Study on Curcumin Antioxidant

1 Introduction

Curcumin is a natural yellow pigment extracted from the rhizomes of turmeric and other plants in the ginger family. It is also found in other plants in the ginger family. Curcumin is a polyphenolic compound [1] with the chemical formula C21H20O6. It is an orange-yellow crystalline powder with a slightly bitter taste. It is insoluble in water and comes in many varieties. It is currently one of the most widely used natural active ingredients [2]. In recent years, studies have found that curcumin has pharmacological effects such as anti-cancer [3], treating arthritis [4], delaying Alzheimer's disease [5], and lowering blood lipids [6], and is widely used in clinical applications.

In the current fast-paced life, with the increase in the pressure of people's daily lives, coupled with the current food safety situation in China, which is not optimistic, more and more people are experiencing physical problems to varying degrees. This article aims to promote the research, development and utilization of curcumin by organizing and explaining the function and pharmacological effects of curcumin in the human body.

2 Physiological functions

2.1 Antioxidant effect

Numerous medical studies and clinical trials have proven that the root cause of human illness is the electronic robbery of human cells. Free radicals ROS, as unsaturated electron substances, enter the human body and compete for electrons, and also directly attack DNA, cell membranes and proteins, thereby causing a variety of diseases. Curcumin can directly remove free radicals, thereby achieving an antioxidant effect.

Song Limin et al. [7] found that the polyphenols in curcumin, as natural antioxidants, have different degrees of reducing power and have a very significant therapeutic effect on diseases caused by free radicals. Li Guanghui et al. [8] showed that curcumin can increase the activity of antioxidant enzymes and improve antioxidant properties. In addition, Liu Feng [9] showed in his research that curcumin can enhance the antioxidant capacity of rat heart muscle cells, thereby producing a mechanism that can protect heart muscle cells from damage. In a study by Zhiqiao [10], it was found that curcumin, as a strong antioxidant, can relieve the damage caused to the human body by free radicals and protect the human joints and brain. This shows that curcumin can be used as an antioxidant to block free radicals from harming the body, thereby reducing the risk of disease and delaying the damage caused to the body.

2.2 Repairing brain damage

The brain, as the highest part of the nervous system, plays a vital role in humans. When our brain is hit or violently impacted from the outside, it can cause direct or indirect trauma to the brain. In addition, brain cells can also be damaged irreversibly when they develop lesions, resulting in high mortality and morbidity rates [11]. Curcumin, as a protective substance for neurons, can effectively reduce and repair brain damage.

In studies by Li Jie [12] and others, it was also pointed out that curcumin can effectively reduce brain damage and improve motor function, as well as exert neuroprotective and neurotrophic effects. In addition, Liang Lan [13] and others investigated the protective effect of curcumin on traumatic brain injury. The study showed that curcumin can play a certain protective role in traumatic brain injury. Dai·W et al. [14] found in their study that curcumin can enhance the transport of transcription factors from the cytoplasm to the nucleus, and concluded that curcumin can increase the activity of antioxidant enzymes, thereby reducing brain damage. After a period of cerebral ischemia, the reflow of blood not only fails to restore the tissue and function of the brain, but can also cause more serious, irreversible damage. Several studies have found that curcumin has a significant repair effect on reducing ischemic reperfusion brain damage [15-17].

In the treatment of chronic ischemic brain damage, Yang et al. [18] found that curcumin can effectively reduce apoptosis of brain cells and has a significant protective effect on the nerves of brain damage induced by chronic cerebral ischemia. Hypoxic brain damage is also very common in clinical practice and is a type of brain damage with extremely high disability and mortality rates [19]. Yin Guangmei et al. [20] conducted a series of studies on the effects of changes in brain tissue and apoptosis during cerebral ischemia-reperfusion injury, and demonstrated that curcumin can reduce the effects of ischemia-reperfusion on brain injury. This shows that curcumin can effectively repair brain trauma and damage caused by cell damage.

