Drug-Seeking Behavior Is Significantly Attenuated in Nutritionally Supplemented Cocaine Withdrawn Sprague-Dawley Rats

Aim: The effect of patented nutritional supplementation on drug-seeking behavior in cocaine addicted rats during acute drug withdrawal was investigated using a biased Conditioned Place Preference (CPP) paradigm. Method: Twenty-four (24) male Sprague-Dawley rats with pre-conditioned preference for the black chamber of the CPP box were randomly divided into Cocaine (COC) or Saline (SAL) treated groups. Rats (n = 12) treated with cocaine hydrochloride 20 mg/kg/ml, i.p. (COC group) were confined individually to the white chamber on days 1, 3, 5 and 7. On alternate days, they were given 1 ml saline vehicle, i.p. and confined to the black chamber. Control rats (SAL group, n = 12) received only vehicle on all 8 days and were confined on alternate days to the white or black chamber. Positive place preference was confirmed for COC rats, which subsequently received 6 increasing daily doses of cocaine. CPP performances of both COC and SAL rats were recorded following an acute 3-day withdrawal period. All animals were then randomly assigned to rats fed either chow reconstituted with the nutritional supplement (COC-S and SAL-S) or standard rat chow (COC-N and SAL-N) for 8 weeks, followed by final CPP performances. Results: Following supplementation, COC-S rats made significantly less entries and time spent in the white chamber (p < 0.05) compared with COC-N rats. COC-S rats exhibited significant place aversion to the white chamber similar to drug-naive animals;whereas COC-N continued to show positive place preference. Conclusion: Drug-seeking behavior that persisted during cocaine withdrawal was significantly diminished in the nutritionally supplemented.

Virgin Coconut Oil Improved Discriminative Learning and Working Memory in Aging Cycling and Non-Cycling Female Sprague-Dawley Rats Supporting Its Beneficial Effect in Retarding Age-Related Cognitive Decline

Aim: Beneficial effects of virgin coconut oil (VCO) consumption to improve cognition in menopausal females remain inconclusive. This study examined the effect of VCO supplementation in aging cycling and non-cycling rodents to assess its impact on cognition. Methods: Sprague-Dawley rats (10 - 18 months) were randomly assigned to a supplemented VCO group (SVCO) that received oral doses of 1.42 mL/kg/day VCO (n = 10) and a non-supplemented (NVCO) group (n = 10). Their performance in a biased Y-maze discriminative learning paradigm was assessed over a 16-week period. Rats were initially allowed 3 minutes to explore the maze (habituated) and subsequently pre-trained in the non-preferred, white chamber to associate the presentation of a tone with a treat (reward). Training involved 4 daily trials initially for 3 weeks during which rats were rewarded if they entered the white arm within 15 sec after tone presentation. Time (days) to attain at least 75% correct responses (CR) determined acquisition latency (AL). Memory retention (MR1) of the learned task was assessed following a 1-week break from training and absence of supplementation (session T1). Following an additional 2-week break, supplementation of SVCO animals resumed and continued to week 16. In week 14, all animals received re-training for 1 week (session T2) followed by another 1-week break and subsequent assessment of memory (MR2). Vaginal smear cytology determinations were performed throughout the study to identify cycling and non-cycling rats. Student’s t-test and ANOVA with Brown-Forsythe and Tukey’s post-hoc tests were used to compare means. Results: C-SVCO rats attained lower AL, and higher CR and MR scores vs their NVCO counterparts (p < 0.05). At session T2, NC-SVCO rats out-performed other groups (p = 0.048, F = 2.64), attaining highest CR scores between sessions (p = 0.026). Conclusion: VCO supplementation attenuated cognitive decline with a more positive impact on non-cycling rodents suggesting a beneficial effect on brain health in females in menopausal transition.

