AIM OF THE STUDY: This study aimed to systematically review all available evidence which purports to support these claims.
MATERIAL AND METHODS: The systematic review accorded with the Cochrane Collaboration framework and PRISMA reporting. Databases including MEDLINE, Excerpta Medica Database (EMBASE), Cochrane library database, and Google Scholar were searched by keywords, Yahom and Ya-hom. Pharmacological and toxicity data from non-animal and animal studies were included.
RESULTS: Twenty-four articles: 2 on in vitro cell lines or bacteria, 3 in vitro cell-free, 5 in vitro animal, 13 in vivo and 1 human mainly reported (A) Cardiovascular effects (i) transient hypotension (0.2-0.8g/kg, intravenous injection (i.v.)), increased cerebral blood flow (2g/kg, single oral) and vascular dilatation/relaxation (ii) elevated blood pressure (BP) (0.2-0.8g/kg, i.v. or 2-4g/kg oral) and vasocontraction. Single Yahom doses (3g) given to healthy volunteers had no effect on cutaneous blood flow, ECG or systolic BP although marginally increased diastolic BP was claimed. (B) Yahom (2-4g/kg) completely inhibited gastric acid secretion evoked by gastric secretagogues. (C) Toxicity: Chronic oral doses of selected Yahoms to rodents (0.001-1g/kg) supports its status as generally regarded as safe.
CONCLUSIONS: Most studies supported declared objectives relating to perceived Yahom actions, but lacked background demonstrating clinical efficacy, and mechanistic data that would validate conclusions. Our study suggests that research into traditional medicinal herbs needs underpinning by appropriate clinical interventions and pharmacovigilance, thereby optimising efficacy and minimizing toxicity by combining traditional wisdom and modern testing.
METHODS: A structured electronic search on worldwide accepted scientific databases (Web of Science, PubMed, Google Scholar, Science Direct, SciFinder, Wiley Online Library) was carried out to compile the relevant information. Some information was obtained from books and database on medicinal plants used in various countries.
RESULTS: About 60 metabolites, mainly polyphenols, and terpenoids have been isolated and identified. However, most of the reported pharmacological studies were based on crude extracts, and only a few of those isolated metabolites, particularly zerumbone have been investigated for biological and pharmacological activities. Many of the mechanistic studies to understand the pharmacological effects of the plant are limited by many considerations with regard to design, experimentation and interpretation.
CONCLUSION: The bioactive metabolites should be further investigated on their safety and more elaborate preclinical studies before clinical trials can be undertaken.
MATERIALS AND METHODS: The information on the medicinal plants was obtained from interview with a traditional medicinal man. The traditional uses and remedies were documented. The literature searches were carried out for the evaluation on the current status of investigations on these plants.
RESULTS: In this study, we present 16 species of plants, which are commonly used among the Jah Hut people to cure some common diseases.
DISCUSSION: This study is important to preserve the knowledge of medicinal plants used by Jah Hut people. The surveys of phytopharmacological literatures of these plants have great pharmacological and ethnobotanical significance.