**3. Conclusion**

Due to their diverse pharmacological properties, active components in medicinal plants have been demonstrated as an essential source of clinical medicines. Traditional medicine uses medicinal plants for health benefits and is thoroughly researched. Any disparity between immune system causes numerous fatal diseases, including cancer, rheumatoid arthritis, and diabetes. According to several recent studies, these disorders can be treated by phytochemicals, present in particular plant species. In vivo, in vitro and ex vivo studies have reported that the administration of phytochemicals such as quercetin, ellagic acid, mangiferin and withanolide, significantly reduced the occurrence of immune-related diseases due to their antioxidant, anti-inflammatory and immunomodulatory activities. Additionally, phytochemicals frequently enhance the Th1 as well as Th2-mediated cytokine production that decreases autoimmune conditions. Despite numerous preclinical and ex vivo studies, other practical proof is needed to support the immunomodulatory action of phytochemicals in preventing and treating immune system-related illnesses. Specific parameter enhancements, like standardised dosage and duration of intervention, are still needed to create the ideal phytochemical immunomodulators.
