BIOLOGICAL ACTIVITIES OF SOME SELECTED NEPALESE MEDICINAL PLANTS AND ISOLATION OF CHEMICAL CONSTITUENTS FROM CALLICARPA MACROPHYLLA

Objective: The main objectives of this study was to analyze the phytochemicals, determine the total flavonoid content, brine shrimp toxicity, antibacterial activity, evaluate the antioxidant, antimicrobial, anti-diabetic activities of nine medicinal plants Callicarpamacrophylla, Bauhinia purpurea, Plumeriarubra, Girardiniadiversifolia, Acacia nilotica, Woodfordiafruticosa (Bark) Woodfordiafruticosa (flower), Terminaliaalata, and Premnabarbata. Methods: The cold percolation method was adopted for the extraction of secondary metabolites in methanol. The preliminary phytochemical analysis was performed by colour differentiation methods. The radical scavenging activity was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The antidiabetic activity was performed by α-amylase enzyme inhibition activity. The chemical constituent was isolated by column chromatography from the biologically active plant fraction. Results: The phytochemical investigation has shown plants are the rich source of secondary metabolites as quinones, saponins, terpenoids and glycosides. Among the nine tested plants, Terminaliaatalia showed the highest radical scavenging activity 96.41±0.47 with IC50 value 6.353 µg/ml, followed by Girardiniadiversifolia 97.26±0.67 with IC50 value 11.52 µg/ml whereas ascorbic acid has 39.85 µg/ml as standard. Bauhinia purpurea showed significant inhibition to the α-amylase enzyme having inhibitory concentration IC50 17.05±13.00 SD in a dose-dependent manner. Woodfordiafruticosa demonstrated significant toxicity to A. salina with LC50 value of 457.08 µg/ml. Callicarpamacrophylla bark showed a potential inhibitory activity against the growth of Straphylococcusaureus as compared to standard chloramphenicol. Active plant extract of Callicarpamacrophylla was subjected for column chromatography. Conclusion: Out of nine plant samples Terminaliaatalia showed the highest radical scavenging activity. The plant extract of Bauhinia purpurea showed significant inhibition to the α-amylase enzyme inhibition. Woodfordiafruticosa demonstrated significant toxicity to A. salina, whereas Callicarpamacrophylla showed the potent antibacterial activity. The active plant extract was subjected for column chromatography and different fractions were collected in solvent polarity basis. Conclusion: The phytochemical investigations showed that plant extracts are the rich sources of secondary metabolites such as alkaloids, flavonoids, saponins, glycosides, polyphenols, coumarins and reducing sugars which showed they are supposed to be responsible for different biological activities. IC50 values showed the varied degree of antioxidant property of which Plumeriarubra and Acacia nilotica exhibit good antioxidant property with IC50 value close to the standard ascorbic acid

EVALUATION OF ANTIOXIDANT AND ANTIBACTERIAL ACTIVITY OF GLYCYRRHIZA GLABRA ROOT EXTRACTS

Objectives: The present study was designed to investigate the phytochemical analysis, antioxidant potential, and antibacterial activities of the traditionally used medicinal plant Glycyrrhiza glabra. Methods: The plant secondary metabolites were extracted through cold percolation using methanol (MeOH) as a solvent. The MeOH extract was further fractionated in different solvents in increasing order of polarity. The antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl assay. The antibacterial activity was studied by agar well diffusion method. Results: The antioxidant potential IC50 was found 43.13, 104.83, and 200.11 μg/ml for ethyl acetate (EtOAc), MeOH, and chloroform (CHCl3) extracts, respectively. The EtOAc fraction showed the potent antioxidant with IC50 43.13 μg/ml compared to the standard ascorbic acid 58.76 μg/ml. The antimicrobial activity exhibited by MeOH extract against Bacillus subtilis (ATCC 6051) and Staphylococcus aureus (ATCC 6538P) zone of inhibition was 18 mm and 17 mm, for chloroform extracts 15 mm and 13 mm, and for EtOAc fraction 11 mm against Bacillus subtilis. The highest dilution that yielded no single bacteria colony on the nutrient agar plates for Bacillus subtilis and S. aureus of MeOH extract was found 0.39 mg/ml and 6.25 mg/ml, for chloroform extract 3.125 mg/ml and 6.25 mg/ml and EtOAc fraction against Bacillus subtilis was 12.50 mg/ml as minimum bactericidal concentration. Conclusion: The plant extracts showed potent antioxidant and antibacterial activity. The results support for using the G. glabra in bacterial infection which provides partial scientific validation for using the plant against bacterial infections

