Angiogenic activity and antioxidant properties of dietary phenolics from "malunggay" (Moringa oleifera, L.) leaves

Date

10-2004

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Evelyn B. Rodriguez

Abstract

SARMIENTO, VICTORLA EDEN GUEVARRA. College of Arts and Sciences. University of the Philippines Los Banos October 2004 Angiogenic Activity and Antioxidant Properties of Dietary Phenolics from "Malunggay- (Moringa olerfera. L.) Leaves.

ADVISER: Evelyn B Rodriguez, Ph D

Phenolic compounds from -malunggay- (Moringa oleifera. L) leaves were extracted using 7:7:6 methanol-acetone-water (MAW) In addition. the leaf extracts were hydrolyzed in acid and base to release any phenolic compounds bound as elycosides and esters, respectively. A descending two-dimensional paper chromatography technique was used to obtain the phenolic profile of the extracts The extracts showed several phenolic components: MAW (14), acid-hydrolyzed (9) and base-hydrolyzed (4) The phenolics were identified or classified into compound types according to their Rf values. color under visible and UV light and color under visible and L-V light in the presence of ammonia times. The major phenolics were eluted from paper with methanol. rechromatographed together with some standards and subjected to UV spectral analysis Quercetin-3-O-glucoside was the major component of the N1AW extract. while quercetin and caffeic acid were the major components of acid-hydrolyzed and base-hydrolyzed extracts, respectively The total phenolic content of the three extracts were determined using the Folin-Ciocalteu phenol reagent and gallic acid and catechin as standards Among the extracts. the acid-hydrolyzed had the highest total phenolic content (18.156 mg catechin equivalent/kg fresh sample and 0.565 mg gallic acid equivalent/kg fresh sample).

The MAW extract was evaluated for its antioxidant properties inhibitorrs action on lipid peroxide and thiobarbituric acid-reactive substances (TBARs, formation, free-radical and reactive-oxygen scavenging activities The 2000 ppm MAW extract exhibited the highest antioxidant activity, inhibiting lipid peroxidation by 57 7°. at 35 days and TBARS formation by 60.3% at 40 days of corn oil autooxidation. Among the reference compounds, butylated hydroxytoluene (BHT) at 200 ppm exhibited a similar activity under the same conditions - effecting 51.1% lipid peroxide inhibition and 57.8% TBARS inhibition.

To gain insight into the mechanism of action as antioxidant, the free-radical (DPPH assay) and reactive-oxygen (H20, assay) scavenging activities of the MAW extract were investigated. The MAW extract had a higher free-radical scavenging activity (27.5% at 100 ppm and 53.0% at 200 ppm) than ascorbic acid (16.3% at 100 ppm and 41.9%) at 200 ppm). However, caffeic acid exhibited the highest free-radical scavenging activity among the three (43.6% at 100 ppm and 72.1% at 200 ppm) The scavenging activities of 100 and 200 ppm of the MAW extract were 0' 3 and 88 4o. respectively In comparison_ caffeic acid at 200 ppm completely scavenged the H2O, in the assay medium. The results have shown that the "malunggay" phenolic extract can scavenge both free radical and reactive oxygen species, specifically 1-1,0:, and thus. is a potent antioxidant

Using the duck embryo assay, the angiogenic activity of different concentrations of MAW extract - 300, 600 and 1200 ppm in phosphate buffer saline 02M. pH7 - were evaluated. Caffeic acid, of the same concentrations, was used for paraIlel studs The untreated duck embryo showed a normal blood vessel formation The phosphate buffer saline-treated duck embryo was the same as the untreated duck embryo. However. the extract and caffeic acid, at all concentrations, reduced the formation of blood vessels in comparison with the untreated duck embryo. The results have demonstrated that "malunggay- phenolic extract possesses an anti-angiogenic property.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

This document is currently not available here.

Share

COinS