Effects of magnolol and honokiol derived from traditional Chinese herbal remedies on gastrointestinal movement

AIM： To study the effects of magnolol and honokiol on isolated smooth muscle of gastrointestinal tract and their relationship with Ca^2＋, and on the gastric emptying and the intestinal propulsive activity in mice.METHODS： Routine experimental methods using isolated gastric fundus strips of rats and isolated ileum segments of guinea pigs were adopted to measure the smooth muscle tension, The effects of magnolol 10^-3, 10^-4, 10^-5 mol/L, and honokiol 10^-4, 10^-5, 10^-6 mol/L on the contractility of gastric fundus strips of rats and ileum of guinea pigs induced by acetylcholine （Ach） and 5-hydroxytryptamine （5-HT） was assessed respectively, The method using nuclein and pigment methylene blue was adopted to measure the gastric retention rate of nuclein and the intestinal propulsive ratio of a nutritional semi-solid meal for assessing the effect of magnolol and honokiol （0.5, 2, 20 mg/kg） on gastric emptying and intestinal propulsion.RESULTS： Magnolol and honokiol significantly inhibited the contractility of isolated gastric fundus strips of rats treated with Ach or 5-HT and isolated ileum guinea pigs treated with Ach or CaCl2, and both of them behaved as non-competitive muscarinic antagonists. Magnolol and honokiol inhibited the contraction induced by Ach in Ca^2＋-free medium and extracellular Ca^2＋-dependent contraction induced by Ach, Each group of magnolol and honokiol experiments significantly decreased the residual rate of nudein in the stomach and increased the intestinal propulsive ratio in mice.CONCLUSION： The inhibitory effect of magnolol and honokiol on contractility of the smooth muscles of isolated gastric fundus strips of rats and isolated ileum of guinea pigs is associated with a calcium-antagonistic effect. Magnolol and honokiol can improve the gastric emptying of a semi-solid meal and intestinal propulsive activity in mice.

Genetic relationship between parasitized and non-parasitized Haloxylon ammodendron in the Alxa Desert

Haloxylon ammodendron （C. A. Mey.） Bunge is a host for the holoparasitic plant Cistanche deserticola Y. C. Ma, the original source of medicinal material known as Herba Cistanchis. The inter-simple sequence repeat marker was used to assess the genetic variations and relationships among six accessions ofH. ammodendron with a total of 120 individuals collected from three localities in the Alxa Desert, Inner Mongolia, China. At each locality, individuals both parasitized （PP） by C. deserticola and non-parasitized （NP） were sampled. The results showed that Nei＇s gene diversity and Shannon＇s index of PP accessions were higher, but were not significantly different, from those of NP accessions. An unweighted pair-group method arithmetic average dendrogram showed two clusters, one that included all PP accessions, and the other the NP accessions. Genetic differentiation therefore existed between PP and NP accessions, which might be attributed to low gene flow between the NP and PP groups （Nm〈 1）. However, the relationship between genetic distance and geographic distance within each group, although not statistically significant in this study, might be associated with high gene flow in both the NP and PP groups.