IN VITRO BIOLOGICAL STUDY OF SEVEN NEPALESE MEDICINAL PLANTS AND ISOLATION OF CHEMICAL CONSTITUENTS FROM CISSAMPELOS PAREIRA

Objective: This study aimed to investigate the phytochemical analysis and biological activities of methanol extracts of seven medicinal plants such as Anisomeles indica, Achyranthes bidentata, Sphenomeris chinensis, Cleistocalyx operculatus, Malvaviscus arboreus, Cissampelos pareira, and Tectaria coadunate collected from Tanahun district of Nepal. Methods: Phytochemical analysis was performed by color differentiation methods adopting the standard protocol. Antioxidant activity of plant extracts was evaluated by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Flavonoid content was estimated by aluminum chloride colorimetric method. Antidiabetic activity was evaluated by α-amylase inhibition assay where acarbose was used as standard. Toxic effect was studied by brine shrimp bioassay. Results: Phytochemical analysis showed the presence of alkaloids, polyphenols, flavonoids glycoside, and terpenoid in most of the extracts. T. coadunate and C. pareira exhibited high antioxidant activity with IC50 41.84 and 52.03 μg/ml, respectively. Whereas, the plant extracts of Malvaviscus arboretum, S. chinensis, and A. bidentata exhibited moderate antioxidant activity with IC50 76.07, 81.05, and 89.93 µg/ml, respectively. The result of flavonoid content showed the values ranged A. indica (1.84 mg quercetin equivalent per gram [mg QE/g]) to A. bidentata (5.93 mg QE/g). C. pareira and S. chinensis exhibited the highest α amylase inhibition activity with IC50 471.68 and 517.59 µg/ml, respectively. Whereas, A. indica and M. arboreus showed moderate activity with IC50 626.12 and 952.39 μg/ml, respectively. C. pareira exhibited against Staphylococcus aureus (ATCC 25923) with a zone of inhibition 12 mm/well, and Escherichia coli (ATCC 25922) 9 mm/well but, T. coadunate showed 14 mm/well against S. aureus. The plant extracts of A. bidentata and C. operculatus showed toxic effect against newly hatched brine shrimp larvae. The chemical compounds isolated from C. pareira indicated by gas chromatography-mass spectrometry analysis were 3-isopropoxy-1,1,1,7,7,7-hexamethyl-3,5,5-tris(trimethylsiloxy) tetrasiloxane, alpha-tocopherol, pentadecanoic acid, and 4,22-stigmastadiene-3-one. The major compound was indicated by percent peak area and base m/z value as alpha-tocopherol. Conclusion: Present study revealed that plant extracts are the potential source of antioxidant, antidiabetic, and antibacterial agents showing different biological activities. The results of this study provide partial scientific support for the traditional application of medicinal plants to cure diabetes and infectious diseases, although further studies are needed to assess the mechanism of action

ESTIMATION OF PHENOLIC CONTENT, FLAVONOID CONTENT, ANTIOXIDANT, AND ALPHA-AMYLASE INHIBITORY ACTIVITY OF SOME SELECTED PLANTS FROM SIRAHA DISTRICT NEPAL

