The Pharmacodynamic Study of Qin Bing Eye Drop on Photokeratoconjunctivitis
500
Figure 4. Effects of different drugs on recovery rates (n =
4).
24 h, 27 h and 30 h as well as Qing Bin eye drop (Shanxi)
group and un-treatment group at 48 h, 72 h and 78 h (Ta-
ble 3). This demonstrated Qing Bin eye drops could be
effective for PKC. The recovery rates of Qing Bin eye
drop (Hebei) in 30 h were above Qing Bin eye drop
(Shanxi).
For the speed of recovery (Table 4), the slopes of
therapeutic groups were more than untreated group in 30
h, which implied all the eye drops including normal sa-
line could relieve the symptoms of PKC quicker than
untreated group, especially in the early stage. Among all
the eye drop groups, the slopes of Qing Bin eye drop
groups in 30 hours, including Hebei and Shanxi, were
higher than levofloxacin group, which suggested Qing
Bin eye drops could be better than control groups. Fur-
thermore, Qing Bin eye drop group (Hebei) was the
highest (0.1205). This indicated that Qingbin eye drop
(Hebei) could be superior to Qing Bin eye drop (Shanxi).
4. Discussions
Photokeratoconjunctivitis (PKD) is caused by excessive
exposure to UV radiation. Excessive UV hydrolyzes the
water molecular in superficial layers of the eye to pro-
duce a large number of oxygen free radicals, which at-
tack cells through various pathways and make cells ne-
crosis and dropping off [6]. As a result, lots of inflam-
matory stimulation factors are released to induce symp-
toms such as ocular pain, tearing, a sense of sand in the
eye and photophbia [7].
Few studies on the animal’s model of electric oph-
thalmia have been reported. In this paper, animal model
was established according to above mechanism of PKD
[8]. As we known, rabbits closed eyes protectively when
exposure to UV. However, they naturally opened eyes
under the statue of anaesthetization. So in present ex-
periment, intravenously anaesthetization was performed
to keep animals cooperative. The injury degree depended
on the intensity, distance and period of UV irradiation [9].
If the period was too long and UV intensity was too large,
eyes of rabbits would be irreversibly damaged and in that
case the effects of eye drops would be inconvenient to be
observed. In contrast, if the degree of electric ophthamia
was too mild, the rabbits would recover quickly and it
was not suitable for observation. After several trials, the
final parameters were optimized: the rabbits’ eyes were
twice exposure to both 254 nm and 365 nm of UV de-
tector for 30 min, twenty centimeters away from light
emission source at 90 degrees. After 2 - 8 hours, the
symptoms of PKD were apparent and the scores were
above 9, which demonstrated the models were success-
ful.
In most clinical cases of PKD, if no inflammation,
symptoms will be self-relief in 6 - 8 hours and gone
within a week or so. This situation explains that the PKD
symptoms of animal model are self-curative. Clinically,
symptomatic treatments are commonly adopted: in early
stage anaesthetic eye drops are instilled to relive pain and
antibiotic eye drops or eye ointments are applied for
prophylaxis of inflammation [10]. According to this rou-
tine therapeutic method, our experiment chose levoflox-
acin eye drop and normal saline as control medicine.
The results showed Qing Bin eye drop groups could
promote the symptoms of PKD recovering quicker than
untreated group. Furthermore, Qing Bin eye drop (Hebei)
had better effects than Shanxi. According to our previous
results (Table 1), the amount of esculin in Qing Bin eye
drop (Hebei, lot. 100715) is more than that of Shanxi (lot.
100819) as well as the synthetic scores. Coumarins are
proven to be the active constituents, which were reported
to have activities such as anti-inflammation, antivirus,
antiarthritis and anticancer [11]. Our results of effects
were consistent with chemical results. This indicated that
chemical constituents of herbs could reflect the effects in
part.
To sum up, in this paper, the animal model of PKC
was successfully established using rabbits’ eyes exposure
to Ultraviolet (UV). The Qin Bing eye drops made of
herbs from Hebei and Shanxi were compared. Results
showed that the effects of Qin Bing Eye drop (Hebei)
were better than Shanxi, which was in consistence with
the chemical results. This demonstrated that main con-
stituents in cortex fraxini as marks of pharmacological
effects were reasonable.
5. Acknowledgements
This research was supported by Longhua Medcial Project
(LYTD-14) and Chinese Medicine Shanghai Health Bu-
reau scientific research fund (No. 2008X002A).
REFERENCES
[1] National Commission of Chinese Pharmacopoeia, “Phar-
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