Characterization of natural cellulosic fiber extracted from Grewia ferruginea plant stem.

The use of natural fibers as reinforcement in polymer composites has gained significant attention due to their eco-friendly, and biodegradability. This study aims to extract and characterize the natural cellulosic fibers from the Grewia ferruginea stem. The fibers were extracted from plant stems using sodium hydroxide and analyzed using Fourier Transform infrared spectroscopy (FTIR) to determine chemical bonds on the fiber and functional group and Thermos-gravimetric analysis (TGA) was used to determine the thermal stability and degradation temperature of the fiber. The crystalline properties of extracted fibers were characterized by x-ray diffraction and surface morphology was characterized by Scanning electron microscopy. The chemical composition of the fibers, including cellulose, hemicellulose, lignin, moisture, extractive content, and fiber linear density, was evaluated. Tensile, thermal, and FTIR studies were conducted to assess the performance properties of the extracted fiber. The analysis revealed that the Grewia ferruginea fibers contain cellulose (60.4-72.6 wt%), hemicellulose (18.5 ± 3.1 %), and lignin (13.55 ± 2.75 %). The extracted fibers have a crystallinity index of 48.76 % and crystallite size of 5.14 nm. The fiber exhibited tenacity, breaking elongation, and Young's modulus values of (52.3 ± 6.5 cN/tex), (3.6 ± 1.8 %), and 43.5 ± 2.3 GPa, respectively. FTIR studies confirmed the presence of biopolymers in the Grewia ferruginea fiber. Additionally, the fibers demonstrated thermal stability up to 275 °C based on thermogravimetric analysis. These findings suggest that the extracted natural cellulosic Grewia ferruginea fiber has the potential to be used as a sustainable reinforcement material in polymeric composites.

Tracking the Variations in Trace Elements, Some Nutrients, Phenolics, and Anthocyanins in Grewia asiatica L. (Phalsa) at Different Fruit Development Stages.

Grewia asiatica L. (phalsa) is a very prevalent berry in Pakistan and is consumed extensively as raw or in the form of juice. Here, for the first time, we assessed phalsa from Pakistan in terms of variations in macro and micro minerals, nutrients, and bio-active phyto-constituents including total phenolic and anthocyanin contents at different fruit developmental stages. It was found that the sugars in phalsa increased from D1 (small at the initial fruit setting stage) to D6 development stage (fully ripened fruit) where sugars at D5 (near to fully ripe) and D6 stages were many times greater than at D1, D2 (unripe close to full-size completion), D3 (close to semi ripe), and D4 stage (semi ripened and full-size attainment). Total acidity of was declined in all developmental stages, where the D1 stage displayed maximum and D6 with the lowest acidity. Ascorbic acid was decreased from D1 to D2 and then increased gradually from D3 to D5 stages. At the D6 stage, again a steep decline in ascorbic acid was observed. The total phenolics (mg gallic acid equivalents/100g) at stage D6 were higher (136.02 ± 1.17), whereas D1 being the lowermost in total phenolic content (79.89 ± 1.72). For anthocyanins (mg/100g), an increasing pattern of changes was observed in all stages of phalsa fruit where the D1 stage showed lower (13.97 ± 4.84) anthocyanin contents which then increased gradually at stage D2 (67.79 ± 6.73), but increased sharply at D3 (199.66 ± 4.90), D4 (211.02 ± 18.85), D5 (328.41 ±14.96) and D6 (532.30 ± 8.51) stages. A total of four anthocyanins such as cyanidin, delphidine-3-glucoside, pelargonidin, and malvidin in phalsa were identified using HPLC procedures, and a significant > 90 % DPPH inhibition in phalsa was observed at the D5 and D6 development stages. The macro and micro minerals including Ni, Zn, Fe, Ca, Cu, Mg, Na, P, and K contents were decreased from initial (D1) stage to the final (D6) development stage, while only Fe displayed an increasing trend from the initial to final fruit development stages (D1-D6). Conclusively, these findings could be of great interest for patients who are intended to consume phalsa as adjuvant therapy against diabetes and metabolic syndromes and other diseases involving reactive oxygen species with minimum metal toxicity.

