International Journal of Pharmacy. Photon 106 (2015) 445-452 https://sites.google.com/site/photonjournals/home/international-journal-of-pharmacy Research Article. ISJN: 8237-7516: Impact Index: 5.50 Ph ton International Journal of Pharmacy The bark extracts of Himalayan gymnosperm Picea smithiana (Wall.): A natural sources of antibacterial and antioxidant agent S.C. Sati*, P. Kumar, S. Joshi Department of Botany, D.S.B. Campus, Kumaun University, Nainital-263002, India S.C. Sati, P. Kumar and S. Joshi receive Gregor Mendel Research Award- 2015 in Pharmacy Article history: Received: 13 September, 2014 Accepted: 16 September, 2014 Available online: 23 March, 2015 Keywords: Picea smithiana, phytochemical screening, antibacterial activity, and gymnosperms plant extract Abbreviations: ZOI: Zone of Inhibition, MIC: Minimum Inhibitory Concentration, MBC: Minimum Bactericidal Concentration Corresponding Author: Sati S.C.* Professor E-mail: [email protected] Kumar P. Research Scholar Joshi S. Assistant Professor Abstract The bark extract of Kumaun Himalayan gymnosperm Picea smithiana was assessed for its active principles. Flavonoids, terpenoid, tannins, alkaloids, saponin, glycosides, quinines, carbohydrates, protein, starch, resin, volatile oil, anthraquinone and phenol were found in both methanol and ethanol bark extracts. The antibacterial potential of methanol and ethanol extracts of bark was investigated against Agrobacterium tumefaciens, Bacillus subtilis, Escherichia coli, Erwinia chrysanthemi and Xanthomonas phaseoli using disc diffusion method. The extracts were further evaluated for minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Both methanol and ethanol extracts of P. smithiana bark were found effective by showing a mark zone of inhibition (ZOI). Methanol extract showed the highest inhibitory activity against A. tumefaciens (ZOI, 19 mm) while ethanol extract exhibited its highest activity for E. chrysanthemi (ZOI, 12 mm). The MIC and MBC values were recorded in the range 31.25250 µg/ml and 62.5-500 µg/ml, respectively. The lowest value of MIC and MBC were recorded against A. tumefaciens in methanol extract (31.25 µg/ml and 62.5 µg/ml respectively). The results of bark extracts were also compared with leaf extracts of P. smithiana for antimicrobial potential. Citation: Sati S.C., Kumar P., Joshi S., 2015. The bark extracts of Himalayan gymnosperm Picea smithiana (Wall.): A natural sources of antibacterial and antioxidant agent. International Journal of Pharmacy. Photon 106, 445-452. All Rights Reserved with Photon. Photon Ignitor: ISJN82377516D749323032015 1. Introduction It is a common view that the natural products are healthier, harmless and more reliable when compared to synthetic products. Nearly, about 80% of the world’s inhabitants relying mainly on traditional medicines for their primary health care (Owolabi et al., 2007). The chemical constituents of plant extracts are a part of the physiological activities of living plants and hence they are believed to have a better compatibility with the human body. It is well known that there is paucity of information on the phytochemical studies and the fraction investigated for biology or pharmacology is also quite meagre. Thus the phytochemical investigation of a given plant is Ph ton desirable as broad spectrum constituents in bioactivities. Healing potential of plant extracts is well known and antimicrobial principal is one of the elements besides other responsible for the healing. Unfortunately, in the last one decade the pace of development of new antimicrobial drug has slowed down while the prevalence of resistance (especially multiple) has increased tremendously (Hugo and Russell, 1984). To increase the alternative resources of antimicrobial drugs one approach is to explore local ethnobotanicaly known medicinal plants which have natural antimicrobial agents 445 (Khulbe and Sati, 2009). The search for novel natural bioactive compounds, a foundation to new drug discovery is receiving greater attention as previously reliable standard new strains of multi drug resistant pathogens (Muller, 2001). and Erwinia chrysanthemi were obtained from G. B. Pant University, Pantnagar, India. Figure 1. Picea smithiana , a. leaves, b. close view of bark Ethnobotanical records and available literature indicate that plants are the sleeping giants of Pharmaceutical industry (Hamburger and Hostettmann, 1991). The drugs present in medicinal plants are divided chemically into a number of groups like alkaloids, carbohydrate, protein, glycosides, terpenoids, steroids, flavonoids, tannins, saponins, starch, volatile