**6.1 Oxidant activity**

Anti-oxidants play an important function in protecting the body against free radicals. They achieve this by stopping the formation of new free radicals species, converting older ones to free radicals, less toxic molecules that can be easily mopped up and preventing radical chain reaction [62]. The principal function of anti-oxidants is in suspending the oxidation of other molecules, by inhibiting the initiation or propagation of oxidizing chain reactions by free radicals and thereby reducing oxidative damage to the human body [63]. Two great mechanisms of procedure have been proposed for antioxidants [64]. The initial is a chain breaking method by which the initial antioxidant provides an electron to the free radical stage in the systems. The second technique involves the destruction of ROS/ reactive nitrogen species initiators (secondary antioxidants) by cutting off chain starting catalysts (**Figure 2**). The potential role in the food industry and human health, antioxidants are getting acceptance all across the globe. Antioxidants are defined as a substance that easily in small amounts, can inhibit or prohibit the oxidation of readily oxidizable elements. The antioxidant is also defined as a substance qualified of inhibiting special oxidizing stimulants or a substance that serves with oxidizing agents prior to creating damage to other fragments or a substance that sequesters metal ions or even a substance efficient of the recovering system such as iron transporting protein [65].

Natural antioxidants have been studied intensively during the past years which are mainly phenolic compounds. Moreover, oxidation is a degenerative process in

**189**

tors [85–87].

**6.2 Antimicrobial**

Ocimum *Phytochemicals and Their Potential Impact on Human Health*

biological systems due to the endogenous reactive oxygen species (ROS). Reactive oxygen species (ROS) are chemical properties originate in the body during metabolism that is overmuch reactive and may have one or expanded unpaired electrons. Oxidative stress, i.e., an inequality between ROS and antioxidant defenses have deleterious aftereffect, such as the peroxidation of membrane lipids and the aggression on biomolecules (proteins, membrane enzymes, carbohydrates and DNA) [66].

Various *Ocimum* species and their extracts or essential oils have been determined

to achieve antioxidant activity [67, 68]. Phenolic acids, hydroxycinnamates, and flavonoids are perhaps the major antioxidants [67]. Vitamin antioxidants (e.g., ascorbic acid and carotenoids) are secondary contributors to the overall antioxidant capacity [69]. In essential oils, unsaturated terpenes having a cyclohexadiene structure (e.g., terpinene) and secondary cyclic oxygenated terpenes (e.g., thymol) may lead to antioxidant capacity, while acyclic unsaturated oxygenated monoterpenes (e.g., linalool), aromatic oxygenated monoterpenes (e.g., eugenol), methylchavicol (estragole), sesquiterpene hydrocarbons (e.g., α-bergamotene, germacrene D, γ-cadinene, δ-cadinene, β-selinene, sesquiterpenes oxygenated (e.g., spathulenol)

Different test methods have been applied, and it becomes to be understood between the complete essential oil and individual components [70–73]. A strong chelating effect on metals as iron or copper has been reported to diminish the presence of ROS obtained from reactions bar with these metals [74]. In addition, the antioxidant actions of *Ocimum* essential oils have also been found employing metal-independent oxidative processes [75] or controlling stable free radicals, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical [71, 76]. The DPPH test, a test widely used to measure the ability to donate hydrogen atoms [77], was applied to measure the antioxidant capacities of *Ocimum* species extracted by different solvent systems; these include the methanol extracts of *O. basilicum* L., *O. canum* Sims., *O. gratissimum* L., *O. kilimandscharicum* Guerke, *O. sanctum*, *O. tenuiflorum* [67, 71, 76, 78–80]; the ethanol extracts from *O. basilicum* L., *O. gratissimum* L., *O. kilimand-*

Particular attention has been focused on the scavenger ability to inhibit the process of low-density lipoprotein (LDL) cholesterol oxidation since it represents a major prevention mechanism against atherosclerosis. Various experimental evidence, using in vitro and in vivo preclinical models, showed a strong action of *Ocimum* essential oils [84]. Moreover, Aqueous extracts *Ocimum sanctum* and 70% ethanol extracts *Ocimum basilicum* L. were able to reduce 5-lipoxygenasedriven cellular recruitment of leukocytes and the damaging consequences of their ability to release ROS while leaving unimpaired the generation of prostaglandins, which promote microvascular blood flow and act as immunomodula-