Pentacyclic triterpenoids from the stem of Grewia bracteata Roth demonstrate promising inhibition on tumour cells.

Grewia bracteata Roth stem was investigated for its anticancer potential for the first time. Initially, polarity-guided extracts from three solvents were screened on HeLa, HCT- 116 and MCF-7 tumours cells. The results revealed that ethyl acetate extract (GSE) significantly (p < 0.05) inhibited HeLa, HCT- 116 and MCF-7 cells with respective IC50 values of 30.58, 14.26 and 22.91 µg/mL. GSE inhibited HCT-116 cells with 6- and 21-folds higher than hexane (GSN) and methanol (GSM) extracts, respectively. Hence, column chromatography of GSE was performed and fractionated to 18 fractions. The obtained fractions were further tested on HCT-116 cells. Amongst, the fractions HF6 and DF1 were active with the respective IC50 values of 25.35 and 31.28, µg/mL (p < 0.05). These active fractions were profiled using H1-NMR, C13-NMR and LC-MS/MS analysis, and found the presence of pentacyclic triterpenoids like betulin diacetate and ursolic acid.

Anticonvulsant potential of Grewia tiliaefolia in pentylenetetrazole induced epilepsy: insights from in vivo and in silico studies.

Epilepsy, a chronic neurological condition, impacts millions of individuals globally and remains a significant contributor to both illness and mortality. Available antiepileptic drugs have serious side effects which warrants to explore different medicinal plants used for the management of epilepsy reported in Traditional Indian Medicinal System (TIMS). Therefore, we explored the antiepileptic potential of the Grewia tiliaefolia (Tiliaeceae) which is known for its neuroprotective properties. Aerial parts of G. tiliaefolia were subjected to extraction with increasing order of polarity viz. hexane, chloroform and methanol. Antioxidant potential of hexane, chloroform and methanol extracts of G. tiliaefolia was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay, total antioxidant capacity (TAC) assay, reducing power assay (RPA) and DNA nicking assay. Additionally, quantitative antioxidant assays were also conducted to quantify total phenolic (TPC) and total flavonoid content (TFC). As revealed by in vitro assays, methanol extract was found to contain more phenolic content. Hence, the methanol extract was further explored for its anticonvulsant potential in pentylenetetrazole (PTZ) induced acute seizures in mice. The methanol extract (400 mg/kg) significantly increased the latency to occurrence of myoclonic jerks and generalized tonic clonic seizures (GTCS). Additionally, it also reduced duration and seizure severity score associated with GTCS. The Grewia tiliaefolia methanol extract was further screened by Ultra High-Performance Liquid Chromatography (UHPLC) for presence of polyphenolic compounds, among which gallic acid and kaempferol were present in higher amount and were further analysed by in silico study to predict their possible binding sites and type of interactions these compounds show with gamma amino butyric acid (GABA) receptor and glutamate α amino-3- hydroxyl-5-methyl-4-isoxazolepropionic acid (Glu-AMPA) receptor. It was revealed that gallic acid and kaempferol had shown agonistic interaction for GABA receptor and antagonistic interaction for Glu-AMPA receptor. We concluded that G. tiliaefolia showed anticonvulsant potential possibly because of gallic acid and kaempferol possibly mediated through GABA and Glu-AMPA receptor.

Neuroprotective activity of novel phenanthrene derivative from Grewia tiliaefolia by in vitro and in silico studies.

