MEDICINAL PLANTS USED FOR PAIN AND INFLAMMATION

 3.3 MEDICINAL PLANTS USED FOR PAIN AND INFLAMMATION

The ethnopharmacological data collated for this review have been grouped using categories in WHO Monographs on Selected Medicinal Plants (World Health Organization, 2007). A summary of the different ethnopharmacological uses of the 31 selected medicinal plants is presented in Table 3.1. In experimental pharmacological assays, 20 herbal medicines examined in the present study possess analgesic, anesthetic, and anti-inflammatory properties in animals. These findings are discussed below.

3.3.1 Fructus Anethhi

Ear inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) was inhibited in mice by a single topical application of an ethanol extract of the fruits (Okuyama, 1995). An aqueous extract of the fruits and essential oil produced analgesic effects in the hot-plate and acetic acid-induced writhing tests (Racz-Kotilla et al., 1995).

3.3.2 Aetheroleum Anisi

The major constituent anethole blocked inflammation by inhibiting tumor necrosis factor (TNF)-induced cellular responses (Chainy et al., 2000).

3.3.3 Fructus Anisi

External application of a methanol extract of the fruits produced an inhibitory effect of ear inflammation induced by TPA in mice (Yasukawa et al., 1993), whereas an ethyl acetate or hexane extract had no effect (Okuyama, 1995). Anethole, a major constituent, inhibited the inflammatory activity via the inhibition of TNF-induced cellular responses (Chainy et al., 2000).

3.3.4 Semen Armeniacae

Amygdalin, a major constituent, administered intragastrically, produced a significant analgesic activity as assayed by the hot-plate and acetic acid-induced writhing

tests in mice (Zhu et al., 1994). Amygdalin had no effects on morphine-dependent

mice. It did not possess the anti-inflammatory property.

3.3.5 Flos arnicae

Intragastric administration of an ethanol extract of Flos Arnicae to rats inhibited carrageenan-induced inflammation (Mascolo et al., 1987). Carrageenan-induced inflammation and Mycobacterium butyricum-induced arthritis were inhibited significantly by intraperitoneal administration of helenalin, a sesquiterpene lactone (Hall et al., 1979). Helenalin, administered intraperitoneally into mice, inhibited acetic acid-induced writhing response, but did not produce a significant analgesic activity in the hot-plate test. It is of interest to note that in vivo, helenalin diminished the activity of prostaglandin synthetase in mouse and rat homogenates and human polymorphonuclear neutrophils (Hall et al., 1980).

3.3.6 Folium azadirachti

Intragastric administration of an aqueous extract of the leaves reduced the number of acetic acid-induced writhing responses and enhanced tail-flick withdrawal responses in mice (Khanna et al., 1995). An aqueous extract of the leaves, administered intragastrically to rats, reduced inflammation and edema in the cotton pellet granuloma assay (Chattopadhyay, 1998). Carrageenan-induced edema was also reduced by intraperitoneal administration of the same extract of the leaves (Chattopadhyay et al., 1994).

3.3.7 oleum Azadirachti

Intramuscular administration of nimbidin, one of the major constituents, decreased paw edema in rats induced by carrageenan and kaolin (Pillai and Santhakumari, 1981). Similar treatment with nimbidin produced a significant reduction in formalin-induced arthritis in ankle joints and fluid exudation due to granuloma induced by cotton oil in rats (Shankaranarayan, 1978).

3.3.8 Flos Carthami

Intragastric administration of an ethanol extract of Flos Carthami produced an anal- gesic activity as assayed by the hot-plate test in mice (Mohsin et al., 1989). Acetic acid-induced writhing response was reduced by subcutaneous administration of a methanol extract of the flowers, whereas the behavioral response in the hot-plate test was unchanged by subcutaneous administration of an aqueous extract of the flowers (Kasahara et al., 1989, 1991).

Intragastric administration of a methanol extract of Flos Carthami produced a significant reduction in the inflammatory response induced by carrageenan, serotonin, bradykinin, histamine, and prostaglandin (Kasahara et al., 1989, 1991). Subcutaenous administration of an aqueous or methanol extract of the flowers inhibited carrageenan-induced inflammation in mice (Kasahara et al., 1989).

3.3.9 Fructus Foeniculi

Intragastric administration of an ethanol extract of the fruits produced an analgesic activity as assayed by the hot-plate test in mice and rats (Mascolo et al., 1987; Tanira et al., 1996).

3.3.10 Radix Gentianae scabrae

Intraperitoneal administration of the alkaloid gentianine reduced the inflammation of the ankle joint of the hind leg induced by formalin and egg white (Sung et al., 1958; Chi et al., 1959).

3.3.11 Gummi Gugguli

Intragastric administration of an ethyl acetate or aqueous extract of the oleo-gum resin reduced mycobacterial adjuvant-induced edema and carrageenan- and Freund’s adjuvant-induced inflammation in rats (Sharma and Sharma, 1977; Duwiejua et al., 1993). Intraperitoneal administration of an ethanol extract of the oleo-gum resin reduced xylene inflammation in mice (Duwiejua et al., 1993). The steroid-containing fraction of a petroleum ether extract decreased Freund’s adjuvant-induced inflamma- tion (Arora et al., 1972).