2.3 Improves Alzheimer's disease

Alzheimer's disease patients have a lot of amyloid protein deposited outside the nerve cells of the brain. Curcumin can dissolve these proteins and prevent their regeneration, thereby improving the effect of Alzheimer's disease. Chen Hanzhe et al. [21] found that the expression and activity of tissue protease in mononuclear cells of the peripheral blood of rats treated with curcumin were both on the rise. Curcumin can help improve learning ability and memory, and can improve spatial learning and memory disorders. Multiple studies have shown that curcumin can significantly reduce apoptosis in the hippocampus, thereby improving learning and memory disorders caused by Alzheimer's disease [22-24]. This shows that curcumin can effectively delay Alzheimer's disease and improve symptoms such as memory impairment, executive dysfunction, personality and behavior changes caused by Alzheimer's disease.

Curry is very rich in curcumin. Studies have found [25, 26] that curcumin can break down amyloid protein in the brain and prevent the production of this protein. Eating more curry may help prevent Alzheimer's disease.

2.4 Anti-cancer effect

Cancer is one of the world's five major incurable diseases. It is similar to normal tissue and cannot be recognized and eliminated by the body's immune system. Among the various factors and types of death that cause death each year, cancer ranks first [27]. Curcumin can regulate gene activity and expression, inhibit the growth of cancer cells, and promote the function of healthy cells.

Liu Bin et al. [28] studied the mechanism of curcumin-induced apoptosis in human melanoma cells and concluded that curcumin not only effectively inhibits the proliferation of human melanoma cells, but also promotes their apoptosis, thus exerting a significant anti-cancer effect.

Shi Danli et al. [29] observed the effect of curcumin on the invasion ability of thyroid cancer cells and concluded that curcumin can effectively inhibit the proliferation and migration of thyroid cancer cells.

Pancreatic cancer is a malignant tumor of the digestive tract that is difficult to diagnose and treat, and has a high degree of malignancy. It has the fourth highest mortality rate among malignant tumors [30]. Song Wei et al. [31] concluded from their study of the inhibitory effect of curcumin on the proliferation of human pancreatic cancer cells and its influence on signal pathways that curcumin can effectively inhibit the expression of pancreatic cancer cells and the activation of signal pathways, thereby inhibiting cancer cell proliferation and differentiation.

Primary liver cancer is also a malignant cancer with high severity and easy metastasis. Its early symptoms are not obvious, and it is often not discovered until the middle or late stages, with a high mortality rate [32, 33]. Li Shengxi et al. [34] concluded that curcumin can effectively inhibit the growth and proliferation of liver cancer cells through the effect of curcumin on the anti-cancer effect of liver cancer cells. 80% of lung cancer patients have non-small cell lung cancer, and most are diagnosed at an advanced stage [35]. Studies have found[36] that curcumin can cause non-small cell carcinoma to undergo mitochondrial autophagy, thereby inhibiting its cancer cell proliferation.

Esophageal cancer is a common malignant tumor of the digestive system, and its incidence ranks sixth among malignant tumors worldwide. The five-year survival rate of patients is low[37], and the exact pathogenesis is still unclear. Li Mingjie [38] studied the effects of curcumin on the proliferation, apoptosis, and gene expression of esophageal cancer EC-9706 cells, and concluded that curcumin can significantly induce apoptosis of these cancer cells. It can further be seen that curcumin can inhibit the proliferation of esophageal cancer, thereby achieving the effect of anti-esophageal cancer.

The above shows that curcumin has the effect of inhibiting the growth, proliferation and differentiation of cancer cells, inducing apoptosis of cancer cells, inhibiting their migration and gene activity expression, etc., and can be further studied as an effective anti-cancer drug.

3 Summary and outlook

Curcumin has few toxic side effects, diverse and powerful functions, and is widely used in medicine. Therefore, curcumin has broad prospects for future application. However, curcumin is insoluble in water and is easily oxidized in vitro, which also greatly hinders its application. In the future, the main research topic for clinicians and researchers will be how to improve curcumin's shortcomings in a form or with a carrier that can overcome these shortcomings. Curcumin still has great market potential waiting to be discovered.

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