Medicinal plants possess range of phytochemicals accountable for their diverse biological activities. Presently, such compounds have been isolated from medicinal plants, characterized and evaluated for their pharmacological potential. In the present study, the efforts have been made to isolate the compound(s) from Grewia tiliaefolia Vahl., plant known for its ameliorative effect on brain related diseases such as anxiety, depression, cognitive disorders and Parkinson's disease. Plant extract was subjected to isolation of compound(s) using column chromatography and isolated compound was characterized by NMR FTIR and LCMS. The isolated compound was novel with the IUPAC name of the compound is propyl 3-hydroxy-10,13-dimethyl-6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro-3H-cyclopenta[a]phenanthrene-17-carboxylate, designated as A-1 and has not been reported before. A-1 was further evaluated for its antioxidant potential using in vitro antioxidant assays (2,2-diphenyl-1-picryl-hydrazyl-hydrate, DPPH assay and reducing power assay, RPA). Also, Acetylcholinesterase (AChE) inhibitory potential of A-1 and extract was analysed. Results showed that A-1 exhibited significantly higher antioxidant activity in both DPPH and RPA assay as compared to plant extract. In case of AChE inhibitory activity again, A-1 has shown significantly higher activity as compared to plant extract. In silico study was conducted to predict its action on proteins playing crucial role in neurological and neurodegenerative disorders such as gamma amino butyric acid (GABA) receptor and glutamate α amino-3-hydroxyl-5-methyl-4-isoxazolepropionic acid (Glu AMPA) receptor in epilepsy and AChE enzyme in Alzheimer's diseases. The compound has shown interaction in following order: AChE > GABA receptor > Glu AMPA receptor. Further, molecular dynamic simulations and ADME studies of A-1 and AChE enzyme revealed that A-1 yielded good results in all parameters and hence can relieve Alzheimer's like symptoms.

Characterization of raw and alkali treated cellulosic Grewia Flavescens natural fiber.

The physicochemical, mechanical, thermal as well as morphological characteristics of alkali treated cellulosic Grewia Flavescens are reported in this paper. Using standard test methods, the chemical constituents of Grewia Flavescens fiber (GFF) are evaluated. Fiber treated in 5% (w/v) NaOH for 45 min soaking time is regarded as optimally surface-modified fiber. After optimal alkalization, there is an enhancement of cellulose content from 58.46% to 68.31%. Mechanical properties of GFF are determined by single fiber tensile test and improved tensile strength is achieved after alkalization. Weibull statistical analysis is performed for diameter and mechanical parameters of raw as well as treated GFF. FTIR spectroscopy reveals the removal of amorphous material from the fiber post-treatment and XRD analysis confirms improvement in crystallinity index from 16.01% to 26.72% and crystal size from 62.90 nm to 68.43 nm after alkalization. Thermal stability and thermal degradation temperature are found to be improved after alkali treatment. Morphological analysis of raw and alkali treated cellulosic GFF shows enhanced rough surface of fiber after alkalization because of elimination of impurities and foreign particles from the fiber surface. Presently studied GFF seems to be a good substitute to the harmful man-made fibers for making of bio composites.

The Chemical Composition and Health-Promoting Effects of the Grewia Species-A Systematic Review and Meta-Analysis.

Globally grown and organoleptically appreciated Grewia species are known as sources of bioactive compounds that avert the risk of communicable and non-communicable diseases. Therefore, in recent years, the genus Grewia has attracted increasing scientific attention. This is the first systematic review which focusses primarily on the nutritional composition, phytochemical profile, pharmacological properties, and disease preventative role of Grewia species. The literature published from 1975 to 2021 was searched to retrieve relevant articles from databases such as Google Scholar, Scopus, PubMed, and Web of Science. Two independent reviewers carried out the screening, selection of articles, and data extraction. Of 815 references, 56 met our inclusion criteria. G. asiatica and G. optiva were the most frequently studied species. We found 167 chemical compounds from 12 Grewia species, allocated to 21 categories. Flavonoids represented 41.31% of the reported bioactive compounds, followed by protein and amino acids (10.7%), fats and fatty acids (9.58%), ash and minerals (6.58%), and non-flavonoid polyphenols (5.96%). Crude extracts, enriched with bioactive compounds, and isolated compounds from the Grewia species show antioxidant, anticancer, anti-inflammatory, antidiabetic, hepatoprotective/radioprotective, immunomodulatory, and sedative hypnotic potential. Moreover, antimicrobial properties, improvement in learning and memory deficits, and effectiveness against neurodegenerative ailments are also described within the reviewed article. Nowadays, the side effects of some synthetic drugs and therapies, and bottlenecks in the drug development pathway have directed the attention of researchers and pharmaceutical industries towards the development of new products that are safe, cost-effective, and readily available. However, the application of the Grewia species in pharmaceutical industries is still limited.

