OBJECTIVE: The current research on kratom and its ingredients is presented.
MATERIAL AND METHODS: An overview of the use and effects of kratom is exemplary given on the basis of reports. The instrumentalization of the drug and its consequences up to the development of addiction are discussed.
RESULTS: Consumption is accompanied by several instrumentalizeable effects so that kratom is used as a therapeutic substance in the self-management of pain, anxiety and depression as well as other substance addictions. Another benefit comes from the performance-enhancing effects on physical work and in a social context. Consumption is usually well controlled, rarely escalates and has few and mostly mild aversive side effects. The danger arises from consumption particularly when there is an escalation of the dose and from mixed consumption with other psychoactive substances. The main alkaloid mitragynine and the more potent 7‑hydroxy-mitragynine are considered mainly responsible for the effect. Both have a complex pharmacology that involves partial µ‑opioid receptor agonism.
DISCUSSION: Epidemiological, clinical and neurochemical studies have shown that kratom only has a limited addictive drug profile, which might suggest a medical use as a remedy or substitute in addiction treatment.
METHODS: Different methods including flow cytometry, comet assay and reverse transcription-polymerase chain reaction (RT-PCR) were used to show the effects of juice exposure on the level of DNA damage and the reduction of cancerous cells. MTT assay is a colorimetric method applied to measure the toxic effects of juice on cells.
RESULTS: The Centella asiatica juice was not toxic to normal cells. It showed cytotoxic effects on tumor cells in a dose dependent manner. Apoptosis in cells was started after being exposed for 72 hr of dose dependent. It was found that the higher percentage of apoptotic cell death and DNA damage was at the concentration above 0.1%. In addition, the juice exposure caused the reduction of c-myc gene expression and the enhancement of c-fos and c-erbB2 gene expressions in tumor cells.
CONCLUSIONS: It was concluded that the Centella asiatica juice reduced liver tumor cells. Thus, it has the potential to be used as a chemopreventive agent to prevent and treat liver cancer.
OBJECTIVES: To assess the effects of sweet potato for type 2 diabetes mellitus.
SEARCH METHODS: We searched several electronic databases, including The Cochrane Library (2013, Issue 1), MEDLINE, EMBASE, CINAHL, SIGLE and LILACS (all up to February 2013), combined with handsearches. No language restrictions were used.
SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared sweet potato with a placebo or a comparator intervention, with or without pharmacological or non-pharmacological interventions.
DATA COLLECTION AND ANALYSIS: Two authors independently selected the trials and extracted the data. We evaluated risk of bias by assessing randomisation, allocation concealment, blinding, completeness of outcome data, selective reporting and other potential sources of bias.
MAIN RESULTS: Three RCTs met our inclusion criteria: these investigated a total of 140 participants and ranged from six weeks to five months in duration. All three studies were performed by the same trialist. Overall, the risk of bias of these trials was unclear or high. All RCTs compared the effect of sweet potato preparations with placebo on glycaemic control in type 2 diabetes mellitus. There was a statistically significant improvement in glycosylated haemoglobin A1c (HbA1c) at three to five months with 4 g/day sweet potato preparation compared to placebo (mean difference -0.3% (95% confidence interval -0.6 to -0.04); P = 0.02; 122 participants; 2 trials). No serious adverse effects were reported. Diabetic complications and morbidity, death from any cause, health-related quality of life, well-being, functional outcomes and costs were not investigated.
AUTHORS' CONCLUSIONS: There is insufficient evidence about the use of sweet potato for type 2 diabetes mellitus. In addition to improvement in trial methodology, issues of standardization and quality control of preparations - including other varieties of sweet potato - need to be addressed. Further observational trials and RCTs evaluating the effects of sweet potato are needed to guide any recommendations in clinical practice.