The effects of acupuncture and moxibustion on allergic asthma rats

Yun-Ying Qiao,Yu-Peng Yang,Shan-Yin Yang

1The Third Clinical College of Shanxi University of TCM,Shanxi,China. 2The Shanxi University of TCM,Shanxi,China.

Abstract

Keywords:Acupuncture and moxibustion;Crh;Allergic asthma;Regulating mind

Background

Allergic asthma is a chronic tracheitis involving eosinophils, mast cells,T cells and other inflammatory cells. It is characterized by airway allergic inflammation and tracheal hyperresponsiveness.Immune mechanism is considered as an important pathogenesis. Previous studies on the mechanism of acupuncture and moxibustion in the treatment of asthma mainly reflected in improving ventilation function, controlling inflammatory response,regulating immune function. At present, more and more studies have found that airway inflammatory response is only a part of the pathogenesis of asthma,and the relationship between neuroendocrine and immune is also an important mechanism of asthma[1].Correcting the neuroendocrine disorder of asthma can provide new ideas for the treatment of asthma.

Studies have shown that corticotropin releasing hormone (CRH) plays an inflammatory role in the peripheral immune system [2-3], which can increase the mRNA expression of TNF-a and IL-6 in macrophages induced by lipopolysaccharide, activate the activity of NF-κB in granulocytes, produce inflammatory mediators,and participate in the immune and inflammatory response. In the pathogenesis of asthma, various stress factors can aggravate asthma by regulating mast cell activity or reducing the content of IL-10 through CRH.It was found that when the asthma attacks repeatedly, the hypothalamic-pituitary-adrenal axis (HPA)was disordered and the expression of CRH mRNA in hypothalamus was significantly down regulated [4-5]. Therefore, the use of CRH receptor or mast cell blockers in the treatment of asthma is a new treatment method [6]. Acupuncture has been used for the treatment of asthma. Randomized controlled trials have shown positive effects of acupuncture for the treatment of asthma [7]. The experiments neuroscientists at Harvard Medical School further confirmed the neuroanatomical mechanisms underlying acupuncture in the treatment of inflammatory diseases [8]. This study aims to observe the regulatory effect of acupuncture and moxibustion on CRH, a key stress factor in the neuroendocrine network to provide theoretical basis for the "mind regulating"effect of acupuncture and moxibustion.

Materials and methods

Animals

Forty healthy male SD rats used in the study were purchased from Beijing Weitong Lihua Co., Ltd,Beijing, China.The rats were around 6-8 weeks of age and weighed approximately 20-25g.They were housed in a clean laboratory at 20-25 ℃for a week. Food and water were given ad libitum. This study was approved by the Ethics Committee of Shanxi University of Traditional Chinese Medicine.

Gouping

The rats were randomly divided into five groups:blank group, model group, sham-acupuncture group,acupuncture group and moxibustion group, eight rats in each group. Ovalbumin (OVA) (A5352, Sigma,USA) was used to sensitise the rats. Except the blank group, the other groups were established by intraperitoneal injection of ovalbumin (OVA) and atomization excitation. The blank group was injected intraperitoneally and atomized with normal saline instead of OVA.After successful modeling, the rats in blank and the model group were only grabbed, bound and fixed every day without treatment; In the sham acupuncture group, non-acupoint tissues were selected for acupuncture treatment every day; Acupuncture group and moxibustion group were treated with acupuncture or moxibustion at selected acupoints.

Asthma model

Referring to the literature requirements [9], the rats were administered intraperitoneal injection of OVA 100mg and aluminum hydroxide 100mg in 1 mL of 0.9% sodium chloride (NaCl) on the first day. From 15th day, the rats were inhaled with 5% OVA in 0.9%NaCl for 20 min, once a day for consecutive 7 days; 7 days after stopping atomization, this procedure was performed again. When the last asthma attack was induced,the incidence of each group rats was recorded.Shortness of breath, abdominal muscle twitch and cyanosis of lips represented the successful replication of the model.

Acupuncture

After successful modeling, acupuncture was performed in sham-acupuncture group and acupuncture group.Referring to Acupoint Atlas of Experimental Animals,the acupuncture acupoint Feiyu (BL13), Danzhong(KN17), Baihui (DU20), Zusanli (ST36) were used in the study. Zusanli acupoints (ST36) are located approximately 5 mm inferolateral to the anterior tibial tubercle. Feiyu acupoint (BL13) is located at the depression lateral to the lower border of the spinous process of the third thoracic vertebra. Danzhong acupoint (KN17) located at the anterior midline of chest, the fourth intercostal space, and the midpoint of the line between the two nipples. Baihui acupoints(DU20)are located at the intersection of the midline of the head and the line connecting the two ear tips(Figure 1). Disposable stainless steel acupuncture needles measuring 0.18× 7 mm (Huatuo 32, China)were bilaterally inserted to a depth of 5 mm and retained for 20 min without any further stimulation.Acupuncture was given one time a day for 7 days by a well-trained acupuncturist.

