Antispasmodic and antidiarrheal activities of rhizomes of Polygonatum verticillatum maneuvered predominately through activation of K⁺ channels: Components identification through TLC

Integrated Metabolomics and Transcriptomics Analysis of Flavonoid Biosynthesis Pathway in Polygonatum cyrtonema Hua

Flavonoids, a class of phenolic compounds, are one of the main functional components and have a wide range of molecular structures and biological activities in Polygonatum. A few of them, including homoisoflavonoids, chalcones, isoflavones, and flavones, were identified in Polygonatum and displayed a wide range of powerful biological activities, such as anti-cancer, anti-viral, and blood sugar regulation. However, few studies have systematically been published on the flavonoid biosynthesis pathway in Polygonatum cyrtonema Hua. Therefore, in the present study, a combined transcriptome and metabolome analysis was performed on the leaf, stem, rhizome, and root tissues of P. cyrtonema to uncover the synthesis pathway of flavonoids and to identify key regulatory genes. Flavonoid-targeted metabolomics detected a total of 65 active substances from four different tissues, among which 49 substances were first study to identify in Polygonatum, and 38 substances were flavonoids. A total of 19 differentially accumulated metabolites (DAMs) (five flavonols, three flavones, two dihydrochalcones, two flavanones, one flavanol, five phenylpropanoids, and one coumarin) were finally screened by KEGG enrichment analysis. Transcriptome analysis indicated that a total of 222 unigenes encoding 28 enzymes were annotated into three flavonoid biosynthesis pathways, which were "phenylpropanoid biosynthesis", "flavonoid biosynthesis", and "flavone and flavonol biosynthesis". The combined analysis of the metabolome and transcriptome revealed that 37 differentially expressed genes (DEGs) encoding 11 enzymes (C4H, PAL, 4CL, CHS, CHI, F3H, DFR, LAR, ANR, FNS, FLS) and 19 DAMs were more likely to be regulated in the flavonoid biosynthesis pathway. The expression of 11 DEGs was validated by qRT-PCR, resulting in good agreement with the RNA-Seq. Our studies provide a theoretical basis for further elucidating the flavonoid biosynthesis pathway in Polygonatum.

A Review Of Preclinical Tools To Validate Anti-Diarrheal Agents

BACKGROUND

Since their inception, preclinical experimental models have played an important role in investigating and characterizing disease pathogenesis. These in vivo, ex vivo, and in vitro preclinical tests also aid in identifying targets, evaluating potential therapeutic drugs, and validating treatment protocols.

INTRODUCTION

Diarrhea is a leading cause of mortality and morbidity, particularly among children in developing countries, and it represents a huge health-care challenge on a global scale. Due to its chronic manifestations, alternative anti-diarrheal medications must be tested and developed because of the undesirable side effects of currently existing anti-diarrheal drugs.

METHODS

Several online databases, including Science Direct, PubMed, Web of Science, Google Scholar and Scopus, were used in the literature search. The datasets were searched for entries of studies up to May, 2022.

RESULTS

The exhaustive literature study provides a large number of in vivo, in vitro and ex vivo models, which have been used for evaluating the mechanism of the anti-diarrheal effect of drugs in chemically-, pathogen-, disease-induced animal models of diarrhea. The advances and challenges of each model were also addressed in this review.

CONCLUSION

This review encompasses diverse strategies for screening drugs with anti-diarrheal effects and covers a wide range of pathophysiological and molecular mechanisms linked to diarrhea, with a particular emphasis on the challenges of evaluating and predictively validating these experimental models in preclinical studies. This could also help researchers find a new medicine to treat diabetes more effectively and with fewer adverse effects.

Quality characteristics, phytochemical analysis, and antioxidant of extract Cuscuta reflexa (Roxb.)

