Pesticides are used to ensure the mass production and quality of foods, depending on the environment where they are grown. Trace amounts of pesticides are ingested through diet and high ratios of its components have been detected in humans. Neonicotinoid insecticides are nicotine analogs that disrupt neurons, induce neural excitation, and cause behavioral abnormalities and chronic toxicity. The herbicide glyphosate causes behavioral disorders due to abnormalities in the balance of intestinal microflora. These abnormalities can be found in the F2-generation and beyond. Glyphosate decreases the number and size of experimental animal fetuses, possibly through abnormal deoxyribonucleic acid methylation in parental germ cells, resulting in transgenerational toxicity. It also causes the death of dopamine neurons, which are believed to be involved in the development of Parkinson’s disease (PD). The intestinal microflora is considerably altered by ingesting pesticides used in crops. Lactic acid bacteria and some other intestinal bacteria have gut-regulating and immunomodulatory effects that have recently been implicated in neurological disorders, such as depression and dementia. Therefore, a healthy diet should be traced back to crops. An agriculture-medicine partnership linking “agriculture” and “preventive medicine” has recently been considered important based on the hypothesis that agriculture and health sectors should collaborate to create a healthy environment for producing healthy food. Although food considerations tend to focus on the functionality of vegetable and fruit components, that of environmental bacteria should also be considered.

Brain metastasis is the most prevalent neurologic problem of systemic cancer and it can increase the mortality rate in patients with cancer. It occurs more in patients with lung cancer, breast cancer, and melanoma. There are several molecular mechanisms in cancer cell progression, invasion, and location in new places during brain metastasis. Significant interactions between cancer cells, the brain microenvironment, and the blood-brain barrier (BBB) play a major role in brain metastasis. This study will focus on molecular mechanisms that contribute to cancer metastasis into the brain and finding new treatments with molecular research. Treatment strategies in patients with brain metastasis include surgical resection, radiotherapy, and chemotherapy; however, the penetration of chemotherapy drugs beyond the BBB is limited. Studying molecular, cellular, and physical mechanisms in brain metastasis helps to improve new strategies in drug delivery across the BBB. There are significant impacts of ion channels in brain metastasis and cancer treatment failure. Targeting molecular mechanisms and ion channels in brain metastasis led to increasing the better response in these patients. In this way, nano-drugs have caused a revolution in effective targeting and drug delivery in cancer treatment. This review describes the advances to facilitate the penetration of drugs in the BBB by using nano-drugs especially those that are targeting ion channels.