3.3.12 Radix Harpagophyti

Intragastric administration of an aqueous or methanol extract of Radix Harpagophyti inhibited inflammation and oedema in the granuloma pouch test and also reduced carageenan-induced inflammation and oedema in rats (Erdos et al., 1978). The same treatment exhibited an analgesic activity in mice as assayed by the hot-plate test, but not by the benzoquinone-induced writhing test. Intrapeirtoneal administration of an aqueous or chloroform extract of Radix Harpagophyti reduced carra- geenan-induced inflammation in mice and rats (Manez et al., 1990; Baghdikian et al., 1997). The same administration route of an aqueous extract exerted an analgesic activity in the writhing test in mice (Lanhers et al., 1992). It is of particular interest that the ethanol extract of the roots containing harpagoside, a main active constituent, inhibited the release of TNF-α induced by lipopolysaccharide in vitro (Fiebich et al., 2001).

3.3.13 Aetheroleum lavandulae

The essential oils, linalyl acetate and linalool, extracted from various natural plants, such as Lavandula angustifolia, possess a variety of pharmacological properties. Intraperitoneally administered linalool of L. angustifolia produced an anesthetic activity in vitro (Ghelardini et al., 1999) and antinociceptive effects in the mouse capsaicin test in vivo (Sakurada et al., 2009). Lavender oils (Aethroleum Lavandulae) inhibited mast cell-dependent ear edema induced by compound 48/80 (Kim and Cho, 1999). As shown in Figure 3.1, administration of lavendar essential oils into the

3.3.14 Strobilus Lupuli

A methanol extract of Strobilus Lupuli and its biologically active constituent humulone reduced TPA-induced inflammation when applied to mouse ears (Yasukawa et al., 1993, 1995).

3.3.15 Gummi myrrha

Intragastric administration of an aqueous suspension of Gummi Myrrha and a sesquiterpene furanoeudesma-1,3-diene exhibited an analgesic activity in mice as assayed by the hot-plate and acetic acid-induced writhing tests (Dolara et al., 1996; Atta and Alkofahi, 1998). Inflammation induced by Freund’s adjuvant, carrageenan, and xylene was reduced significantly by an intragastric administration of an aqueous and ether extract of Gummi Myrrha in mice and rats (Tariq et al., 1985; Duwiejua et al., 1993; Atta and Alkofahi, 1998).

3.3.16 Herba passiflorae

Intragastric administration of an ethanol (30%) extract of the aerial parts of Herba Passiflorae reduced the incidence of phenylbenzoquinone-induced writhing response (Leslie, 1978). The same extracts, administered through the intragastric route in mice, reduced carrageenan-induced inflammation and edema in the cotton pellet granuloma assay (Sopranzi et al., 1990; Borrelli et al., 1996). An ethanol (60%) extract of Herba Passiflorae had no effect on the tail-flick latency (Borrelli

et al., 1996).

3.3.17 Fructus schisAndrAe

Of the major constituents of Fructus Schisandrae, externally applied gomisin A (schisandrol B) in mice was the most potent in reducing TPA-induced inflammation in mice (Yasukawa et al., 1992).

3.3.18 Radix scutellariae

External application of an ethanol extract of Radix Scutellariae reduced TPA- and arachidonic acid-induced inflammation in mice (Cuellar et al., 2001). The flavonoid baicalein, one of the major constituents of the roots, was more effective on adjuvant- induced arthritis than on carrageenan-induced edema (Butenko et al., 1993). It is noteworthy that baicalin inhibits the binding of chemokines to human leukocytes and cells transfected with chemokine receptors (Li et al., 2000).

3.3.19 Radix cum herba taraxaci

A methanol extract of the leaves of Radix cum Herba Taraxaci, applied externally on mice, reduced TPA-induced ear inflammation (Yasukawa et al., 1993). Intragastric administration of an ethanol extract reduced benzoquinone-induced writhing (Tita et al., 1993) and inhibited carrageenan-induced edema in mice (Mascolo et al., 1987). The analgesic activity was also observed in the hot-plate test by intraperitoneal injec- tion of the same extract (Tita et al., 1993).

3.3.20 Cortex Uncariae

A hydroalcoholic extract from the stem bark of Cortex Uncariae was more potent than an aqueous freeze-dried extract in inhibiting carrageenan-induced edema (Aguilar et al., 2002). In vitro, the decoction of the stem bark of Cortex Uncariae inhibited oxidative- and ultraviolet irradiation-induced cytotoxicity and TNF-α production (Sandoval et al., 2000). Administration of the extract (Cortex Uncariae) in the drinking water attenuated indomethacin-induced intestinal inflammation in rats (Sandoval-Chacon et al., 1998).

3.3.21 Fructus Zizyphi

An ether extract of Fructus Zizyphi, administered orally to rats, significantly inhibited carrageenan-induced edema and cotton pellet-induced granulomas (Shah et al., 1989). Intragastric administration of the same extract of the fruits prolonged the responsive latencies as assayed by the tail-flick and hot-plate test in mice (Shah et al., 1989).

Soure: Giacinto Bagetta, Marco Cosentino, Marie Tiziana Corasaniti, Shinobu Sakurada (2012); Herbal Medicines: Development and Validation of Plant-derived Medicines for Human Health; CRC Press