Pharmacological basis for the antihypertensive activity of Grewia asiatica fruit extract.

In the management of cardiovascular disorders, medicines from herbal sources have played a vital role through centuries. The following study was commenced in order to lay possible pharmacological foundation associated with medicinal uses of edible fruit of Grewia asiatica in hypertension through in-vitro method. In this study isolated atrial preparation of Guinea pig was used where crude ethanolic extract of Grewia asiatica fruit (Ga.Cr) decreased the force and rate of spontaneous atrial contractions (0.03-10mg/kg). In isolated rat aortic ring preparations previously vasoconstricted by phenylephrine and High K+, it also resulted in dose dependent vasodilation (0.01-10 mg/kg).In the presence of L-NAME, the relaxation curve of Ga.Cr was partially inhibited showing involvement of Nitric oxide (NO) mediated pathway. The speculative analysis contemplated that Ga.Cr has blood pressure reducing potentials through inhibition of Ca++ influx via Ca++ channels, its release from intracellular stores and through other means like NO mediated pathways.

Bio-Potency and Molecular Docking Studies of Isolated Compounds from Grewia optiva J.R. Drumm. ex Burret.

In the study, two novel compounds along with two new compounds were isolated from Grewia optiva. The novel compounds have never been reported in any plant source, whereas the new compounds are reported for the first time from the studied plant. The four compounds were characterized as: 5,5,7,7,11,13-hexamethyl-2-(5-methylhexyl)icosahydro-1H-cyclopenta[a]chrysen-9-ol (IX), docosanoic acid (X), methanetriol mano formate (XI) and 2,2'-(1,4-phenylene)bis(3-methylbutanoic acid (XII). The anticholinesterase, antidiabetic, and antioxidant potentials of these compounds were determined using standard protocols. All the isolated compounds exhibited a moderate-to-good degree of activity against acetylcholinesterases (AChE) and butyrylcholinesterase (BChE). However, compound XII was particularly effective with IC50 of 55 µg/mL (against AChE) and 60 µg/mL (against BChE), and this inhibitory activity is supported by in silico docking studies. The same compound was also effective against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) radicals with IC50 values of 60 and 62 µg/mL, respectively. The compound also significantly inhibited the activities of α-amylase and α-glucosidase in vitro. The IC50 values for inhibition of the two enzymes were recorded as 90 and 92 µg/mL, respectively. The in vitro potentials of compound XII to treat Alzheimer's disease (in terms of AchE and BChE inhibition), diabetes (in terms of α-amylase and α-glucosidase inhibition), and oxidative stress (in terms of free radical scavenging) suggest further in vivo investigations of the compound for assessing its efficacy, safety profile, and other parameters to proclaim the compound as a potential drug candidate.

Evaluation of Grewia ferruginea Hochst ex A. Rich Mucilage as Suspending Agent in Metronidazole Benzoate Suspension.

Various species of the genus Grewia have been investigated for different pharmaceutical applications as excipients, yet a study on the potential use of Grewia ferruginea mucilage (GFM) as a suspending agent is lacking. Thus, this study is aimed at evaluating the efficacy of Grewia ferruginea mucilage (GFM) as a suspending agent in metronidazole benzoate suspension. The suspensions were prepared using 0.5%, 1%, 1.5%, and 2% w/v of GFM and compared with suspensions prepared from xanthan gum (XGM) and sodium carboxyl methyl cellulose (SCMC) in similar concentrations. The prepared suspensions were evaluated for visual appearance, pH, rheology, sedimentation volume, redispersibility, degree of flocculation, and in vitro drug release profile. Stability study was done at different storage conditions for three months. The results indicated that all the prepared suspension formulations exhibited pseudoplastic flow characteristics with viscosity imparting ability of the suspending agents in the order of XGM > GFM > SCMC (p < 0.05). The flow rate and redispersibility of the formulations prepared with GFM were significantly lower than those with SCMC and higher than those prepared with XGM. At 0.5% w/v suspending agent concentrations, the sedimentation volume of the formulations was in the order of XGM > GFM > SCMC (p < 0.05). However, at all other concentrations, the sedimentation volume of the formulations prepared with GFM had similar results with XGM but exhibited significantly higher sedimentation volume than SCMC. The formulations with GFM showed a higher degree of flocculation at 0.5% w/v concentration but were comparable at 1.5% w/v with XGM containing formulations. The pH, assay, and in vitro release profile of all assessed formulations were within the pharmacopial limit. Thus, based on the finding of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as a suspending agent in suspension formulations.

