In the forms of either herbs or functional foods, plants and their products have attracted medicinal, culinary, and nutraceutical applications due to their abundance in bioactive phytochemicals. Human beings and other animals have employed those bioactive phytochemicals to improve health quality based on their broad potentials as antioxidant, anti-microbial, anti-carcinogenic, anti-inflammatory, neuroprotective, and anti-aging effects, amongst others. For the past decade and half, efforts to discover bioactive phytochemicals both in pure and crude forms have been intensified using the Caenorhabditis elegans aging model, in which various metabolic pathways in humans are highly conserved. In this review, we summarized the aging and longevity pathways that are common to C. elegans and humans and collated some of the bioactive phytochemicals with health benefits and lifespan extending effects that have been studied in C. elegans. This simple animal model is not only a perfect system for discovering bioactive compounds but is also a research shortcut for elucidating the amelioration mechanisms of aging risk factors and associated diseases.

Dendrobium officinale is one of the most widely used medicinal herbs, especially in Asia. In recent times, the polysaccharide content of D. officinale has garnered attention due to the numerous reports of its medicinal properties, such as anticancer, antioxidant, anti-diabetic, hepatoprotective, neuroprotective, and anti-aging activities. However, few reports of its anti-aging potential are available. Due to high demand, the wild D. officinale is scarce; hence, alternative cultivation methods are being employed. In this study, we used the Caenorhabditis elegans model to investigate the anti-aging potential of polysaccharides extracted from D. officinale (DOP) grown in three different environments; tree (TR), greenhouse (GH), and rock (RK). Our findings showed that at 1000 µg/mL, GH-DOP optimally extended the mean lifespan by 14% and the maximum lifespan by 25% (p < 0.0001). TR-DOP and RK-DOP did not extend their lifespan at any of the concentrations tested. We further showed that 2000 µg/mL TR-DOP, GH-DOP, or RK-DOP all enhanced resistance to H₂O₂-induced stress (p > 0.05, p < 0.01, and p < 0.01, respectively). In contrast, only RK-DOP exhibited resistance (p < 0.01) to thermal stress. Overall, DOP from the three sources all increased HSP-4::GFP levels, indicating a boost in the ability of the worms to respond to ER-related stress. Similarly, DOP from all three sources decreased α-synuclein aggregation; however, only GH-DOP delayed β-amyloid-induced paralysis (p < 0.0001). Our findings provide useful information on the health benefits of DOP and also provide clues on the best practices for cultivating D. officinale for maximum medicinal applications.