In many cases, the antioxidative activity (**Figure 3**) of essential oils cannot be attributed to the main compounds; minor compounds and synergistic effect may

For thousands of years, folk medicine has used *Ocimum* leaf for the treatment of infections. Such protective properties have been confirmed by several studies performed in the last decades using *Ocimum* essential oil [29] or isolated compounds. Gram-positive and Gram-negative bacteria, as well as antiprotozoal and also *anti-Trichomonas vaginalis*, resulted sensitive to the antiproliferative action of *Ocimum oil* and its derivatives [29, 88–90]. At present, the exact mechanism responsible for the antimicrobial activity of *Ocimum* oil and its derivatives is still not completely

*DOI: http://dx.doi.org/10.5772/intechopen.88555*

may act as pro-oxidants [68].

*scharicum* Guerke, *O. sanctum* [76, 79, 81–83].

significantly contribute to the activity.

#### Ocimum *Phytochemicals and Their Potential Impact on Human Health DOI: http://dx.doi.org/10.5772/intechopen.88555*

*Phytochemicals in Human Health*

biological activities. During the last two decades, it has been shown that *Ocimum* oil and its constituents possess different biological activities including antioxidant,

*Different species of Ocimum (a) Ocimum basilicum L.; (b) Ocimum kilimandscharicum Guerke; (c) Ocimum gratissimum L.; (d) Ocimum canum Sims.; (e) Ocimum tenuiflorum L. syn. O. sanctum L. (purple type);* 

Anti-oxidants play an important function in protecting the body against free radicals. They achieve this by stopping the formation of new free radicals species, converting older ones to free radicals, less toxic molecules that can be easily mopped up and preventing radical chain reaction [62]. The principal function of anti-oxidants is in suspending the oxidation of other molecules, by inhibiting the initiation or propagation of oxidizing chain reactions by free radicals and thereby reducing oxidative damage to the human body [63]. Two great mechanisms of procedure have been proposed for antioxidants [64]. The initial is a chain breaking method by which the initial antioxidant provides an electron to the free radical stage in the systems. The second technique involves the destruction of ROS/ reactive nitrogen species initiators (secondary antioxidants) by cutting off chain starting catalysts (**Figure 2**). The potential role in the food industry and human health, antioxidants are getting acceptance all across the globe. Antioxidants are defined as a substance that easily in small amounts, can inhibit or prohibit the oxidation of readily oxidizable elements. The antioxidant is also defined as a substance qualified of inhibiting special oxidizing stimulants or a substance that serves with oxidizing agents prior to creating damage to other fragments or a substance that sequesters metal ions or even a substance efficient of the recover-

Natural antioxidants have been studied intensively during the past years which are mainly phenolic compounds. Moreover, oxidation is a degenerative process in

antimicrobial, anticancer, and anti-inflammatory properties.

ing system such as iron transporting protein [65].

**6.1 Oxidant activity**

*(f) Ocimum tenuiflorum (white type).*

**Figure 2.**

**188**

biological systems due to the endogenous reactive oxygen species (ROS). Reactive oxygen species (ROS) are chemical properties originate in the body during metabolism that is overmuch reactive and may have one or expanded unpaired electrons. Oxidative stress, i.e., an inequality between ROS and antioxidant defenses have deleterious aftereffect, such as the peroxidation of membrane lipids and the aggression on biomolecules (proteins, membrane enzymes, carbohydrates and DNA) [66].

Various *Ocimum* species and their extracts or essential oils have been determined to achieve antioxidant activity [67, 68]. Phenolic acids, hydroxycinnamates, and flavonoids are perhaps the major antioxidants [67]. Vitamin antioxidants (e.g., ascorbic acid and carotenoids) are secondary contributors to the overall antioxidant capacity [69]. In essential oils, unsaturated terpenes having a cyclohexadiene structure (e.g., terpinene) and secondary cyclic oxygenated terpenes (e.g., thymol) may lead to antioxidant capacity, while acyclic unsaturated oxygenated monoterpenes (e.g., linalool), aromatic oxygenated monoterpenes (e.g., eugenol), methylchavicol (estragole), sesquiterpene hydrocarbons (e.g., α-bergamotene, germacrene D, γ-cadinene, δ-cadinene, β-selinene, sesquiterpenes oxygenated (e.g., spathulenol) may act as pro-oxidants [68].