Cuscuta reflexa is an extensive leafless, parasitic climber that has been used since ancient times for various purposes and as a therapeutic plant in different areas of Pakistan. The phytochemical, antibacterial, antioxidant, and fatty acid investigations were carried out on the leaves, stems, and fruit extracts of C. reflexa. Preliminary phytochemical screening has shown the presence of various phytochemicals such as carbohydrates, protein, amino acids, alkaloids, flavonoids, phenols, glycosides, saponins, tannins, terpenoids, steroids, and phenolic compounds. The percentage variation of some components fluctuated like moisture (6.85-10.34%), ash (5.38-7.83%), acid insoluble ash (0.28-0.71%), water-soluble ash (0.78-0.96%), hexane extractives (1.23-1.91%), alcohol extractives (10.39-12.23%), water extractives (25.34-30.35%), loss on drying (1.16-1.47%) and crude fiber (15.04-18.26%) for leaves, stems, and fruits respectively. The level of free fatty acid was different as follows: leaves (2.37%), stems (2.16%), and fruits (2.94%); a high value of peroxide was observed in stems, followed by leaves and fruits. The iodine and saponification values in leaves, stems, and fruits were found in the range of 105-116 g I2/100 g, and 165-175 mg KOH/g. The antibacterial activity was carried out by the disc diffusion method against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria. It was found that all extracts of the selected plant were most active against E. coli with a zone of inhibition of 4, 4, and 6 at MIC 250 as compared to S. aureus, which showed a zone of inhibition of 3, 4, and 5 at MIC 250 µg/ml. The antioxidant potential of the leaves, stems, and fruit extracts, examined on the basis of their scavenging activity of free radicals, was found to be good. The result of the gas chromatography-mass spectroscopy (GC-MS) analysis reveals that linoleic acid (38.10–40.53%) is the most abundant fatty acid of C. reflexa and the smallest amount was found in tricosanoic acid (0.12-0.19%). In general, the isolated compounds were reported to possess anticarcinogenic, antitumor, antimicrobial, and anti-inflammatory properties. It was concluded that C. reflexa has a markedly therapeutic potential to heal wounds and may provide the pharmacological basis for its folk uses.

Antisecretory and Spasmolytic Activities of Aqueous and Ethanolic Stem Bark Extracts of Nauclea diderrichii in Wistar Rats

Background

Diarrheal diseases are a major cause of morbidity and mortality throughout the world and particularly in developing countries. Nauclea diderrichii is a plant used in traditional medicine in the treatment of anemia, fever, gastric ulcer, malaria, abdominal pain, skin infections, and diarrhea. The present work is aimed at evaluating the antisecretory and spasmolytic activities of aqueous and ethanolic stem bark extracts of Nauclea diderrichii in Wistar rats.

Methods

The effect of aqueous and ethanolic extracts of Nauclea diderrichii was tested at doses of 100, 200, and 300 mg/kg on castor oil-induced secretory diarrhea, misoprostol-induced fluid accumulation, and the effect of pretreatment with yohimbine and glibenclamide. They were also tested on normal motility and castor oil- and carbachol-induced hypermotility.

Results

The results showed that the aqueous and ethanolic extracts of Nauclea diderrichii significantly (p < 0.001) inhibited castor oil-induced secretory diarrhea at all the doses. Both extracts significantly (p < 0.001) inhibit fluid accumulation induced by misoprostol. The pretreatment with glibenclamide reduced the antidiarrheal activity of aqueous extract of Nauclea diderrichii. The pretreatment with yohimbine did not alter the effect of the aqueous extract of Nauclea diderrichii. On intestine transit as on castor oil- and carbachol-induced motility, the aqueous and ethanolic extracts at doses of 100 and 200 mg/kg reduced significantly (p < 0.05, p < 0.01, and p < 0.001) the travelled distance by charcoal and peristaltic index.

Conclusions

The study demonstrated that the aqueous and ethanolic extracts of Nauclea diderrichii possess antisecretory and antispasmolytic properties hence its use in traditional medicine against diarrhea.

In Vitro Antioxidant and Alpha-Glucosidase Inhibition Activity of Polygonatum verticillatum of Karnali, Nepal

Background:

Diabetes mellitus is a metabolic disorder that has become a major health issue in modern era due to the long-term health consequences. α-amylase and α-glucosidase are the key enzymes involved in the digestion of starchy foods, and the inhibition of these enzymes is regarded as a postprandial hyperglycemia control strategy.

Objective:

The primary goal of this work is to examine the antioxidant activity as well as α-glucosidase inhibitory activity of Polygonatum verticillatum rhizomes via in vitro test.

Method:

The in vitro α-glucosidase inhibition activity was performed using p-nitrophenyl α-D¬-glucopyranoside (PNPG) substrate. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay was performed to estimate the antioxidant activity.

Results:

The in vitro -glucosidase inhibitory activity of Polygonatum verticillatum was investigated for the very first time. Of the three fractions and a crude extract, the ethyl acetate (EA) fraction disclosed potent inhibition activity against α-glucosidase enzyme with an IC50 value of 22.3 ± 0.1 μg/mL. Likewise, the IC50 values for dichloromethane (DCM) fraction and the crude extract against α-glucosidase were reported 34 ± 0.1 μg/mL, and 402.2 ± 0.2 μg/mL, respectively. Similarly, the EA fraction, crude extract, and DCM fraction disclosed promising antioxidant activity with IC50 55 ± 0.3 μg/mL, 171.5 ± 0.6 μg/mL, and 164.1 ± 3.4 μg/mL, respectively.

Conclusion:

These findings concluded that among the crude extract and fractions of Polygonatum verticillatum of Nepalese origin, the EA fraction constituted a potent α-glucosidase inhibiting and antioxidant agent. Further research is required to expose the inhibiting compounds.

