/

“The data show the susceptibility of the test bacteria to hemp extract, ordered from the most susceptible to the least susceptible, as follows: P. syringae pv. tabaci > P. syringae pv. tomato > E. carotovora.

This study indicates that hemp extract is effective in controlling E. carotovora, P. syringae pv. tabaci, and P. syringae pv. tomato. However, the hemp extract is more effective against both Pseudomonas spp. than E. carotovora. The difference could be due to their difference in cell wall structure, resistance mechanisms, and metabolic pathways.

More studies are needed to determine how hemp extract causes stress to bacteria such as interference with quorum sensing, biofilm formation, and oxidative stress. Moreover, to ensure sustainable agricultural practices that are safe and affordable for low-income farmers, synergistic effect studies are needed between hemp compounds in the extract and, more importantly, between hemp extracts and other plant extracts.”

https://www.mdpi.com/1420-3049/29/24/5902