Objectives: The purpose of this research was to estimate the phenolic content, flavonoid content, antioxidant, antibacterial, and α-amylase inhibitory activity of some selected plants such as Anethum sowa, Trigonella foenum-graecum, Lepidium sativum, Cuscuta reflexa, Eclipta alba, Leucas cephalotes, and Tinospora cordifolia collected from Siraha district of Nepal using in vitro studies. Methods: Methanol extracts of these medicinal plants were prepared by cold percolation method. Preliminary phytochemical screening was performed by color differentiation method. Total phenolic and flavonoid content were estimated by Folin-Ciocalteu reagent method and aluminum chloride colorimetric method. Antioxidant potential was evaluated by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Furthermore, the α-amylase enzyme inhibitory activity was studied using starch as a substrate, pancreatic α-amylase as the enzyme, and acarbose as standard. Results: Phytochemical screening showed that the plant extracts were found a rich source of secondary metabolites. The phenolic content estimation showed T. foenum-graecum 939.764±0.01, L. sativum 551.63±0.02, A. sowa 306.34±0.06, L. cephalotes 233.19±0.03, T. cordifolia 211.76±0.02, E. alba 202.67±0.02, and C. reflexa Roxb. 145.09±0.09 mg milligram gallic acid equivalent per gram. The flavonoid content estimation showed T. cordifolia 852.07±0.11, L. sativum 553.81±0.05, E. alba 322.13±0.02, A. sowa 329.02±0.05, L. cephalotes 164.93±0.02, and C. reflexa Roxb. 146.37±0.00 mg milligram quercetin equivalent per gram. The antioxidant potential showed by E. alba IC50 33.48±0.82 μg/ml and the values ranged from E. alba 33.48±0.82 to A. sowa 47.62±1.09 μg/ml. The α-amylase inhibitory activity showed by A. sowa 76.78±2.00–E. alba 777.36±9.66 μg/ml. The result of brine shrimp toxicity showed LC50 value >1000 μg/ml. Among the seven plant extracts, only the plant extract of E. alba showed a zone of inhibition 14 mm against Staphylococcus aureus. Conclusions: The plant extract of T. foenum-graecum showed the highest phenolic content, and T. cordifolia showed the highest flavonoid content. The highest antioxidant potential exhibited by E. alba and the highest α-amylase inhibition activity showed by A. sowa. The plant extract of E. alba showed moderate antibacterial activity against S. aureus. All plant extracts were found non-toxic against brine shrimp larvae although further study is needed to assess its mechanism of action

ESTIMATION OF TOTAL PHENOL AND ANTIOXIDANT ACTIVITY OF ZANTHOXYLUM ARMATUM OF NEPALESE ORIGIN

Objective: The aim of this study was to analyze the phytoconstituents, estimation of total phenolic content and in vitro antioxidant activity of Zanthoxylum armatum from Myagdi district of Nepal. Methods: The seeds extract of Zanthoxylum armatum was prepared by cold percolation in hexane, ethyl acetate and methanol with continuous agitation. Phytochemical analysis for each extracts was performed by color differentiation method adopting the standard protocol. Antioxidant potential of the extracts was performed by DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay by taking ascorbic acid as standard. Total phenolic content was estimated by Folin–Ciocalteu reagent method. Results: The analysis of secondary metabolites showed the presence of quinones and terpenoidsin almost all extracts while alkaloids, polyphenols, tannins and saponins were abundant in polar extracts. The results of antioxidant activity showed the methanol extract of Zanthoxylum armatum IC50 87.47µg/ml was found to be more antioxidant as compared to the standard ascorbic acid IC50 66.40 µg/ml. Ethyl acetate extract showed moderate antioxidant activity with IC50 142.04 µg/ml, whereas hexane extract showed the poor antioxidant activity with IC50 384.03 µg/ml. The result of total phenolic content showed, ethyl acetate fraction has the highest 26.28±9.35 mg GAE/g as compared to methanol extract 23.36±14.80 mg GAE/g and hexane extract showed the poor phenolic content 20.05±8.0 mg GAE/g. Conclusion: The seeds extracts of Zanthoxlum armatum were found the rich source of secondary metabolites. The methanol extract was found potent antioxidant as compared to ethyl acetate and hexane extract. It is concluded that further activity guided isolation approaches will be needed on methanol extract to identify the active compound responsible for in vivo and in vitro antioxidant activity

EVALUATION OF ANTIOXIDANT POTENTIAL AND QUANTITATIVE ESTIMATION OF PHENOLIC AND FLAVONOID CONTENT IN SOME SELECTED NEPALESE MEDICINAL PLANTS

