Anti-staphylococcal activity of soilless cultivated cannabis across the whole vegetation cycle under various nutritional treatments in relation to cannabinoid content.

Antibiotic resistance in staphylococcal strains and its impact on public health and agriculture are global problems. The development of new anti-staphylococcal agents is an effective strategy for addressing the increasing incidence of bacterial resistance. In this study, ethanolic extracts of Cannabis sativa L. made from plant parts harvested during the whole vegetation cycle under various nutritional treatments were assessed for in vitro anti-staphylococcal effects. The results showed that all the cannabis extracts tested exhibited a certain degree of growth inhibition against bacterial strains of Staphylococcus aureus, including antibiotic-resistant and antibiotic-sensitive forms. The highest antibacterial activity of the extracts was observed from the 5th to the 13th week of plant growth across all the nutritional treatments tested, with minimum inhibitory concentrations ranging from 32 to 64 µg/mL. Using HPLC, Δ9-tetrahydrocannabinolic acid (THCA) was identified as the most abundant cannabinoid in the ethanolic extracts. A homolog of THCA, tetrahydrocannabivarinic acid (THCVA), reduced bacterial growth by 74%. These findings suggest that the cannabis extracts tested in this study can be used for the development of new anti-staphylococcal compounds with improved efficacy.

Selective Cytotoxicity of Medical Cannabis (Cannabis sativa L.) Extracts Across the Whole Vegetation Cycle Under Various Hydroponic and Nutritional Treatments.

Introduction: The use of Cannabis sativa L. in health care requires stringent care for the optimal production of the bioactive compounds. However, plant phenotypes and the content of secondary metabolites, such as phytocannabinoids, are strongly influenced by external factors, such as nutrient availability. It has been shown that phytocannabinoids can exhibit selective cytotoxicity against various cancer cell lines while protecting healthy tissue from apoptosis. Research Aim: This study aimed to clarify the cytotoxic effect of cannabis extracts on colorectal cell lines by identifying the main active compounds and determining their abundance and activity across all developmental stages of medical cannabis plants cultivated under hydroponic conditions. Materials and Methods: Dimethyl sulfoxide extracts of medical cannabis plants bearing the genotype classified as chemotype I were analyzed by high-performance liquid chromatography, and their cytotoxic activity was determined by measuring cell viability by methylthiazolyldiphenyl-tetrazolium bromide assay on the human colon cancer cell lines, Caco-2 and HT-29, and the normal human epithelial cell line, CCD 841 CoN. Results: The most abundant phytocannabinoid in cannabis extracts was tetrahydrocannabinolic acid (THCA). Its maximum concentrations were reached from the 7th to the 13th plant vegetation week, depending on the nutritional cycle and treatment. Almost all extracts were cytotoxic to the human colorectal cancer (CRC) cell line HT-29 at lower concentrations than the other cell lines. The phytocannabinoids that most affected the cytotoxicity of individual extracts on HT-29 were cannabigerol, Δ9-tetrahydrocannabinol, cannabidiol, cannabigerolic acid, and THCA. The tested model showed almost 70% influence of these cannabinoids. However, THCA alone influenced the cytotoxicity of individual extracts by nearly 65%. Conclusions: Phytocannabinoid extracts from plants of the THCA-dominant chemotype interacted synergistically and showed selective cytotoxicity against the CRC cell line, HT-29. This positive extract response indicates possible therapeutic value.