The sesquiterpenes polygodial and drimanial in vitro affect glutamatergic transport in rat brain

Persicaria hydropiper (L.) Delarbre: A review on traditional uses, bioactive chemical constituents and pharmacological and toxicological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Various plant parts of Persicaria hydropiper (L.) Delarbre (Syn.: Polygonum hydropiper L., Family: Polygonaceae) are used in traditional medicine systems as astringent, sedative, antiseptic and also for the treatment of respiratory disorders, edema and snake bites. It is also used as a spice in many Asian countries.

AIM OF THE REVIEW

The main aim of this review is to critically analyze the reported traditional uses, bioactive chemical constituents and pharmacological activities of P. hydropiper.

MATERIALS AND METHODS

Scientific database including PubMed, Scopus, SciFinder and secondary resources including books and proceedings were searched using relevant terminologies related to P. hydropiper and available scientific information was critically analyzed.

RESULTS

Analysis of the scientific literature regarding the traditional uses revealed that P. hydropiper is used as a medicine and as spice in food preparations in various parts of the world. Various compounds including flavonoids, phenylpropanoid derivatives, and sesquiterpenoids among others were reported as active compounds. The extracts and compounds from P. hydropiper showed diverse biological activities including anti-inflammatory, antioxidant, cytotoxic, antimicrobial activities, etc. CONCLUSION: Although various research reports showed diverse biological activities for extracts and compounds obtained from P. hydropiper, very few studies were performed using animal models. Many of these studies also lacked proper experimental setting such as use of positive and negative controls and selection of dose as in most of these studies very high doses of extracts were administered. Further, as P. hydropiper is widely used in the treatment of snake bites and insect bites, such effects of extracts and/or compounds are not well explored. Future studies on P. hydropiper should be focused to establish the links between the traditional uses, active compounds and reported pharmacological activities.

Dopamine Burden Induced the Inactivation of Sonic Hedgehog Signaling to Cognitive Decline in Minimal Hepatic Encephalopathy

Minimal hepatic encephalopathy (MHE) is induced by elevated intracranial dopamine (DA). The relationship of the Shh pathway with memory loss in MHE, however, is elusive. In the current study, rats with MHE induced with DA displayed downregulation of the Shh pathway. Additionally, injection of Shh into MHE/DA-treated rats reversed downregulation of BDNF/NT3, whereas administration of cyclopamine (Cyc) enhanced the inhibition of expression of BDNF/NT3. Furthermore, naringin (Nrg) substantially prevented cognitive impairment in MHE/DA-treated rats and upregulated the Shh pathway, paralleling the elevated expression of BDNF/NT3. Overall, our results indicate that the Shh pathway can induce the expression of BDNF/NT3, and DA causes memory loss by inactivation of Shh pathway signaling to BDNF/NT3 in MHE rats, which is reversed by Nrg. Our study may provide new theory basis of pathogenesis and therapeutic target of MHE.

Ethnobotanical, Phytochemical, Pharmacological, and Toxicological Aspects of Persicaria hydropiper (L.) Delarbre

Persicaria hydropiper (L.) Delarbre, belonging to Polygonaceae family, is a common weed found in most of the temperate countries including Bangladesh, China, Malaysia, and Japan. The plant is also referred to as “marsh pepper” or “smart weed.” It appears to be a useful herb with evidence-based medicinal properties. The present work addresses the botanical description, traditional uses, phytochemistry, pharmacology, and toxicology of P. hydropiper. All plant parts have been commonly used in the traditional systems of medicines. Flavonoids are the major group of phytochemical components followed by drimane-type sesquiterpenes and sesquiterpenoids, as well as phenylpropanoids. Different extracts and plant parts showed remarkable pharmacological activities including antioxidant, antibacterial, antifungal, antihelminth, antifeedant, cytotoxicity, anti-inflammatory, antinociceptive, oestrogenicity, antifertility, antiadipogenicity, and neuroprotection. Mutagenicity and acute and subchronic toxicities of the plant were also reported. P. hydropiper has tremendous medicinal properties that could further be investigated for the development of evidence-based herbal products.

Naturally Occurring Compounds Affect Glutamatergic Neurotransmission in Rat Brain

Natural products, including those derived from plants, have largely contributed to the development of therapeutic drugs. Glutamate is the main excitatory neurotransmitter in the central nervous system and it is also considered a nociceptive neurotransmitter, by acting on peripheral nervous system. For this reason, in this study we investigated the effects of the hydroalcoholic extracts from Drymis winteri (polygodial and drimanial), Phyllanthus (rutin and quercetine), Jathopha elliptica (jatrophone), Hedyosmum brasiliense (13HDS), Ocotea suaveolens (Tormentic acid), Protium kleinii (alphabeta-amyrin), Citrus paradise (naringin), soybean (genistein) and Crataeva nurvala (lupeol), described as having antinociceptive effects, on glutamatergic transmission parameters, such as [(3)H]glutamate binding, [(3)H]glutamate uptake by synaptic vesicles and astrocyte cultures, and synaptosomal [(3)H]glutamate release. All the glutamatergic parameters were affected by one or more of these compounds. Specifically, drimanial and polygodial presented more broad and profound effects, requiring more investigation on their mechanisms. The putative central side effects of these compounds, via the glutamatergic system, are discussed.