Different test methods have been applied, and it becomes to be understood between the complete essential oil and individual components [70–73]. A strong chelating effect on metals as iron or copper has been reported to diminish the presence of ROS obtained from reactions bar with these metals [74]. In addition, the antioxidant actions of *Ocimum* essential oils have also been found employing metal-independent oxidative processes [75] or controlling stable free radicals, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical [71, 76]. The DPPH test, a test widely used to measure the ability to donate hydrogen atoms [77], was applied to measure the antioxidant capacities of *Ocimum* species extracted by different solvent systems; these include the methanol extracts of *O. basilicum* L., *O. canum* Sims., *O. gratissimum* L., *O. kilimandscharicum* Guerke, *O. sanctum*, *O. tenuiflorum* [67, 71, 76, 78–80]; the ethanol extracts from *O. basilicum* L., *O. gratissimum* L., *O. kilimandscharicum* Guerke, *O. sanctum* [76, 79, 81–83].

Particular attention has been focused on the scavenger ability to inhibit the process of low-density lipoprotein (LDL) cholesterol oxidation since it represents a major prevention mechanism against atherosclerosis. Various experimental evidence, using in vitro and in vivo preclinical models, showed a strong action of *Ocimum* essential oils [84]. Moreover, Aqueous extracts *Ocimum sanctum* and 70% ethanol extracts *Ocimum basilicum* L. were able to reduce 5-lipoxygenasedriven cellular recruitment of leukocytes and the damaging consequences of their ability to release ROS while leaving unimpaired the generation of prostaglandins, which promote microvascular blood flow and act as immunomodulators [85–87].

In many cases, the antioxidative activity (**Figure 3**) of essential oils cannot be attributed to the main compounds; minor compounds and synergistic effect may significantly contribute to the activity.

#### **6.2 Antimicrobial**

For thousands of years, folk medicine has used *Ocimum* leaf for the treatment of infections. Such protective properties have been confirmed by several studies performed in the last decades using *Ocimum* essential oil [29] or isolated compounds. Gram-positive and Gram-negative bacteria, as well as antiprotozoal and also *anti-Trichomonas vaginalis*, resulted sensitive to the antiproliferative action of *Ocimum oil* and its derivatives [29, 88–90]. At present, the exact mechanism responsible for the antimicrobial activity of *Ocimum* oil and its derivatives is still not completely

**Figure 3.** *Types of antioxidants.*

clarified, although various modes of action in the bacterial cell have been discussed including degradation of the cell wall, damage to cytoplasmic membrane and membrane proteins, leakage of cell contents, coagulation of cytoplasm, and depletion of proton motive force [91–93].

The antibacterial and antifungal activities of *Ocimum* species have been studied on various bacteria and fungi [29, 94–96]. These studies indicate that essential oils are more efficient antifungals and antibacterials compared to the polar extracts [97–99]. *Ocimum sanctum* essential oils showed remarkable antimicrobial activity against bacteria and other microorganisms, such as periodontopathogens [100], mainly due to the presence of oxygenated monoterpenes in their chemical compositions [101].

The essential oil and methanol extracts of five *Ocimum* species have an appreciable activity against seven human pathogenic bacteria [29], essential oils of *Ocimum* species showed strong antimicrobial activity against all seven microorganisms tested. Oils of seven *Ocimum* taxa (*O. americanum* L., *O. basilicum* L., *O. campechianum* Mill., *O.* x *citriodorum* Vis., *O. kilimandscharicum* Baker ex Gürke and three botanical varieties and cultivars of *Ocimum basilicum* L.: 'Genovese', var. difforme and var. purpurascens)) showed strong antimicrobial activity against all 8 microorganisms tested by Carovic-Stanko et al. [102].

