Anticonvulsant activity of methanolic extract of Withania cogulans in mice.

Mental and neurological diseases including depression, Parkinson's disease, dementia, epilepsy, anxiety disorders and bipolar disorders account for a considerable amount of the world's disease burden. Unfortunately, drugs used in the treatment of neurological diseases are expensive, symptomatic and they produce undesirable side effects. People from different cultures prefer to use medicinal plants for the treatment of various ailments ranging from plain to perplex disorders because they are most affordable, cost effective and easily accessible source of treatment in the primary healthcare system throughout the world. Withania coagulans, an erect grayish under-shrub belongs to family Solanaceae. It is common in Pakistan, East India, Iran and Afghanistan. The objective of this study was to analyze the anti-seizure activity of crude methanolic extract of Withania coagulans fruits (MeWc). For screening of this activity, maximal electroshock seizures model (MES) and chemically-induced seizures models were used. In maximal electroshock seizures test MeWc showed significant dose dependent percent protection against hind-limb tonic extension; significant and dose-dependent increase in latency to myoclonic jerks and tonic clonic convulsions and decrease in seizures duration were observed in PTZ-induced seizures. In strychnine-induced convulsions MeWc significantly increased latency to hind-limb tonic extension and percent protection from death in a dose-dependent manner. Thus, it was inferred from the experiments that extract of Withania coagulans showed anticonvulsant activity.

Comparison of acute and chronic effects of Bacopa monnieri, Ginkgo biloba, and Lavandula angustifolia and their mixture on learning and memory in mice.

Forty-seven million people are living with memory-related disorders worldwide. Phytomedicines are gaining extensive interest in the treatment of these ailments. Memory-enhancing (acute and chronic) potentials of commercial grade extracts of Bacopa monnieri (200 mg/kg, po), Ginkgo biloba (150 mg/kg, po), and Lavandula angustifolia (200 mg/kg, po) and their mixture (B. monnieri 100 mg/kg, G. biloba 75 mg/kg, and L. angustifolia 100 mg/kg, po) were compared for their synergistic/additive effects on the Morris water maze (MWM) test and elevated plus maze (EPM) test in scopolamine-induced amnesia in mice. Escape latency and accumulative path length were significantly reduced both in acute (up to day 6) and chronic trials (days 8-14) in B. monnieri-, G. biloba-, and L. angustifolia-treated animals and their mixtures (n = 8, p < .05) in MWM. Furthermore, in probe trials (acute on day 7 and chronic on day 15), the number of crossing-overs at platform position and time spent in platform quadrant were significantly increased, while transfer latency in EPM was decreased in treated animals as compared to the saline group (n = 8, p < .05). The mixture showed synergistic effects on memory enhancement as compared to each extract individually in mice. Further studies may be carried out on the active compounds of B. monnieri at the cellular and molecular levels.

Evaluation of safety profile and stress suppressant activity of Rosa moschata in mice.

Stress is a state that seriously disturbs psychological or physiological homeostasis of the body and subsequently affects the morphology and function of the hippocampus. Currently available anti-stress medications provide limited benefits with cost of severe adverse effects. In the present study, effect of Rosa moschata extract was evaluated using acute restraint model in mice. The stress suppressant activity of Rosa moschata was evaluated by using elevated plus maze test (EPM), dark light box test and open field test (OFT) following restraint stress protocol. Results showed that the Rosa moschata extract significantly enhanced the number of transitions and the time spent in the open arm in the EPM, increased the number of transitions and time spent in the light compartment of the dark light box, and also enhanced the locomotor activity in OFT, as compared to the stress group. In addition, LD50 of the plant extract is greater than 5000mg/Kg. Thus the findings of our studies show that Rosa moschata significantly alleviates stress following the acute restraint stress in mice. Further studies dealing with underlying mechanism and characterization of active fraction/compound may provide an alternative therapy for stress and related neurological conditions.

Borneol inhibits TRPA1, a proinflammatory and noxious pain-sensing cation channel.

Borneol, a natural product isolated from several species of Artemisia, Blumea and Kaempferia, has a widespread use in traditional medicine. TRP ion channels are a class of nonselective cation channel proteins involved in a variety of physiological and pathological processes in mammals. TRPA1, a member of TRP family of cation channels, is involved in plethora of processes including noxious-cold, noxious-pain sensations, inflammation and the detection of irritant chemicals. Borneol is chemically related to camphor (a known inhibitor of TRPA1 ion channels); therefore, it is beneficial to investigate the effects of borneol on TRPA1. In the present investigation it was found that borneol inhibits TRPA1 mediated cationic currents in low millimolar range (IC50 0.3mM) in heterologous expression systems like Xenopus oocytes and in neurons cultured from trigeminal ganglia. Effects of nicotine, a known chemical irritant and agonist of TRPA1 are also inhibited by borneol in both systems. It is concluded that borneol, being an inhibitor of TRPA1, could be a safer therapeutic-combination in clinical situations where TRPA1 channelopathies like neuropathic-pain, trigeminal neuralgia or nicotine withdrawal treatments are involved.

Camphor modulates TRPV3 cation channels activity by interacting with critical pore-region cysteine residues.

TRPV3 ion channels mediate thermo-transduction, nociception, inflammation and dermatitis in mammals. TRPV1-4 proteins have been shown to have conserved cysteine-residues in the pore-forming regions. These residues participate in channel activation via S-nitrosylation of channel proteins. Camphor is a commonly used ligand for TRPV3 channels. Thus the knowledge about the potential binding/interacting site(s) for camphor will help to design effective and potent analgesic compounds. In an overlap-extension PCR method, following primer-pairs were used to mutate conserved cysteine-residues in the pore-region of TRPV3 channels; GATTGAGAATcCTCCAAGGACAAAAAGGAC, TRPV3-C612S-Fw and GTCCTTGGAGgACTTCTCAATCAGTCAGTGAGG, TRPV3-C612S-Rv primers pair. And for TRPV3-C619S: GGACTCcAGTTCCTATGGCCAGC, TRPV3-C619S-Fw and GCTGGCCATAgGAACTGGAGTCC, TRPV3-C619S-Rv respectively. All cDNA constructs were confirmed by DNA-sequencing and used to make cRNAs. Oocytes expressing mTRPV3-C619S and mTRPV3-C612S mutant channels were challenged with 2-APB (1 mM), camphor (10 mM) and dihydrocarveol (10 mM) either at -40 mV or +40 mV holding potentials in voltage-clamp experiments. Responses of both mutants to 2-APB were similar to wild-type mTRPV3. Interestingly, responses to camphor were totally lost in mTRPV3-C619S mutant, while responses to dihydrocarveol remained intact. In contrast mTRPV3-C612S displayed slightly altered (16±2 % reduction) phenotype with respect to camphor sensitivity. It is concluded that pore-region cysteines play critical role in camphor sensitivity of TRPV3 ion channels.