POLYPHENOLS AND BIOLOGICAL ACTIVITIES OF Feijoa ...

108 S.M. El-shenawy et al.
benzoyl fragment). 1 H and 13 C NMR data
are listed in Table 1.
Quercitrin (10)
Yellow amorphous powder; R f
-values: 0.50
(S 1
), 0.64 (S 2
) same as (9) on PC; it gave
dark purple spot by long UV light turned
to green with FeCl 3
and orange with Naturstoff
reagent. UV λ max
(MeOH) nm: 255,
299 sh, 353; (+ NaOMe): 268, 325 sh, 400;
(+ NaOAc): 270, 320 sh, 370; (+ NaOAc/
H 3
BO 3
): 260, 299 sh, 374; (+ AlCl 3
): 273, 304
sh, 408; (+ AlCl 3
/HCl): 268, 304 sh, 353 sh,
398. Negative HRESI/MS: m/z 447.09296
[M-H] ‾ (calcd.: 447.09312), 301.03607
[M-deoxyhexoside] ‾ = [quercetin-H] ‾ , (MS 3 )
178.93030 (C 9
H 7
O 4
, cinnamoyl fragment),
150.93245 (C 6
H 3
O 4
, benzoyl fragment). 1 H
and 13 C NMR data are listed in Table 1.
Pharmacological studies
Animals
Adult male pathogen-free Sprague-Dawley
rats (120-130 g) and Swiss mice weighing
(20-30 g) were purchased from the animal
house of National Research Centre were
used. The animals were housed in standard
metal cages in an air-conditioned room at
22 ± 3˚C, 55 ± 5% humidity, and 12 h light
and provided with standard laboratory
diet and water ad libitum. All experimental
procedures were conducted in accordance
with the guide for care and use of laboratory
animals and in accordance with the
Local Animal Care and Use Committee. The
distilled water was used as a vehicle for
extract and paracetamol and 5 % sodium
bicarbonate for indomethacin.
Determination of median lethal dose
(LD 50
)
The LD 50
of the AME-80 was determined
using rats. No percentage mortality was
recorded after 24 hours up to dose of 5
g/kg and according to Semler (1992) who
reported that if just one dose level at 5 g/kg
is not lethal, regulatory agencies no longer
require the determination of an LD 50
value.
So the experimental doses used were 1/20,
1/10 and 1/5 of 5/ g/kg of AME-80 (250,
500 and 1000 mg kg -1 ).
Analgesic activity
This activity was determined by measuring
the responses of animals to both thermal
and chemical stimulus.
Thermal test
Hot-plate test was conducted using an
electronically controlled hot-plate (Ugo
Basile, Italy) adjusted at 52°C ± 0.1°C
and the cut-off time was 30s (Eddy and
Leimback, 1953). Five groups of mice
each of six were used. The time elapsed
until either paw licking or jumping is
recorded 60 min before, and 1 and 2 h
after oral administration of AME-80 (250,
500, 1000 mg kg -1 ), saline and tramadol
(20 mg kg -1 orally, a reference analgesic
drug, October Pharma, 6 th October, Egypt)
(Sacerdote et al., 1997).
Chemical test
Acetic acid-induced writhing in mice was
performed according to the convenient
published method (Collier et al., 1968). The
mice were divided into six groups each of
six and received the same doses of AME-
80, control as mentioned before, in thermal
test. Indomethacin (25 mg kg -1 , Epico,
Egypt) was used as reference drug. After
60 min interval, the mice received 0.6 %
acetic acid ip (0.2 ml/mice). The number
of writhes in 30 min period was counted
and compared.
Anti-inflammatory activity
Anti-inflammatory activity in acute model
was carried out according to the convenient
reported method (Winter et al., 1962). Rats
were divided into five groups each of six and
received orally saline as control, AME-80
(250, 500, 1000 mg kg -1 ), and indomethacin
(25 mg kg -1 orally) one hour before induction
of oedema by subplanter injection of
100 µL of 1 % carrageenan injection (Sigma,