‘Chewing sticks prevent tooth decay better than conventional toothpastes’
Nigerian researchers have demonstrated that three local chewing sticks performed better than fluoride-based and conventional toothpastes in preventing tooth decay. The local chewing sticks are: Fagara zanthoxyloides (candlewood or Senegal prickly ash/orin ata in Yoruba), Vernonia amygdalina (bitter leaf) and Massularia accuminata (chewing stick (pako ijebu in Yoruba/atu uhie in Igbo)).
The study titled “A Study of the Anticaries Activity of Three Common Chewing Sticks and Two Brands of Toothpaste in South West Nigeria” was published in British Journal of Pharmaceutical Research. The researchers from the Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Olabisi Onabanjo University, Ago-Iwoye, Ogun State, include: Odeleye Olubola Florence; Okunye Olufemi Lionel; Kesi Christopher; and Abatan Temitope Olubunmi.
They concluded: “The chewing sticks used in this study showed good antimicrobial activity against the isolates and could provide better care than fluoride toothpastes. The active compounds if isolated would be good caries-controlling components of herbal toothpastes.”
The researchers evaluated three common chewing sticks and two brands of toothpaste in southwest Nigeria for the ability to control caries-causing bacteria.
With an increase in tooth decay and gum diseases all over the world, there is need to produce oral cleaning agents that will better control caries-causing bacteria. Three common chewing sticks – Fagara zanthoxyloides (FZ), Vernonia amygdalina (VA) and Massularia accuminata (MA)- and two brands of toothpaste- Close Up and Macleans- were evaluated for their anti-caries activities.
Zanthoxylum zanthoxyloides (Fagara zanthoxyloides) is a glabrous shrub or tree with an English or common name of candlewood or Senegal prickly ash. It is called Orin ata in Yoruba. It belongs to the family Rutaceae. Its chewing sticks are obtained either from the stems or the roots and they give a warm pungent and numbing effect on the palate. These plants have also been reported to possess antisickling, antiparasitic and antiseptic activities and have been known to be used to treat other ailments including toothache, sexual impotence, gonorrhoea, malaria, dysmenorrhoea, urinary and venereal diseases and abdominal pain.
Veronica amygdaline commonly called bitter leaf, is a perennial shrub belonging to the family Asteraceae. In Nigeria, the Edo calls it oriwo; Hausa, chusar doki (a horse tonic food containing the leaves); fatefate/mayemaye (a food prepared from the leaves); Ibibio, atidot; Igbo, onugbu; Tiv, ityuna; and Yoruba, ewuro. The plant is used as an anti-helminth, anti-malarial, laxative, digestive tonic, appetizer and febrifuge and for the topical treatment of wounds. This plant also has a measure of anti caries activity. The roots and stems of this plant are used as chewing sticks and have been known to possess a measure of anti caries activity.
Commonly called Chewing stick, Massularia acuminata (synonym Randia acuminata) is of the family Rubiaceae. It is called pako-ijebu and orin-ijebu in Yoruba and atu uhie in Igbo. It grows as a shrub or small tree. The inhibitory properties of the plant are attributed to its phytochemicals, which include saponins, flavonoids, glycosides, tannins and anthraquinones. Massularia acuminata is a traditionally used herb in Yoruba medicine, used as a chewing stick and aphrodisiac; the chewing stick aspect was researched for being an anti-gingivitis agent.
According to Handbook of African Medicinal Plants, Second Edition, by Prof Maurice Iwu, Massularia acuminata has been shown to possess significant antimicrobial activity against oral pathogens associated with orodental infections, including Bacteroides gingivalis and B. melaninogenicus. The aqueous extract of the plant has a Microbial Inhibition Concentration (MIC) of 0.5 and 2 ug/ml against Bacteroides gingivalis and B. melaninogenicus, respectively. The adherence of Streptococcus mutans to the surfaces of the teeth was effectively inhibited by a one per cent concentration of the aqueous extract of Massularia.
Meanwhile, according to the study on local chewing sticks, fifty isolates of Staphylococcus aureus, one of the bacteria often implicated in dental caries, isolated from patients presenting with various dental problems at the University College Hospital (UCH), Ibadan, Nigeria were obtained from the Medical Microbiology Department of the Hospital.
