@article {237, title = {Phytochemical and Antimicrobial Evaluation of Lauridia tetragona (L.F) R.H. Archer: A Medicinal Plant Used for the Management of Dysentery in the Eastern Cape Province of South Africa}, journal = {Pharmacognosy Research}, volume = {11}, year = {2019}, month = {April 2019}, pages = {134-139}, type = {Original Article}, chapter = {134}, abstract = {

Objective: The present investigation evaluated the in vitro phytochemical and antimicrobial potential of the methanol and acetone leaf extracts of Lauridia tetragona (L.F), a plant consumed as a herb in South Africa. Materials and Methods: Spectrophotometry assays using Folin{\textendash}Ciocalteu, aluminum chloride, and vanillin{\textendash}hydrochloric acid were used for the determination of phenols, flavonoids, and proanthocyanidin contents of the extracts, respectively. The agar dilution technique was used for the antimicrobial evaluation. The inhibitory activity of the extracts was tested on five Gram-negative and five Gram-positive bacteria and four fungi. Results: The methanol extract had a higher phenol (54.87 {\textpm} 4.01 mg gallic acid equivalent [GAE]/g) and proanthocyanidin (78.55 {\textpm} 0.83 mg catechin equivalent [CE]/g) content than the acetone extracts with 45.27 {\textpm} 3.93 mg GAE/g and 63.54 {\textpm} 1.67 mg CE/g, respectively. The acetone extract, however, had higher flavonoid content (462.45 {\textpm} 1.93 mg quercetin equivalent [QE]/g) than the methanol extract (412.20 {\textpm} 3.85 mg QE/g). The minimum inhibitory concentration (MIC) of the antibacterial assay ranged from 2.5 to 5 mg/mL. All the bacteria except Staphylococcus aureus were susceptible to the acetone extract. Five bacteria, three Gram positive and two Gram negative, were resistant while the remaining five were susceptible to the methanol extract. Conversely, all the fungi tested were susceptible to both extracts with a MIC which ranged from 0.63 to 10 mg/mL. Conclusion: The results obtained revealed that Gram-positive and Gram-negative bacteria and fungi showed some degree of susceptibility to the plant extracts. This gives an indication of broad-spectrum activity exhibited by the crude extracts of L. tetragona and supports its ethnomedicinal usage.

}, keywords = {Antimicrobial, Celastraceae, Dysentery, Lauridia tetragona, Phytochemical, Spectrophotometry}, doi = {10.4103/pr.pr_41_18}, author = {Olubunmi Abosede Wintola and Anthony Jide Afolayan} } @article {228, title = {Identification of Antidiabetic Compounds from Polyphenolic-rich Fractions of Bulbine abyssinica A. Rich Leaves}, journal = {Pharmacognosy Research}, volume = {10}, year = {2018}, month = {February 2018}, pages = {72-80}, type = {Original Article}, chapter = {72}, abstract = {

Background: Bulbine abyssinica has been reported to possess a variety of pharmacological activities traditionally. Previous work suggested its antidiabetic properties, but information on the antidiabetic compounds is still lacking. Objective: The present research exertion was aimed to isolate and identify biologically active polyphenols from B. abyssinica leaves and to evaluate their efficacy on carbohydrate digesting enzymes. Materials and Methods: Fractionation of the polyphenolic contents from the methanolic extract of B. abyssinica leaves was executed by the silica gel column chromatography to yield different fractions. The antioxidant activities of these fractions were carried out against 2,2{\textquoteright}-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazyl radicals, and ferric ion-reducing antioxidant power (FRAP). In vitro antidiabetic experimentation was performed by evaluating the α-amylase and α-glucosidase inhibitory capacity. The isolated polyphenols were then identified using liquid chromatography and mass spectroscopy (LC/MS). Results: Out of the eight polyphenolic fractions (BAL 1{\textendash}8), BAL-4 has the highest inhibitory activity against ABTS radicals whereas BAL-6 showed potent ferric ion-reducing capacity. BAL-5 was the most effective fraction with antidiabetic activity with IC50 of 140.0 and 68.58 {\textpm} 3.2 {\textmu}g/ml for α-amylase and α-glucosidase inhibitory activities, respectively. All the fractions competitively inhibited α-amylase, BAL-5 and BAL-6 also inhibited α-glucosidase competitively, while BAL-4 and BAL-1 exhibited noncompetitive and near competitive inhibitions against α-glucosidase, respectively. The LC/MS analysis revealed the presence of carvone in all the fractions. Conclusions: The present study demonstrates the antioxidant and antidiabetic activities of the isolated polyphenols from B. abyssinica.

}, keywords = {Antidiabetics, Antioxidants, Bulbine abyssinica, Liquid chromatography and mass spectroscopy, Medicinal plants, Polyphenolics}, doi = {10.4103/pr.pr_55_17}, author = {Samuel Wale Odeyemi and Anthony Jide Afolayan} } @article {218, title = {Quantitative Phytochemical Constituents and Antioxidant Activities of the Mistletoe, Phragmanthera capitata (Sprengel) Balle Extracted with Different Solvents}, journal = {Pharmacognosy Research}, volume = {10}, year = {2018}, month = {February 2018}, pages = {16-23}, type = {Original Article}, chapter = {16}, abstract = {

Objective: The investigation aimed to evaluate the in vitro quantitative phytochemical compositions and antioxidant capacity of the dried leaves of Phragmanthera capitata extracted with different solvents. Methodology: Different phytochemical assays were used to evaluate the phenols, flavonoids, and proanthocyanidin contents of the acetone, methanol, ethanol, and aqueous extracts of the sample. Antioxidant activity was measured using 2,2diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), Ferric reducing antioxidant power (FRAP), nitric oxide, and total antioxidant capacity (TAC) assays. Results: Methanol had the highest extraction yield (21.50\%) followed by aqueous (10.87\%). Acetone and ethanol yielded 6.87\% and 4.3\%, respectively. However, acetone and ethanol extracts had more phenolic content (218.6 {\textpm} 3.38 and 214.8 {\textpm} 3.56 mg gallic acid equivalent (GAE)/g, respectively) that were significantly higher (P \< 0.05) than the methanol and aqueous extracts (203.8 {\textpm} 1.95 and 175.5 {\textpm} 0.32 mg GAE/mg, respectively). Acetone extract also had more flavonoid and proanthocyanidin contents (679.8 {\textpm} 6.26 mg quercetin equivalent/g and 645.7 {\textpm} 6.35 mg catechin equivalent/g, respectively) that were significantly higher than the other solvent extracts (P \< 0.05). All the solvent fractions showed great antioxidant activities with the acetone fraction having the highest capacity based on ABTS, DPPH, and TAC assays (half maximal inhibitory concentration [IC50] = \<5 {\textmu}g/ mL, 24.5 {\textmu}g/mL, and 85 {\textmu}g/mL respectively). The methanol extract however had FRAP and nitric oxide antioxidant activities (IC50 = 302 {\textmu}g/ mL and \<25 {\textmu}g/mL respectively). Conclusion: The findings of this study provide evidence that P. capitata has potential as a natural source of antioxidant with acetone showing to be the best extractant of the polyphenolics with corresponding higher antioxidant activities.

}, keywords = {Extractant, Loranthaceae, Mistletoe, Phragmanthera capitata, Polyphenolics, Total antioxidant activity}, doi = {10.4103/pr.pr_65_17}, author = {Franklin Uangbaoje Ohikhena and Olubunmi Abosede Wintola and Anthony Jide Afolayan} }