Antibacterial Activity of Pluchea indica and Piper betle Ethanol Extract on Staphylococcus epidermidis and Pseudomonas aeruginosa

Medicinal plants are widely used for the treatment of different infectious diseases. This study was aimed to investigate antibacterial activity of Pluchea indica (P. indica) and Piper betle (P.betle) ethanol extract on Staphylococcus epidermidis (S. epidermidis) and Pseudomonas aeruginosa (P. aeruginosa) using agar disk diffusion method. Ethanol extract of Piper betle showed more potent antibacterial activity than P. indica against S. Epidermidis with the highest inhibiton zone at 30.71 mm and 21.73 mm from 1 mg/ml concentration, respectively. In contrast, against P. aeruginosa, the ethanol extract of P. indica was more potent than P. betle with 21.44 mm and 20.12 mm of inhibition zone on 1 mg/ml concentration, respectively. There was no increased effect from the combination of these two extracts against these bacteria. When comparing the antibacterial activity of these extract with tetracycline as the standard, we found that antibacterial activity of P. indica at the concentration of 0.9 mg/ ml was comparable with that of tetracycline at concentration of 12.52 μg/ml, while P. betle needed 0.3 mg/ml concentration to had similar activity with 10.51 μg/ml of tetracycline. In conlusion, the antibacterial activity of ethanol extracts of P. indica and P. betle indicated that these extract had sufficient potential to warrant further examination and development as a new antibacterial agent.


Introduction
Inappropriate use of antimicrobial drugs contributes to the emergence and spread of drug resistant.2][3] Medicinal plants are widely used empirically for the treatment of infectious disease.Investigation of safety and efficacy of these plants as the candidate of potential antimicrobial agent is considered necessary. 4,5donesia has enormous variety of medicinal plants, including Piper betle (P.betle) and Pluchea indica (P.indica).P. betle is usually used for the treatment of mouth ulcers, hemorrhoids, stomach disorders, etc. P. indica is known as body deodorizing agent.[8][9][10] Pharmacology and Clinical Pharmacy Research e-ISSN: 2614-0020 Staphylococcus epidermidis (S. epidermidis) and Pseudomonas aeruginosa (P.aeruginosa) are two most prevalent bacterial pathogens infecting respiratory disease, urinary tract, eyes, and burn wounds.Their presence was associated with poor patient outcomes. 11,12evious studies showed that P. indica extract could inhibit the growth of several gram-positive bacteria, including B. cereus, B. subtilis, and S. aureus.P. betle also had potential antibacterial activity against S. aureus, E. coli, S. typhi, and S. dysenteriae. 13,14owever, there is a lack of study investigating antibacterial activity of these extracts against S. epidermidis and P. aeruginosa.Therefore, we conducted this study to investigate antibacterial activity of ethanol extract of P. indica and P. betle against S. epidermidis and P. aeruginosa.

Materials and instruments
The materials used in this study included P.
Each petri dish was incubated at 37 °C for 18-24 hours.After incubation, the clear zone formed around the hole was measured in diameter by using a vernier caliper.The concentrations which gave inhibiton zone more than 20 mm in the first experiment were selected and combined.The similar antibacterial testing was then performed for these combination.

Antibacterial activity compared to tetracycline
Comparation of antibacterial activity between these extracts and tetracycline aimed to understand the extent to which antibacterial diameter of perforator: 9 mm activity of the extract was similar with that of standard treatment.The score was obtained by comparing inhibition zone of the extract and the standard.The result of comparative observation was then illustrated in a curve with concentration log data on x-axis and inhibiton zone diameter (mm) on y-axis.This curve was used to compare the substance which had the highest antibacterial activity.

