Antimicrobial activity of selected indigenous medicinal herbs against human pathogenic bacteria

The traditionally use of indigenous medicinal plants in the treatment of burn, dermatrophytes and human infectious diseases and also still essential part of primary public health care. Antimicrobial activities of nine medicinal plants were determined in vitro through agar well diffusion method against pathogenic microorganism species of gastrointestinal tract. Medicinal plants extract of Cocculus pendulus, Malva neglecta, Rhazya stricta, Jaubertia aucheri, Corchorus depressus, Salvia bucharica, Microcephala lamellate, Berberis baluchistanica and Artemisa absinthium were found sensitive to Clostridium spp. The extracts of Malva neglecta, Jaubertia aucheri, Salvia bucharica and Berberis baluchistanica were observed sensitive to E. coli. Similarly the extracts of Malva neglecta, Jaubertia aucheri, Rhazya stricta, Corchorus depressus, and Artemisa absinthium were found sensitive to Salmonella spp. The extracts of Cocculus pendulus, Malva neglecta, Jaubertia aucheri, Corchorus depressus, Salvia bucharica, Microcephala lamellate, Berberis baluchistanica and Artemisa absinthium were sensitive to Shigella spp. The extracts of Cocculus pendulus, Jaubertia aucheri and Berberis baluchistanica were found sensitive to Klebsiella spp. The extracts of Cocculus pendulus, Rhazya stricta, Corchorus depressus, Microcephala lamellate and Artemisa absinthium were revealed resistance to E. coli. The extracts of Cocculus pendulus, Salvia bucharica, Microcephala lamellate and Berberis baluchistanica were revealed resistance to Salmonella spp. The extract of Rhazya stricta was revealed resistance to Shigella spp. The extracts of Malva neglecta, Rhazya stricta, Corchorus depressus, Salvia bucharica, Microcephala lamellate and Artemisa absinthium were revealed to resistance to Klebsiella spp. The extract of Jaubertia aucheri was highly sensitivity against E. coli, Salmonella spp, Shigella spp, Clostridium spp and Klebsiella spp.


Introduction
The herb meaning is grass which derived from the Latin word "herba", and primarily it was applied to a wide range of leafy vegetables.Herbs are seed plants that do not produce woody stems like a tree and live long enough to develop and produce flowers and seeds [1].Many decades herbs have been used for their flavor, medicinal, antimicrobial and anti-oxidative properties.The most important part of herbs are considered as powerful tools to establish wellness such as stimulate production of enzymes that detoxify carcinogens, inhibit cholesterol synthesis, block estrogen, lower blood pressure and prevent blood clotting [2].In addition herb plants providing nutrition and have an important source of chemical compounds, which could be used for medicinal purposes by human.According to the ancient human knowledge the importance of medicinal plants are date back to many centuries ago [3].However, medicinal plants have been used as traditional medicine with excellent efficacious remedies and serve as dietary source to animals and humans.The plants provide sufficient nutrients to meet the metabolic requirements for their health, growth and productivity and also play essential role reducing the risk or delaying the onset of diseases and disorders [4], [5].The world's population approximately 80% relies on traditional medicine for their primary health care.

Preparation of plants extract
The plant samples were dried and grind into fine powder by using a blender (ANEX-AG-179 GL).The samples were soaked in 50 ml methanol (LAB-SCAN ASIA Co., LTD) and shake twice a day, placed for two weeks at room temperature (25 0 C).After two weeks, the mixture was twice filtered by Watt-man No-14 filter paper (Watt-man Grade 14), than methanol was completely evaporated by the help of rotary evaporator (Buchi Rotaryevaporator Model R-205).The obtained semisolid extracts were kept (open air) for two days and the extracts were stored at 8 0 C for the further analysis [17].

Pathogenic microorganisms
The human pathogenic microorganisms such as E. coli, Salmonella spp, Shigella spp, Clostridium spp and Klebsiella spp were used for antibacterial activity.The bacteria were purified and biochemically characterized through different selective media (MacConkey Reinforced Clostridium and Salmonella-Shigella agar media), and tests (Indole, MR-VP and Sugar fermentation tests).The entire tests were performed three times at 37 0 C and were incubated according to bacteria.

Preparation of medium
Brain heart infusion broth and agar (1.5%) were prepared by using distilled water for the growth of bacteria and pH of the medium was adjusted at 7.0 pH.The dissolved medium was autoclaved at 15 lbs pressure at 121 0 C for 15 minutes.Three times experiments were performed to the confirmation of the sensitivity and resistance on herbal extracts for bacterial growth.

Agar well diffusion method
Agar diffusion method was used to determine the antimicrobial activity of medicinal plants.The 6 mm holes were made in agar plate and 50 ul extract solution was poured in it.After 24hrs the zone of inhibition was recorded.

Results
The antimicrobial activity of methanol extracts of 9 (nine) indigenous medicinal herbs were investigated by using agar well diffusion method against human pathogenic bacteria such as E. coli, Salmonella spp, Shigella spp, Clostridium spp and Klebsiella spp.
In the agar well diffusion method the Cocculus pendulus extract showed maximum zone of inhibition against Clostridium spp, Klebsiella spp, Shigella spp while E. coli and Salmonella spp were resistance to Cocculus pendulus extract as shown in Table 1.

Biochemical tests
Different biochemical tests were performed for the confirmation of Gram negative and Gram positive bacteria as shown in Table 10.

Table 1 .
Zone of inhibition on Cocculus pendulus extract against pathogenic bacteria

Table 2 .
Zone of inhibition on the Malva neglecta extract against pathogenic bacteria

Table 3 . Zone of inhibition on the Jaubertia aucheri extract against pathogenic bacteria Botanical Name Common Name E. coli Salmonella spp Shigella spp Clostridium spp
The Rhazya stricta extract showed maximum zone of inhibition against Clostridium spp, Salmonella spp while Klebsiella spp, Shigella spp and E. coli were resistance to Rhazya stricta extract as shown in Table4.

Table 7 . Zone of inhibition on the Microcephala lamellate extract against pathogenic bacteria Botanical Name
The Berberis baluchistanica extract showed maximum zone of inhibition against E. coli, Clostridium spp, Shigella spp and Klebsiella spp while Salmonella spp were resistance to Berberis baluchistanica extract as shown in Table8.