Protective Effect of Tilia americana var. mexicana Against Kainic Acid-induced Damage in Brain, Liver, and Kidney: Behavioral and Biochemical Changes.

Tiliaamericana var. mexicana (Tilia) possesses anticonvulsant, antioxidant, neuroprotective, and hepatoprotective activities. The spectrum of anticonvulsant activity in status epilepticus models has not been sufficiently explored. We evaluated the effects of ethyl acetate (EAc), and methanol (ME) extracts on kainic acid (KA)-induced seizures by measuring rats'behavior (severity and latency) and lipoperoxidation in different brain areas (cerebellum, brain hemispheres, cortex, and medulla), kidneys, and liver. Male Wistar rats were administered KA (10 mg/kg, i.p.) after three days of pretreatment with Tilia extract (100 mg/kg). The EAc and ME Tilia extracts significantly decreased the severity of phase 1 and phase 2 seizures, respectively. The ME Tilia extract increased the latency to seizure (27 ± 2 min) compared to the control (13 ± 2 min). The ME and EAc Tilia extracts significantly prevented the increased lipid peroxidation caused by KA-induced seizures in the cerebellum, brain hemispheres, cortex, medulla, liver, and kidneys. The vehicle olive oil (OO) also showed anticonvulsant effects, decreasing the severity of seizures to phase 3 and lipoperoxidation levels in the cerebellum, brain hemispheres, cortex, medulla, liver, and kidneys. The anticonvulsant activity of Tilia is mediated by antioxidant effects in central and systemic areas that involve synergistic interactions among the chemical constituents of these extracts (glucosides of quercetin and kaempferol), while vehicle OO showed the same effects, probably due to its constituent oleuropein.

Biochemical and molecular modulation of CCl4-induced peripheral and central damage by Tilia americana var. mexicanaextracts.

Around the world, species from the genus Tilia are commonly used because of their peripheral and central medicinal effects; they are prepared as teas and used as tranquilizing, anticonvulsant, and analgesic agents. In this study, we provide evidence of the protective effects of organic and aqueous extracts (100 mg/kg, i.p.) obtained from the leaves of Tilia americana var. mexicana on CCl4-induced liver and brain damage in the rat. Protection was observed in the liver and brain (cerebellum, cortex and cerebral hemispheres) by measuring the activity of antioxidant enzymes and levels of malondialdehyde (MDA) using spectrophotometric methods. Biochemical parameters were also assessed in serum samples from the CCl4-treated rats. The T. americana var. mexicana leaf extracts provided significant protection against CCl4-induced peripheral and central damage by increasing the activity of antioxidant enzymes, diminishing lipid peroxidation, and preventing alterations in biochemical serum parameters, such as the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-globulin (γ-GLOB), serum albumin (ALB), total bilirubin (BB), creatinine (CREA) and creatine kinase (CK), relative to the control group. Additionally, we correlated gene expression with antioxidant activity in the experimental groups treated with the organic and aqueous Tilia extracts and observed a non-statistically significant positive correlation. Our results provide evidence of the underlying biomedical properties of T. americana var. mexicana that confer its neuro- and hepatoprotective effects.

Status epilepticus: Using antioxidant agents as alternative therapies.

The epileptic state, or status epilepticus (SE), is the most serious situation manifested by individuals with epilepsy, and SE events can lead to neuronal damage. An understanding of the molecular, biochemical and physiopathological mechanisms involved in this type of neurological disease will enable the identification of specific central targets, through which novel agents may act and be useful as SE therapies. Currently, studies have focused on the association between oxidative stress and SE, the most severe epileptic condition. A number of these studies have suggested the use of antioxidant compounds as alternative therapies or adjuvant treatments for the epileptic state.

Contributions of microdialysis to new alternative therapeutics for hepatic encephalopathy.

Hepatic encephalopathy (HE) is a common complication of cirrhosis, of largely reversible impairment of brain function occurring in patients with acute or chronic liver failure or when the liver is bypassed by portosystemic shunts. The mechanisms causing this brain dysfunction are still largely unclear. The need to avoid complications caused by late diagnosis has attracted interest to understand the mechanisms underlying neuronal damage in order to find markers that will allow timely diagnosis and to propose new therapeutic alternatives to improve the care of patients. One of the experimental approaches to study HE is microdialysis; this technique allows evaluation of different chemical substances in several organs through the recollection of samples in specific places by semi-permeable membranes. In this review we will discuss the contributions of microdialysis in the understanding of the physiological alterations in human hepatic encephalopathy and experimental models and the studies to find novel alternative therapies for this disease.