oils, phlobatannins, resins, fat, quinone and anthroquinone (Parmer et al., 1999; Harborne and Baxter, 2001). They may provide novel or lead compounds which may be used as a natural source of antimicrobial drugs in controlling various diseases of plants and animals. Therefore, such plants should be investigated to enrich the knowledge and their properties, safety and efficacy (Nascimento et al., 2000). The most important bioactive compounds of plants are alkaloids, flavonoids, tannins and phenolic compounds that produce a definite physiologic action on the human body. The phytochemical research based on ethno-pharmacological information is generally considered an effective approach in the discovery of new anti-infective agents from higher plants (Duraipandiyan et al., 2006). 1.1 Justification/ aim Thus keeping the above account in mind the present investigation was carried out on the phytochemical and antibacterial assessment of stem bark extracts of Himalayan spruce Picea smithiana (Wall.). 2. Experimental 2.1 Materials and methods 2.1.1 Collection of plant material Picea smithiana Wall. (Pinaceae) is a beautiful ornamental big gymnospermous tree plant commonly known as west Himalayan spruce, (Fig. 1.a). The bark of P. smithiana was collected from Nainital, Kumaun Himalaya, India (Fig. 1.b) and authenticated by the Department of Botany, Kumaun University, Nainital. A voucher specimen was deposited in the herbarium. 2.1.3 Microorganisms Used Five (Gram +ve and −ve) bacteria Bacillus subtilis MTCC 121, Escherichia coli MTCC 40, Agrobacterium tumefaciens MTCC 609, were obtained from Institute of Microbial Technology, Chandigarh, India whereas Xanthomonas phaseoli Ph ton 2.1.2 Extraction procedure The bark of P. smithiana was thoroughly washed and dried at room temperature. The dried material was powdered in an electric grinder. To prepare a stock solution, 50 g of this powder was added to 200 ml of solvents (w/v). Solvents used for extraction were methanol and ethanol. Powdered bark was dissolved in solvent in 250 ml Erlenyer flask and kept in a shaker for 6-10 hrs. The prepared extract was filtered through Whatman filter paper no.1. The final filtrate was concentrated on a rotary evaporator under vacuum at 20° C and utilized for antibacterial assessment (Mohanta et al., 2007). 2.2 Phytochemical analysis of extract The phytochemical analysis of methanol and ethanol bark extracts were carried out by using standard procedures following Harborne (1998) as given below: 2.2.1 Tests for Carbohydrates Molisch’s test: 1 ml of extract was treated with few drops of Molisch’s reagent (α-naphthol, 20% in ethyl alcohol). Then about 1ml of concentrated sulfuric acid was added belatedly along the sides of the tube. Formation of violet color indicates the presence of carbohydrates. 446 Fehling’s test: 1 ml of Fehling’s A (Copper sulphate in distilled water) and 1ml of Fehling’s B (Potassium tartarate and sodium hydroxide in distilled water) reagents were mixed and boiled for minute. Then equal volume of test solution was added to the above mixture. The solution was heated in a boiling water bath. Brick red precipitate was observed, indicating the presence of carbohydrates. Iodine test: Crude extract was mixed with 2 ml of iodine solution. A dark blue or purple coloration indicated the presence of the carbohydrate. 2.2.2 Test for Proteins Millon’s test: Crude extract when mixed with 2ml of Millon’s reagent, white precipitate appeared which turned red upon gentle heating that confirmed the presence of protein. Xanthoproteic test: The extracts were treated with few drops of conc. Nitric acid. Formation of yellow colour indicates the presence of proteins. 2.2.3 Tests for Glycosides Keller- Killiani test: 1ml of glacial acetic acid containing traces of ferric chloride and 1ml of concentrated sulfuric acid, 1ml of extract was added carefully. Appearance of brown ring at the interface shows the presence of glycosides. A violet ring may also appear below the brown ring. Legal’s test: Extracts were treated with sodium nitropruside in pyridine and sodium hydroxide. Formation of pink to blood red colour indicates the presence of cardiac glycosides. Borntrager’s test: To 1ml of extract, 1ml of benzene and 0.5 ml dilute ammonia solution were added. A reddish pink color indicates the presence of glycosides. Baljet test: To 1ml of extract, 1ml of sodium picrate is added. Appearance of yellow to orange color detects the presence of glycosides. 2.2.4 Tests for Saponins Foam test: 1 ml of extract was shaken vigorously with 20 ml of distilled water for 5- 10 minutes in graduated cylinders. Formation of one centimeter layer of foam indicated the presence of saponins. 