Recent studies have discovered a pathway that links stress to the onset of disease through the activation of certain genes.  The experience of psychological stress activates transcription factors that activate genes. In a study by Cole et al., it was concluded that GABA -1 transcription factor activates the interleukin -6-gene. This gene codes for a protein that activates the inflammatory response which directs an immune response to the site of the inflammation.  Chronic inflammation makes an individual more susceptible to diseases such as cancer , heart disease , and diabetes .
The time of action of senna is usually 8–10 hours, and thus the dose should be taken at night ( 24 ). The action of the sennosides augments, without disrupting, the response to the physiological stimuli of food and physical activity ( 24 ). The sennosides abolish the severe constipation of patients suffering from severe irritable bowel syndrome ( 26 ). In therapeutic doses, the sennosides do not disrupt the usual pattern of defecation times and markedly soften the stool ( 24 ). Sennosides significantly increase the rate of colonic transit ( 27 ) and increase colonic peristalsis, which in turn increase both faecal weight and dry bacterial mass ( 24 , 28 ). Due to their colonic specificity, the sennosides are poorly absorbed in the upper gastrointestinal tract ( 29 ).