Gamma-decanolactone attenuates acute and chronic seizures in mice: a possible role of adenosine A1 receptors

Gamma-decanolactone: Preliminary evaluation as potential antiparkinsonian drug

Treatment of Parkinson's disease (PD) includes the use of monoamine oxidase-B (MAO-B) inhibitor drugs. In this work we have evaluated the possible gamma-decanolactone (GD) effect in vitro to inhibit the A and B isoforms of human monoamine oxidase (hMAO) enzyme and their citotoxicity in human hepatoma cell line (HepG2). Also, binding studies to A₁, A_2A A_2B and A₃ adenosine receptors were performed. A docking study of gamma-decanolactone has been carried out with the molecular targets of MAO-A and MAO-B isoforms. The physicochemical properties and ability to cross physiological barriers, as the blood brain barrier (BBB), was elucidated by computational studies. The in vivo assays, the rota-rod test, body temperature assessment and open field test were performed in reserpinized mice (1.5 mg/kg, i.p.; 18:00 before) to evaluate the effect of gamma-decanolactone (300 mg/kg), alone or associated with Levodopa plus Benserazide (LD + BZ, 100:25 mg/kg, i.p.). Gamma-decanolactone inhibited preferentially the MAO-B in a reversible manner, with an inhibitory concentration of 50% (IC₅₀) 55.95 ± 9.06 μM. It was shown to be a safe drug since only at the highest concentration decreased the viability of HepG2 cells. It also does not bind to adenosine receptors investigated in this study. The molecular docking study show that the gamma-decanolactone ligand adopts a relatively compact conformation in the active site of hMAO-B, while we note an extended conformation of gamma-decanolactone ligand in the hMAO-A isoform. The physicochemical properties obtained, and the theoretical models utilized for the evaluation of ability to cross the BBB, predict a good gamma-decanolactone bioavailability and access to the central nervous system (CNS). In the in vivo studies, gamma-decanolactone partially reversed the ataxia of the reserpinized mice at 01:00 h and 01:30 h post-administration. Concomitant treatment of gamma-decanolactone with LD + BZ, at 01:30 h showed a potentiation of the reversibility of ataxia and facilitated the reversal of hypothermia caused by reserpine for all measured times (P <0.01 vs vehicle), except at 24:00 h, but not reversed the hypokinesia in the open field test. In summary, the results herein obtained and in conjunction with previous studies, suggest that gamma-decanolactone could be a drug with potential utility as antiparkinsonian drug.

Gamma-Decanolactone Alters the Expression of GluN2B, A1 Receptors, and COX-2 and Reduces DNA Damage in the PTZ-Induced Seizure Model After Subchronic Treatment in Mice

Gamma-decanolactone (GD) has been shown to reduce epileptic behavior in different models, inflammatory decreasing, oxidative stress, and genotoxic parameters. This study assessed the GD effect on the pentylenetetrazole (PTZ) model after acute and subchronic treatment. We evaluated the expression of the inflammatory marker cyclooxygenase-2 (COX-2), GluN2B, a subunit of the NMDA glutamate receptor, adenosine A1 receptor, and GD genotoxicity and mutagenicity. Male and female mice were treated with GD (300 mg/kg) for 12 days. On the tenth day, they were tested in the Hot Plate test. On the thirteenth day, all animals received PTZ (90 mg/kg), and epileptic behavior PTZ-induced was observed for 30 min. Pregabalin (PGB) (30 mg/kg) was used as a positive control. Samples of the hippocampus and blood were collected for Western Blotting analyses and Comet Assay and bone marrow to the Micronucleus test. Only the acute treatment of GD reduced the seizure occurrence and increased the latency to the first stage 3 seizures. Males treated with GD for 12 days demonstrated a significant increase in the expression of the GluN2B receptor and a decrease in the COX-2 expression. Acute and subchronic treatment with GD and PGB reduced the DNA damage produced by PTZ in males and females. There is no increase in the micronucleus frequency in bone marrow after subchronic treatment. This study suggests that GD, after 12 days, could not reduce PTZ-induced seizures, but it has been shown to protect against DNA damage, reduce COX-2 and increase GluN2B expression.