Plants are a source of large amount of drugs comprising to different groups such as antispasmodics, emetics, anti-cancer, antimicrobials etc. A large number of the plants are claimed to possess the antibiotic properties in the traditional system and are also used extensively by the tribal people worldwide. It is now believed that nature has given the cure of every disease in one way or another. Plants have been known to relieve various diseases in Ayurveda. Therefore, the researchers today are emphasizing on evaluation and characterization of various plants and plant constituents against a number of diseases based on their traditional claims of the plants given in Ayurveda. Extraction of the bioactive plant constituents has always been a challenging task for the researchers. In this present review, an attempt has been made to give an overview of certain extractants and extraction processes with their advantages and disadvantages.

https://www.researchgate.net/file.PostFileLoader.html?id=52ecff43cf57d71b748b45c9&assetKey=AS%3A272427580362754%401441963204700

Phytochemical screening and Extraction: A Review

Natural products from medicinal plants, either as pure compounds or as standardized extracts, provide unlimited opportunities for new drug leads because of the unmatched availability of chemical diversity. Due to an increasing demand for chemical diversity in screening programs, seeking therapeutic drugs from natural products, interest particularly in edible plants has grown throughout the world. Botanicals and herbal preparations for medicinal usage contain various types of bioactive compounds. The focus of this paper is on the analytical methodologies, which include the extraction, isolation and characterization of active ingredients in botanicals and herbal preparations. The common problems and key challenges in the extraction, isolation and characterization of active ingredients in botanicals and herbal preparations are discussed. As extraction is the most important step in the analysis of constituents present in botanicals and herbal preparations, the strengths and weaknesses of different extraction techniques are discussed. The analysis of bioactive compounds present in the plant extracts involving the applications of common phytochemical screening assays, chromatographic techniques such as HPLC and, TLC as well as non-chromatographic techniques such as immunoassay and Fourier Transform Infra Red (FTIR) are discussed.

/pdf/extraction-isolation-and-characterization-of-bioactive-1j6nvrmsjv.pdf

Extraction, Isolation and Characterization of Bioactive Compounds from Plants' Extracts

Antimicrobial activity of 18 ethnomedicinal plant extracts were evaluated against nine bacterial strains (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Ervinia sp, Proteus vulgaris) and one fungal strain (Candida albicans). The collected ethnomedicinal plants were used in folk medicine in the treatment of skin diseases, venereal diseases, respiratory problems and nervous disorders. Plants were collected from Palni hills of Southern Western Ghats and the ethnobotanical data were gathered from traditional healers who inhabit the study area. The hexane and methanol extracts were obtained by cold percolation method and the antimicrobial activity was found using paper disc diffusion method. All microorganisms were obtained from Christian Medical College, Vellore, Tamil Nadu, India. The results indicated that out of 18 plants, 10 plants exhibited antimicrobial activity against one or more of the tested microorganisms at three different concentrations of 1.25, 2.5 and 5 mg/disc. Among the plants tested, Acalypha fruticosa, Peltophorum pterocarpum, Toddalia asiatica,Cassia auriculata, Punica granatum and Syzygium lineare were most active. The highest antifungal activity was exhibited by methanol extract of Peltophorum pterocarpum and Punica granatum against Candida albicans. This study evaluated the antimicrobial activity of the some ethnomedicinal plants used in folkloric medicine. Compared to hexane extract, methanol extract showed significant activity against tested organisms. This study also showed that Toddalia asiatica, Syzygium lineare, Acalypha fruticosa and Peltophorum pterocarpum could be potential sources of new antimicrobial agents.

/pdf/antimicrobial-activity-of-some-ethnomedicinal-plants-used-by-3ztfdlf0ld.pdf

Antimicrobial activity of some ethnomedicinal plants used by Paliyar tribe from Tamil Nadu, India.

