The Efficacy of Hibiscus Sabdariffa in Xerostomia

Xerostomia, defined as the subjective complaint of dry mouth, is one of the most prevalent and challenging adverse effects for head and neck cancer (HNC) patients treated with radiotherapy (RT) in definitive or adjuvant setting with or without concomitant chemotherapy (CHT). It represents a toxicity that can resolve over time, but often translates into a permanent condition that seriously affects swallowing, speaking and oral health, impairing several domains of patients' quality of life (QoL). Symptomatically, xerostomia may range from mild discomfort to severe oral disease accompanied by signs and symptoms affecting the oral cavity, including mucous membranes, lips, tongue, salivary glands and teeth. In the most severe cases it can cause severe depression. Although radiation-induced xerostomia (RIX) is multifactorial, it is primarily the consequence of damage to the major and minor salivary glands that are usually included in the radiation fields or are in their close proximity. Thus, the severity of glandular injury and potential for recovery depends on the irradiated gland volume, the cumulative radiation dose and the capability of surviving cells to repopulate. Such injury causes diminution in function of the salivary glands and the consequences are reduction in saliva volume, consistency, pH, immunoglobulins and antimicrobial proteins. The efficacy of Aqualief in treating xerostomia, or dry mouth, in patients contacting a randomized, placebo-controlled, double-blind trial was evaluated by a previous study. Aqualief contains two key ingredients, carnosine and karkadé (Hibiscus sabdariffa), which were selected and mixed with normalizing saliva pH and increasing saliva buffering activity. These parameters are often impaired in xerostomia patients, leading to acid-induced enamel and dental erosion and promoting the growth of aciduric bacteria. Aqualief was found to normalize saliva pH to a neutral value and significantly increase the saliva flow rate in xerostomic patients. After six days of treatment, saliva pH was increased toward a neutral value, and the saliva flow rate was increased by almost 60%, compared to the basal value. This improvement was more than three times greater than that achieved with a placebo, which only increased resting salivation by 19%.