Abstract: There is a long and venerable history of the use of plants to improve dental health and promote oral hygiene. Plants contain phytochemicals such as alkaloids, tannins, essential oils and flavonoids which have pronounced antimicrobial activity. Plants have also been incorporated into dentifrices and have been used to provide natural chewing gums for oral hygiene, to treat toothache, gingivitis and periodontal disease. There is a potentially valuable role for Phytotherapy in assisting with the management of gingival and periodontal diseases. The evidence and research which supports such a role for a few plants and plant products has been reviewed in this study.
INTRODUCTION
Chronic gingival inflammatory conditions primary etiology is often investigated to be bacterial plaque and its byproducts (Botelho et al., 2007). The association between poor oral hygiene, dental plaque and the severity of periodontal diseases is also well established (Botelho et al., 2007). Numerous antimicrobial agents have been and are being tested throughout the world in order to determine which agents are efficacious and safe in preventing plaque formation and/or inhibiting the colonization of periodontopathogens within the plaque (Tsao et al., 1982).
Plants (herbs) and naturally derived products from plants (herbal supplements) have been used to enhance health and for medicinal purposes for thousands of years (Cohan and Jacobsen, 2000). Most herbal supplements have been utilized for centuries based on empirical and testimonial support for their efficacy (Cohan and Jacobsen, 2000). Development in alternative medicine research has led to many mouth rinses and toothpastes based on plant extracts (Ozaki et al., 2006). The scientific evidence-based literature also supports the efficacy and safety of numerous herbs today (Cohan and Jacobsen, 2000). Hence scientific evaluation for safety and efficacy is needed for the drugs of alternative medicine (Subash et al., 2011).
TERMINOLOGY
Therapy comes from the Latin word therapia, originally from Greek therapeia, from therapeuein which means to treat medically. The Latin prefix phyto stands for plant and is called photon in Greek. In other words "Phytotherapy" can be called herbal medicine (http://www.scienceinafrica.co.za/2004/june/phytotherapy.htm) It is the study of the use of extracts from natural origin as medicines or health-promoting agents (Zhao, 2007). The term phytonutrients refer to plant nutrients with particular biological activities in supporting human health. Phytonutrients emphasize more specifically natural bioactive compounds from plants with general benefits to human health.
RATIONALE FOR PHYTOTHERAPY
Phytotherapy has a long history and has been used worldwide. For plant after plant, isolates demonstrate effects that are immune-enhancing, anti-inflammatory and anti-cancer (Lee, 2005). Some phytotherapy strategies have been well recognized since they have been extensively studied in chemistry and pharmacology and are partly proven by clinical trials (Jiang et al., 2005). There are also noted advantages of advocating phytotherapy which include (1) unique mechanisms of action, (2) typically low side-effect profiles, (3) low cost and (4) a high level of acceptance (Shoskes, 2002).
USEFUL PARTS AND ACTIVE CONSTITUENTS
Many plants are being studied for their potential as phytonutrients or phytotherapy materials (Jiang et al., 2005). The literature suggests several plants and plant parts which have anti-inflammatory, antioxidant, antibacterial, astringent and other useful properties.
| Table 1: | List of useful plant parts and their active constituents |
These properties can be made use of in the treatment of gingival and periodontal diseases. Compared to plant-derived drugs that often consist of one single natural compound in combination with other minor chemicals, herbs or phytotherapy materials often contain multiple bioactive components with multiple targets during intake and therapy (Jiang et al., 2005). Various plants along with their useful parts and active constituents have been listed in Table 1.
Alkaloids are naturally occurring chemical compounds containing basic nitrogen atoms. They often have pharmacological effects and are used as medications (http://en.wikipedia.org/wiki/Alkaloids). Volatile oils are concentrated, hydrophobic liquids containing volatile aroma compounds from plants. Various essential oils have been used medicinally at different periods in history. Medical applications range from skin treatments to remedies for cancer (http://en.wikipedia.org/wiki/Volatile_oils).
Polyphenols are a group of chemical substances found in plants, characterized by the presence of more than one phenol unit. Polyphenols can be mainly divided into tannins, lignins and flavonoids (http: //en.wikipedia.org/wiki/Polyphenols). Tannins are astringent, bitter plant polyphenols that either bind and precipitate or shrink proteins. The anti-inflammatory effect of tannins helps control all indications of inflammation. The ability of tannins to form a protective layer over the exposed tissue keeps wounds from being infected further. Tannins are also beneficial when applied to the mucosal lining of the mouth (http://en.wikipedia.org/wiki/Tannins). Flavonoids are water soluble polyphenolic molecules containing 15 carbon atoms. They have antioxidant activityActivities attributed to flavonoids include: anti-allergic, anti-cancer, antioxidant, anti-inflammatory and anti-viral (http://www.phytochemicals.info/phytochemicals/flavonoids.php).
Vitamin C is essential to prevent disease associated with connective tissue and to improve immune cell functions. It is also used to regenerate vitamin E (Jiang et al., 2005). Carotenoids are organic pigments that are naturally occurring in the chloroplasts and chromoplasts of plants and some other photosynthetic organisms like algae, some types of fungus and some bacteria. Most carotenoids have antioxidant activity and they are efficient free-radical scavengers (http://en.wikipedia.org/wiki/Carotenoids).
