Molecular authentication of Maytenus sp by PCR-RFLP

Resumo

Maytenus aquifolia and Maytenus ilicifolia are native plants from South America and popularly known as ‘Espinheira-santa’. Both are used as tea due to their efficiency in the treatment of ulcer, gastritis and indigestion. However, adulteration of processed Maytenus genus tea with Sorocea genus may happen due to their botanical similarity, compromising the quality of the products and opening a derogatory business opportunity that may lead to the discrediting of medicinal plant products. This study aimed to distinguish Maytenus sp and Sorocea bonplandii by PCR-RFLP of a chloroplast DNA (cpDNA) intergenic region. Three commercial products of processed tea leaves of Maytenus sp, and in natura leaves of Maytenus sp and S. bonplandii were analyzed. PCR detected unique fragments for all samples in natura. The trnH-psbA region amplicon of both M. ilicifolia and M. aquifolia was 660 bp, and for S. bonplandii was 565 bp. These PCR products can be used as markers to distinguish the two genera. Forty-five percent of the processed samples presented only Maytenus genus, without adulterations. However, the amplification of 38% of the samples suggests adulteration with S. bonplandii while 17% seem to be adulterated with another plant (fragment of 649 bp in brand A and 690 bp in brand B). Three out of the fifteen restriction enzymes were able to detect M. ilicifolia and M. aquifolia in natura and in processed leaf samples. It was concluded that PCR technique is efficient to distinguish Maytenus sp from S. bonplandii, and other adulterating plants in processed commercial products of ‘Espinheira-santa’ tea. The trnH-psbA spacer of cpDNA is easily amplified and has satisfactory discriminating capacity to help in authentication processes of samples of the genera in natura and in processed plants.