**3. What is the role of flavonoids on human health?**

hepatoprotective, anti-inflammatory, anticancer activities, growth regulators [11]. Wound results in edema, redness followed by pain. Inflammation is the major characteristics as a result of wound due to the release of eicosanoids, prostaglandins, leukotrienes and reactive oxygen species. By controlling all these factors will result in healing the wound faster. Recent students on Buddleja species and three Ghanaian species *Spathodea campanulata*, *Commelina diffusa* and *Secamone afzelii* showed antioxidant and anti-inflammatory properties. These antioxidant and anti-inflammatory properties were due to the presence of flavonoids and other bioactive compounds that works in combination to heal the wound [12]. The chapter deals with the study of role of flavonoids, mechanism of action that involves in healing the wound.

Healing the wound with medicinal plants is an alternative method of treatment used by traditional wound healer. The most commonly used plants all over the world is *Curcuma longa.* In Malaysia, there are few more species that act as wound healing such as *Elephantopus scaber*, *Centella asiatica, Clinacanthus nutans* and *Aloe barbadensis.* List of famous medicinal plants that

**Medicinal plants Pharmacological uses Reference** *Aloe barbadensis miller* Anti-oxidant, anti-inflammatory, wound healing, antimicrobial [13–16]

> anti-inflammatory activity, anti-herpes simplex virus type 1 and type 2 activity, anti-oxidant and protective effect against oxidative induced hemolysis

> neuroprotective activity, immunomodulatory activity, anti-inflammatory activity, hepatoprotective activity, insecticidal activity, and antioxidant activity

antidiabetic activity, anthelmintic, antibacterial activity, antifungal activity,

activity, hypotensive effect, immunomodulating property, bronchial catarrh, dysentery, diarrhea and to prevent falling of hair promotes the growth of hair,

hepatoprotective activity, antioxidant activity, larvicidal activity

*Chromolaena odorata* Wound healing, analgesic, anti-inflammatory and antipyretic activities [22, 23]

[17, 18]

[19, 20]

[24, 25]

[26]

[27, 28]

[29, 30]

[31]

[21]

**2. Wound healing medicinal plants**

96 Phytochemicals - Source of Antioxidants and Role in Disease Prevention

anti-microbial

plays an important role in wound healing is mentioned in **Table 1**.

*Azadirachta indica* Anti-malarial, wound healing, antiseptic, febrifuge, antihelminthic,

*Centella asiatica* Antimicrobial activity, anticancer activity, wound healing activity,

*Lantana camara* Anticancer activity, wound healing, anti-inflammatory activity,

and antimicrobial activity

**Table 1.** List of medicinal plants in healing the wound.

to combat AIDS, anti-microbial

*Curcuma longa Linn.* Hepatoprotective, nephroprotective, anticoagulant, wound healing, anti-HIV

*Clinacanthus nutans* Anti-papillomavirus infectivity, anti-viral activity on varicella-zoster virus,

*Elephantopus scaber* Antimicrobial, hepatoprotective, antioxidant, antidiabetic, anti-inflammatory, analgesic, antiasthmatic, antiplatelet, and wound healing

*Euphorbia neriifolia* Analgesic, hepatoprotective, immunostimulant, anti-inflammatory, mild CNS depressant, wound healing, radioprotective

*Tridax procumbens* Hepatoprotective activity, anti-inflammatory, wound healing, antidiabetic

Flavonoids are phenolic substances isolated from a wide range of vascular plants, with over 8000 individual compounds known [32]. They possess wide variety of activities such as antimicrobial [33], anti-oxidant [34], anti-cancer [35], anti-inflammatory [36] and wound healing [37]. Among all flavonoids there are some flavonoids such as flavan-3-ols and flavonols, possess a wide spectrum due to suppress a number of microbial virulence factors and show synergism with antibiotics [38]. While there has been a major focus on the antioxidant properties, there is an emerging view that flavonoids, and their in vivo metabolites, do not act as conventional hydrogen-donating antioxidants but may exert modulatory actions in cells through actions at protein kinase and lipid kinase signaling pathways. Flavonoids, and more recently their metabolites, have been reported to act at phosphoinositide 3-kinase (PI 3-kinase), Akt/protein kinase B (Akt/PKB), tyrosine kinases, protein kinase C (PKC), and mitogen activated protein kinase (MAP kinase) signaling cascades. Inhibitory or stimulatory actions at these pathways are likely to affect cellular function profoundly by altering the phosphorylation state of target molecules and by modulating gene expression [39]. In many molecular mechanisms of action for prevention against cancer, flavonoids play a major role by interacting between different types of genes and enzymes. Many mechanisms of action have been identified, including carcinogen inactivation, antiproliferation, cell cycle arrest, induction of apoptosis, inhibition of angiogenesis, antioxidation, and reversal of multidrug resistance or a combination of these mechanisms [40].