PREPARATIONS AND MARKERS
Phytonutrients have been traditionally used as tinctures, oils or as components of toothpastes and mouthrinses. They are predominantly for topical usage only and not for systemic consumption. Some phytonutrients may also be taken in the form of tea or boiled syrup.
Fine et al. (2007) stated that rinsing with an essential oil mouthrinse can have an impact on the subgingival plaque flora. Yamanaka et al. (2007) conducted a study in which it was concluded that cranberry polyphenol fraction inhibits biofilm formation and the Arg-gingipain and Lys-gingipain activities of P. gingivalis.
Al-Bayati and Sulaiman (2008) investigated the aqueous extracts of Salvadora persica for its antimicrobial activity against 7 isolated oral pathogens (Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and Candida albicans) and found that the extracts inhibited all the isolated microorganisms.
Hirasawa et al. (2002) determined the usefulness of green tea catechin for the improvement of periodontal disease using a slow-release local drug delivery system. Green tea catechin showed a bactericidal effect against black-pigmented, Gram-negative anaerobic rods and the combined use of mechanical treatment and the application of green tea catechin using a slow release local delivery system was effective in improving periodontal status.
Habiboallah et al. (2008) formulated a novel cost-benefit material by mixing ghee from sheep butterfat with the powdered rhizomes of Curcuma longa and evaluated its potential therapeutic effect on acceleration of surgical wound healing. They suggested a positive potential therapeutic effect on surgical wound healing particularly improvement of periodontal treatment consequences after surgery.
For comparison chlorhexidine gluconate 0.2% is considered to be the gold standard to treat human gingival disease (Rahmani and Radvar, 2005). A spartate aminotransferase appears to have the potential to serve as a biological marker to monitor orthodontic tooth movement (Rohaya et al., 2009). Human gingival fibroblast (GHF1) cell lines were used to assess plant phytonutrients cytotoxicity using clonogenic assay and the total cellular GSH level was analyzed using a photometrical assay (Shokrzadeh and Ebadi, 2006). The bony turnover specifically the bone formation can be monitored through the expression of alkaline phosphatase activity in the gingival crevicular fluid during orthodontic treatment (Asma et al., 2008). Spectrum of pathogenicity of the periodontal disease and effective management of diagnosis by use of multiplex PCR using the subgingival plaque samples (Faghri et al., 2007). Subgingival plaque samples were used for presence of Epstein-Barr virus type 1 (EBV-1) in patients with chronic periodontitis with nested-PCR (Moghim et al., 2007). The analysis of plaque index, gingival index and bleeding on probing can give vital data on gingival inflammation and plaque formation (Amoian et al., 2010).
SIDE EFFECTS
Most phytotherapy strategies are ahead of the scientific basis and without strict controls in quality, safety and efficiency (Zhao, 2007). Certain herbals may cause direct effects on oral tissues, including tongue numbness, burning of the tongue and mouth/throat irritation (Cohan and Jacobsen, 2000). Toxicity is usually seen only when excessive amounts of phytochemicals are ingested. This is rarely encountered because phytotherapy for gingival inflammation usually involves only topical application and systemic administration is not required.
Another risk with herbal supplements, as with exposure to nearly all substances, is that of an allergic reaction that can manifest in the oral mucous membranes, gingiva, tongue, or elsewhere. Indirect oral effects may also be seen which include halitosis, excess saliva and blood pressure increase and irritability (Cohan and Jacobsen, 2000).
PHYTOTHERAPY RESEARCH IN INDIA
Use of plants as a source of medicine has been inherited and is an important component of the health care system in India. India is the largest producer of medicinal herbs and is appropriately called the botanical garden of the world. The officially documented plants with medicinal potential in India are 3000 but traditional practitioners use more than 6000 (Seth and Sharma, 2004). Several institutes in the country are working extensively in this area in order produce newer and more effective phytochemicals which can be manufactured on a mass scale and made available to the common man at low and affordable costs. These include The Central Institute of Medicinal and Aromatic Plants (CIMAP) at Lucknow, The Indian Council of Medical Research (ICMR) at New Delhi, The French Institute of Pondicherry (FIP) at Pondicherry, The Central Drug Research Institute (CDRI) at Lucknow, The National Botanical Research Institute (NBRI) at Lucknow, The Tropical Botanic Garden Research Institute (TBGRI) at Thiruvananthapurnam and The Medicinal Plant Conservation Park at Auroville.
CONCLUSION
Phytotherapy, the most ancient medication, is still useful today. It can be believed that many unstudied plants might have some secrets for the medical world (http://www.wisegeek.com/what-is-phytotherapy.htm). However, concerns from scientists, professionals and customers continuously arise, due to increases in the use of phytochemicals. Quality, safety, long-term adverse effects and toxicity are the primary concerns (Zhao, 2007). A systematic approach through experimental and clinical validation of efficacy is required for a plant identified for phytotherapy, as is done in modern medicine; animal toxicity studies are also required to establish the potential adverse effects.