Melatonin from Plants: Going Beyond Traditional Central Nervous System Targeting – A Comprehensive Review of its Unusual Health Benefits

Melatonin was primarily identified for its indispensable roles in animals. Recently, it has been described as a potent regulator of several physiological pathways in plants. In humans, it has shown effects in the prevention or as an adjuvant treatment for several diseases mainly related to the immune system, inflammation, and oxidative stress. Moreover, a melatonin-rich diet is linked to several health benefits, such as regulation of the circadian rhythm, regulation of the immunological system, epilepsy control, reduced allergic reactions, delaying the aging process, diminishing hormones related to cancer, and delaying Alzheimer’s and Parkinson’s disease symptoms. This review aimed to show the effects of melatonin in diseases beyond its traditional use. The outcome of clinical trials showed that it can present scavenging of free radicals (reducing reactive oxygen species) and inflammation (reducing the synthesis of inflammatory cytokines modulating the immune system. Moreover, it can minimize apoptosis, insulin resistance, blood pressure, LDL-c, body mass index, adipose tissue mass, waist circumference, adhesion molecules, endothelial impairment, plaque formation, and muscle atrophy. It can also reduce hyperleptinemia, alanine aminotransferase, and liver fat. These effects result in neuro and cardioprotection, improvement of liver diseases, rheumatoid arthritis, dermatitis, COVID-19, polycystic ovaries, dermatitis, and sepsis. We conclude that plant melatonin can benefit patients with many diseases besides sleep problems and neurodegeneration. Plant melatonin may also be more cost-effective, less adverse, and more sustainable than synthetic; therefore, it is better than the typical already sold. However, more clinical trials should show adequate doses, formulation, and treatment time.