Certain plants products widely used in the traditional medicine system of India were studied for immunostimulant activity. In the present study, strong stimulation of antigen specific and non specific immunity was evidenced by increase in haemagglutinating antibody (HA) titre, plaque forming cells (PFC) and in macrophage migration index (MMI), in mice fed with 50% ethanolic extract of these plants. The observation provides scientific basis for wide spread use of these plant products which are likely to play a role in Indian traditional medicine as tonic for rejuvenation therapy and chronic ailments.

	Key words: Macrophage migration index, haemagglutinating antibody, immunostimulant.

/pdf/techniques-for-evaluation-of-medicinal-plant-products-as-5emujvyl0b.pdf

Techniques for evaluation of medicinal plant products as antimicrobial agents: Current methods and future trends

Medicinal plants have recently received the attention of the pharmaceutical and scientific communities and various publications have documented the therapeutic value of natural compounds in a bid to validate claims of their biological activity. Attention has been drawn to the antimicrobial activity of plants and their metabolites due to the challenge of growing incidences of drug-resistant pathogens. Some plants have shown the ability to overcome resistance in some organisms and this has led to researchers’ investigating their mechanisms of action and isolating active compounds. Particular focus is on establishing the effect of the plant(s) extracts in terms of their microstatic and microcidal action and the spectrum of organisms affected. This has enabled exploitation of plants for the treatment of microbial infections and in the development of new antimicrobial agents. This requires rigorous research and it is therefore imperative to follow standard methods to authenticate claims of antimicrobial action. Results comparability is largely dependent on the techniques employed in the investigations and conclusive results can only be obtained if methods are standardized and universal. This paper reviews the current methods used in the investigations of the efficacy of plants as antimicrobial agents and points out some of the differences in techniques employed by different authors.

/pdf/assessment-techniques-of-antimicrobial-properties-of-natural-4g7puos6nu.pdf

Assessment techniques of antimicrobial properties of natural compounds of plant origin: current methods and future trends

The antibacterial effect of some selected Indian medicinal plants was evaluated on bacterial strains like Bacillus cereus ATCC11778, Staphylococcus aureus ATCC25923, Enterobacter aerogenes ATCC13048, Escherichia coli ATCC25922 and Klebsiella pneumoniae NCIM2719. The solvents used for the extraction of plants were water and methanol. The in vitro antibacterial activity was performed by agar disc diffusion and agar well diffusion method. The most susceptible Gram-positive bacteria was B. cereus, while the most susceptible Gram-negative bacteria was K. pneumoniae. The extracts of Abrus precatorius, Cardiospermum halicacabum and Gmelina asiatica could not inhibit any of the bacterial strains investigated. The most active antibacterial plant was Caesalpinia pulcherrima. The significant antibacterial activity of active extracts was compared with the standard antimicrobics, piperacillin (100 µg/disc) and gentamicin (10 µg/disc). The results obtained in the present study suggest that Caesalpinia pulcherrima can be used in treating diseases caused by the test organisms.

/pdf/in-vitro-antimicrobial-activity-and-phytochemical-analysis-3vhbpksvso.pdf

In vitro Antimicrobial Activity and Phytochemical Analysis of Some Indian Medicinal Plants

Twelve medicinal plants were screened, namely Abrus precatorius L., Caesalpinia pulcherrima Swartz., Cardiospermum halicacabum L., Casuarina equisetifolia L., Cynodon dactylon (L.) Pers., Delonix regia L., Euphorbia hirta L., Euphorbia tirucalli L., Ficus benghalensis L., Gmelina asiatica L., Santalum album L., and Tecomella undulata (Sm.) Seem, for potential antibacterial activity against 5 medically important bacterial strains, namely Bacillus subtilis ATCC6633, Staphylococcus epidermidis ATCC12228, Pseudomonas pseudoalcaligenes ATCC17440, Proteus vulgaris NCTC8313 and Salmonella typhimurium ATCC23564. The antibacterial activity of aqueous and methanol extracts was determined by agar disk diffusion and agar well diffusion method. The methanol extracts were more active than the aqueous extracts for all 12 plants studied. The plant extracts were more active against Gram-positive bacteria than against Gram-negative bacteria. The most susceptible bacteria were B. subtilis, followed by S. epidermidis, while the most resistant bacteria were P. vulgaris, followed by S. typhimurium. From the screening experiment, Caesalpinia pulcherrima Swartz. showed the best antibacterial activity; hence this plant can be further subjected to isolation of the therapeutic antimicrobials and further pharmacological evaluation.

