Browsing by Author "Heenkenda, A.P."

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    Assessment of the antibacterial activity and genetic diversity of three black pepper varieties (Piper nigrum Linn.)
    (Uva Wellassa University of Sri Lanka, 2013) Karunathilaka, K.A.S.; Pathirana, P.R.S.; Rajapaksha, I.G.M.; Thilakarathne, L.; Heenkenda, A.P.; Senevirathne, J.M.; Dunuwille, S.W.M.B.; Sooriyapathirana, S.D.S.S.
    Piper nigrum (black pepper) is an important spice to enhance flavor, color, aroma and taste of food. Black pepper is also considered as a medicinal plant species which is used to treat asthma, chronic indigestion, obesity, sinus, congestion and fever (Ravindran, 2000). It has an antibacterial activity further highlighting its medicinal importance (Dorman and Dean, 2000). In Sri Lanka, black pepper is considered as one of the important export agricultural crops. However, neither medicinal properties nor the antibacterial effect of pepper in Sri Lankan pepper germplasm has been studied in detail. In neighboring India, there were reports on the antibacterial activity of pepper on Bacillus cereus and Bacillus subtilis (Perez and Anesini, 1994). According to Chaudhry and Tariq, (2006) “piperine, ([1-[5-[1, 3-benzodioxol-5-yl]-1- oxo-2, 4, pentadienylpiperridine), a pungent alkaloid present in black pepper enhances the bioavailability of various structurally and therapeutically diverse drugs”. The genetic diversity of pepper germplasm has been studied using Inter-Simple Sequence Repeat (ISSR) markers, microsatellite markers and Randomly Amplified Polymorphic DNA (RAPD) markers. The present study was conducted to assess the antibacterial activity of pepper oleoresin (an extract from pepper) from three varieties of P. nigrum in Sri Lanka and also to assess their genetic diversity using RAPD markers. Methodology P. nigrum samples: three P. nigrum varieties, Panniyur-1, MB12 and GK49 were used for the analysis. Seeds were collected from these three varieties to extract oleoresin and young leaves were picked to extract DNA. The samples were collected from Central Research Station, Department of Export Agriculture, Matale, Sri Lanka. Preparation of oleoresin: pepper seeds were ground into a fine powder using a mechanical grinder. Ten grams of powder was weighed and filled into a thimble. The thimble was placed in a Soxhelt apparatus and was exposed to several cycles of distillation. The concentrated solution was rotary evaporated to extract the oleoresin. Evaluation of the antibacterial activity: the antibacterial activity of pepper oleoresin against Escherichia coli (Ingerson-Mahar and Reid, 2011) and Staphylococcus aureus using agar well diffusion method. Mueller Hinton agar plates were prepared. The two strains of microbial solution were prepared with compared to the 0.5 McFarland solution and then they were spreaded on the agar surfaces. Wells were cut by using sterile cork borer and bottom of the wells was sealed with a little bit of medium. Pepper oleoresins were loaded in to the wells by using a micropipette and petri dishes were finally incubated at 37 C for overnight in an incubator.