Among the antifungal activities, the *in vitro* antifungal activity of *O. basilicum* L. essential oil against Aspergillus flavus fungal growth and aflatoxin B1 production [103], essential oils of *O. basilicum* L. showed strong antifungal activity against *A. flavus*, and the main components were linalool, 1,8-cineol, eugenol, methyl cinnamate, α-cubebene, caryophyllene, β-ocimene and α-farnesene.

**191**

Ocimum *Phytochemicals and Their Potential Impact on Human Health*

For a long time, the polyphenols of the *Ocimum* oil of the diet have been considered to play a role for the prevention of certain types of cancer in the Asian origin [104]. Even more than in *Ocimum* oil, constituents present in *Ocimum* leaf extract has shown strong antioxidant potency and inhibition of cancer cell proliferation, thus suggesting the protection against the genotoxic action of the ROS as one of the mechanisms explaining the anticancer effects of these compounds. Indeed, either methanol aqueous *Ocimum basilicum* L. leaf extract or the isolated constituents eugenol epoxide free radical scavenging activity and growth inhibition at low micromolar concentration on human breast cancer cell lines (MCF-7 and MDA-MB-231) [105, 106] and Human cancerous cell lines (HL60 promyelocytic blood leukemia cells) [107]. Such findings were further confirmed by other in vitro reports, testing the effects of *Ocimum basilicum* L. against four different humans cancer cell lines viz. human cervix adenocarcinoma HeLa cells, human melanoma FemX cells, human chronic myelogenous leukemia K562 cells, and human ovarian SKOV3 cells [108]. Furthermore, Karthikeyan et al. [109] demonstrated regression of tumors caused by orally administrated aqueous and ethanolic extracts of *Ocimum sanctum* in mice that developed spontaneous soft

Monga et al. [110] studied the antimelanoma and radioprotective activity of essential oils obtained by 50% alcoholic aqueous leaf extract from five species of *Ocimum* viz. *Ocimum sanctum* (SE), *Ocimum gratissimum*, *Ocimum basilicum*, *Ocimum canum*, and *Ocimum kilimandscharicum*, were evaluated using C57BL and Swiss albino mice tumorigenesis; growth inhibition has in fact been associated with (a) reduction of tumor volume (b) blockage of messengers of pathways involved in cell proliferation was evident in all the oils but the greater was shown by that obtained from *Ocimum tenuiflorum* (syn. *O. sanctum*) compared to other *Ocimum* species. In various experiments and test systems, some mono-and sesquiterpenes showed activity, where camphor, 1,8-cineole and limonene were of greatest interest. Camphor, 1,8-cineole and limonene, the anti-inflammatory compound of *Ocimum kilimandscharicum* oil, showed a strong time-and dose-dependent cytotoxic effect on human ovarian cancer cell [111]. The potential antitumor effects of camphor have been shown previously [112, 113], and the mechanistic action of camphor against cancer included the improvement of immune function [114] and the radiosensitizing effect on transplantable mammary adenocarcinoma in mice [112]. Ursolic acid showed some potentiating effect on the anticancer activity of rosmarinic acid, cinnamic acid, caffeic acid, sinapic acid, and ferulic

For decades, investigation on the health-promoting effects of Asian diet has been revealed that *Ocimum* oil consumption is a key factor in the cardiovascular protection found in Asian origin [115]. It is well established that the healthful properties of *Ocimum basilicum* L. oil depend largely on its Cardiac glycosides and catecholamines content [116]. But, many arguments prove that in *Ocimum* oil there are little bioactive components, much than Cardiac glycosides and catecholamines, effective for its cardiovascular protective properties: among them, the ethanolic fraction of *Ocimum* oil, and in specific omega-3 fatty acids have proved antioxidant, anti-platelet aggregation, vasodilatory, and anti-inflammatory effects, all engaged

*DOI: http://dx.doi.org/10.5772/intechopen.88555*

**6.3 Anticancer activity**

tissue sarcomas.

acid on various cell lines [106].

**6.4 Cardiovascular protection**

in this health beneficial action [117–119].
