α-Glucosidase and α-amylase inhibitory constituent of Carex baccans: Bio-assay guided isolation and quantification by validated RP-HPLC–DAD

Antioxidant, Diabetic and Inflammatory Activities of Alpinia calcarata Roscoe Extract

BACKGROUND

Alpinia calcarata (AC) Roscoe of Zingiberaceae popularly known as lesser galangal has a widespread occurrence in China, India, Sri-Lanka, Bangladesh, Malaysia, Indonesia and Thailand. Essential oil (Eoil) was obtained from leaves/rhizomes of AC via hydro-distillation process.

METHODS

To identify chemical ingredients in oil from leaves/rhizomes of AC through GC/MS technique for volatile components and their anti-oxidant, inflammatory/diabetic activities.

RESULTS

The 38 and 65 components were found to make up 99.9 and 99.6 %, respectively in total of Eoil composition of AC leaves/rhizomes. Key chemical constituents were eucalyptol (28.7 % in leaves; 25.4 % in rhizomes), camphor (12.8 % in leaves; 4.2 % in rhizomes), and carotol (9.8 % in leaves; 5.6 % in rhizomes) found in oil of AC leaves/rhizomes. Colorimetric assay showed anti-oxidant activities in leaves and rhizomes are IC50=71.01±0.71 μg/mL and IC50=73.83±0.49 μg/mL, respectively in the Eoils. Eoils had high anti-oxidant capabilities in IC50-values of AC-L-Eoil=43.09±0.82&AC-Rh-Eoil=68.11±0.87 in reducing power in μg/mL was found. Albumin test of rhizome oil had IC50-values of 15.19±0.25 μg/mL. Concentrations range of 7.81 μg/mL and 250 μg/mL in the Eoils of AC leaves and rhizome, respectively by α-glucosidase inhibition assay.

CONCLUSION

Our findings demonstrated that leaf oil was slightly more promising results than rhizome oil of AC extract, which was ultimately showed medicinal potential of secondary metabolites with anti-oxidant, diabetic/inflammatory activities. Further, Eoils of AC have a wide range of pharmacological potential and promising anti-diabetic effects.

Untargeted metabolomics, optimization of microwave-assisted extraction using Box-Behnken design and evaluation of antioxidant, and antidiabetic activities of sugarcane bagasse

INTRODUCTION

The fruit wastes, in particular agricultural wastes, are considered potential and inexpensive sources of bioactive compounds.

OBJECTIVE

The current study was aimed at the preparation of an optimized extract of sugarcane bagasse using microwave-assisted extraction (MAE) technology and comparative evaluation of chemical composition, antioxidant, and antidiabetic activities with extract prepared through maceration technique.

METHODOLOGY

Box-Behnken Design (BDD) with response surface methodology was applied to observe interactions of three independent variables (ethanol concentrations [%], microwave power [W], and extraction time [min]) on the dependent variables (total phenolic content [TPC] and antioxidant status via 2,2-diphenyl-1-picrylhydrazyl [DPPH] to establish optimal extraction conditions. The ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) analysis was applied for untargeted metabolite profiling, and in vitro assays were used for evaluation of the antidiabetic and antioxidant potential of the extract. Moreover, an in silico study was used to predict the interaction of five dominant compounds from the UHPLC-Q-TOF-MS profile against the dipeptidyl peptidase-IV (DPP-IV) enzyme.

RESULTS

The optimal conditions for the extraction were established at 60% (v/v) ethanol, 500 W microwave power, and 5 min time with TPC 12.83 ± 0.66 mg GAE/g d.w. and DPPH 45.09 ± 0.07%. The UHPLC-Q-TOF-MS analysis revealed the presence of a total of 106 compounds in the extract. Moreover, the extract prepared through MAE technology presented higher TPC and DPPH findings than the extract prepared through maceration. Similarly, the extract was also found with good antidiabetic activity by inhibiting the DPP-IV enzyme which was also rectified theoretically by a molecular docking study.

CONCLUSION

The current study presents a sustainable and an optimized approach for the preparation of sugarcane bagasse extract with functional phytoconstituents and higher antidiabetic and antioxidant activities.

