Identification of phenolic compounds and evaluation of antibacterial properties of Piper sarmentosum Roxb. against rice pathogenic bacteria

Aims: Piper sarmentosum Roxb. has a long history of medicinal usage and potential in treating many diseases and ailments. It is known for its medicinal properties and contains a variety of active chemical compounds. This study was conducted to identify and quantify the phenolic compounds of the leaf and fruit extract of P. sarmentosum, as well as their antibacterial activities. Methodology and results: High Performance Liquid Chromatography (HPLC) was carried out to identify the phenolic compounds in the samples. Antibacterial performance of the samples was measured using agar well and disc diffusion assay, where its MIC values were then determined. After going through HPLC-UV, the major phenolic compounds identified in both extracts were tannic acid, gallic acid, quercetin and naringin. The leaf and fruit of P. sarmentosum exhibited moderate to strong antibacterial activity when tested against pythopathogenic bacteria with an inhibition range of 10.67-17.33 mm at 100 mg/mL. Conclusion, significance and impact of study: The leaf and fruit extracts of P. sarmentosum were proven to have effective inhibitory effects on Pseudomonas fuscovaginae and Xanthomonas oryzae pv. oryzae, which are also the causal agents of sheath brown rot and bacterial leaf blight in rice. This is believed to be due to the presence of the phenolic compounds in these samples. In a subsequent study, the researchers are planning to apply a formulation, developed from the crude extract, in the glasshouse and field trial.

How likely does the Microenvironnmental Interaction at a Pesticide-Treated Farming Village could Potentially Affect their Community through Dermal Pathway in a Developing Country, Malaysia?

This paper aims to investigate the potential pesticide dermal contamination among the agricultural community by observing the microenvironmental and macroactivity interaction between farm children and adult farmer. A 24 hours timeline activity was observed and recorded in the agricultural farming village, Kuala Selangor. In this study, 2 homes were monitored for 2 days following a pesticide application. A total of 2 adult farmers and 5 children (7-10 year old) were recruited to participate in this study. Twenty-four hour videotape segments and time-activity diaries were collected during the study. The microenvironment and macroactivity interaction were modelled in this study. By considering only the potential dermal exposure pathway, the different biological vulnerability and exposure pattern to pesticides were observed. Finding showed a greater extent of interaction between human and its environment, where adult farmers are the main contributor of environmental contaminants, and children is one of the vulnerable receivers of the contaminants’ residuals from the environment. The daily activities and behaviors practiced by the agricultural community were among the contributing factors which help to highlight the pesticide dermal contamination pathway in the farming village. This study recommends the necessary to consider the microenvironment and macroactivity of the target community when assess their exposure levels to the environment contaminants.​