**3. Antioxidant and anticancer activity of** *Momordica charantia*

Secondary metabolites are attracting attention for their effects in preventing diseases due to oxidative stress, which leads to degeneration of cell membranes and leads to many pathological diseases. They play a major role in preventing disease due to oxidative stress, which leads to many pathological diseases [11–14]. Recent investigations have shown that antioxidants with free radical scavenging properties have great importance as therapeutic agents in preventing aging process and in scavenging free radical mediated diseases [11–14]; such as diabetes, atherosclerosis and other complications [15].

Many studies have shown that *M. charantia* is a good natural source of antioxidants such as bioactive phytochemicals mainly include polysaccharides, saponins and phenolics; that possess an activity against oxidant damage in vitro and in vivo [32]. *M. charantia* and its ethanolic extracts are analyzed to contain high antioxidant activities that are well correlated with phenolic compounds [32]. Bitter melon and its extracts are demonstrated to have stronger antioxidant activity than other solvent extracts, by increasing the activities of catalase and levels of reduced glutathione, bitter melon is proved to exhibit inhibited stress-induced lipid peroxidation [32, 33].

Several phytochemicals, including bitter melon extracts, are described to possess potentials in anticancer therapies [34]. The extracts of bitter melon have been investigated for their potential use as anticancer agents; suggesting that dietary consumption of bitter melon could help to lower risk of several cancers [34]. *M. charantia* extracts and its monomer components have shown strong anticancer activity against various tumors such as lymphoid leukemia, lymphoma, choriocarcinoma, melanoma, breast cancer, skin cancer and prostate cancer [35]. Furthermore, bitter melon extracts are shown to decrease human prostate cancer cell growth due to the selective induction of apoptosis [35, 36].

Anticancer properties of bitter melon extracts are reported to have ability to modulate several deregulated signaling pathways in different type of cancer, like MAPK pathway, through the modulation of cell cycle proteins, thereby inducing cell cycle arrest, inducing apoptosis or other cell death pathways. Cucurbitane-type triterpene glycosides have been showed to have significant antitumor activity in hepatic carcinoma derived cell lines [36].

It is well known that tumor progression toward malignity is strongly related to chronic inflammation that is responsible for tumor invasion of surrounding normal tissues and angiogenesis. Bitter melon components are suggested to exert their antitumor effects by modulation of the inflammation status.

#### **4. Antiinflammatory activity of** *Momordica charantia*

Inflammation is known to be a complicated immune process that can be defined by the sequential release of mediators such as pro-inflammatory cytokines, including interleukin (IL)-1, interferon (IFN)-c, IL-6, IL-12, IL-18, tumor necrosis factor (TNF), and the granulocyte-macrophage stimulating factor. It is settled by anti-inflammatory cytokines such as IL-4, IL-10, IL-13, IFN-a, and the transforming growth factor (TGF)-b [37]. Inflammation is known as an overall a

#### *Bitter Melon: A Multifunctional Medicinal Plant with Powerful Bioactive Compounds DOI: http://dx.doi.org/10.5772/intechopen.98812*

protective response against xenobiotics, but chronic inflammation is also known to be detrimental to tissues; causing in chronic inflammation-derived diseases, such as autoimmune diseases, cardiovascular diseases, systemic lupus erythematosus (SLE), aging-associated diseases, such as Alzheimer's or Parkinson's disease; and cancers. It is known that oxidative stress and inflammation activate each other and oxidative stress plays a role in chronic infectious diseases [37]. Chronic inflammation is shown to promote tumor initiation and malignant progression of many cancers, considering the importance of inflammatory changes in different cancer types, preventing or reversing inflammation has become an important approach to control cancer progression [16, 37]. Thus, inhibition of the overproduction of inflammatory mediators, especially pro-inflammatory cytokines IL-1b, IL-6, and TNF-a, may prevent or suppress a variety of inflammatory diseases [16, 37].

Dietary habits contribute to a chronic state of inflammation, which can alter gut microbiota and immune status. Various dietary components have demonstrated to modulate chronic inflammatory conditions and to be helpful in their therapy [16]. Bitter melon dietary supplementation has been widely studied to treat several diseases, such as obesity and cancer, promising to possess hypoglycemic and lipidlowering properties [17]. Chronic inflammation is involved in the pathogenesis of different diseases, such as metabolic syndrome, obesity, cancer, cardiovascular disease, and a neurodegenerative diseases [16, 17]. In diabetic patients, inflammation contributes to increase blood glucose concentration in developing cardiovascular diseases and obesity. The beneficial properties of *M. charantia* appear to be due to anti-inflammatory and antioxidant activities by acting on several important signal pathways involved in inflammation [38].

Several investigations suggest that oxidative stress plays a role in chronic inflammatory diseases; which are closely related in pathophysiological processes that can activate each other [39–41]. Bitter melon has shown to have beneficial properties dependent on its anti-inflammatory and anti-oxidant activities [41–43]; regulating inflammation mainly through NF-κB signaling pathway inhibition, reducing TNF-α production [44]. It is also reported that bitter melon extracts reduced TNF-αinduced expression of inflammatory markers, including inducible NO synthase, p65 subunit of NF-κB, TNF-α, and IL-1β [45]. The bitter melon containing diet also reported to normalize serum levels of the cytokines suggesting its role in reducing inflammation, obesity and insulin resistance in obese mice [46]; suggesting that bitter melon supplementation may be useful as a preventive agent in individuals at risk for inflammatory-related diseases [47]. Therefore, bitter melon has antiinflammatory effects by acting on several important signaling pathways involved in inflammation.

Xanthine oxidase, which is a key enzyme for the induction of hyperuricemia and gout, it is involved in many inflammation related diseases [48]. Cucurbitane-type triterpene glycosides isolated from bitter melons fruits is proved to inhibit xanthine oxidase activity [49]. Antioxidant compounds in bitter melon showed potential natural antioxidant activity to inhibit the lipid peroxidation [50]. demonstrating anti-inflammatory effects of phenolic compounds present in the bitter melons extract [51].

The wound-healing activity of the olive oil macerate of *M. charantia* was investigated in wound models. Experimental data have shown that *M. charantia* has wound-healing and anti-inflammatory effects [52]. *M. charantia* has been investigated and reported to play a role in suppressing gastric inflammation against gastric ulcers from ethanol [53]. It is also shown that *M. charantia* can suggest an alternative in reducing the need for analgesic drug consumption by reducing pain and improving symptoms in diseased individuals [54].