Characterization of natural cellulosic fiber extracted from Grewia damine flowering plant's stem.

Grewia damine is a flowering plant found in India and Sri Lanka. The fiber taken out from the stem bark of G. damine is found to be novel and selected for characterization study. The G. damine stem bark fiber (GDSF) has rich in cellulose contents (57.78 ± 3.56%). Its lower density (1.378 ± 0.036 g/cm3) makes it fit for use in lightweight applications. The weight percentage values of the chemical constituents confirm the use of GDSF for structural applications. Crystallinity index of GDSF was noted as 30.35%. The mechanical properties of GDSF were predicted as 375.6 ± 16.58 MPa tensile strength and 126.2 ± 11.93 GPa modulus of elasticity. The morphological and atomic force microscopy study results revealed that the fiber has rough surface even in its raw form. Hence it can be used to prepare composite specimens with better bonding strength between fiber and polymer. The thermal stability of GDSF was noted as 326 °C. Weibull distribution plots were drawn for validating the physical and tensile property values of GDSF.

Physicochemical Characterization of Grewia ferruginea Hochst. ex A. Rich Mucilage for Potential Use as a Pharmaceutical Excipient.

Gum and mucilages from natural sources are in recent times increasingly investigated for pharmaceutical applications. Different studies have shown that the gum and mucilage fraction of various species of the genus Grewia were found to be effective viscosity enhancers, stabilizers, disintegrants, suspending agents, gelling agents, bioadhesives, film coating agents, and binders. However, no study has been conducted on the potential use of Grewia ferruginea mucilage (GFM) as a pharmaceutical excipient. Therefore, this study was aimed at characterizing the Grewia ferruginea bark mucilage for its potential use as a pharmaceutical excipient. The mucilage was extracted from the Grewia ferruginea inner stem bark through aqueous extraction, precipitated with 96% ethanol, dried, and powdered. The powdered mucilage was characterized for different physicochemical properties such as powder property, loss on drying, solubility and swelling index, ash value, pH, viscosity, moisture sorption property, microbial load, and acute oral toxicity. According to the results, the percentage yield of the final dried and powdered GFM was found to be 11.96% (w/w). The density and density-related properties of the mucilage showed good powder flow property. The GFM exhibited pseudoplastic flow behavior. Moisture sorption property of GFM revealed its hygroscopic nature, and its solubility and swelling property was increased with temperature. The pH of GFM was near neutral. Microbial load of the mucilage was within the pharmacopoeial limit, and the oral acute toxicity test revealed that the mucilage is safe up to 2000 mg/kg. From the investigations of this study, it can be concluded that Grewia ferruginea bark mucilage has the potential to be utilized as an excipient in pharmaceutical formulations.

Mechanical and release behaviour of theophylline from matrix tablets containing psyllium powder in combination with grewia polysaccharides.

This study was aimed at investigating the effect of grewia polysaccharides on the mechanical and release properties of tablet matrices containing binary mixtures of the polysaccharide with psyllium. Two grades of grewia polysaccharides (GG and GDS) were extracted and binary mixtures of the polysaccharides with psyllium were formulated into tablet matrices containing theophylline as the model drug. The true, bulk and tapped densities, Carr's compressibility index of the powders and binary composites were determined before tablet compression. Tablet properties (hardness, porosity, and drug release from the matrices) were investigated. The dissolution test was carried out in 0.1 M HCl (pH 1.2) and phosphate buffer (pH 6.8). The results show that GG and GDS produced tablets with good mechanical strength (108.33 N and 95.70 N, respectively) while psyllium produced softer tablets (7.13 N). The combination of psyllium and grewia polysaccharides in the matrices resulted in a significant increase in the mechanical strength of the matrices when compared to matrices containing psyllium alone as the matrix former. The results also showed that GG and GDS reduced the dissolution rate and effectively eliminated the burst release of theophylline from the psyllium matrices at both pHs. The matrices of GG or GDS and the binary mixtures conform to non-Fickian anomalous diffusion with n > 0.45. When overcoming the burst release of drug from matrices such as psyllium, grewia polysaccharides may provide an effective reduction and a more sustained drug release from such matrices.