https://journals.tubitak.gov.tr/biology/issues/biy-05-29-4/biy-29-4-3-0506-4.pdf

Efficacy of Aqueous and Methanol Extracts of Some Medicinal Plants for Potential Antibacterial Activity

The aqueous and methanol extracts of 12 plants each belonging to different families were evaluated for antibacterial activity against medically important bacteria viz. B. cereus ATCC11778 , S. epidermidids ATCC12228 , E. aerogenes ATCC13048, P. vulgaris NCTC 8313, S. typhimurium ATCC 23564. The in vitro antibacterial activity was performed by agar disc diffusion and agar well diffusion method. The aqueous extracts were inactive but methanol extracts showed some degree of antibacterial activity against the tested bacterial strains. S. typhimurium was the most resistant bacteria while B. cereus was the most susceptible bacteria. Amongst the plant species screened, methanol extract of Bauhinia variegata bark showed best antibacterial activity. (Afr. J. Biomed. Res. 10: 175 – 181)

/pdf/antibacterial-and-phytochemical-studies-on-twelve-species-of-1duf40wuah.pdf

Antibacterial and phytochemical studies on twelve species of Indian medicinal plants

The aqueous and ethanolic extracts of Launaea procumbens Roxb (Labiateae), Vitis vinifera L (Vitaceae) and Cyperus rotundus L (Cyperaceae) were evaluated for antimicrobial activity against clinically important bacteria viz Alcaligenes faecalis ATCC8750, Bacillus cereus ATCC11778, Bacillus subtilis ATCC6633, Enterobacter aerogenes ATCC13048, Escherichia coli ATCC25922, Klebsiella pneumoniae NCIM2719, Proteus mirabilis NCIM224, Proteus vulgaris NCTC8313, Pseudomonas aeruginosa ATCC27853, Pseudomonas pseudoalcaligenes ATCC17440, Salmonella typhimurium ATCC23564, Staphylococcus aureus ATCC25923, Staphylococcus epidermidis ATCC12228, Staphylococcus subfava NCIM2704 and Candida tropicalis ATCC4563 The in vitro antimicrobial activity was performed by agar disc diffusion and agar well diffusion method The ethanolic extracts of all the plants were active against all the investigated bacterial strains while all the aqueous extracts were inactive except for Vitis vinifera L S typhimurium was the most resistant bacterial strain against all the extracts (Afr J Biomed Res 9:89 – 93, May 2006) Keywords: antimicrobial activity, aqueous extract, ethanolic extract, Launaea procumbens Roxb, Vitis vinifera L and Cyperus rotundus L

/pdf/in-vitro-antimicrobial-activities-of-extracts-of-launaea-17pwzsv425.pdf

In-vitro Antimicrobial Activities of Extracts of Launaea procumbens Roxb. (Labiateae), Vitis vinifera L. (Vitaceae) and Cyperus rotundus L. (Cyperaceae)

http://www.scielo.br/pdf/bjm/v38n2/v38n2a04.pdf

Jigna Parekh

Papers

In vitro Antimicrobial Activity and Phytochemical Analysis of Some Indian Medicinal Plants

Efficacy of Aqueous and Methanol Extracts of Some Medicinal Plants for Potential Antibacterial Activity

Antibacterial and phytochemical studies on twelve species of Indian medicinal plants

In-vitro Antimicrobial Activities of Extracts of Launaea procumbens Roxb. (Labiateae), Vitis vinifera L. (Vitaceae) and Cyperus rotundus L. (Cyperaceae)

In vitro antibacterial activity of the crude methanol extract of Woodfordia fruticosa Kurz. flower (Lythraceae)