Evaluation of CNS depressant and anti-anxiety activities of leaves of Convolvulus pluricaulis

BACKGROUND

Convolvulus pluricaulis is a native plant that is commonly mentioned in Ayurveda as a Rasayana and is primarily recommended for use in mental stimulation and rejuvenation therapy. Convolvulus pluricaulis is used as a brain tonic. The plant is reported to be a prominent memory-improving drug. It is used as a psychostimulant and tranquilizer. It is reported to reduce mental tension.

OBJECTIVE

The present study aimed to explore the protective effect of hydroalcoholic extract from the leaves of Convolvulus pluricaulis, along with CNS depressant and anti-anxiety activities, in models of mice.

METHODS

The extract from leaves of Convolvulus pluricaulis were sequentially isolated with a mixture of water and alcohol solution in the soxhlet apparatus. An acute toxicity study was conducted as per OECD guidelines no. 423, in which 18 Albino male mice were treated with different doses (1, 10, 100, 500, 1000, and 2000 mg/kg) of hydroalcoholic extract of Convolvulus pluricaulis and assessed for toxicity parameters for 14 days. Various psychomotor activities of hydroalcoholic extract from leaves of Convolvulus pluricaulis for 100, 200, and 300 mg/kg doses were performed in mice by using various tests like actophotometer, open field, rota-rod, grip strength tests, elevated plus maze, hole board test, inclined plane, chimney test.

RESULTS

The hydroalcoholic extract from leaves of Convolvulus pluricaulis was found to fall under category 4 in the acute toxicity study. Therefore, 100, 200, and 300 mg/kg doses of hydroalcoholic extract of leaves of Convolvulus pluricaulis were selected for the further pharmacological study. The results of psychomotor tests (actophotometer, open field, rota-rod, grip strength, hole board test, inclined plane, chimney test, elevated plus maze, light-dark model) for test doses 100, 200, and 300 in mice showed CNS depressant and anti-anxiety effects.

CONCLUSION

Hydroalcoholic extract from leaves of Convolvulus pluricaulis at the 100, 200, and 300 mg/kg doses has shown CNS depressant and anti-anxiety effects in mice models.

Novel insights on acetylcholinesterase inhibition by Convolvulus pluricaulis, scopolamine and their combination in zebrafish

Acetylcholinesterase (AChE) inhibitors increase the retention of acetylcholine (ACh) in synapses. Although they alleviate cognitive deficits in Alzheimer's disease, their limited benefits warrant investigations of plant extracts with similar properties. We studied the anti-AChE activity of Convolvulus pluricaulis (CP) in a zebrafish model of cognitive impairment induced by scopolamine (SCOP). CP is a perennial herb with anti-amnesiac and anxiolytic properties. It contains alkaloid, anthocyanin, coumarin, flavonoid, phytosterol and triterpenoid components. Isoxazole (ISOX) was used as a positive control for AChE inhibition. CP-treated 168 hpf larvae showed a similar pattern of AChE inhibition (in the myelencephalon and somites) as that of ISOX-treated larvae. CP was superior to ISOX as evidenced by the retention of avoidance response behavior in adult zebrafish. Molecular docking studies indicated that ISOX binds Ser203 of the catalytic triad on the human AChE. The active components of CP-scopoletin and kaempferol-were bound by His447 of the catalytic triad, the anionic subsite of the catalytic center, and the peripheral anionic site. This suggested the ability of CP to mediate both competitive and non-competitive modes of inhibition. Surprisingly, SCOP showed AChE inhibition in larvae, possibly mediated via the choline-binding sites. CP + SCOP induced a concentration-dependent increase in AChE inhibition and ACh depletion. Abnormal motor responses were observed with ISOX, CP, ISOX + SCOP, and CP + SCOP, indicative of undesirable effects on the peripheral cholinergic system. Our study proposes the examination of CP, SCOP, and CP + SCOP as potential AChE inhibitors for their ability to modulate cognitive deficits.