2.2.5 Test for Terpenoids Salkowski test: 5 ml of each extract was mixed in 2 ml of chloroform, and concentrated sulphuric acid (3 ml) was carefully added to form a layer. A reddish brown coloration of the inter face was formed to show positive results for the presence of terpenoids. Ph ton Trichloroacetic acid test: To 1ml of extract, 2 ml of trichloroacetic acid was added. Formation of colored precipitate showed the presence of terpenoids. 2.2.6 Tests for Phenolic compounds Ferric chloride test: Extracts were treated with 34 drops of ferric chloride solution. Formation of bluish black colour indicates the presence of phenols and tannin. Lead acetate test: On addition of lead acetate solution to the extract white precipitate appeared. Dilute HNO3 test: On addition of dilute HNO3 solution to the extract reddish colour appeared. 2.2.7 Test for Alkaloids Mayer’s test: Filtrates were treated with Mayer’s reagent (Potassium Mercuric Iodide). Formation of a yellow coloured precipitate indicates the presence of alkaloids. Wagner’s test: Filtrates were treated with Wagner’s reagent (Iodine in Potassium Iodide). Formation of brown/reddish precipitate indicates the presence of alkaloids. Dragendroff’s test: To 1 ml of extract, 2ml of Dragendroff’s reagent is added. Orange red precipitate is formed indicating the presence of alkaloids. 2.2.8 Test for Flavonoids Alkaline reagent test: Small quantity of each extract sample was taken and added with lead acetate solution. After few minutes appearance of yellow colour precipitates which indicated the presence of flavonoids. Shinoda test: To 1 ml of extract, few drops of concentrated HCl were added. To this solution 0.5 gram of magnesium turnings were added. Observance of pink coloration indicated the presence of flavonoids. Lead acetate test: To the 1 ml of extract, lead acetate solution was added. Formation of yellow precipitate showed the presence of flavonoids. Ferric chloride test: To 1ml of extract, 1ml of ferric chloride (5% in water) was added. Formation of brown color confirmed the presence of flavonoids. 2.2.9 Test for Starch To 1 ml of aqueous extract was added 10 ml of NaCl saturated solution. After heating, starch reagent was added a blue-purplish colour is a positive test for the presence of starch. 447 2.2.10 Test for Volatile Oils NaOH-HCl test: 2 ml of extract solution was shaken with 0.1ml of dilute sodium hydroxide and a small quantity of dilute HCl. A white precipitate was formed with volatile oils. 2.2.11 Test for Phlobatannins 1 ml of extract was boiled with 1% aqueous HCl. The formation of red precipitate indicated the presence of phlobatannins. 2.2.12 Tests for Resins Turbidity test Distilled water (5ml) was added to the extract. The occurrence of turbidity showed the presence of resins. 2.2.13 Test for Quinones Few drops of concentrated Sulphuric acid was added to 1 ml of extract appearance of red colour indicate the presence of quinons. 2.2.14 Test for Tannins In 1 ml of extract add few drops of 5% FeCl3. Appearance of green colour indicates presence of gallotannin, and brown colour indicates the presence of tannins. 2.2.15 Test for Fat Few drops of sudanIII added in to 1 ml of extract, red colour appears with oil droplets. 2.2.16 Test for Anthraquinones Few drops of concentrated Sulphuric acid were added to 5 ml of extract. To this solution 1 ml of ammonia was added. Appearance of rose-pink colour indicates presence of anthraquinones. 2.3 Screening for Antibacterial Activity Antibacterial tests of P. smithiana bark extract on selected microorganisms were carried out using disc-diffusion method (Bauer et al., 1966). A small sterile cotton swab was dipped into the 24-hour-old culture of bacteria and was inoculated by streaking the swab over the entire agar surface. After inoculation the plates were allowed to dry at room temperature in laminar chamber. The filter paper discs (5 mm) loaded with 40µl of extract were placed on the surface of the agar plates. After 5 min the plates were kept for incubation at 37±2° C for 24 h. Gentamycin (30 mg) was used as positive controls and the respective solvent were taken as negative control. After 24 h of incubation, the dishes were observed for bioactivity (Plate- 1) and the diameter was observed for zone of inhibition (ZOI). All tests were performed in triplicate and observed values of ZOI are expressed as mean value with standard error of means (SEM). Ph ton 2.4 Determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) All the