Acute and Subchronic Exposure to Hemp (Cannabis sativa L.) Leaf Oil: Impacts on Vital Organs in Sprague-Dawley Rats

<b>Background/Objectives</b>: Hemp (<i>Cannabis sativa</i> L. subsp. <i>sativa</i>) is a plant within the <i>Cannabis sativa</i> species and utilized for several applications, including antioxidation, antihypertension, and anti-inflammation. To our knowledge, no prior study has assessed the acute and sub-chronic oral safety of hemp leaf oil in Sprague-Dawley rats under Thailand-compliant THC levels. This study investigates the acute and sub-chronic effects of Hemp leaf oil (HLO) on the heart, liver, and kidneys of male and female Sprague-Dawley rats. <b>Methods</b>: Six-week-old male and female Sprague-Dawley rats were administered HLO (1.5 mL/kg) intragastrically, either as a single dose or a repeat dose over 28 days. <b>Results</b>: No changes in body or organ weights were observed following acute and sub-chronic HLO administration in sex-matched groups. Moreover, blood pressure and heart rate remained comparable across groups after acute and sub-chronic HLO treatment. Both acute and sub-chronic administration of HLO did not influence electrolyte balance, liver enzymes, total protein, albumin, blood urea nitrogen, or creatinine levels. Hematoxylin and eosin staining revealed the normal morphology of the heart, liver, and kidneys in rats subjected to HLO, during both acute and sub-chronic treatment. <b>Conclusions</b>: In conclusion, our data suggested that both acute and sub-chronic administration of HLO at 1.5 mL/kg could be safe for the vital organs. These findings support the potential use of HLO in therapeutic applications, particularly in scenarios when the safety of essential organs is at stake.