Medicinally important plant-foods offer a balanced immune function, which is essential for protecting the body against antigenic invasion, mainly by microorganisms. Immunomodulators play pivotal roles in supporting immune function either suppressing or stimulating the immune system's response to invading pathogens. Among different immunomodulators, plant-based secondary metabolites have emerged as high potential not only for immune defense but also for cellular immunoresponsiveness. These natural immunomodulators can be developed into safer alternatives to the clinically used immunosuppressants and immunostimulant cytotoxic drugs which possess serious side effects. Many plants of different species have been reported to possess strong immunomodulating properties. The immunomodulatory effects of plant extracts and their bioactive metabolites have been suggested due to their diverse mechanisms of modulation of the complex immune system and their multifarious molecular targets. Phytochemicals such as alkaloids, flavonoids, terpenoids, carbohydrates and polyphenols have been reported as responsible for the immunomodulatory effects of several medicinal plants. This review illustrates the potent immunomodulatory effects of 65 plant secondary metabolites, including dietary compounds and their underlying mechanisms of action on cellular and humoral immune functions in in vitro and in vivo studies. The clinical potential of some of the compounds to be used for various immune-related disorders is highlighted.
The WSE is a highly polar, gummy and mucilaginous bioactive content of the Nigella sativa (L.) seeds. This study reports the anxiolytic and anti-inflammatory effects of WSE investigated using Elevated Plus Maze (EPM) and Hole-Board Test (HBT) in adult mice and human RBCs haemolysis inhibition and protein denaturation respectively. The oral WSE treatment (100 & 200 mg/kg b.w/day) for 72 hours has exhibited slightly better anxiolytic effect (p
Blumea lacera is an edible plant with imperative medicinal values. However, the anxiolytic and antidepressant roles of B. lacera have not been well-explained. Therefore, the current study aims to explore the impending bioactive metabolites and roles of B. lacera methanol leaf extract (Me-BLL) in attenuating anxiety and depression through several experimental and computer-aided approaches. The chemical characterization of Me-BLL was performed through standard phytochemical and GC-MS analyses. To explore the neuropharmacological insights, Swiss albino mice were treated with Me-BLL at doses of 200-400 mg/kg, p.o. The anxiolytic effects were observed employing elevated plus maze (EPM), light-dark box (LDB), and hole-board (HBT) tests, while antidepressant effects were evaluated using forced swimming (FST) and tail suspension tests (TST). Diazepam (1 mg/kg, i.p.) and fluoxetine HCl (20 mg/kg, p.o.) were used as the reference standard. The phytochemical analyses revealed several bioactive metabolites, including higher contents of total phenolics and flavonoids. The EPM and LDB tests demonstrated an increased time spent in open arms and light box, and the HBT showed an increased number of head dipping, indicating the anxiolytic effects of Me-BLL. The TST and FST revealed a decrease in immobility time, meaning the persuasive antidepressant effects. The antioxidative effects of Me-BLL have also been observed prominently. Correspondingly, the computer-aided investigation confirmed several bioactive lead molecules. Specifically, thymol and cuminol revealed potential anxiolytic and antioxidant effects, while stigmast-5-en-3.beta.-ol and gamma-sitosterol possessed promising antidepressant effects. Taken these results as a base, the plant has imperative potentials in managing anxiety and depression-like disorders.