Evaluation of the anti-diarrheal effects of the whole plant extracts of Cuscuta reflexa Roxb in pigeons

•

The antidiarrheal activity of C. reflexa was evaluated in pigeons using the juice, aqueous, and methanol extracts.

•

The antidiarrheal effect of C. reflexa was evaluated using different reported research models.

•

The juice, aqueous, and methanol extract of C. reflexa exhibit significant anti-motility and anti-secretory potential.

Background

Cuscuta reflexa (dodder) belonging to the family Convolvulaceae has many ethno-medicinal uses such as antidiarrheal and antiemetic. This plant has been employed to treat diarrhea, where the antidiarrheal use of this plant is well established in different communities around the world without scientific bases. In addition, the antibacterial, anthelmintic, anticholinergic, and antihistaminic effects of this parasitic vine are partly responsible for the folkloric antidiarrheal use of this plant. In the present study, the antidiarrheal activity of C. reflexa was evaluated in pigeons (Columba livia) using the juice (JCR), aqueous (CRAE), and methanol (CRME) extracts.

Methods

The antidiarrheal effect of C. reflexa was evaluated using different reported research models, with few modifications. In pigeons, diarrhea was induced by administration of castor oil (6 mL/kg, PO), ampicillin (250 mg/kg, IP), magnesium sulfate (2 gm/kg, PO), and cisplatin (6 mg/kg, IV). In these experiments, loperamide (2 mg/kg, IM) was used as a positive control, whereas JCR (1 mL/kg (1%) and 1 mL/kg (2%), CRAE (50, 100 and 200 mg/kg) and CRME (50, 100 and 200 mg/kg) were administered intramuscularly at different doses into each pigeon in the test groups.

Results

In addition to cisplatin-induced diarrhea, all paradigms tested gave significant results (P < 0.01). The JCR, at different doses, exhibited a significant (p < 0.01) a dose-dependent antidiarrheal effect on both the frequency and the onset of diarrhea. Similarly, CRAE and CRME, at doses of 100 and 200 mg/kg, showed considerable (p < 0.001) inhibition against the onset and frequency of diarrhea. On the other hand, JCR, CRAE, and CRME exerted significant effects (p < 0.001) on the percentage inhibition (PI) of diarrhea and gastrointestinal charcoal transit in a dose-dependent manner. In this respect, the maximum PI (p < 0.01) of JCR, CRAE, and CRME in different experimental paradigms was 43.13, 49.14, and 55.99 %, respectively.

Conclusions

Taken all together, results from this study reveal that the juice, aqueous, and methanol extract of C. reflexa exhibit significant anti-motility and anti-secretory potential. These findings may explain the medicinal use of C. reflexa in folk medicine as an antidiarrheal medicinal plant.

Traditional Herbal Knowledge among the Inhabitants: A Case Study in Urgam Valley of Chamoli Garhwal, Uttarakhand, India

The Indian Himalaya is rich in plant species, including many medicinal plants, greatly valued by local inhabitants for health care needs. The study in Urgam Valley of Uttarakhand, India, is to identity and document traditional knowledge of medicinal plants. The study revealed high consensus on medicinal plant usage, with 51 species belonging to 31 families used for local health care. Number of species and uses known increases with age, and elders and specialist healers retain higher levels of traditional medicinal plant knowledge, having unique knowledge of medicinal plants and their uses as well as preparation.

Potent in Vitro α-Glucosidase Inhibition of Secondary Metabolites Derived from Dryopteris cycadina

α-glucosidase is responsible for the hydrolysis of complex carbohydrates into simple absorbable glucose and causes postprandial hyperglycemia. α-glucosidase inhibition is thus the ideal target to prevent postprandial hyperglycemia. The present study was therefore designed to analyze the effects of various compounds isolated from Dryopteris cycadina against α-glucosidase including β-Sitosterol 1, β-Sitosterol3-O-β-d-glucopyranoside 2, 3, 5, 7-trihydroxy-2-(p-tolyl) chorman-4-one 3, Quercetin-3-0-β-d-glucopyranoside (3^/→0-3^///)- β-d- Quercetin -3-0- β –d-galactopyranoside 4 and 5, 7, 4^/-Trihydroxyflavon-3-glucopyranoid 5. The in vitro spectrophotometric method was used for the analysis of test compounds against possible inhibition. Similarly, molecular docking studies were performed using the MOE software. These compounds showed concentration-dependent inhibition on α-glucosidase, and compounds 1 (IC₅₀: 143 ± 0.47 µM), 3 (IC₅₀:133 ± 6.90 µM) and 5 (IC₅₀: 146 ± 1.93 µM) were more potent than the standard drug, acarbose (IC₅₀: 290 ± 0.54 µM). Computational studies of these compounds strongly supported the in vitro studies and showed strong binding receptor sensitivity. In short, the secondary metabolites isolated from D. cycadina demonstrated potent α-glucosidase inhibition that were supported by molecular docking with a high docking score.

