Evaluation of the hypoglycemic, hypolipidemic and anti alpha amylase effects of extracts of the twigs and fruits of ficus ovata vahl (moraceae)

II.5.3. Determination of Nitric Oxide level

Principle: This is based on the reaction of diazotization described by Griess in 1879. It describes the chemical reaction between sulphanilamide and naphtylethylenediamine dihydrochloride (NED) under acidic conditions (phosphoric acid). Sulphanilamide and NED compete for nitrite in the Griess reaction. This reagent detects NO₂^- in a variety of biological and experimental liquid samples such as plasma, serum, urine and tissue culture. This system detects the nitrite formed which is one of the primary stable and non volatile compounds from degradation of nitric oxide in biological mediums (Manish et al., 2006).

Reagents: N-1-naphtylethylene dichloride diamine (NED)

· Sulphanilamide: 1% sulphanilamide in 5% orthophosphoric acid

· Standard nitrite: 0.1M of sodium nitrite in distilled water.

A solution of sulphanilamide and dichloro N-1-naphtylethylene diamine was prepared and allowed for 15-30 minutes at room temperature.

Procedure: In 100 uL of sample, 100 uL of sulphanilamide solution was added and pre-incubated for 5-10 minutes at room temperature while protected from light. After pre-incubation, 100 uL of dichloro N-1-naphtylethylene diamine was added and incubated for 5-10 minutes at room temperature and protected from light.

The presence of a purple/mangenta colour is an indicator of the presence of nitrite formed.

The absorbance was read at 540nm. (å (reactivity) = 39500M^-1CM^-1)

II.6. Statistical analysis

SPSS program: version 10.0 for Windows was used and the results presented as mean #177; SEM. Differences between means were done by a one-way analysis of variance (ANOVA) followed by post hoc test using Tamhane and LSD. Values of p< 0.05 were taken to imply statistical significance.

CHAPTER III. RESULTS AND DISCUSSION

III.1.Results

III.1.1. Yield of extraction and phytochemical screening

The results of the extraction are represented on the table XII below.

Table XII: Yield of extraction

	Twigs	Twigs	Fruit	Fruit
solvent	Ethanol:water(1:1)	Ethanol	Ethanol	Ethanol:water(1:1)
% yield	7.28	5.66	2.78	7.21

Two solvent system were used for the extraction of the fruits and twigs of F. ovata which where ethanolic and hydroethanolic solvent systems. The above results show that the hydroethanolic solvent gave higher yield than the ethanolic solvent for extraction of the fruits and twigs.

The result of phytochemical screening are represented on table XIII below

Table XIII: The phytochemical screening results.

	Alkaloids	Saponins	Flavonoids	Tannins	Phlobatannins	Glycosides	Phenols
FOEF	+	+	+	+	-	+	+
FOET	-	+	+	+	+	+	+
FOHF	+	+	+	+	-	+	+
FOHT	+	+	+	+	+	+	+

FOEF= Ficus ovata ethanolic fruits; FOET= Ficus ovata ethanolic twigs; FOHF= Ficus ovata hydroethanolic fruits; FOHT= Ficus ovata hydroethanolic twigs

Generally, extracts of fruits and twigs of Ficus ovata contain groups of bioactive compounds such as alkaloids, glycosides, saponins, and polyphenols such as flavonoids, tannins and phenols. Phlobatannins were absent in the fruit extracts of Ficus ovata and alkaloids where absent in ethanolic fruits.