The pharmacological properties of Gypsophila eriocalyx: The endemic medicinal plant of northern central Turkey

The aim of this study is to evaluate and compare the biological properties of different extracts (methanol, ethanol, and water) obtained from Gypsophila eriocalyx (G. eriocalyx), a medicinal plant traditionally used in Turkey. The components of different extracts were defined using the GC-MS method. The effects of G. eriocalyx extracts on cell proliferation, apoptosis, and cell cycle arrest in MDA-MB-231 breast cancer as well as in vitro antioxidant, enzyme inhibition, and antimicrobial activities were investigated. In accordance with the results obtained, although ethanol and methanol extracts of G. eriocalyx show higher antioxidant activity than G. eriocalyx water extract, enzyme inhibition activities of the extracts were not found to be significant compared to the reference drug. The methanol and ethanol extract of G. eriocalyx exhibited moderate antimicrobial activity against Staphylococcus aureus and methanol extract showed significant antimicrobial activity against Bacillus cereus. In addition, both extracts significantly inhibited cell viability in a dose-dependent manner in breast cancer cells. The cell growth inhibition by methanol and ethanol extracts induced S phase cell-cycle arrest and apoptosis in MDA-MB-231 cells. Lastly, in order to compare the activities of the chemicals found in Gypsophila eriocalyx plant extract, their activities against various proteins that are breast cancer protein (PDB ID:1A52 and 1JNX), antioxidant protein (PDB ID: 1HD2), AChE enzyme protein (PDB ID: 4M0E), BChE enzyme protein (PDB ID: 5NN0), and Escherichia coli protein (PDB ID: 4PRV)were compared. Then, ADME/T analysis calculations were made to examine the effects of molecules with high activity on human metabolism. Eventually, G. eriocalyx is thought to be a potent therapeutic herb that can be considered as an alternative and functional therapy for the management of diseases of a progressive nature related to oxidative damage such as infection, diabetes, cancer, and Alzheimer's disease.

α-Viniferin, a dietary phytochemical, inhibits Monoamine oxidase and alleviates Parkinson's disease associated behavioral deficits in a mice model

Parkinson's disease (PD) is one of the most prevalent age-related neurodegenerative disorders. Behavioral complexities worsen over time due to progressive dopaminergic (DArgic) neuronal loss at substantia nigra region of brain. Available treatments typically aim to increase dopamine (DA) levels at striatum. DA is degraded by Monoamine oxidase (MAO), thus dietary phytochemicals with MAO inhibitory properties can contribute to elevate DA levels and reduce the ailment. Characterization of naturally occurring dietary MAO inhibitors is inadequate. Based on available knowledge, we selected different classes of molecules and conducted a screening process to assess their potential as MAO inhibitors. The compounds mostly derived from food sources, broadly belonging to triterpenoids (ursane, oleanane and hopane), alkaloid, polyphenolics, monoterpenoids, alkylbenzene, phenylpropanoid and aromatic alcohol classes. Among all the molecules, highest level of MAO inhibition is offered by α-viniferin, a resveratrol trimer. Cell viability, mitochondrial morphology and reactive oxygen species (ROS) generation remained unaltered by 50 μM α-viniferin treatment in-vitro. Toxicity studies in Drosophila showed unchanged gross neuronal morphology, ROS level, motor activity or long-term survival. α-Viniferin inhibited MAO in mice brain and elevated striatal DA levels. PD-related akinesia and cataleptic behavior were attenuated by α-viniferin due to increase in striatal DA. Our study implies that α-viniferin can be used as an adjunct phytotherapeutic agent for mitigating PD-related behavioral deterioration.

Curcusinol from the fruit of Carex baccans with antibacterial activity against multidrug-resistant strains

ETHNOPHARMACOLOGICAL RELEVANCE

Carex baccans, known as Shan-Bai-Zi or Ye-Gao-Liang in China, is a traditional medicinal herb used by several ethnic groups in Yunnan Province. It is utilized for the treatment of wound infections, ulcers, and dysentery. However, there is currently a dearth of research reports on its antimicrobial potential.

AIM OF THE STUDY

The substance basis of the antimicrobial activity of C. baccans will be unveiled, and the in vitro and in vivo antibacterial activities against multidrug-resistant bacteria of its major active compounds, as well as their preliminary mechanisms of action, will be investigated.