fractions were further tested for the minimum inhibitory concentration and minimum bactericidal concentrations. MIC was performed at seven concentrations of extracts (500, 250, 125, 62.5, 31.25, µg/ml) following serial dilution technique. All the discs showing no visible growth of microorganisms were sub cultured and incubated at 37°C for overnight. The highest dilution showing 100% inhibition was recorded as MBC. 3. Results The results of phytochemical screening of the stem bark of P. smithiana are listed in table-1. It is evident from the test that the ethanolic and methanolic extract of bark contain carbohydrates, glycosides, proteins, saponins, terpenoids, tannins, phenol, alkaloids, flavonoids, starch, volatile oils, resins, quinines and anthraquinone, while it was found negative for fat and phalobatanins acids (Table 1). The antimicrobial activity against 3 plants pathogenic and 2 animal pathogenic microorganisms at 1000 µg/ml concentration of P. smithiana bark extract in the form of ZOI (Zone of Inhibition) is presented in (Table 2). The preliminary antibacterial screening indicated that the methanol extract and ethanol extract of P. smithiana are effective against the test organisms. Both the extracts of P. smithiana showed a significant zone of inhibition ranging from 9-19 mm (ZOI). The results showed that methanol extract was more active against all the tested bacterial strains than ethanol extract. The highest ZOI was observed for A. tumefaciens at 1000 µg/ml concentration. Ethanol extract showed the lowest activity among all other extract of P. smithiana bark. Its highest activity was found against E. chrysanthemi having ZOI 12 mm. The range of MIC and MBC values of extracts were 62.5-500µg/ml and 125-500 µg/ml respectively (Table. 3). The lowest MIC 31.25 µg/ml was recorded against A. tumefaciens and B. subtilis for methanol extract and against A. tumefaciens for chloroform extract. The lowest MBC value was observed against A. tumefaciens for methanol extract. It is interesting to note that all the fractions were found active against all the tested microbes (Table 2-3). 4. Discussion The use of medicinal plants as natural remedies is considered more effective and safe alternative treatment of various diseases because most of the 448 Table 1: Phytochemical evaluation of P. smithiana bark extracts Plant Observation Metabolites Ethanol Methanol extract extract Carbohydrates + + Glycoside + + Protein + + Saponins + + Terpenoids + + Tannins + + Phenol + + Alkaloids + + Flavonoids + Starch + + Volatile oils + + Phlobatannins Resins + + Quinones + + Fat Anthraquinone + + Key; + = present; - = absent Table 2: Antibacterial activity of different extracts of P. smithiana bark Microorganisms E M G A. tumefaciens 9±0.7 19±0.7 23±0.5 B. subtilis 11±0.7 16±0.6 25±0.6 E. 12±0.6 15±0.3 21±0.4 chrysanthemi E. coli 10±1.2 14±1.4 23±0.6 X. phaseoli 11±0.7 14±1.4 24±0.6 *All the values are mean ± Standard Error of Mean (SEM) of three determinations E- Ethanol, M- Methanol; G – Gentamycin (+control) Table 3: Antibacterial activity of different extracts of P. smithiana leaves (Based on Sati and Joshi, 2013 for comparison) Microorganisms A. tumefaciens B. subtilis E. chrysanthemi E. coli X. phaseoli Diameter of Inhibition Zone (mm)* 17±0.3 22±1.4 21±0.0 11±0.6 na 13±0.3 21±0.3 13±0.6 13±0.6 22±0.0 20±0.9 21±1.9 22±1.3 26±1.8 21±1.0 Table 4: MIC and MBC evaluation of P. smithiana bark Concentration (µg/ml) Microorganisms Ethan Methanol ol MIC MBC MIC MBC A. tumefaciens 250 500 31.25 62.5 B. subtilis 125 250 31.25 125 E. chrysanthemi 62.5 125 62.5 125 E. coli 62.5 250 62.5 125 X. phaseoli 62.5 125 31.25 250 bacteria have developed resistance against commercially available antibiotics. Moreover antibiotics may cause some side effects like allergic Ph ton reactions as well as, disturbances of normal fauna of intestine. The available literature indicates that Picea has been used for remedies of some ailments (Karting et al., 1999; Canillac and Mourey, 2001; Radulescu et al., 2011; Liu et al., 2011). Recently Sati and Joshi (2013) reported antibacterial potentialities of P. smithiana leaves. The present study screened the phytochemical and antibacterial properties of methanol and ethanol extract of stem bark of P. smithiana. As evident from table-1 the stem bark of studied plant contains various phytochemical groups and methanol extracts showed the presence of maximum phytoconstituents as compared to other extracts. It may be due the fact that methanol, was comparatively more polar in nature. Thus the preliminary phytochemical screening would be useful in