Cipura paludosa Extract Prevents Methyl Mercury‐Induced Neurotoxicity in Mice

Abstract

Cipura paludosa (Iridaceae), a native plant widely distributed in the north of Brazil, is used in traditional medicine as an anti-inflammatory and analgesic agent, against tuberculosis and gonorrhoea and for regulation of menstrual flow. However, scientific studies on the pharmacological properties of C. paludosa are scarce. We have examined the potential protective effects of the ethanolic extract of C. paludosa against methyl mercury (MeHg)-induced neurotoxicity in adult mice. MeHg was diluted in drinking water (40 mg/l, freely available) and the ethanolic C. paludosa extract (CE) was diluted in a 150 mM NaCl solution and administered by gavage (10 and 100 mg/kg body weight, respectively, twice a day). Because treatment lasted for 14 days and each animal weighed around 40 g, the total dosage of plant extract given to each mouse was 5.6 and 56 g, respectively. After the treatment period, MeHg exposure induced a significant deficit in the motor coordination, which was evident by a reduction (90%) in the falling latency in the rotarod apparatus. Interestingly, this phenomenon was completely recovered to control levels by CE co-administration, independent of dosages. MeHg exposure inhibited cerebellar glutathione peroxidase (mean percentage inhibition of 42%) -an important enzyme involved in the detoxification of endogenous peroxides -and this effect was prevented by co-administration of CE. Conversely, MeHg exposure increased cerebellar glutathione reductase activity (mean percentage inhibition of 70%), and this phenomenon was not affected by C. paludosa co-administration. Neither MeHg nor CE changed the cerebellar glutathione levels. This study has shown for the first time, the in vivo protective effects of CE against MeHg-induced neurotoxicity. In addition, our findings encourage studies concerning the beneficial effects of C. paludosa on neurological conditions related to excitotoxicity and oxidative stress.

Effect of Selenium on the Levels of Cytokines and Trace Elements in Toxin-Mediated Oxidative Stress in Male Rats

“…The kidney, liver, gastrointestinal system, and central nervous system are the main target sites of mercury toxicity [6]. Past studies have already documented the deleterious effects of heavy metal toxins in humans which may induce lipid peroxidation and may promote oxidative stress in tissues [7][8][9][10]. Lead and mercury exposure, air pollution, and organic compounds all have the potential to damage brain functioning yet remain understudied [6].…”

Evaluation of antinociceptive and anti-inflammatory activities of the topical preparation of Cipura paludosa (Iridaceae)

“…Previous phytochemical studies of this plant have shown the presence of terpins, steroids, alkaloids, quinines and fenolic compounds, as well as hongconin, eleutherin e isoeleutherin compounds (Lucena et al 2007a;Lucena et al 2007b, Lucena et al 2010. It is possible that the anti-inflammatory effect…”

“…Previous studies have indicated a series of biological activities for Cipura paludosa (Iridaceae) including antinociceptive and anti-inflammatory (Lucena et al 2007a), and antioxidant and antiglutamatergic (Lucena et al 2007b) effects. The anti-allodynic action of the active principle(s) present in the ethanolic extract of Cipura paludosa is most probably associated with its anti-inflammatory action.…”

“…The material was filtered and the solvent was evaporated in a rotary vacuum evaporator, yielding the crude ethanolic extract. Previous studies have revealed the presence of flavonoids, alkaloids and terpens in the same type of ethanolic extract (Lucena et al 2007a;Lucena et al 2007b;Lucena et al 2010).…”

“…The authors also showed that the ethanolic extract of this plant inhibits acetic acid-and-glutamate-induced nociception in mice, as well as inhibits inflammatory processes, suggesting potential "antiglutamatergic" and antioxidant effects of Cipura paludosa (Iridaceae). A second report from the same group has shown that the Cipura paludosa extract prevents methylmercury (MeHg)-induced neurotoxicity in adult mice, suggesting an effect of Cipura paludosa (Iridaceae) on the central nervous system (Lucena et al 2007b). …”