MATERIALS AND METHODS

An antibacterial bioactivity-guided isolation method was used to isolate and identify the active compound curcusinol from C. baccans. UPLC-DAD-MS was employed for the quantitative analysis of curcusinol. The antibacterial activity, resistance profile, synergistic effects, anti-biofilm activity, and potential mechanisms of action of curcusinol against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and other multidrug-resistant bacteria (Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii) were investigated using various methods, including the broth microdilution method, scanning electron microscopy, time kill assay, multi-generational resistance induction assay, checkerboard synergy assay, anti-biofilm assay, and metabolomics. Furthermore, the therapeutic efficacy of curcusinol was assessed in vivo by establishing an animal skin wound infection model of MRSA.

RESULTS

Curcusinol was isolated from the fruit of C. baccans, which accounts for 3.1% of the dry weight of the fruit. Curcusinol exhibited significant bactericidal and anti-biofilm activities against antibiotic-resistant Gram-positive bacteria in vitro. Furthermore, curcusinol acted as an antibiotic adjuvant to enhance the activity of various commonly used antibiotics against both Gram-positive and Gram-negative antibiotic-resistant bacteria without cytotoxicity to mammalian cells (A549 and RAW264.7) at 64 μM. Moreover, curcusinol affected arginine biosynthesis, cysteine and methionine metabolism, and alanine, aspartate, and glutamate metabolism significantly in MRSA cells under stress. Additionally, curcusinol effectively treated MRSA-infected mouse skin wounds and accelerated wound healing in vivo.

CONCLUSIONS

The results of this study not only support the traditional uses of C. baccans but also demonstrate that its major active compound, curcusinol, is an effective plant-derived bactericidal agent and antibacterial adjuvant with potential applications in the treatment of skin infections.

Genome Assembly and Microsatellite Marker Development Using Illumina and PacBio Sequencing in the Carex pumila (Cyperaceae) from Korea

This study is the first to report the characterization of Carex pumila genomic information. Assembly of the genome generated a draft of C. pumila based on PacBio Sequel II and Illumina paired-end sequencing, which was assembled from 2941 contigs with an estimated genome size of 0.346 Gb. The estimate of repeats in the genome was 31.0%, and heterozygosity ranged from 0.426 to 0.441%. The integrity evaluation of the assembly revealed 1481 complete benchmarked universal single-copy orthologs (BUSCO) (91.76%), indicating the high quality of the draft assembly. A total of 23,402 protein-coding genes were successfully predicted and annotated in the protein database. UpsetR plots showed that 7481 orthogroups were shared by all species. The phylogenetic tree showed that C. pumila is a close but distant relative of Ananas comosus. C. pumila had greater contraction (3154) than expansion (392). Among the extended gene families, aquaporins have been found to be enriched. Primers for microsatellite markers determined 30 polymorphic markers out of 100. The average number of alleles amplified by these 30 polymorphic markers was 4 to 12, with an average polymorphism information content (PIC) value of 0.660. In conclusion, our study provides a useful resource for comparative genomics, phylogeny, and future population studies of C. pumila.

Antibacterial activity and action mechanism of curcusionol from Carex siderosticta Hance against Ralstonia nicotianae

BACKGROUND

Tobacco bacterial wilt is a typical soil-borne disease caused by Ralstonia nicotianae, which causes huge losses in tobacco production every year. The crude extract of Carex siderosticta Hance was shown to have antibacterial activity against R. nicotianae during our search, and the natural antibacterial components were sought after using bioassay-guided fractionation of the compounds.

RESULT

Ethanol extract of Carex siderosticta Hance with the minimum inhibitory concentration (MIC) value of 100 μg/mL against R. nicotianae in vitro. The potential of these compounds as antibactericides against R. nicotianae were assessed. Curcusionol (1), showed the highest antibacterial activity against R. nicotianae with MIC value of 12.5 μg/mL in vitro. In the protective effect tests, the control effect of curcusionol (1) was 92.31 and 72.60%, respectively, after application of 7 and 14 days, at a concentration of 1500 μg/mL, being comparable to that of streptomycin sulfate at a concentration of 500 μg/mL, confirming that curcusionol (1) showed the potential for the development of new antibacterial drugs. RNA-sequencing, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed that curcusionol mainly destroys R. nicotianae cell membrane structure and affects quorum sensing (QS) to inhibit pathogenic bacteria.

CONCLUSION

This study revealed that the antibacterial activity of Carex siderosticta Hance makes it a botanical bactericide against R. nicotianae, while curcusionol as lead structures for antibacterial development is obvious by its potent antibacterial activity. © 2023 Society of Chemical Industry.

