AIM OF THE STUDY: The present study was intended to evaluate anti-cholinesterase potential of 177 Malaysian plant extracts from 148 species known to have related ethnomedicinal uses such as anti-inflammatory, anti-oxidant, anti-diabetic, epilepsy, headache, memory enhancement and anti-aging.
MATERIALS AND METHODS: Anti-cholinesterase screening against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was performed on the basis of in-vitro colorimetric 96-well microplate-based assay method. Potent active plant extracts were subjected to liquid-liquid extraction and acid-base fractionation for further analysis.
RESULTS: Fifty-seven plant extracts exhibited potent anti-cholinesterase activities (50-100% inhibition) at 200 μg/ml. Majority of the active plants originated from Fabaceae family. Coccoloba uvifera (L.) L. stem extract manifested the lowest IC50 of 3.78 μg/ml for AChE and 5.94 μg/ml for BChE. A few native species including Tetracera indica (Christm. & Panz.) Merr., Cyrtostachys renda Blume and Ixora javanica (Blume) DC. showed cholinesterase inhibition despite limited local medical applications. Further anti-AChE evaluation (50 μg/ml) of 18 potent plant extracts harbored active polar components in butanol and water fractions, except Senna pendula (Willd.) H.S.Irwin & Barneby (leaves and stems), Acacia auriculiformis Benth. (leaves), Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg (leaves), and Macaranga tanarius (L.) Mull.Arg. (leaves) that showed inhibitory activity in less polar fractions. The acidic extraction of these four plant species improved their inhibition level against AChE.
CONCLUSION: This study rendered a preliminary overview of anti-cholinesterase activity from diverse Malaysian botanical families in which provided the medical relevance toward these native plant species, especially ones with limited ethnobotanical record or practice.
AIM OF THIS REVIEW: The present study is a critical assessment of the state-of-the-art concerning the traditional uses, the phytochemistry and the pharmacology of species belonging to the genus Hedyosmum to suggest further research strategies and to facilitate the exploitation of the therapeutic potential of Hedyosmum species for the treatment of human disorders.
MATERIALS AND METHODS: The present review consists of a systematic overview of scientific literature concerning the genus Hedyosmum published between 1965 and 2018. Moreover, an older text, dated from 1843, concerning the traditional uses of H. bonplandianum Kunth has also been considered. Several databases (Francis & Taylor, Google Scholar, PubMed, SciELO, SciFinder, Springer, Wiley, and The Plant List Database) have been used to perform this work.
RESULTS: Sixteen species of the genus Hedyosmum have been mentioned as traditional remedies, and a large number of ethnomedicinal uses, including for the treatment of pain, depression, migraine, stomach-ache and ovary diseases, have been reported. Five species have been used as flavouring agents, tea substitutes or foods. Sesterterpenes, sesquiterpene lactones, monoterpenes, hydroxycinnamic acid derivatives, flavonoids, and neolignans have been reported as the most important compounds in these species. Studies concerning their biological activities have shown that members of the Hedyosmum genus possesses promising biological properties, such as analgesic, antinociceptive, antidepressant, anxiolytic, sedative, and hypnotic effects. Preliminary studies concerning the antibacterial, antioxidant, antiplasmodial, and antifungal activities of these plants as well as their cytotoxic activities against different tumour cell lines have been reported. Some active compounds from the Hedyosmum genus have been used as starting points for the innovative and bioinspired development of synthetic molecules. A critical assessment of these papers has been performed, and some conceptual and methodological problems have been identified regarding the materials and methods and the experimental design used in these studies, including a lack of ethnopharmacological research.
CONCLUSIONS: The present review partially confirms the basis for some of the traditional uses of Hedyosmum species (mainly H. brasiliense) through preclinical studies that demonstrated their antinociceptive and neuroprotective effects. Due to promising preliminary results, further studies should be conducted on 13-hydroxy-8,9-dehydroshizukanolide and podoandin. Moreover, several essential oils (EOs) from this genus have been preliminarily investigated, and the cytotoxic and antibacterial activities of H. brasiliense and H. sprucei EOs certainly deserve further investigation. From the promising findings of the present analysis, we can affirm that this genus deserves further research from ethnopharmacological and toxicological perspectives.