scholarly journals Phytochemical Screening, Free Radical Scavenging and α-Amylase Inhibitory Activities of Selected Medicinal Plants from Western Nepal

Medicines ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 70 ◽  
Author(s):  
Kusum Sai ◽  
Rashmi Thapa ◽  
Hari Prasad Devkota ◽  
Khem Raj Joshi

Background: More than 700 plants are reported to be used for medicinal purposes in Nepal; however, many of them are not studied for their scientific evidences. The aims of the present study were the estimation of the total phenolic and flavonoid contents, and the evaluation of the free radical scavenging and α-amylase inhibitory activities of five selected medicinal plants from western Nepal: Aeschynanthus parviflorus Wall. (Gesneriaceae), Buddleja asiatica Lour. (Loganiaceae), Carica papaya L. (Caricaceae), Drepanostachyum falcatum (Nees) Keng f. (Gramineae) and Spondias pinnata (L. f.) Kurz (Anacardiaceae). Methods: The total phenolic content (TPC) and total flavonoid content (TFC) were measured using Folin-Ciocalteu’s phenol reagent and aluminium chloride methods, respectively. A 1,1–diphenyl–2–picrylhydrazyl (DPPH) free radical scavenging assay was used to evaluate the free radical scavenging activity and an α-amylase inhibitory assay was carried out to determine the in vitro antidiabetic activity. Results: The phytochemical screening of five hydroalcoholic plant extracts revealed the presence of various secondary metabolites, including alkaloids, flavonoids, reducing sugars, saponins, terpenoids and tannins. The amounts of total phenolics and flavonoids were found to be the highest in B. asiatica leaf extract, which also showed the most potent free radical scavenging activity. Extract of C. papaya fruits showed the highest α-amylase inhibitory activity, whereas the extracts of B. asiatica leaves and S. pinnata leaves exhibited moderate activity. Conclusions: Some of the medicinal plants selected in this study showed high TPC and TFC values and potent bioactivities. These results may provide the scientific evidences of the traditional uses of these plants. However, further detailed studies on bioactive compounds isolation and identification and evaluation of in vivo pharmacological activities should be performed in future.

2013 ◽  
Vol 2 (4) ◽  
pp. 92-96 ◽  
Author(s):  
Md. Hasanuzzaman ◽  
Md. Ramjan Ali ◽  
Marjan Hossain ◽  
Sourov Kuri ◽  
Mohammad Safiqul Islam

The present study was designed to investigate the phytochemical screening, the free radical scavenging activity and to determine the total phenolic content of methanolic extract and different solvent soluble fractions of Averrhoa bilimbi Linn. (Oxalidiaceae) fruits. The free radical scavenging activity was evaluated by analyzing the bleaching rate of 1,1-diphenyl-2-picrylhydrazyl (DPPH), and total phenolic content was determined by using Folin-Ciocalteau reagent, which results were expressed in gallic acid equivalent (mg of GAE/g of sample). The phytochemical screening revealed the potent source of different phytochemical constituents on different extractives including, phenol, flavonoid, tannin that are responsible for antioxidant action. In the determination of total phenolic content, different extractives showed a significant content of phenolic compounds ranging from 50.23-68.67 mg of GAE/g of extractive. The plant sample displayed significant DPPH free radical scavenging activity with highest IC50 value in crude methanolic extract (30.365 ?g/ml) followed by chloroform, carbon tetrachloride, pet-ether and aqueous soluble fractions having value of 32.852 ?g/ml, 36.708 ?g/ml, 50.35 ?g/ml, and 79.918 ?g/ml, respectively as opposed to that of the scavenging effects of BHT of 19.656 ?g/ml.DOI: http://dx.doi.org/10.3329/icpj.v2i4.14058 International Current Pharmaceutical Journal, March 2013, 2(4): 92-96


2020 ◽  
Vol 15 (1) ◽  
pp. 34-43
Author(s):  
Alex Zohmachhuana ◽  
Malsawmdawngliana Malsawmdawngliana M ◽  
Lalrinzuali K Lalrinzuali ◽  
Lalnunmawia F Lalnunmawia ◽  
Vabeiryureilai M Vabeiryureilai ◽  
...  

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1617
Author(s):  
Tina Kostka ◽  
Johanna Josefine Ostberg-Potthoff ◽  
Karlis Briviba ◽  
Seiichi Matsugo ◽  
Peter Winterhalter ◽  
...  

Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, “copigments” (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC–PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC–PDA–ESI–MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.


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