Influence of different pretreatments and drying methods on the chemical compositions and bioactivities of Smilacis Glabrae Rhizoma

Background

The processing of medicinal plant materials is one of the important factors influencing the components and biological activities of TCMs. Smilax glabra Roxb. is an herbal vine widely distributed in China, and its dried rhizome (Smilacis Glabrae Rhizoma, SGR) is often used in traditional medicines and functional foods. The processing methods of fresh cutting for SGR slices have been included in ancient Chinese herbal works, some local standards of TCMs, and the current Chinese Pharmacopoeia. Nevertheless, to date, the scientific basis for the processing of fresh medicinal materials for SGR slices has not been revealed.

Methods

To optimize the processing method for preparing SGR slices from the fresh rhizomes, the chemical compositions of the un-pretreated and pretreated (boiling, steaming) samples before and after drying (sun-drying, shade-drying, oven-drying), and the contents of astilbin isomers in dried SGR were analyzed by UHPLC-Q-TOF-MS/MS and UHPLC-DAD methods, respectively. Then, the antioxidant, anti-inflammatory, xanthine oxidase and α-glucosidase inhibitory activities of the prepared SGR slices were investigated by biological assays.

Results

A total of fifty-two compounds were identified from the un-pretreated and pretreated samples and a total of forty-nine compounds were identified from the subsequently dried samples. After pretreated by boiling and steaming, the contents of neoastilbin, neoisoastilbin, and isoastilbin in the prepared samples all increased. As a quality marker of SGR, the content of astilbin was unchanged or decreased slightly compared with that in the un-pretreated samples. During the drying process, the contents of the four astilbin stereoisomers in the un-pretreated samples increased significantly, while those in the pretreated samples had a slight increase or decrease. The effects of different processing methods were sorted according to the bioactivities of the prepared SGR. As a result, SGR slices prepared with no pretreatment followed by a sun-drying process have a higher astilbin content, better bioactivities and more energy savings, representing the optimum processing method for SGR slices.

Conclusions

This study reveals the scientific basis for the processing of fresh medicinal materials for SGR slices. The results provide scientific information for the quality control of SGR and its rational applications in herbal medicines and functional foods.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00614-7.

The effects of different protease treatments on the techno-functional, structural, and bioactive properties of bovine casein

In this study, bovine sodium caseinate (NaCas) was hydrolyzed with four proteases, alcalase, savinase, subtilisin A, and flavourzyme. In addition to the structural changes occurred through the enzymatic hydrolysis, the solubility, oil binding capacity, zeta potential, emulsification properties, and in vitro antioxidant capacity, anti-carcinogenic and antidiabetic properties of hydrolysates were determined. FTIR combined with hierarchical cluster analysis (HCA) made in Amide I region enable to classification of the samples based on the changes of the secondary structure depending on the enzyme type and degree of fragmentation. Technological properties of NaCas were enhanced through the enzymatic hydrolysis, and those were more prominent in serine-type enzymes, regardless of the enzyme type, all hydrolysates showed high antioxidant capacities. All hydrolysates, specifically those produced by savinase and alcalase, reduced the viability of the carcinogenic Caco-2 cells in a dose-dependent manner and showed a very low level of cytotoxicity against healthy HEK-293 cells. The hydrolysis treatment made a significant contribution to the antidiabetic activity of NaCas. Particularly alcalase and savinase hydrolysates suppressed the activity of α- amylase and α- glucosidase. Therefore, the generated milk protein hydrolysates could be used in functional food developments for specific dietary purposes.

Chemistry and Pharmacology of Cyperaceae Stilbenoids: A Review

Cyperaceae is a cosmopolitan plant family with approx. 5000 species distributed worldwide. Several members of this family are used in traditional medicines for the treatment of different diseases. In the last few decades, constituents with great chemical diversity were isolated from sedges, and a wide range of biological activities were detected either for crude extracts or for pure compounds. Among the isolated compounds, phenolic derivatives are the most important, especially stilbenoids, and flavonoids. To date, more than 60 stilbenoids were isolated from 28 Cyperaceae species. Pharmacological investigation of Cyperaceae stilbenoids revealed that several compounds possess promising activities; mainly antiproliferative, antibacterial, antioxidant and anthelmintic effects. Isolation, synthesis and pharmacological investigation of stilbenes are increasing constantly. As Cyperaceae species are very good sources of a wide variety of stilbenes, and several of them occur in large amount worldwide, they are worthy for phytochemical and pharmacological investigations. Moreover, stilbenes are important from chemotaxonomical point of view, and they play a key role in plant defense mechanisms as well. This review summarizes the stilbenoids isolated from sedges, and their biological activities.