Δ⁹-Tetrahydrocannabinol Produced Positive Place Preference in Mice without Significant <i>Ex-Vivo</i>Effect on Hepatic Arylamine N-Acetyltransferase Activity: Implications for Its Addictive Liability and Absence of Effect on Xenobiotic Metabolism

Aim: Δ9-Tetrahydrocannabinol (Δ9-THC) is a potentially addictive cannabinoid. Its impact on the activity of liver arylamine N-Acetyltransferase (NAT) has not been reported. This study investigated the rewarding effects of Δ9-THC in mice and whether Δ9-THC had any impact ex-vivo and in-vitro on NAT activity. Methods: Thirty-six Swiss albinomice randomly assigned to six groups (n = 6) completed a biased, 8-week Conditioned Place Preference (CPP) paradigm. Mice exhibiting ~80% preference for the black chamber at pre-conditioning were selected. Treatment groups were administered Δ9-THC (0.10, 0.50 or 2.0 mg/kg/mL, ip) or amphetamine (AMP, 5.0 mg/kg/mL, ip);while untreated groups (controls) received vehicle solutions (coconut oil or 0.9% saline). Entries and time spent in the white, drug-paired chamber during a 15-min post-conditioning exploration of the CPP apparatus were compared with the pre-conditioning exploratory scores. Livers from Δ9-THC treated and untreated mice were excised and NAT enzyme activity determined ex-vivo using a spectrophotometric assay with p-anisidine as substrate. The impact of varying concentrations of Δ9-THC (0.00 - 162 μM) on the activities of NAT from untreated mice livers were also investigated in-vitro. Results: Δ9-THC treated mice entered and spent significantly more time in the drug-paired CPP chamber (p ≤ 0.05) at post-conditioning vs pre-conditioning (F = 11.22). Mice treated with 2.0 mg/kg Δ9-THC made significantly more entries into the drug-paired chamber (p ≤ 0.05) as compared with their vehicle controls. AMP-treated mice displayed significant (p < 0.001) increases in both entries and time spent in the drug-paired chamber at post-conditioning (positive place preference). In-vitro NAT evaluations revealed a dose-dependent inhibitory impact of Δ9-THC on NAT activity with an IC50 value of 34.97 ±1.58 μM. Ex-vivo evaluations of livers from Δ9-THC treated mice showed no significant impact on liver NAT enzyme activity. Conclusion: Δ9-THC induced significant conditioned place preference (drug reward) and produced a moderate dose-dependent inhibition on NAT activity in-vitro, but not ex-vivo.

Drug Seeking Behavior of Amphetamine Addicted Sprague-Dawley Rats Is Eliminated after Nutritional Supplementation

Aim: The effectiveness of nutritional supplementation on drug-seeking behavior of amphetamine-addicted rats during withdrawal was investigated using a biased conditioned place preference (CPP) paradigm. Method: Twenty-four male Sprague-Dawley rats exhibiting baseline preference for the black chamber during a 20-minute pre-conditioning exploration of the CPP box completed the study. On alternate days of an 8-day schedule, twelve rats (Group AMP) were randomly selected, given either amphetamine sulfate (5 mg/ml, i.p.) and confined to the white chamber;or vehicle (1 ml saline, i.p.) and confined to the black chamber. A significant increased percentage time spent and number of entries made by Group AMP to the drug-paired, white chamber on the test day confirmed amphetamine addiction. Group AMP subsequently received increasing doses of amphetamine over 6 days. Following acute drug withdrawal, their CPP performance was compared with that of vehicle treated rats (Group SAL). Groups AMP and SAL were equally divided and randomly assigned to animals fed chow reconstituted with the nutritional supplement (AMP-S and SAL-S) over 8 weeks or standard rat chow (AMP-N and SAL-N). CPP performances for all rats were determined blindly from video recordings following this period. Results: Nutritionally supplemented, amphetamine withdrawn rats (AMP-S) exhibited significantly decreased percentage entries and time spent in the white chamber (p ?ve, control animals. Conclusion: Drug-seeking behavior by amphetamine-addicted animals was eliminated after treatment with a nutritionally supplemented diet.