Results and Discussion
Phytochemical screening result showed that both extracts contained alkaloids, flavonoids, tannins, phenolics, monoterpenes, steroids, triterpenoids and quinones (Table 1 and 2).Table 3 shows the result of antibacterial activity from P. indica and P. betle leaves ethanol extract against S. epidermidis and P. aeruginosa bacteria.We found that mean inhibiton zone diameter of P. indica extract against S. epidermidis was 21.73 mm at 1 mg/ ml concentration and against P. aeruginosa was 21.44 mm with the same concentration.P. betle could produce inhibitory zone with diameter of 21.92 mm at concentration 0.4 mg/ml against S. epidermidis, while against P. aeruginosa, it gave 20.12 mm inhibitory zone with the same concentration.Table 4 shows the inhibitory zone of combination of these extracts.There was a difference in inhibitory diameter for both bacteria.For S. epidermidis, combination 1 (0.15 mg / ml P. betle and 0.45 mg/ml P. indica) gave a mean inhibitory diameter of 20.15 mm, while against P. aeruginosa it could produce a mean inhibitory diameter of 18.43 mm.Combination 2 gave inhibitory diameter of 21.19 mm and 22.41 mm, against S. epidermidis and P. aeruginosa respectively.There was no increased effect of antibacterial acitivity of combined extract of P. indica and P. betle.diameter of perforator: 9 mm tested for their antibacterial activity against S. epidermidis and P. aeruginosa using the agar diffusion method.The results of the test can be seen in Table 5.The result of tetracycline standard curve with log concentration data on x-axis and inhibitory diameter (mm) on y-axis was illustrated in figure 1.Based on linear regression equation with y = 4.558 x + 16.76 R 2 = 0,942 in Figure 1, for P. aeruginosa bacteria, activity produced by P. indica at concentration of 1 mg/ml was comparable with that of tetracycline at the concentration of 9.89 μg/ml.The antibacterial activity produced by P. betle at the concentration of 1 mg/ml was comparable with that of tetracycline at 11.49 μg/ml.The combination 1 (0.3 mg/ml P. betle and 0.45 mg/ml P. indica) was comparable to 14 μg/ ml tetracycline while combination 2 (0.5 mg/ml P. betle and 0.5 mg/ml P. indica) was equivalent to 10 μg/ml (Figure 1).

Various concentration of tetracycline were
Based on linear regeression equation with y = 4,554x + 17,84 with R² = 0.940 in Figure 2, for S. epidermidis bacteria, antibacterial activity of P. indica at concentration of 0.9 mg/ml was comparable with that of tetracycline at 12.52 μg/ml, and the antibacterial activity produced by P. betle at 0.3 mg/ml was comparable with 10.51 μg/ml tetracycline.The activity produced by combination 1 was comparable with 12.92 μg/ml tetracycline and combination 2 was equivalent to the activity of tetracycline at the concentration of 9.98 μg/ml.
Our finding was comparable with previous studies. 14,15Bioactive compounds which might contribute in the antibacterial activity of these plants were dependent on solvent system.Previous study showed that organic solvent could retain more antibacterial compunds compared to water solvent.Since our study used ethanol solvent for extraction, the result was comparable.Several studies reported that terpenoid, flavonoid, alkaloid, and tannin were responsible for the antibacterial acitivity. 16

Conclusion
The ethanol extract of P. betle showed more potent antibacterial activity against S. epidermidis compared to P. indica, while against P. aeruginosa, P. indica was more potent than P. betle.There was no increased effect from the combination of these extracts against two bacteria.P. indica and P. betle had sufficient potential to warrant further examination and development as a new antibacterial agent.Further research might be needed to identify and isolate bioactive substances which contribute in antibacterial activity from these plants.

Figure 1 .
Figure 1.Standard curve of tetracycline antibacterial activity against P. aeruginosa Log Concentration of Tetracycline (µg/ml)

Figure 2 .
Figure 2. Standard curve of tetracycline antibacterial activity against S. epidermidis Log Concentration of Tetracycline (µg/ml)

Table 1 . Phytochemical screening of P. betle
betle leaves, P. indica leaves, S. epidermidis and P. aeruginosa.Agar nutrient solution was obtained by dissolving it with distilled water and stirring it on water bath until a clear solution was obtained.20 ml sterilized agar nutrient solution was put into petri dishes.50 μl bacterial suspension was added into petri dish.It was then homogenized until hardened agar formed.Using perforator, a hole was formed on each agar with a diameter of 10 mm.50 μl of various concentration of P. indica and P. betle extracts were put in each