Giganteone A and malabaricone C as potential pharmacotherapy for diabetes mellitus

The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC₅₀ 59.61 µM) and 5 (IC₅₀ 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.

Determination of biological activity of Tragopogon porrifolius and Polygonum cognatum consumed intensively by people in Sivas

Objective

This study was aimed to investigate the in vitro antioxidant, antimicrobial, cytotoxicity, and enzyme inhibition activities of Tragopogon porrifolius and Polygonum cognatum which are naturally grown and consumed intensively by people in Sivas, Turkey.

Methods

Plant materials were extracted with aqueous ethanol by maceration method. The components of the extracts were determined using the Gas Chromatography Mass Spectrometry. Antimicrobial, cytotoxic and enzyme inhibition activities of the extracts were investigated by micro dilution, XTT assay and 96-micro-well plate methods, respectively. The antioxidant activity evaluated using the DPPH radical scavenging, thiobarbituric acid and reducing power methods. The total phenol and total flavonoid content was also examined.

Results

GC–MS analysis revealed the presence of 31 compounds inP. cognatum extract and 29 compounds in T. porrifolius extract. According to the results, T. porrifolius extract showed high level of antioxidant activity in comparison to P. Cognatum extract. T. porrifolius exhibited higher α-glucosidase inhibitory activity, and both extract showed strong α-amylase inhibition activity compared to reference drug acarbose. T. porrifolius and P. cognatum ethanolic extracts exhibited antimicrobial activity in the concentration range of 0.039–2.5 mg/ml. Both extracts also exhibited significant anticancer effect on MDA-MB-231 breast cancer cells. The IC₅₀ values of T. porrifolius and P. cognatum extracts in MDA-MB-231 cells were determined as 0.0625 mg/mL and 0.053 mg/mL, respectively.

Conclusion

Our findings demonstrated that T. porrifolius and P. cognatum ethanolic extracts have promising effect on antioxidant, antimicrobial and cytotoxic activity as well as enzyme inhibition activity, and hence further studies required to identify specific compounds responsible for these activities.

Molecular Insight and Mode of Inhibition of α-Glucosidase and α-Amylase by Pahangensin A from Alpinia pahangensis Ridl

The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC₅₀ =114.80 μm) and α-glucosidase (IC₅₀ =153.87 μm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.

In vitro antioxidant assessment, screening of enzyme inhibitory activities of methanol and water extracts and gene expression in Hypericum lydium

Hypericum lydium Boiss. is a perennial plant of the Hypericaceae family, which has been used in particular to treat depression. The aim of this study was to determine in vitro antioxidant, antimicrobial activities, anticholinesterase (acetylcholinesterase (AChE)/butyrylcholinesterase (BChE)), antidiabetic activities (α-glucosidase/α-amylase) and Tyrosinase inhibitor activity of methanol and water extracts of H. lydium. Also, gene expression has been evaluated in the shoot and root by microarray technology. So, in general, the purpose of this study is to study the active molecules such as antioxidant, antimicrobial, antidiabetic, enzymes and genes in the plant, which is the first to be reported. The experiments were conducted in a completely randomized design with three replications. In addition, gene expression was compared in the shoot and root parts. Expression profiling was carried out by microarrays. According to the results, the highest chemical components were determined in methanol extract rather than water extract. There was a difference between the obtained components. While the highest antioxidant activity was determined from the methanol extract of plant herbs for DPPH Free Radical Scavenging Activity, antioxidant activity was the same in both methanol and water extracts using the ABTS method. The methanol extract demonstrated stronger anticholinesterase (AChE and BChE) and α-amylase inhibition activity. This study was complemented by the detection of antioxidant activity and some enzyme inhibition activity in the methanol extract. Microarray showed 10,784 genes had significantly different expression in root and shoot. There was a positive effect of methanol extract in respect of different activities compared to the water extract. Gene expression showed that the number of expressed genes in the root was greater than the shoot.

