The Dioscorea Genus (Yam)—An Appraisal of Nutritional and Therapeutic Potentials

Abstract

The quest for a food secure and safe world has led to continuous effort toward improvements of global food and health systems. While the developed countries seem to have these systems stabilized, some parts of the world still face enormous challenges. Yam (Dioscorea species) is an orphan crop, widely distributed globally; and has contributed enormously to food security especially in sub-Saharan Africa because of its role in providing nutritional benefits and income. Additionally, yam has non-nutritional components called bioactive compounds, which offer numerous health benefits ranging from prevention to treatment of degenerative diseases. Pharmaceutical application of diosgenin and dioscorin, among other compounds isolated from yam, has shown more prospects recently. Despite the benefits embedded in yam, reports on the nutritional and therapeutic potentials of yam have been fragmented and the diversity within the genus has led to much confusion. An overview of the nutritional and health importance of yam will harness the crop to meet its potential towards combating hunger and malnutrition, while improving global health. This review makes a conscious attempt to provide an overview regarding the nutritional, bioactive compositions and therapeutic potentials of yam diversity. Insights on how to increase its utilization for a greater impact are elucidated.

Metabolome Profiling of Eight Chinese Yam (Dioscorea polystachya Turcz.) Varieties Reveals Metabolite Diversity and Variety Specific Uses

“…Wild yams have long been used for the medicinal and food purposes. This could be possibly due to its readily availability in respective natural habitats as well as due to its unique bioactive compound profiles [ 45 ]. We found that WS was rich in polysaccharides e.g., D-fructose, D-galactose, and D-mannose, and the other varieties have lower contents ( Supplementary Table S1 ).…”

“…Furthermore, a comparative genomic study could reveal the genetic mechanism of higher diosgenin production in both MS and WS and no production (as per our metabolome results) in ST and TG. A high proportion of yams is used for nutritional purposes in China [ 45 ] and, therefore, both ST and TG are rich in amino acids and derivatives as well as organic acids and phenolic acids. Thus, the metabolite profiles of each of the tested varieties offer unique uses.…”

Metabolite Profiling of Dioscorea (Yam) Leaves to Identify Bioactive Compounds Reveals Their Potential as Renewable Resources

“…Yam species have high nutritional and pharmacological value because they contain polysaccharides, steroidal saponins, allantoin, and polyphenols, such as flavonoids [ 2 ]. A number of recent studies have demonstrated that yam roots exhibit various biological and pharmacological activities, such as antioxidant, cholesterol-lowering, growth hormone releasing, and anti-inflammatory, as well as show protective effects against ethanol-induced gastric ulcers [ 2 , 3 , 4 ]. While yam roots are widely utilized for nutritional and medicinal purposes, yam leaves (the main by-product of yam) are generally burned or discarded as waste, resulting in environmental pollution [ 5 ].…”

Larvicidal potency of Dioscorea sansibarensis leaf extract against vector mosquitoes: Anopheles gambiae s.s. and Culex quinquefasciatus

“…In that regard, researchers have transformed their interests towards the development and uses of botanical products for controlling mosquitoes and other insects which are considered safe and environmentally friendly alternatives (Isman 2000). Phytochemical products have a long history of uses and proven evidence of efficacy as antimicrobial, antioxidants, anti-inflamatory, insecticidal, and repellants (Obidiegwu et al 2020). Furthermore, several studies have explored and established the efficacy of botanical extracts and essential oils for vector control (Kalimuthu et al 2012, Kweka et al 2008, Kovendan et al 2013.…”

“…It is the climber which produces both bulbils and underground tubers. The tubers/yams of various Dioscorea spp are used for food in many countries, with therapeutic values (Obidiegwu et al 2020), other species have been characterized as toxic. Dioscorea sansibarensis vegetative parts are evergreen with broad leaves but always undamaged by chewing insects; the destructive herbivores also avoid feeding on them (Mauti et al 2019).…”