مجله دانشکده پزشکی اصفهان
پیاپی 744 (هفته چهارم دی 1402)

Dry bite in snakebite is when progressive local symptoms, systemic manifestations, and laboratory disorders are not seen, generally there is no need for antivenom. The purpose of this research was to investigate the pattern of dry bites and their treatment outcome in the referral center.

In this cross-sectional study, patients with viper bites who were admitted to the poisoning department of Khurshid Hospital in Isfahan from April 2013 to 2019 as dry bites; were studied. Demographic characteristics, local, systemic, and laboratory symptoms of these patients were collected and analyzed.

During this period, 47 patients (33.81% of all snakebites) had dry bites. Bites were more common in men and more in spring and summer, and the north of Isfahan province than in other regions. Snake bites were more frequent in the upper limbs, lower limbs and, trunk, respectively. The most common symptom of the patients was pain at the bite site (63.8%), which improved with anti-inflammatory drugs in 63.8% and without any specific treatment in 36.2% of cases. During hospitalization and follow-up, the patients did not have any complications.

Pain was the most common symptom in hospitalized patients with dry bites caused by viper bites; However, many snakebite patients did not require antivenom. This finding can indicate that pain at the bite site alone does not justify the requirement to receive antivenom.

Dracocephalum kotschyi is an herbal medicine with spasmolytic and anti-inflammatory properties. Pharmacological studies have indicated that D. kotschyi extract prevents pulmonary inflammation and fibrosis. In addition, D. kotschyi extract had bronchodilatory action. However, so far, its cardiovascular effect has not been investigated. The present study aimed to assess the effect of D. kotschyi extract and its essential oil on isolated heart and aortic contractions in vitro.

Essential oil and hydroalcoholic extract were prepared with hydrodistillation and, maceration respectively. Male Wistar rats were killed with CO2 asphyxiation. The heart and aortic artery were carefully dissected and placed in an organ bath filled with a physiological solution saturated with oxygen, and their contractions were recorded on a physiograph apparatus. Effects of various concentrations of the D. kotschyi extract and essential oil were investigated on the heart and aortic contractions separately and compared with the control group.

The essential oil of D. kotschyi had an inhibitory effect on both myocadiac and aortic contractions. While the D. kotschyi extract in concentration that completely inhibited contraction of the ileum did not affect myocardial contractions. At concentrations above 200µg/ml, D. kotschyi extract had a positive inotropic effect on the cardiac muscle, however, at these concentrations it inhibited aortic artery contraction.

The D. kotschyi essential oil had a more potent vasodilatory effect than the extract on the aortic artery contractions. However, unlike D. kotschyi hydroalcoholic extract which had positive inotropic action, the essential oil had negative inotropic action on myocardial contraction.