Exploring the antidiabetic and anti-obesity properties of Samanea saman through in vitro and in vivo approaches

In recent years, diabetes and obesity have become a major problem in global health care because of changes in lifestyle, food habits, and age-related metabolic disorders. Diabetes mellitus is one of the most common diseases, affecting millions of people worldwide. Currently, herbal drugs are used to control obesity and diabetes. The present study investigates the anti-obesity, antidiabetic, and antioxidant activities of Samanea saman leaf extract. A methanolic extract of S. saman leaves was prepared by a maceration method. The S. saman leaf extract was studied for its inhibitory effect on glucose utilization using specific in vitro procedures to analyze its antioxidant, anti-obesity, and antidiabetic activities via different assays, such as α-amylase and α-glucosidase inhibition assay, glucose uptake by yeast cells, nonenzymatic glycosylation assay followed by glucose diffusion assay. The outcome of the study showed that the methanolic extract strongly inhibited the pancreatic lipase, α-amylase, and glucosidase activities, compared with the standard drug. The results showed that the extract possessed considerable antioxidant and antidiabetic activities, and further studies are needed to confirm the results using an in vivo model. Thus, it is proposed that S. saman can be used as a therapeutic agent.

Ethnobotany of Anti-hypertensive Plants Used in Northern Pakistan

Hypertension is one of the most important factors responsible for cardiovascular ailments worldwide. It has been observed that herbal products and alternative herbal therapies played a significant role in decreasing hypertension. The aim of the current study is to provide significant ethnopharmacological information, both qualitative and quantitative on medicinal plants related to hypertension from Northern Pakistan. The documented data were quantitatively analyzed for the first time in this area. A total of 250 participants were interviewed through semi-structured discussions and questionnaires. Quantitative indices including FC (Frequency citation), FIV (Family importance value), RFC (Relative frequency of citation) and DCI (Disease Consensus index) were calculated. A total of 192 plant species, belonging to 77 families were reported to be used in treatment of hypertension in Northern Pakistan. The most dominant life form reported was herbs (54%), with decoction (72 reports) and leaves (55.1%) were commonly utilized plant part. Highest FIV was recorded in Lamiaceae (327 FIV). RFC ranged from 0.08 to 1.08% while DCI varied from 0.233 to 0.000. In this study original data was compared with thirty one previous national and international published papers from neighboring region to compare the medicinal uses and obtain some novel plant species. About 42% of the medicinal plant species were reported for the first time in treatment of hypertension in comparison to these 31 published papers. Different phytochemical activities of antihypertensive plants were also reported from literature. This research work documents the traditional knowledge of medicinal plants usage and provides baseline in designing clinical trials and pharmacological analysis for treatment of hypertension.

Subcritical water extraction as a cutting edge technology for the extraction of bioactive compounds from chamomile: Influence of pressure on chemical composition and bioactivity of extracts

The study was designed to determine the relationship between chemical structure, bioactivity and pressure during the subcritical water extraction (SCW) of chamomile. Extraction was carried out at isothermal conditions (100 °C) at five different pressures (10, 30, 45, 60 and 90 bar). Twenty three polyphenolic compounds were identified in the extracts, whereby apigenin was found to be the dominant compound (61.53-1344.99 mg/kg). Results suggest that the lowest applied pressure has negligible effect on phenolic recovery from chamomile, but also the use of pressures above than 45 bar was proven as needlessly. By using in vitro assays, influence of pressure on antioxidant, cytotoxic and enzyme-inhibitory activities of the extracts was evaluated. Extracts obtained at 30, 45 and 60 bar exhibited stronger bioactivities than at 10 and 90 bar. It was concluded that pressure exert a significant influence on chemical composition of extracts, and thus on biological activity of chamomile extracts.

In vitro and in vivo anti-diabetic and hepatoprotective effects of edible pods of Parkia roxburghii and quantification of the active constituent by HPLC-PDA

ETHNOPHARMACOLOGICAL RELEVANCE

Parkia roxburghii G. Don. is a traditional medicinal plant and its pods are extensively used as food and medicine. It is believed by the traditional healers to have medicinal properties to treat diabetes, hypertension and urinary tract infections (Jamaluddin et al., 1994).

MATERIALS AND METHODS

The methanolic extract of pods of P roxburghii and fractions were screened for their α-glucosidase and α-amylase inhibitory activity. Anti-hyperglycemic effects were studied on streptozotocin (45mg/kg b.w.) induced diabetes in albino rats (seven groups, n=7 n=6), using different doses for 14 days. Plasma glucose concentration (HbA1c) was analysed using whole blood, while SGOT, SGPT, TG, TC and uric acid were analysed using serum, employing commercial kits. Quantitative analysis of the major active constituent was carried out by HPLC-PDA.