Protective role of Convolvulus pluricaulis on lipid abnormalities in high-fat diet with low dose streptozotocin-induced experimental rat model

BACKGROUND

The methanolic extract of Convolvulus pluricaulis had earlier shown lipid lowering activity in Triton induced reversible hyperlipidemia model, but, the hypolipidemic activity in irreversible models and hypoglycaemic activity are not investigated so far.

OBJECTIVE

This study was designed to validate the lipid and glucose-lowering actions of C. pluricaulis methanolic extract (CPME) by using ingredients from the Indian diet for induction of hyperlipidemia and diabetes on experimental rats.

MATERIALS AND METHODS

Experimental animals were divided into four groups having six animals in each group (n = 6). Animals of Group I II, III and IV received - no treatment, 0.9% NaCl, Glipizide (GPZ) 5 mg/kg and CPME 400 mg/kg once daily for two weeks respectively. Animals of all groups except group I were fed a high fat-based Indian diet for 21 days followed by a single STZ (35 mg/kg) i.p. administration in model induction phase. Afterwards, animals were sacrificed, and the pancreas was dissected for histological changes, and blood was collected for measuring lipid parameters, FBS, insulin levels, and HOMA scores.

RESULTS

CPME significantly ameliorate the lipid abnormalities in HFD-STZ-treated experimental model (p < 0.001) but fails to reverse the hyperglycaemia developed in diabetic rats with no protective effect on islet architecture (p > 0.05) as compared to experimental group while, GPZ showed protective effect on both lipid abnormalities and hyperglycemia by modulating the levels of lipid parameters and insulin respectively.

CONCLUSION

In conclusion, the study confirm that CPME possesses significant hypolipidemic activity but fails to reverse the hyperglycaemia developed in diabetic rats.

Medical Plants and Nutraceuticals for Amyloid-β Fibrillation Inhibition

Plaque formation due to amyloid-β oligomerization and fibrillation is a key issue for its deposition in the brains of dementia and Alzheimer's disease patients. Related drugs preventing this peptide fibril accumulation bear the potential of considerable medical and social value. In this study, we performed in vitro fibrillation inhibition tests with eight different medical plant extracts and nutraceuticals using fluorescence spectroscopy. Successful inhibition of the following plant extracts and nutraceuticals were obtained: Withania somnifera, Centella asiatica, Bacopa monnieri, and Convolvulus pluricaulis, providing new drug candidates for the prevention and treatment of Alzheimer's disease.

Chemical composition, antioxidant potential, macromolecule damage and neuroprotective activity of Convolvulus pluricaulis

Herbal medicines are known to mitigate radical induced cell damage. Hence identification and scientific validation of herbal medicines contribute to better use in Ayurvedic/Unani research. In the present study, we investigated antioxidant and anti-apoptotic properties of Convolvulus pluricaulis (C. pluricaulis). C. pluricaulis exhibited antioxidant potential evident by free radical scavenging activities. C. pluricaulis pretreatment inhibited H₂O₂ induced macromolecule damage such as plasmid DNA damage and AAPH induced oxidation of bovine serum albumin and lipid peroxidation of rat hepatic tissues. Further to identify the neuroprotective properties of C. pluricaulis, SHSY5Y cells were treated with H₂O₂ with or without pretreatment of C. pluricaulis. The C. pluricaulis pretreatment at 50 μg/ml dose exhibited 50% cell survival against 100 μM H₂O₂ challenge for 24 h and it also decreased the lactate dehydrogenase leakage. Further C. pluricaulis pretreatment restored and regulated the antioxidant and apoptosis markers such as SOD, CAT, p53, and caspase-3 and inhibited, reactive oxygen species generation and depolarization of the mitochondrial membrane. C. pluricaulis possess a high content of flavonoids and polyphenols and GC-MS and FTIR analysis showed a wide variety of compounds which may contribute to the observed effects.