Toxicological, anticholinesterase, antilipidemic, antidiabetic and antioxidant potentials of Grewia optiva Drummond ex Burret extracts.

Background In this study, Grewia optiva Drummond ex Burret root extracts were assessed for use as a remedy for oxidative stress, diabetes mellitus and neurological disorders. Methods The antioxidative potentials of the extracts were determined using DPPH and ABTS assays, whereas their enzyme inhibitory potentials were determined against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase and α-amylase. In the in vivo experiments, methanol extract was orally administered to mice (n = 5) at four doses of 200, 300, 400 and 500 mg kg-1 for 30 days and its effect on glucose, triglycerides, total cholesterol, etc. were investigated. Results The highest free radical scavenging activities against DPPH and ABTS radicals were recorded for the methanol and ethyl acetate extracts, and their respective IC50 values were 75 and 88 µg/mL. In addition, these two fractions were highly active in inhibiting AChE and BChE, with IC50 values of 120 and 185 µg/mL, respectively. Moderate inhibition (µg/mL) was recorded against α-glucosidase (69.02 ± 1.02 and 64.29 ± 2.41) and α-amylase (65.12 ± 2.02 and 63.29 ± 1.41) and these were comparable to the inhibitory activities exhibited by the standard, acarbose. All the extracts showed high phenolic and flavonoid contents, which correlated with their antioxidant, anticholinesterase, α-glucosidase and α-amylase activities. The phenolic compounds in the crude extract and fractions were determined using the standard HPLC method and bioactive compounds, namely, morin, ellagic acid, kaempferol-3-(p-coumaroyl-diglucoside)-7-glucoside, apigenin-7-O-rutinoside, quercetin-3-(caffeoyl-diglucoside)-7-glucoside, etc., which were detected at various retention times. Significant decrease in cholesterol, triglyceride and blood glucose levels were observed. Conclusion G. optiva is a good source of antioxidants and other phytochemicals, some of which possess anticholinesterase, anti-glucosidase, and anti-amylase activities, and can be used to treat different health conditions such as oxidative stress, neurological disorders, and diabetes mellitus.

Isolation, pharmacological evaluation and molecular docking studies of bioactive compounds from Grewia optiva.

BACKGROUND: Traditionally, Grewia optiva is widely used for the treatment of many diseases like dysentery, fever, typhoid, diarrhea, eczema, smallpox, malaria and cough. METHODS: Shade-dried roots of G. optiva were extracted with methanol. Based on HPLC results, chloroform and ethyl acetate fractions were subjected to silica column isolation and four compounds: glutaric acid (V), 3,5 dihydroxy phenyl acrylic acid (VI), (2,5 dihydroxy phenyl) 3',6',8'-trihydroxyl-4H chromen-4'-one (VII) and hexanedioic acid (VIII) were isolated in pure form. Ellman's assay was used to determine the anticholinesterase potential of isolated compounds while their antioxidant potential was estimated by DPPH and ABTS scavenging assays. RESULTS: Amongst the isolated compounds, VI and VII exhibited excellent percent inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) (83.23±1.11, 82.72±2.20 and 82.11±2.11, 82.23±1.21, respectively, at 1000 µg/mL) with IC50 of 76, 90, 78 and 92 µg/mL, respectively. Highest percent radicals scavenging against DPPH and ABTS (87.41±1.20 and 86.13±2.31) with IC50 of 64 and 65 µg/mL, respectively, were observed for compound VII. Molecular docking studies also supported the binding of compound VI and VII with the target enzyme. The para-hydroxyl group of the phenolic moiety is formed hydrogen bonds with the active site water molecule and the side chain carbonyl and hydroxyl residues of enzyme. CONCLUSION: The isolated compounds inhibited the DPPH and ABTS-free radicals, and AChE and BChE enzymes. It was concluded that these compounds could be used in relieving the oxidative stress and pathological symptoms associated with excessive hydrolysis of acetyl and butyryl choline. The results of the study were supported by docking studies for compounds VI and VII.