RESULTS

Bioactivity guided chemical investigation of the edible pods of P roxburghii identified sub-fraction EA-Fr 5 which significantly inhibited α-glucosidase (IC50 0.39±0.06 µgmL(-1)), reduced the blood glucose level to normal, and lowered the elevated levels of liver function enzymes SGOT and SGPT in STZ-induced diabetic rats. EA-Fr 5 was found to contain epigallocatechin gallate (1) and hyperin (2) which exhibited significantly higher α-glucosidase inhibitory potency with IC50 0.51±0.09 and 0.71±0.03µM respectively. EA-Fr 5 contained 379.82±2.90mg/g of EGCG, the major active constituent which manifests a broad spectrum of biological activities.

CONCLUSION

The present investigation for the first time reports the occurrence of EGCG and hyperin in P roxburghii and substantiates the traditional use of pods of P roxburghii as dietary supplement for management of diabetes with significantly promising α-glucosidase inhibitory potency and anti-hyperglycemic as well as hepatoprotective effects.

A potent alpha-glucosidase inhibitor from Myristica cinnamomea King

A dimeric acylphenol and a potent α-glucosidase inhibitor, giganteone D (IC50 5.05μM), was isolated and characterized from the bark of Myristica cinnamomea King. The bark also yielded an acylphenol with an unprecedented skeleton for which the name cinnamomeone A (IC50 358.80μM) was proposed. Their structures were established by means of NMR and MS spectrometric analyses. The Lineweaver-Burk plot of giganteone D indicated that it was a mixed-type inhibitor. This is the first report on the α-glucosidase inhibiting potential of acylphenols.

Screening of antidiabetic and antioxidant activities of medicinal plants

Diabetes is a common metabolic disorder characterized by abnormally increased plasma glucose levels. Postprandial hyperglycemia plays an essential role in development of type-2 diabetes. Inhibitors of carbohydrate-hydrolyzing enzymes (such as α-glucosidase and α-amylase) offer an effective strategy to regulate/prevent hyperglycemia by controlling starch breakdown. Natural α-amylase and α-glucosidase inhibitors, as well as antioxidants from plant-based sources, offer a source of dietary ingredients that affect human physiological function in order to treat diabetes. Several research studies have investigated the effectiveness of plant-based inhibitors of α-amylase and α-glucosidase, as well as their antioxidant activity. The aim of this review is to summarize the antidiabetic and antioxidant properties of several medicinal plants around the world. Half inhibitory concentration (IC50, for enzyme suppression) and half effective concentration (EC50, for antioxidant activity) values of less than 500 μg/mL were defined as the most potent plant-based inhibitors (in vitro) and are expected to provide interesting candidates for herbal treatment of diabetes, as foods, supplements, or refined drugs.

Anti-diabetic potential of selected ethno-medicinal plants of north east India

ETHNOPHARMACOLOGICAL RELEVANCE

Through one-to-one interaction with the traditional healers, the present study has identified 15 medicinal plant species traditionally used as remedies to control diabetes.

MATERIALS AND METHODS

The methanolic extracts were screened for their α-glucosidase inhibitory activity. Hypoglycemic activity was assessed following glucose, sucrose and starch tolerance test on normal and STZ induced diabetic rats.

RESULTS

Ficus cunia extract had the highest α-glucosidase inhibitory potency with IC50 1.39±0.74 µg mL(-1) followed by Schima wallichi (IC50 1.43±0.20 µg mL(-1)) and Wendlandia glabrata (IC50 1.67±0.33 µg mL(-1)). In STZ induced diabetic rat model, F. cunia and W glabrata extracts reduced blood glucose concentration to near normal up to 14 days when administered 48 h after STZ.

CONCLUSION

The present study supports the traditional use of some of these medicinal plants in anti-diabetic remedies. The present study contributes to evidence for use of traditional medicine.

