Barakol suppresses norepinephrine-induced inhibition of spontaneous longitudinal smooth muscle contractions in isolated rat small intestine

Myogenic oxidative imbalance interferes with antral motility in obese subjects

BACKGROUND

Obesity is characterized by a systemic low-grade chronic inflammatory oxidative condition that affects vascular and cardiac smooth muscle relaxation. In human antrum, relaxation is mediated by vasoactive intestinal peptide (VIP) through cAMP and cGMP signaling pathways. A genome-wide association study has demonstrated an association between VIP and obesity.

AIM

To evaluate smooth muscle activity in human obese antrum, both in in vitro preparations as well as in vivo.

METHODS

Antral muscle strips and cells were isolated from surgical gastric samples from obese and normal weight subjects. Muscle contraction and relaxation, myogenic oxidative stress and inflammatory status were analyzed in vitro. Distal antral motility was evaluated in vivo by magnetic resonance imaging.

RESULTS

Obese antral muscle cells showed an oxidative-inflammatory imbalance with overexpression of NLRP3 inflammasome, increased IL-1β secretion and caspase1-activation, and reduced antioxidant capacity associated with a myogenic motor impairment of VIP-induced relaxation. The intracellular alterations were characterized by a decreased activation of the cAMP-signaling pathway and a decreased expression of eNOS. These in vitro alterations coincided with the hindering of antral motor activity observed in vivo. Apocynin treatment, counteracting oxidative stress, reverted alterations observed in obese antral muscle.

CONCLUSION

Antral myogenic activity of obese subjects can be impaired by alterations of signaling pathways induced by oxidative stress.

Leguminous Plants in the Indonesian Archipelago: Traditional Uses and Secondary Metabolites

Indonesia is one of the richest countries with respect to plants resources. People from various ethnic, language, and religious groups have used the plants as alternative medicines, health foods and beverages for hundreds of years. To establish modern application for these understudied plant resources, ethnopharmacological data from more than 40 leguminous plants in Indonesia, spanning the western to the eastern parts of the Indonesian archipelago, were reviewed. In particular, bioactive secondary metabolites, including flavonoids, were described in detail to promote research into these plants as functional foods, nutraceuticals, and medicines.

Pancreatic Lipase Inhibitory Activity of Cassiamin A, a Bianthraquinone from Cassia siamea

In continuation towards the discovery of potential antiobesity lead(s) from natural products, we have screened n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH) extracts of 33 Indian medicinal plants (200 extracts) for in vitro pancreatic lipase inhibitory activity. Of the screened extracts, the EtOAc extract of Cassia siamea roots showed 74.3±1.4% enzyme inhibition at 250 μg/mL concentration. Bioassay guided fractionation of the active extract afforded 6 known compounds viz. chrysophanol (1), physcion (2), emodin (3), cassiamin A (4), friedelin (5) and cycloart-25-en-3β,24-diol (6). These compounds were further evaluated for pancreatic lipase inhibitory activity. Cassiamin A (4), a bianthraquinone, was found to be most active with an IC50 value of 41.8±1.2 μM and compounds 2 and 5 were found to be moderate enzyme inhibitors. Results indicate the antiobesity potential of C. siamea through pancreatic lipase inhibition.