Effects of exogenous melatonin on growth and physiological characteristics of Agropyron mongolicum seedlings under drought stress.

To clarify the alleviation effect of exogenous melatonin (MT) on Agropyron mongolicum under drought stress, we examined the response of A. mongolicum 'Yanchi' seedlings to simulated drought stress with polyethylene glycol 6000 (PEG-6000), by investigating the effects of exogenous addition of different concentrations (0, 1, 10, 50, 100, 150 and 200 mg·L-1) of MT on seedlings growth and physiological characteristics under drought stress. The results showed that drought stress significantly inhibited the growth of A. mongolicum seedlings, and that exogenous addition of different concentrations of MT could alleviate the growth inhibition caused by drought stress, with the strongest mitigation effect observed at MT concentration of 100 mg·L-1. Compared with the drought stress treatment alone, exogenous addition of 100 mg·L-1 MT under drought stress increased plant height, aboveground dry weight, and leaf relative water content by 58.2%, 121.2% and 48.1%. The contents of chlorophyll a, chlorophyll b, carotenoids increased by 48.7%, 80.8% and 38.3%, superoxide dismutase, peroxidase and root activity increased by 12.6%, 33.9% and 39.1%, and the contents of ascorbic acid and glutathione increased by 19.5% and 18.3%, respectively. The contents of proline, soluble sugar and soluble protein were increased by 16.2%, 32.6% and 14.3%, while that of malondialdehyde, hydrogen peroxide and superoxide anion radical were decreased by 45.8%, 65.8% and 30.8%, respectively. In summary, exogenous addition of 100 mg·L-1 MT could improve drought tolerance of A. mongolicum seedlings by promoting growth, enhancing antioxidant capacity, increasing the content of osmoregulation substances, inhibiting the excessive production of reactive oxygen, and reducing membrane peroxide level.

[Effect of cervical paravertebral block combined with acupuncture intervention on cervicogenic headache].

OBJECTIVE: To observe the therapeutic effect of cervical paravertebral block plus acupuncture treatment for cervicogenic headache. METHODS: Sixty cases of cervicogenic headache were randomly and equally divided into cervical paravertebral block (control) group and acupuncture plus cervical paravertebral block (acupuncture) group. Paravertebral block was performed by injection of 5 mL of 0.3% lidocaine solution containing triamcinolone (10 mg) into the 2nd cervical paravertebral tissue from the cross point between the posterior border of the sternomastoid muscle and the angle of jaw, once every week for three weeks. Manual acupuncture stimulation was applied to Baihui (GV 20), unilateral Fengchi (GB 20) and Jiaosun (SJ 20), once daily for 3 weeks. The patients' headache severity was assessed by visual analogue scale (VAS) and their cervical vertebral activity assessed by range of motion (ROM) before and after the treatment. RESULTS: Compared with pre-treatment in the same one group, the scores of both VAS and ROM at time points of one, two and three weeks after the treatment were significantly decreased in the control and acupuncture groups (P < 0.05), suggesting a marked improvement of both headache and cervical motion after the treatment. Comparison between the two groups showed that the VAS and ROM scores of the acupuncture group were evidently lower than those of the control group at each time point after the treatment (P < 0.05), displaying a better therapeutic effect of acupuncture plus paravertebral block for cervicogenic headache. CONCLUSION: Acupuncture combined with cervical paravertebral block is effective in relieving cervicogenic headache and improving cervical vertebral activity in cervicogenic headache patients, and can strengthen the therapeutic effect of simple paravertebral block.