Objective: The aim of this study is to evaluate the antioxidant potential, determination of total phenolic and flavonoid content in nine selected medicinal plants Spondias pinnata, Melia azedarach, Ageratina adenophora, Urtica dioica, Curcuma longa, Bauhinia variegata, Elaeocarpus angustifolius Blume, Achyranthes aspera, and Psidium guajava from Kavre district of Nepal using in vitro studies. Methods: Methanolic plant extracts were prepared by cold percolation method. The methanol extract of nine medicinal plants collected from Kavre district of Nepal, was screened for assessing bioactive phytoconstituents followed by antioxidant property, total phenolic, and flavonoid content. Different plants collected were powdered and extracted with methanol, concentrated by a rotatory evaporator and analyzed for the presence of phytochemicals. The antioxidant potential of the plant extracts was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Results: The phytochemical analysis of methanolic extracts of all nine medicinal plants displayed the presence of various secondary metabolites such as alkaloids, flavonoids, polyphenols, saponins, and quinones. The extract of S. pinnata showed the highest percentage of radical scavenging activity up to 87.94±1.88 with 50% inhibitory concentration (IC50) 17.51±1.27 μg/mL, followed by B. variegata, 80.63±1.06 with IC50 value 26.55±2.61 μg/mL. The standard, ascorbic acid has IC50 value of 20.13±1.17 μg/mL. Further, the ethyl acetate fraction of S. pinnata showed the maximum percentage of radical scavenging (85.92±1.37) with IC50 value of 46.95±1.17 μg/mL. Moreover, S. pinnata displayed the highest total phenolic content (TPC) 48.26±1.23 mg GAE/g (milligram gallic acid equivalent per gram) extract while the highest flavonoid content was displayed by Melia azedarach 41.07±1.53 mg QE/g (milligram quercetin equivalent per gram) extract measured by the Folin–Ciocalteu reagent method and aluminum chloride colorimetric method. Conclusions: The preliminary results of this study have put forward the extract of S. pinnata showed the highest percentage of radical scavenging activity and S. pinnata displayed the highest TPC while the highest flavonoid content was displayed by Melia azedarach methanolic extracts although the further studies are needed to assess its mechanism of action

ANALYSIS OF PHYTO-CONSTITUENTS, ANTIOXIDANT, AND ALPHA AMYLASE INHIBITORY ACTIVITIES OF PERSEA AMERICANA MILL., RHODODENDRON ARBORETUM SM. RUBUS ELLIPTICUS SM. FROM ARGHAKHANCHI DISTRICT NEPAL

Objective: To evaluate the phytochemical, antioxidant activities, and α-amylase inhibition assay for methanolic extract of three ethnomedicinal plants, namely Persea americana Mill., Rubus ellipticus Sm., and Rhododendron arboretum Sm. collected from Arghakhanchi District of Nepal using in vitro studies.Methods: Methanolic plant extracts were prepared by cold percolation method. Analysis of phytochemical constituents was carried out using standard methods. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to evaluate in vitro antioxidants activities. Furthermore, inhibition effect of extracts on α- amylase enzyme was carried out by using starch as a substrate, pancreatic α-amylase as the enzyme, and acarbose as standard.Results: Phytochemical screening of methanolic extract of all three selected plants displayed the presence of different chemical constituents such as alkaloids, polyphenols, flavonoids, terpenoids, saponins, glycosides, and tannins. The results of DPPH assay revealed that R. ellipticus and R. arboreum were most active with half maximal inhibitory concentration (IC50) values 33.41 μg/ml and 47.28 μg/ml, respectively. R. ellipticus was found to be effective toward α-amylase inhibition with IC50 values 269.94 μg/ml.Conclusion: The preliminary results of this study have put forward R. ellipticus into promising herbs with good antioxidant activities and α-amylase inhibition potential although further studies are needed to assess its mechanism of action

Phytochemical analysis, biological activities, and GC profiling of extracts of some medicinal plant growing in Nepal

The present study was aimed to determine the antioxidant, α amylase inhibition, and antibacterial activities on ten traditionally used medicinal plant extracts, namely Cyperus rotundus, Citrus medica, Gaultheria fragrantissima, Jasminum humile, Osyris wightiana, Buddleja asiatica, Berberis aristata, Robus ellipticus, Schima wallichii, and Smilax ovalifolia growing in Nepal. The bioactive fraction of J. humile was subjected for GC analysis. The free radical scavenging properties of plant extracts were assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and antibacterial activity was performed by the well diffusion method. The antidiabetic activity was assessed α amylase inhibition assay. The chemical compounds were isolated from the active plant fraction by silica column chromatography, and the collected fractions were analyzed by GC and FTIR. The phytochemical analysis showed that plant extracts were rich sources of secondary metabolites. The in vitro antioxidant activity showed IC50 ranging from 30.57±0.02 to 155.65±0.10 µg/mL. The promising antioxidant activity was demonstrated by S. wallichii of IC50 30.57±0.02 µg/mL and J. humile 35.28±0.54 µg/mL, respectively whereas, the S. ovalifolia, exhibited the moderate antioxidant activity of IC50 155.65±0.10 µg/mL. The J. humile showed significant antidiabetic activity of IC50 59.4±23.47 µg/mL. The antidiabetic activities exhibited ranged from IC50 of 77.29±2.05 (S. wallichii to 608.28±71.50 µg/mL (C. rotundus). The R. ellipticus showed maximum ZOI (22 mm) against the Staphylococcus aureus (ATCC 25923), whereas J. humile (20 mm), O. wightiana (18 mm), and G. fragrantissima (16 mm) showed moderate antibacterial activity against the S. aureus. The C. rotundus, J. humile, S. ovalifolia, O. wightiana, and B. asiatica showed promising antibacterial activity against E. coli (ATCC 25922) with ZOI 15, 17, 14, 17, and 18 mm respectively. These findings provide partial scientific support for traditional uses of these medicinal plants against diabetes and infectious diseases. Therefore, the J. humile could be a promising source of natural antidiabetic and antioxidant compounds that may be drug candidates for future drug development. To the best of our knowledge, this work is the first attempt to perform all these biological activities and phytochemical analyses growing in the particular region of Nepal