Structure and physicochemical properties of Ghanaian grewia gum.

Grewia polysaccharides were isolated using sodium metabisulphite and phosphate buffers and the influence of the different extraction techniques on the chemical composition and structural characteristics of the extracts were determined. Structure and chemical composition of the resulting polysaccharide extracts were determined using FT-IR and NMR spectroscopy, neutral sugar analysis, size exclusion chromatography coupled to multi-angle light scattering (SEC-MALS), dilute solution viscometry and steady shear rheology. Chemical composition was similar irrespectively of the extraction solvent used and ranged between 11.1 and 16.5% for protein, 53.4 and 66.9% for total carbohydrate, 18.5 and 35.1% for total uronic acid and 23.5 and 28.6% for rhamnose. Predominate sugars in the extracts were rhamnose and uronic acids with spectroscopy showing the presence of esterified groups. Intrinsic viscosity varied between 6.5 and 9.1 dL g-1 and related with molar mass (754-2778 × 103 g mol-1). Grewia polysaccharide dispersions at 1 g dL-1 exhibited a shear thinning flow behaviour with crude and sodium metabisulphite extracts having higher viscosities. Overall, differences in extraction techniques produced grewia samples with tailored bulk properties for use in the food and pharmaceutical industries.

Biogenic synthesis of iron oxide nanoparticles using Agrewia optiva and Prunus persica phyto species: Characterization, antibacterial and antioxidant activity.

A phytoextract mediated synthesis of iron oxide nanoparticles using Agrewia optiva (Dhaman or Biul) and Prunus persica (Peach) leaf extract as capping and stabilizing agent without using hazardous toxic chemicals via biogenic route has been studied. The biogenic method of synthesis is convenient, rapid, cost effective and ecofriendly. The green synthesized nanoparticles were characterized by Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, Attenuated total reflectance spectroscopy, X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy and dynamic light scattering measurements. The antibacterial study was determined by agar well diffusion method to measure the efficiency of both phyto species extract and its mediated iron oxide nanoparticles against five gram positive bacterial stains such as Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus pyrogenes (S. pyrogenes), Corynebacterium diphtheriae (C. diphtheriae) and Corynebacterium xerosis (C. xerosis) and three gram negative bacterial stains such as Escherichia coli (E. coli), Klebsiella pneuomoniae (K. pneuomoniae) and Pseudomonas aeruginosa (P. aeruginosa). The antibiotic Ciprofloxacin and Gentamicin have been used as reference standard drugs for gram positive and gram negative bacterial stains, respectively. The antioxidant activity of the phyto extracts and prepared nanoparticles have been performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay employing l-ascorbic acid as a standard.

Grewia tiliaefolia and its active compound vitexin regulate the expression of glutamate transporters and protect Neuro-2a cells from glutamate toxicity.

AIM: Glutamate is a major neurotransmitter involved in several brain functions and glutamate excitotoxicity is involved in Alzheimer's disease (AD). In the current study, the neuroprotective effect of the Indian medicinal plant Grewia tiliaefolia (GT) and its active component vitexin was evaluated in Neuro-2a cells against glutamate toxicity. MATERIALS AND METHODS: Neuro-2a cells were exposed to glutamate to cause excitotoxicity and the neuroprotective effect of GT and vitexin were evaluated using biochemical studies (estimation of reactive oxygen species, reactive nitrogen species, protein carbonyl content, lipid peroxidation level, mitochondrial membrane potential and caspase-3 activity), molecular docking studies, gene expression and western blot analysis. KEY FINDINGS: Glutamate exposure to Neuro-2a cells induced oxidative stress, loss of membrane potential, suppressed the expression of antioxidant response genes (Nrf-2, HO-1, NQO-1), glutamate transporters (GLAST-1, GLT-1) and induced the expression of NMDAR, Calpain. However, pre-treatment of cells with GT/vitexin inhibited oxidative stress mediated damage by augmenting the expression of Nrf-2/HO-1 pathway, inducing the expression of glutamate transporters and downregulating Calpain, NMDAR. Molecular docking showed that vitexin effectively binds to NMDAR and GSK-3ß and thereby can inhibit their activation. GT/vitexin also inhibited glutamate induced Bax expression. SIGNIFICANCE: Methanol extract of G. tiliaefolia and its active component vitexin can act in an antioxidant dependent mechanism as well as by regulating glutamate transporters in mitigating the toxicity exerted by glutamate in Neuro-2a cells. Our results conclude that GT/vitexin can act as potential drug leads for the therapeutic intervention of AD.