Moxibustion treatment

The acupoint selection of moxibustion was the same as that of the acupuncture group. A moxa sticks was suspended at the selected acupoints of rats in moxibustion group, a form of heat therapy, for 20 minutes,successively 7 days.

Symptom scores of rats

According to the literature [10], the symptoms of rats at 10 min of the last sensitisation and after treatment were scored. The scores were 0 for stable breathing, 1 for shortness of breath, 2 for dyspnea, 3 for dyspnea with wheezing or mucus secretion, and 4 for irregular breathing or sudden death.

Determination of serum CRH

After treatment, rats in each group were anesthetized by intraperitoneal injection of 2% pentobarbital sodium (60mg / kg). Blood was collected from the heart and centrifuged at 1500 rpm for 15 minutes. The supernatant was collected and stored in a refrigerator at-20 ℃/-70 ℃for detection.

Statistical analysis

All statistical analyses were performed using SPSS version 16.0. Data were analysed using ANOVA. The data were expressed as the mean ± SD.P<0.05 was considered to indicate statistical significance.

Table 1 Comparison of symptom scores of rats among groups after the modeling and treatment（ ¯x±s）

Table 2 Serum CRH content of rats in each group after treatment （ ¯x±s）

Results

Behavior of rats

After atomization inhalation of OVA, the rats showed nose scratching, irritability, sneezing, and then shortness of breath, abdominal muscle twitch, and cyanosis of lips.After repeated sensitisation, rats were mentally depressed, with dry hair color and slow weight gain. Normal rats did not have the above manifestations, occasionally showed scratching nose,sneezing. It showed that models was successfully established. After being sensitised by OVA, the symptoms scores of rats were significantly increased.After treatment,the symptoms of each treatment group were significantly reduced. Compared with the model group, the symptom scores in acupuncture group and moxibustion group decreased significantly (All P <0.01) (Table 1).After treatment, compared with model group, the CRH in acupuncture and moxibustion groups were significantly reduced (All P ＜ 0.01).Compared with the sham acupuncture group, the CRH in acupuncture group were significantly reduced (P＜0.05)(Table 2).

Discussion

Studies have shown that [11] long-term or high-dose glucocorticoid systemic administration can negatively feedback inhibit HPA function, resulting in so-called hormone dependent asthma. On the contrary, many mild asthma patients can quickly stop the attack or self-healing without treatment. This may be related to the neuroendocrine immune regulation of patients.Therefore, in the case of the increasingly prominent side effects of exogenous hormones, improving the endogenous anti-inflammatory mechanism of asthma,improving the body's anti-inflammatory ability, and correcting the endocrine disorders of asthma can be a new idea for the treatment of asthma. As a key factor in the neuroendocrine network, CRH plays an inflammatory role in the peripheral immune system[2,3].

In this study, the content of serum CRH in rats with allergic asthma was detected. It was found that the content of CRH in serum of rats with allergic asthma was significantly increased, and showed the symptoms of rapid breathing, abdominal muscle convulsion, bow back stagnation, mental depression, dry hair color.After acupuncture and moxibustion, the content of serum CRH in rats decreased significantly, and the symptoms were improved significantly. It is suggested that acupuncture can not only reduce inflammatory reaction, improve the overall state of asthmatic rats,but also have neuroendocrine and immunomodulatory effects.

Previous studies have shown that bronchial asthma is a typical psychosomatic disease, and emotional and psychological factors play an important role in its pathogenesis [12]. Psychological stress can promote asthma through the activation of monocyte macrophages or lymphocytes. In the neuroendocrine immune network, neuroendocrine as an upstream link plays a key role in the pathogenesis of asthma. It is more important to explore the neuroendocrine regulation of acupuncture in the treatment of allergic asthma.Clinically,acupuncture and moxibustion in the treatment of many diseases can achieve better results through its regulating mind effect. The results showed that the content of CRH in all rats, including sham acupuncture group, was significantly reduced after acupuncture stimulation,which also confirmed the role of regulating mind of acupuncture in the treatment of allergic asthma. However, the serum CRH content in the acupuncture group decreased more significantly than that in the sham acupuncture group,indicating the specific effect of acupoints.