The isolates were challenged with the toothpastes, undiluted, as well as ethanol and aqueous extracts of the chewing sticks using the agar cup diffusion method. The chewing sticks were also screened for secondary metabolites using standard procedures.The results showed that the ethanol extracts of Fagara zanthoxyloides (FZ) showed the highest anti-caries activity followed by Vernonia amygdalina (VA) and then Massularia acuminata (MA). 43 isolates (86 per cent) were sensitive to the ethanol extract of Fagara zanthoxyloides while 36 (72 per cent) and 25 (50 per cent) were sensitive to Vernonia amygdalina and Massularia acuminata respectively.
“Both brands of toothpaste were inferior to the ethanol extracts of all the chewing sticks in anti-caries activity. Only 15 (30 per cent) and 20 (40 per cent) of the isolates were sensitive to Close up and Macleans respectively. 16 (32 per cent), 14 (28 per cent) and 10 (20 per cent) of the isolates were sensitive to the aqueous extracts of FZ, MA and VA respectively.” The researchers concluded: “The active constituents in the ethanol extracts of the chewing sticks will be useful as anti caries components of herbal toothpastes which are becoming common in the market.”
Until now, some of these chewing sticks have been shown to possess varying degrees of antimicrobial activity against oral microbial flora which indicates therefore, that the chewing sticks, in addition to providing mechanical stimulation of the gums, also destroy microbes, a feature which is absent in the common toothpaste and brush method. This advantage of the chewing sticks over the conventional toothpaste and brush could explain why many Africans have strong teeth.
The extracts of some chewing sticks have been demonstrated to have anti-plaque and antimicrobial activities against certain oral bacteria like Streptococcus mutans, Bacteroides gingivitis and oral anaerobes commonly implicated in dental caries and orodental infections. The researchers added: “Chewing sticks therefore can safeguard against dental problems, which is probably the reason why dental caries (decay) is not rampant in certain parts of Nigeria where the use of chewing sticks is frequent. Thus, the World Health Organization has encouraged the use of chewing sticks. In Nigeria, about 80-90 per cent of the population in rural areas use chewing sticks, mainly because they are readily available, cheap and efficacious.
“The cleansing efficacy of chewing sticks is attributed to the mechanical effects of its fibers, the release of beneficial chemicals or a combination of both. Some African chewing sticks have also been reported to contain fluoride ions, silicon, tannic acid, sodium bicarbonate and other natural plaque inhibiting substances that can reduce bacterial colonization and plaque formation.
The researchers noted: “The presence of saponins and tannins in all the three plants, of anthraquinone in Massularia acuminata and of alkaloids in Fagara zanthoxyloides and Vernonia amygdalina can be linked to the antibacterial activity of the plants. Cowan had shown that antibacterial effect of plant materials was due to the presence of alkaloids, tannins and anthraquinones. It had also been reported by Hagerman et al. that tannins form irreversible complexes with proline- rich proteins which could lead to inhibition of cell wall protein synthesis, a property that may explain the mode of action of the chewing stick extracts used in this work. In addition to its antibacterial effect, saponins also have antifungal properties.
“The test organism used for this study, Staphylococccus aureus is one of the organisms often implicated in dental caries. It accounts for over 70 per cent of dental caries cases from the research works carried out by Daniyan and Abalaka and had highest proportion in the work of Oluremi et al. It is a pathogenic organism that causes dental infections and are now widely isolated from the oral cavity.
“The extracts of the three chewing sticks produced a greater activity at a concentration of 100mg/ml than the two brands of toothpaste. This is similar to the work carried out by Antwi-boasiako et al. where the plant extracts of Garcinia kola (bitter kola) had a greater antimicrobial effect than the pepsodent toothpaste used. The ethanol extract of Fagara zanthoxyloides gave a better antimicrobial activity against all the fifty isolates than the ethanol extracts of Vernonia amygdalina and Massularia acuminata. 43 (86 per cent) of the isolates were sensitive to the ethanol extracts of Fagara zanthoxyloides while 36 (72 per cent) and 25 (50 per cent) were sensitive to Vernonia amygdalina and Massularia acuminata respectively.
“The ethanol extracts of the plant materials had a better antimicrobial action than the aqueous extracts which is in accordance with a research work by Isawumi and Rotimi et al. The aqueous extracts of the plant materials showed a poor inhibitory action against the test organism. This may be due to poor solubility nature of the active principles of the plants in water. The two brands of toothpaste had weaker antimicrobial activity than the plant extracts. This is not unexpected since chemical toothpastes owe their antimicrobial property to the presence of fluorides as part of their ingredients. Macleans however had a better inhibitory action than close up.”