Effect of Shankhpushpi on Alcohol Addiction in Mice

Alcohol addiction is a worldwide problem. It has mainly two components: dependence and withdrawal. Characteristic properties of most anti-addictive compounds include anti-anxiety, anticonvulsant, antidepressant, and nootropic actions. Shankhpushpi (Convolvulus pluricaulis. Convolvulaceae), known ethnopharmacologically as brain tonic, possess all the properties mentioned above. Here, we screen shankhpushpi for possible anti-addictive potential. Effect of shankhpushpi churna was measured on ethanol withdrawal anxiety using elevated plus maze. The role of shankhpushpi on chronic ethanol consumption (21 days) was measured using two bottle choice protocol of voluntary drinking. We also measured the effect of the above herb on cortico-hippocampal GABA levels. Shankhpushpi was found to reduce alcohol withdrawal anxiety in a dose-dependent manner. The herb also decreased ethanol intake and increased water intake significantly (P < 0.001) after 4 days of administration. Both these effects were blocked (P < 0.001) by GABAA antagonist suggesting the role of GABAA receptor. Chronic administration of shankhpushpi also significantly (P < 0.01) increased cortico-hippocampal GABA levels in mice. Shankhpushpi reduced both alcohol dependence and withdrawal in a GABAA-dependent manner, thus showing anti-addictive potential.

Genetic diversity and chemical profiling of different populations of Convolvulus pluricaulis (convolvulaceae): an important herb of ayurvedic medicine

Convolvulus pluricaulis Choisy, commonly known as "Shankhpushpi", is an ayurvedic medicinal plant recommended as a brain tonic to promote intellect and memory, eliminate nervous disorders and to treat hypertension. Because of increasing demand of the drug, this plant species has been over-exploited. As a consequence, many unrelated plants are being sold by the crude drug dealers in India in the name of "Shankhpushpi". Information on its existing gene pool is currently lacking. We developed molecular (Random Amplification of Polymorphic DNA) and chemical (high performance liquid chromatography) markers that could distinguish the genuine plant species from its adulterants. Molecular characterization confirmed higher genetic variation at inter-zonal level as compared to intra-zonal populations. A total of 37 reproducible amplicons were generated of which 22 were polymorphic. The number of amplicons was in the range of 6-11 and genetic distance for the studied primers ranged from 0.07 to 0.34. Fifty nine per cent polymorphism was obtained across different geographical locations. Dendrogram studied through unweighted pair group method of arithmetic analysis differentiated all the genotypes into two major clusters, Cluster I had the single population of Rajasthan and Cluster II was represented by genotypes of Delhi, Haryana, Madhya Pradesh and Rajasthan. The Kaempferol content ranged from 0.07 to 0.49 mg/g and Delhi population was the highest accumulator.

In vivo investigation of the neuroprotective property of Convolvulus pluricaulis in scopolamine-induced cognitive impairments in Wistar rats

AIM

To investigate the neuroprotective effect of Convolvulus pluricaulis aqueous extract (AE) against scopolamine (1 mg/kg body weight (bwt))-induced neurotoxicity in the cerebral cortex of male Wistar rats.

MATERIALS AND METHODS

The study was carried out on male Wistar rats (age matched, weight 250 ± 20 g). The present study investigated cognitive-enhancing property of AE using Elevated plus maze (EPM) (transfer latency [TL]) and Morris water maze (MWM). Besides evaluating the effect of extract on neurochemical enzymes, in vivo antioxidant and free radical scavenging activities were also screened. All the measured parameters were compared with rivastigmine tartrate (1 mg/kg bwt) which was taken as standard.

RESULTS

Pretreatment of rats with AE (150 mg/kg bwt) significantly reduced scopolamine-induced increase in the TL in EPM, whereas in MWM, administration of extract improved the impairment of spatial memory induced by scopolamine. The activity of acetylcholinesterase (AChE) was significantly inhibited by extract within the cortex and hippocampus. Reduced activities or contents of glutathione reductase, superoxide dismutase, and reduced glutathione within the cortex and hippocampus induced by scopolamine were elevated by the extract. Taken together, it could be postulated that extract may exert its potent-enhancing activity through both anti-AChE and antioxidant action.

CONCLUSION

AE possesses neuroprotective potential, thus validating its use in alleviating toxic effects of scopolamine.