Phytochemistry, Biological Activities, and Chemical Profiling of Berberis asiatica

This study focused on chemical profiling and assessed the total phenolic and flavonoid content as well as the antioxidant and antibacterial effect of the medicinal plant Berberis asiatica. The results revealed that this plant has high concentrations of TPC (Total phenol content) and TFC (Total flavonoid content) of 37.686 ± 2.728 mg GAE/g and 115.568 ± 8.012 mg QE/g, respectively. The DPPH free radical scavenging assay demonstrated strong inhibition, with an IC50 of 205.7 ± 5.353 μg/mL, and also showed robust antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae with a zone of inhibition (ZOI) of 14 mm and 19 mm, respectively. The extract exhibited an excellent inhibitory potential against S. aureus, and K. pneumoniae with an MIC (Minimum inhibitory concentration) of 0.39 mg/mL, and 3.125 mg/mL respectively, indicating significant inhibitory action. Furthermore, the MBC (Minimum bactericidal concentration) for both S. aureus and K. pneumoniae was found to be 6.25 mg/mL, emphasizing the extract's consistent bactericidal effectiveness against these bacteria. These findings underscore the potential utility of the methanolic extract of Berberis asiatica as a natural antibacterial agent. GC-MS analysis of hexane fraction indicates the plant is rich in secondary metabolites, specifically 2,2-dimethyl-3-pentanol, 2-methyl-2-pentanol, 2,5-dimethyl-4-hydroxy-3-hexanone, 3-hexanol, 4-methyl-2-pentanol are identified. Overall, this study highlights the importance of plant-based natural products as potential sources of antioxidants and antibacterial agents that contributes to the future drug development process

Phytochemistry, Biological Activities, and Chemical Profiling of Berberis asiatica

This study focused on chemical profiling and assessed the total phenolic and flavonoid content as well as the antioxidant and antibacterial effect of the medicinal plant Berberis asiatica. The results revealed that this plant has high concentrations of TPC (Total phenol content) and TFC (Total flavonoid content) of 37.686 ± 2.728 mg GAE/g and 115.568 ± 8.012 mg QE/g, respectively. The DPPH free radical scavenging assay demonstrated strong inhibition, with an IC50 of 205.7 ± 5.353 μg/mL, and also showed robust antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae with a zone of inhibition (ZOI) of 14 mm and 19 mm, respectively. The extract exhibited an excellent inhibitory potential against S. aureus, and K. pneumoniae with an MIC (Minimum inhibitory concentration) of 0.39 mg/mL, and 3.125 mg/mL respectively, indicating significant inhibitory action. Furthermore, the MBC (Minimum bactericidal concentration) for both S. aureus and K. pneumoniae was found to be 6.25 mg/mL, emphasizing the extract's consistent bactericidal effectiveness against these bacteria. These findings underscore the potential utility of the methanolic extract of Berberis asiatica as a natural antibacterial agent. GC-MS analysis of hexane fraction indicates the plant is rich in secondary metabolites, specifically 2,2-dimethyl-3-pentanol, 2-methyl-2-pentanol, 2,5-dimethyl-4-hydroxy-3-hexanone, 3-hexanol, 4-methyl-2-pentanol are identified. Overall, this study highlights the importance of plant-based natural products as potential sources of antioxidants and antibacterial agents that contributes to the future drug development process