Anti-diabetic molecules from Cycas pectinata Griff. traditionally used by the Maiba-Maibi

Bioactivity guided chemical investigation on active anti-diabetic constituents of the fruits of Cycas pectinata Griff. (FCP) characterized EAFr-5 as the most potent sub fraction which significantly reduced the blood glucose level to normal in STZ induced diabetic rats. It was shown to contain the biflavonoids amentoflavone (1) and 2,3-dihydroamentoflavone (2) which exhibited significantly high inhibitory potency against α-glucosidase (IC50 8.09 ± 0.023 and 9.77 ± 0.032 μM, respectively) and α-amylase (IC50 73.6 ± 0.48 and 39.69 ± 0.39 μM, respectively). This is the first report of bioactivity guided isolation of anti-diabetic constituents from the traditionally used fruits of Cycas pectinata Griff.

Evaluation of anticonvulsant, sedative, anxiolytic, and phytochemical profile of the methanol extract from the aerial parts of Swertia corymbosa (Griseb.) wight ex C.B. Clarke

The objective of the present study was to evaluate the anxiolytic, antidepressant, and anticonvulsant activity of the methanolic extract of Swertia corymbosa (SCMeOH). After acute toxicity test, oral treatment with SCMeOH at doses of 125, 250, and 500 mg/kg behavioral models of open field, elevated-plus-maze, actophotometer, rotarod, pentylenetetrazole, isoniazid, and maximal electroshock induced seizure models were utilized. In open field test, SCMeOH (125, 250, and 500 mg/kg) (P < 0.01, P < 0.001) increased the number of rearings. However, the number of central motor and ambulation (P < 0.01, P < 0.001) were reduced. Likewise, the number of entries and the time spent in open arm were increased while the number of locomotion was decreased (P < 0.001) in elevated-plus-maze and actophotometer test, respectively. SCMeOH (125-500 mg/kg) protected the mice against the pentylenetetrazole and isoniazid induced convulsions; it causes significant (P < 0.01 and P < 0.001) dose dependent increase in latency of convulsion. Treatment with SCMeOH reduced the duration of the tonic hind limb extension induced by electroshock. Two major compounds such as gentiopicroside and swertianin were analyzed by HPLC system.

RETRACTED: Anti-diabetic activity of Swertia corymbosa (Griseb.) Wight ex C.B. Clarke aerial parts extract in streptozotocin induced diabetic rats

ETHNOPHARMACOLOGICALS RELEVANCE

Swertia corymbosa locally called as Shirattakuchi have a long history of use in Ayurveda herbal preparations in Indian traditional system of medicine. It has been used in folklore medicine for the treatment of diabetes.

AIM OF THE STUDY

The present study aimed to investigate the effect of the methanolic extract of Swertia corymbosa (SC) in diabetic and to analyze its chemical composition by HPLC-ESI/MS that may correlate with their pharmacological activities.

MATERIALS AND METHODS

The in vitro anti-diabetic activity of the extracts was measured by using α-glucosidase and α-amylase enzyme inhibitory activity. The methanolic extract of Swertia corymbosa were administered orally (125, 250 and 500 mg/kg, for 28 days) to streptozotocin-induced diabetic rats. Hypoglycemic effects, oral glucose tolerance test, change in body weight and lipid profile, biochemical analysis and histopathological examination were assessed. High-performance liquid chromatography-electrospray ionization/mass spectrometry (HPLC-ESI/MS) method was also developed to analyze the chemical composition.

RESULTS

In vitro anti-dabetic study, the methanol extract of SC is found to be a potent inhibitor of α-glucosidase and α-amylase activity. Oral administration of SC and standard drug for 28 days caused a significant decrease in the concentrations of blood glucose level, total cholesterol (TC), serum triglycerides (TGs), low-density lipoprotein-cholesterol (LDL-C), malondialdehyde (MDA) and significant increase in the concentrations of high density lipoprotein-cholesterol (HDL-C), serum insulin and body weight. Furthermore, activities of antioxidative enzymes, including SOD, GPx, GSH and CAT were enhanced dosed dependently with SC. Histopathological studies of the pancreas showed the regeneration of the β-cells by extract which were earlier necrosed by streptozotocin. Ten major compounds such as loganic acid (1), swertiamarin (2), sweroside (3), gentiopicroside (4), isovitexin (5), amoroswertin (6), amarogentin (7), gentiacaulein (8), decussatin (9) and swertianin (10) were analyzed by HPLC-ESI/MS system.

CONCLUSIONS

These results demonstrate that SC aerial parts of methanolic extract is an effective anti-diabetic and antioxidant activities which provides the scientific proof for the folklore medicine.