TLC separation and antioxidant activity of flavonoids from Carissa bispinosa, Ficus sycomorus, and Grewia bicolar fruits

BACKGROUND: Carissa bispinosa, Ficus sycomorus, and Grewia bicolar are edible fruit plants that grow in the wild. The plants produce yellow-, red-, and purple-colored fruits and thus can be good sources of flavonoids for fighting oxidative reactions in humans, food, and the pharmaceutical industry. The present study aimed at isolating flavonoids from C.bispinosa, F. sycomorus, and G. bicolar fruits and determining their antioxidant activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azino-bis 3-ethylbenz-thiaz-oline-6-sulfonic acid (ABTS) model radical assays. METHODS: Analytical and preparative thin-layer chromatography was used to isolate flavonoids from the fruits using methanol/chloroform/hexane (7:2:1,v/v/v) as a mobile phase system. The ABTS and DPPH radical scavenging methods were used to test for the antioxidant activity of the samples, using quercetin and catechin as reference standards. RESULTS:Thin-layer chromatographic profiling revealed two different types of flavonoids from each plant.C. bispinosa yielded two flavonoid bands, Rfvalues 0.11 and 0.38;G. bicolaryielded two flavonoid bands,Rfvalues 0.63 and 0.81; andF.sycomorus also yielded two types of flavonoids, Rfvalues 0.094 and 0.81. All the extracted flavonoids exhibited significant antioxidant activity of over 80% at a concentration of 200 mg/L. The order of radical scavenging activity for the 200-mg/Lsamples is G. bicolar Rf(0.81) >C. bispinosa Rf(0.113) >F. sycomorus Rf(0.094) >F. sycomorus Rf(0.047) >C. bispinosa Rf(0.38) >G. bicolar Rf(0.63).G. bicolar(Rf= 0.81) exhibited antioxidant activitythat was superior to that of catechin. CONCLUSION:The present study results show that C. bispinosa,F. sycomorus,and G. bicolar contain different flavonoid types with significant antioxidant activity of over 80% at a concentration of 200 mg/L. Therefore, the fruits can be used as a source of natural antioxidants which can be used as nutraceuticals to promote health, as preservatives to delay peroxidation of foods, and as flavoring for packed foods.

Anti-bacterial, free radical scavenging activity and cytotoxicity of acetone extracts of Grewia flava.

BACKGROUND: Bacterial infections of the gastrointestinal tract (GIT) cause vomiting, diarrhoea and even systemic disease. There is a need for the development of natural products into alternative and safer medicines. OBJECTIVES: This study evaluated the anti-microbial activity of extracts prepared from berries, leaves, bark and roots of the edible plant Grewia flava. METHODS: The anti-bacterial activity was evaluated by the broth microdilution method. Anti-oxidant activity of the most active extracts was performed by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The cytotoxicity of the extracts was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The acetone extracts of the leaves and roots showed the best activity with MIC values as low as 0.03 mg/mL against Staphylococcus aureus and Salmonella typhimurium and 0.07 mg/mL against Bacillus cereus, Escherichia coli and Staphylococcus aureus. Quantitative analysis of the scavenging ability showed that acetone extracts exhibited good free radical scavenging activity in a dose-dependent manner. The berries extract had the highest LC50 (lowest toxicity) of 551.68 68 µg/mL. CONCLUSION: Acetone extract of leaves and roots of Grewia flava contain anti-microbial and anti-oxidant compounds and could therefore be used as a natural product with little toxicity to host cells.