Antimicrobial Homoisoflavonoids from the Rhizomes of Polygonatum verticillatum

Three homoisoflavonoids, including a new compound, 5,7-dihydroxy-3-(4-methoxybenzyl)-8-methyl chroman-4-one (1), together with two known compounds, 5,7-dihydroxy-3-(2-hydroxy-4-methoxybenzyl)-8-methylchroman-4-one (2) and 5,7-dihydroxy-3-(2-hydroxy-4-methoxybenzyl)-chroman-4-one (3), were isolated from the rhizomes of Polygonatum verticillatum (L.) All. (P. verticillatum). Isolated compounds were characterized on the basis of UV, FT-IR, ESI-MS, and 1D-, 2D-NMR data. Further, different extract fractions and pure compounds from Polygonatum verticillatum were screened for their antimicrobial potential. Among three pure compounds, compound 2 was found most potent with good zone of microbial growth inhibition as compared to the standards.

Pharmacological evaluation of smooth muscle relaxant and cardiac-modulation potential of Phyla nodiflora in ex-vivo and in-vivo experiments

OBJECTIVE

To investigate the pharmacological basis of its uses of Phyla nodiflora (P. nodiflora) for the treatment of anomalies predominantly by smooth muscle containing tissues such as gastrointestinal/vascular/broncho spasm and cardiovascular modulation.

METHODS

The crude hydroalcoholic extract of P. nodiflora (Pn.Cr) and its fractions were evaluated on isolated rabbit jejunum, rat trachea, aorta and atrium. To access the contractile or relaxant effects of testing materials, the tissues were mounted in isolated organ bath and responses were recorded with transducers coupled with data acquisition system. BALB/c mice were challenged with castor oil for the assessment of in-vivo antidiarrheal activity. Normotensive rats were used for in-vivo hypotensive study.

RESULTS

Hydroalcoholic extract of Pn.Cr at variable concentrations inhibited the natural spontaneous rhythm and 80 mmol/L K⁺ mediated contractions in isolated segment of jejunum with EC₅₀ values of 3.18 and 1.91 mg/mL respectively. Verapamil, a Ca²⁺ channel blocker, demonstrated akin pattern in jejunum and therefore possibly suggesting calcium blocking activity. On isolated rat tracheal tissue, Pn.Cr showed relaxation of high-K⁺ and carbachol mediated contractions (EC₅₀ values: 1.24 and 2.42 mg/mL). Pn.Cr treatment relaxed the rat aortic ring in a cumulative doses with high-K⁺ and phenylephrine-induced contractions (EC₅₀ values 0.25 and 0.92 mg/mL). Activity based fractionation of Pn.Cr showed that dichloromethane fraction was more potent for relaxing the tissues spasm compared to aqueous fraction. In-vivo experiments, significant protection by Pn.Cr (P < 0.05) was observed in castor oil-induced diarrhea (50-500 mg/kg) whereas hypotensive effect in anesthetized rats was seen at the dose range of 1-10 mg/kg of Pn.Cr (P < 0.05).

CONCLUSION

This study suggests the blockage of calcium channel in the smooth muscles as a pharmacological application to make usage of P. nodiflora in the management of diarrhea, asthma and hypotensive effect.

Isolation and characterization of quinine from Polygonatum verticillatum: A new marker approach to identify substitution and adulteration

Polygonatum verticillatum (Mahameda) is an important ingredient of Ashtawarga and Ayurvedic formulations. Nowadays, it comes under the category of endangered plants due to large scale and indiscriminate collection of wild material. To overcome the scarcity, substitutes of Mahameda are also commonly used in market. These additives are different from the authentic plant by Ayurvedic and pharmacological theory of drug action, thereby resulting in substitution/adulteration. Substitution is a critical issue in isolation and quantification of the therapeutically active ingredients that can be used as markers in the identification of substitution/adulteration. Methanolic extract of the rhizomes of P. verticillatum was subjected to preliminary phytochemical screening for the detection of phytoconstituents, followed by column chromatography for isolation of the marker. The column was first eluted with pure hexane, and polarity of the solvent was gradually increased. A total of 1180 fractions were collected and pooled on the basis of thin-layer chromatography profile. The single compound was isolated and confirmed by chemical test, melting point, spectral analysis, and comparison with literature. Phytochemical screening of the extract shows the presence of alkaloids, flavonoids, carbohydrates, terpenoids, and phenolics. A pure white crystalline powder was isolated by column chromatography which was characterized as (6-methoxyquinolin-4-yl-8-vinylquinuclidin-2-yl) methanol, i.e. Quinine. The isolated compound, Quinine, was identified as a novel compound in Mahameda as it has not been reported in the genus Polygonatum, till now. It can be used as a marker for the identification of substitution/adulteration and standardization of P. verticillatum.