the detection of bioactive principles and drug discovery from this studied plant material. Antimicrobial properties of substances are desirable tools in the control of infectious diseases microorganisms. The active components usually interfere with growth and metabolism of microorganisms in a negative manner (Aboaba et al., 2006). Several phenolic compounds like tannins present in the cells of plants are potent inhibitors of many hydrolytic enzymes such as proteolytic macerating enzymes used by plant pathogens. Similarly saponins and glycosides also have antifungal as well as hydrolyzing properties to release phenolics which are toxic to microbial pathogens (Aboaba et al., 2001). Due to stressful climatic and geophysical conditions, Kumaun Himalaya plants offer greater possibilities of having novel molecules and even larger quantities of active compounds (Kaul, 2010, Sati and Joshi, 2011). Phytochemicals may be described as non-nutritive plant chemicals that have protective or disease preventive properties. They are regarded as non essential nutrients (Okwu and Okwu, 2004). The preliminary phytochemical analysis and antibacterial assessment of P. smithiana bark showed promising results. Thus the present investigation would be a milestone in the qualitative phytochemical analysis and antimicrobial potentiality of high altitude Kumaun Himalayan gymnospermous plant. Recently Sati and Joshi (2013) studied the antimicrobial activity of P. smithiana leaf extracts. Their findings are summarised in (Table-4) compared with results of present study on bark extracts. As evident from Fig 2 and 3 the ethanol and methanol leaf extracts had slightly better activity than bark but it should also keep in mind that barks are considered composed a waste products of plant. The results of the present study also showed that the bark extracts of P. 449 smithiana contain many phytochemical components which are potentially significant against many microbes responsible for various diseases. alkaloids, saponin, glycosides, quinines, carbohydrates, protein, starch, resin, volatile oil, anthraquinone and phenol were found in both methanol and ethanol bark extracts. Graphical Abstract The antibacterial potential of methanol and ethanol extracts of bark was investigated against Agrobacterium tumefaciens, Bacillus subtilis, The bark extract of Kumaun Himalayan gymnosperm Picea smithiana was assessed for its active principles. Flavonoids, terpenoid, tannins, Ph ton 450 Escherichia coli, Erwinia chrysanthemi and Xanthomonas phaseoli using disc diffusion method. Both methanol and ethanol extracts of P. smithiana bark were found effective by showing a mark zone of inhibition (ZOI). Methanol extract showed the highest inhibitory activity against A. tumefaciens (ZOI, 19 mm) while ethanol extract exhibited its highest activity for E. chrysanthemi (ZOI, 12 mm) The MIC and MBC values were recorded in the range 31.25-250 µg/ml and 62.5-500 µg/ml, respectively. The lowest value of MIC and MBC were recorded against A. tumefaciens in methanol extract (31.25 µg/ml and 62.5 µg/ml respectively). The results of bark extracts were also compared with leaf extracts of P. smithiana for antimicrobial potential. Justification of research Kumaun Himalayan gymnosperm Picea smithiana extracts have been used in traditional medicine since time immemorial to control various types of human diseases. Form the literature survey it is revealed that no substantial work has been carried out on the bark of P. smithiana. Hence, an effort was made to investigate the phytochemical analysis and antimicrobial activity. Antimicrobial activity help to confirm the inhibitory potential of extracts while phytochemical screening suggest the presence of secondary metabolites in plant which will be helpful to discover novel natural compounds. In the present study we focused the antibacterial potential of different concentration of P. smithiana bark extracts against gram positive and gram negative bacterial strains. Conclusion Relying upon the results obtained it can be concluded that the bark extracts of Kumaun Himalayan gymnosperm Picea smithiana has antimicrobial potentialities against the bacterial strains. Out of the two extracts i.e. ethanol and methanol, ethanolic extract showed greater antibacterial activity than methanolic extract. The phytochemical screening of the bark extracts of P. smithiana also indicate that the presence of some compounds i.e. alkaloids, flavonoids, tannins and phenols which are not only useful for antimicrobial but also as antioxidant. 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