A review on medicinal plants used for treating ototoxicity and acoustic trauma induced hearing loss

Hearing loss induced by chemotherapy and acoustic trauma is mainly associated with two factors, free radical formation and apoptosis pathway activation. Despite numerous efforts on reducing the effects of these factors, no definite strategy is still determined to interfere with and control these processes. In recent studies, various protective agents, including antioxidants have been used on animal models, to inhibit the formation of free radicals thus improving hearing loss.In this review article we will discuss the role of traditional herbal medicine in treatment of noise/drug induced hearing loss, focusing on medicinal plants' active substances,as well as their mechanisms of action in reducing or preventing the formation of free radicals thus increasing the rate of survival of cochlea cells. Data have been gathered since year 2000, from scientific publications including the following keywords: deafness, drug toxicity, acute trauma, medicinal herbs and oxidative stress. The study includes all herbs and medicinal plants that have been experimentally used in studies on animal models and clinical trials. The results from these studies indicate the effectiveness of most of these herbs and their active substances through their antioxidative properties. Medicinal plants reported in this review can thus be considered as effective remedies intreating noise/drug induced hearing loss,yet further studies need to be done.

Antioxidant and cytotoxic properties of protein hydrolysates obtained from enzymatic hydrolysis of Klunzinger's mullet (Liza klunzingeri) muscle

Today, consumers are looking for functional foods that promote health and prevent certain diseases in addition to provide nutritional requirements. This study aimed to evaluate the antioxidant and cytotoxic properties of Liza klunzingeri protein hydrolysates. Fish protein hydrolysates (FPHs) were prepared from L. klunzingeri muscle using enzymatic hydrolysis with papain at enzyme/substrate ratios of 1:25 and 1:50 for 45, 90 and 180 min. The antioxidant activities of the FPHs were investigated through five antioxidant assays. The cytotoxic effects on 4T1 carcinoma cell line were also evaluated. The amino acid composition and molecular weight distribution of the hydrolysate with the highest antioxidant activity were determined by HPLC. All six FPHs exhibited good scavenging activity on ABTS (IC50=0.60-0.12 mg/mL), DPPH (IC50= 3.18-2.08 mg/mL), and hydroxyl (IC50=4.13-2.07 mg/mL) radicals. They also showed moderate Fe+2 chelating capacity (IC50=2.12-12.60 mg/mL) and relatively poor ferric reducing activity (absorbance at 70 nm= 0.01-0.15, 5 mg/mL). In addition, all hydrolysates showed cytotoxic activities against the 4T1 cells (IC50=1.62-2.61 mg/mL). 94.6% of peptide in hydrolysate with the highest antioxidant activity had molecular weight less than 1,000 Da. L. klunzingeri protein hydrolysates show significant antioxidant and anticancer activities in vitro and are suggested to be used in animal studies.

Effects ofMatricaria chamomilla extract on motor coordination impairment induced by scopolamine in rats

Objective:To evaluate the effect of ethanolic extract of chamomile on balance and motor learning in rats receiving scopolamine and intact rats. Methods: Fourty-two rats were divided into 6 groups (n = 7). Control group received distilled water. Rats in Group 2 were given 1 mg/kg scopolamine. Groups 3 and 4 received chamomile extract 200 mg/kg and 500 mg/kg, respectively, and scopolamine simultaneously for 20 days. Intact groups (Groups 5 and 6) only received chamomile extract 200 mg/kg and 500 mg/kg, respectively. Motor coordination of rats was assessed with rotarod apparatus. Results:According to the obtained results, compared with the control group, scopolamine significantly decreased time spent on rotarod performance (P Conclusions: The results of this study indicated the high antioxidant property and protective effect of chamomile extract on motor coordination in the groups that received scopolamine.

Inhibitory effect ofThymus vulgaris extract on memory impairment induced by scopolamine in rat

Objective:To investigate the effect ofThymus vulgaris (T. vulgaris) on learning and memory functions in scopolamine-induced memory deficit in rats. Memory enhancing activity in scopolamine-induced amnesic rats was investigated by assessing the Morris water maze and passive avoidance paradigm. Methods:A total of 42 male Wistar rats were divided into 6 equal groups as follow: control group: received water, scopolamine treated group: received scopolamine 1 mg/kg for 15 days, two scopolamine+T. vulgaris treated groups: received scopolamine andT. vulgaris extract 50 and 100 mg/kg body weight per day for 15 days, two intact groups: receivedT. vulgaris extract 50 and 100 mg/kg body weight per day for 15 days. Results: Administration ofT. vulgaris extract significantly restored memory and learning impairments induced by scopolamine in the passive avoidance test and Morris water maze test. Conclusions:T. vulgaris extract has repairing effects on memory and behavioral disorders produced by scopolamine and may have beneficial effects in the treatment of Alzheimer's disease.