The standardized extract of Centella asiatica L. Urb attenuates the convulsant effect induced by lithium/pilocarpine without affecting biochemical and haematological parameters in rats.

BACKGROUND: Status epilepticus (SE) is a type of epileptic activity characterized by a failure of the inhibitory mechanisms that limit seizures, which are mainly regulated by the GABAergic system. This imbalance increases glutamatergic neurotransmission and consequently produces epileptic activity. It is also associated with oxidative stress due to an imbalance between reactive oxygen species (ROS) and antioxidant defences. Unfortunately, long-term treatment with anti-epileptic drugs (AEDs) may produce hepatotoxicity, nephrotoxicity, and haematological alterations. In this way, some secondary metabolites of plants have been used to ameliorate the deterioration of nervous system disorders through their antioxidant properties, in addition to their anticonvulsant effects. An example is Centella asiatica, a plant noted to have a reputed neuroprotective effect related to its antioxidant activity. However, similar to conventional drugs, natural molecules may produce side effects when consumed in high doses, which could occur with Centella asiatica. Therefore, we aimed to evaluate the effect of a standardized extract of Centella asiatica L. Urb with tested anticonvulsant activity on biochemical and haematological parameters in rats subjected to lithium/pilocarpine-induced seizures. METHODS: Twenty-eight adult male Wistar rats were randomly divided into four groups (n = 7 each): vehicle (purified water), Centella asiatica (200 and 400 mg/kg), and carbamazepine (CBZ) (300 mg/kg) as a pharmacological control of anticonvulsant activity. Treatments were administered orally every 24 h for 35 consecutive days. On Day 36, SE was induced using the lithium/pilocarpine model (3 mEq/kg, i.p. and 30 mg/kg s.c., respectively), and the behavioural and biochemical effects were evaluated. RESULTS: Centella asiatica 400 mg/kg increased the latency to the first generalized seizure and SE onset and significantly reduced the time to the first generalized seizure compared to values in the vehicle group. Biochemical parameters, i.e., haematic cytometry, blood chemistry, and liver function tests, showed no significant differences among the different treatments. CONCLUSION: The dose of Centella asiatica that produces anticonvulsant activity in the lithium/pilocarpine model devoid of hepatotoxicity, nephrotoxicity, and alterations in haematological parameters suggests that the standardized extract of this plant could be of utility in the development of new safe therapies for the treatment of convulsions associated with epilepsy.

Bioavailability of two oral formulations of a single dose of levofloxacin 500 mg: an open-label, randomized, two-period crossover comparison in healthy Mexican volunteers.

BACKGROUND: Levofloxacin is a synthetic fluoroquinolone with a broad spectrum of antibacterial activity. It is indicated for the treatment of respiratory, sinus, skin, and urinary tract infections. Although generic formulations of oral levofloxacin are marketed in Mexico, a literature search did not identify published data concerning the bioavailability of these formulations; these data would be relevant to secure marketing of a test formulation in Mexico. OBJECTIVE: The aim of this study was to compare the bioavailability and determine the bioequivalence of a test formulation (an oral tablet containing levofloxacin 500 mg) with its corresponding listed reference-drug formulation in Mexico (a list issued by Mexican Health Authorities). METHODS: A single-dose, open-label, randomized-sequence, 2-period crossover design was used in this study. Eligible participants were healthy Mexican adults of either sex, randomly assigned to receive the test formulation followed by the corresponding reference formulation, or vice versa, with a 1-week washout period between doses. After a 10-hour overnight fast, the participants received the assigned formulation. Plasma concentrations of levofloxacin were determined using high-performance thin-layer chromatography, and densitometric analysis was performed at 300 nm. For the analysis of pharmacokinetic parameters, including C(max), AUC0(-24), and AUC(0-infinity)), blood samples were drawn at baseline and at 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, 6, 8, 12, and 24 hours after administration. The test formulation was considered to meet the criteria for bioequivalence if the geometric mean ratios (test/reference) were with- in the predetermined range of 80% to 125%. Tolerability was determined by clinical assessment, vital signs, laboratory analysis, and interviews with participants about adverse events. RESULTS: A total of 26 participants were enrolled, including 14 men and 12 women with a mean (SD) age of 24 (4) years (range, 18-34 years), weight of 62.2 (10.0) kg (range, 45.5-80.0 kg), height of 163 (9) cm (range, 148-176 cm), and body mass index of 23.3 (2.4) kg/m(2) (range, 19.2-27.1 kg/m(2)). The 90% CIs for log-transformed C(max), AUC(0-24), and AUC(0-infinity) were 94.48% to 106.22%, 90.01% to 116.44%, and 85.11% to 114.00%, respectively. Eleven participants reported a total of 20 adverse events during the study. None of the adverse events were considered serious. CONCLUSIONS: In this small study in healthy, fasting Mexican adults, a single 500-mg dose of the test formulation of orally administered levofloxacin met the regulatory requirements to assume bioequivalence based on the rate and extent of absorption. Both formulations were well tolerated.