**3.4 Antiarthritis activity**

Arthritis is an autoimmune disorder that causes pain, swelling, and stiffness in the joints. There are at least 100 types of arthritis, commonly known as connective tissue disorders, which can affect people of all ages, gender, and races. However, there is significant evidence to suggest that both the elderly and women are greatly affected. More than three decades ago, capsaicin was first shown to have protective effects in experimental arthritis [79]. Further, Inman et al. observed that capsaicin concomitantly administered with methylated bovine serum albumin (mBSA) into the rat knee markedly reduced the severity of arthritis in comparison with the contralateral inflamed knee treated with vehicle, supporting a protective role for capsaicin in reducing the severity of antigeninduced arthritis in felines [80]. According to the trend, capsaicin cream is used to reduce pain caused by many types of arthritis. Specifically, it works by decreasing a certain natural substance in the human body (substance P) that helps transmit pain signals to the brain.

### **3.5 Antioxidant activity**

The family of free radicals generated from the oxygen is referred to as reactive oxygen species (ROS), which cause damage to other molecules by extracting electrons from them in order to attain stability. ROS are various forms of activated oxygen which include free radicals such as superoxide anion radicals (O2 − ), hydroxyl radicals (OH<sup>−</sup> ), non-free radicals (H2O2), and singlet oxygen [81]. The molecular basis of many diseases is known to involve oxidative stress caused by free radicals [82]. Recently progressive research has been directed at natural antioxidants. By using the DPPH free radical assay, Dubey et al. evaluated the antioxidant potential and free radical scavenging activities of some selective chili genotypes from the North East region of India in terms of inhibitory concentration (IC50), efficiency concentration (EC50), and anti-radical power (ARP) [83]. Likewise, Ayob et al. also determined the antioxidant activity of three varieties of Himalayan red chili (Kashmiri Local, Kupwari Local, and Shalimar Long) in North India by using DPPH radical scavenging activity, Hydroxyl radical scavenging activity, and Ferric reducing power, based on EC50 values [84].

### **3.6 Cardioprotective activity**

Cardiovascular disease remains a leading cause of disability and premature death globally. The disease is mimicked by the narrowed lumen of arteries and reduced blood flow to the heart. According to a report presented at the American Heart Association's Scientific Sessions 2020, regular intake of chili peppers could significantly reduce the risk of dying from cardiovascular diseases. Moreover, very recent striking findings of a pooled longitudinal analysis by Bonaccio et al. illustrated the cardiovascular benefits of *Capsicum annuum*. This study was conducted on an Italian Cohort comprising over 22,000 men, and women originally enrolled in the Moli-sani study cohort. The results demonstrated that the use of *Capsicum annuum* is associated with a lower risk of cardiovascular mortality [85]. Most importantly, the cardiovascular system is known to be rich in capsaicin-sensitive sensory nerves, which suggests that capsaicin may regulate cardiovascular function [86]. Also, capsaicin could protect against heart disease via a transient receptor potential vanilloid subfamily member 1 (TRPV1)-mediated modulation of coronary blood flow [87]. Furthermore, the antioxidant and antiplatelet properties of capsaicin and its function in regulating energy metabolism may also contribute to its beneficial effects on the cardiovascular system [88, 89].

### **3.7 Neuroprotective activity**

Neurodegenerative diseases such as Alzheimer's disease are often characterized by multifactorial clinical features such as loss of memory function, protein aggregation, progressive loss of neurons, cognitive impairment, neuronal cell dysfunction, and/or death. Capsaicin is a vanilloid agonist known to activate the TRPV1, recently reported to be involved in neurodegeneration [90]. A study by Veldhuis et al. demonstrated that capsaicin and the vanilloid antagonist capsazepine, peripherally administered, have been shown to exhibit neuroprotection against ouabain-induced excitotoxicity in rats [91]. Moreover, in the latest evidence, Abdel-Salam et al. reported the effect of the TRPV1 agonist capsaicin on epileptic seizures, neuronal injury, and brain oxidative stress in a model of status epilepticus induced in the rat by intraperitoneal (i.p.)

*Pharmacological Properties and Health Benefits of* Capsicum *Species: A Comprehensive Review DOI: http://dx.doi.org/10.5772/intechopen.104906*

injections of pentylenetetrazole (PTZ). This study shows that 2 mg/kg of capsaicin decreased brain oxidative stress, the severity of seizures and neuronal injury, and its coadministration with phenytoin afforded neuronal protection [92].
