Quality Control of Certain Herbal Products and Their Individual Components Used for Digestive Tract Disorders and Their Proposed Mechanism

Abstract

Aims: To assess the quality of fifteen plants in three herbal tea products (1,2 and 3) used in the Egyptian market for the alleviation of digestive tract disorders, namely; constipation, diarrhea and flatulence, respectively and evaluate antioxidant activity of the volatile oils of some individual components of herbal teas. Study Design: The presence of pesticides, heavy metals, microbial contaminant was documented. Moreover, some pharmacopoeial constants were calculated. In addition, the chemical compositions of their essential oils were determined and their antioxidant activities were assessed. Place and Duration of Study: Department of Pharmacognosy Faculty of Pharmacy, Misr University for Science and Technology, Agricultural Pesticide Committee (APC) and Micro Analytical Center, Cairo University between February 2012 and July 2013. Methodology: Analysis of the pesticides and the essential oils were performed using GC/FID and GC/MS and determination of heavy metals was carried out using wet digestion method. Microbial contaminants were detected by serial dilution method and the pharmacopoeial constants was evaluated according to their official methods. The antioxidant activity was assessed using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging capacity assay. Results: Out of thirteen organochlorine pesticides residues were studied p,p-DDT is present in all the samples (0.0003- 0.05 mg/kg). All the tested products were regarded as safe based on the WHO measurements. However, all the herbal teas exceeded the accepted limits of fungal (yeast) and pathogenic bacteria (E. coli) by the FIP. The total concentrations of aflatoxins in the three samples were 1.25, 0.52 and 3.43 μg/kg respectively. In addition, results indicated to the absence of cadmium and lead. Based on the GC analyses, altogether 112 volatile components were identified in the essential oils of nine plants belonging to Apiaceae, Asteraceae and Lamiaceae. Regarding to families Apiaceae, Asteraceae and Lamiaceae the major constituents were Anethole 93.52%, α-Bisabolol oxide B 69.55% and 1-terpinen-4-ol 33.99% respectively. The antioxidant activity confirmed that anise and dill oils showed the highest antioxidant activity as evidenced by their IC50 being 4.218 and 4.930 mg/ml, respectively. While, marjoram and fennel oils exhibited moderate activity displaying IC50 values of 12.158 and 14.413 mg/ml, respectively. Conclusion: All the three herbal teas were considerably safe for human consumption as recommended by the different pharmacopeias. Moreover, it was proposed that their antioxidant activity might be the core of their efficacy being effective in the maintenance of the integrity and function of the gastrointestinal tract in addition to prohibition of free radicals that predispose inflammation.