1H nuclear magnetic resonance-based metabolite profiling of guava leaf extract: an attempt to develop a prototype for standardization of plant extracts.

BACKGROUND: Herbal medicines are fast gaining popularity. However, their acceptability by modern practitioners is low which is often due to lack of standardization. Several approaches towards standardization of herbals have been employed. The current study attempted to recognize key peaks from 1H NMR spectra which together would comprise of a spectral fingerprint relating to efficacy of Psidium guajava (guava) leaf extract as an antidiarrhoeal when a number of unidentified active principles are involved. METHODS: Ninety samples of guava leaves were collected from three locations over three seasons. Hydroalcoholic (water and ethanol, 50:50) extracts of these samples were prepared and their 1H NMR spectra were acquired. Spectra were also obtained for quercetin, ferulic acid and gallic acid as standards. Eight bioassays reflecting different stages of diarrhoeal pathogenesis were undertaken and based on pre-decided cut-offs, the extracts were classified as 'good' or 'poor' extracts. The bioactivity data was then correlated with the 1H NMR profiles using Regression or Orthogonal Partial Least Square-Discriminant Analysis (OPLS-DA). RESULTS: OPLS-DA showed seasonal and regional segregation of extracts. Significant models were established for seven bioassays, namely those for anti-bacterial activity against Shigella flexneri and Vibrio cholerae, adherence of E. coli, invasion of E. coli and S. flexneri and production and binding of toxin produced by V. cholerae. It was observed that none of the extracts were good or bad across all the bioassays. The spectral analysis showed multiple peaks correlating with a particular activity. Based on NMR and LC-MS/MS, it was noted that the extracts contained quercetin, ferulic acid and gallic acid. However, they did not correlate with the peaks that segregated extracts with good and poor activity. CONCLUSIONS: The current study identified key peaks in 1H NMR spectra contributing to the anti-diarrhoeal activity of guava leaf extracts. The approach of using spectral fingerprinting employed in the present study can thus be used as a prototype towards standardization of plant extracts with respect to efficacy.

Psidium guajava: A Single Plant for Multiple Health Problems of Rural Indian Population.

The rural population in India faces a number of health problems and often has to rely on local remedies. Psidium guajava Linn. (guava), a tropical plant which is used as food and medicine can be used by rural communities due to its several medicinal properties. A literature search was undertaken to gauge the rural health scenario in India and compile the available literature on guava so as to reflect its usage in the treatment of multiple health conditions prevalent in rural communities. Towards this, electronic databases such as Pubmed, Science Direct, google scholar were scanned. Information on clinical trials on guava was obtained from Cochrane Central Register of Controlled Trials and Clinicaltrial.gov. The literature survey revealed that guava possesses various medicinal properties which have been reported from across the globe in the form of ethnobotanical/ethnopharmacological surveys, laboratory investigations and clinical trials. Besides documenting the safety of guava, the available literature shows that guava is efficacious against the following conditions which rural communities would encounter. (a) Gastrointestinal infections; (b) Malaria; (c)Respiratory infections; (d) Oral/dental infections; (e) Skin infections; (f) Diabetes; (g) Cardiovascular/hypertension; (h) Cancer; (i) Malnutrition; (j) Women problems; (k) Pain; (l) Fever; (m) Liver problems; (n) Kidney problems. In addition, guava can also be useful for treatment of animals and explored for its commercial applications. In conclusion, popularization of guava, can have multiple applications for rural communities.

Approaches in fostering quality parameters for medicinal botanicals in the Indian context.

India is among the important megabiodiversity centers of the world with nearly 45,000 known plant species. This diversity coupled with a rich heritage of traditional knowledge has made India a home to several important time-honored systems of health care such as Ayurveda, Siddha and Unani. Herbal medicines, however, are associated with a number of shortcomings including uniform efficacy and lack of appropriate quality control measures at various stages of product development. The review intends to outline the importance of fostering quality parameters towards standardization and manufacturing of botanicals for India to emerge as a leader in global market of herbal products. Literature survey was carried out on important parameters for processing and manufacturing of botanicals. The review highlights that there have been constant efforts for developing state of the art technologies in the field of herbal research. It also reflects that Government authorities have also taken a number of initiatives to formulate appropriate guidelines from standardization of raw materials to obtaining botanical products. However, in the Indian context, there exist certain lacunae in the current regulatory mechanisms which need to be strengthened and stringently implemented to ensure safety, purity and efficacy of herbal medicines. Towards this the approaches being developed globally can be adopted. Based on the literature reviewed, in our opinion, four areas viz., benefit sharing, investment by industry, standardization and national/international networking structure need immediate attention for strengthening Traditional Systems of Medicine in India.

Bactericidal Effect of Selected Antidiarrhoeal Medicinal Plants on Intracellular Heat-Stable Enterotoxin-Producing Escherichia coli.

Diarrhoeal diseases due to enterotoxigenic Escherichia coli continue to be a cause of global concern. Medicinal plants have been gaining popularity as promising antidiarrhoeal agents. In the present study, four antidiarrhoeal plants, viz. Aegle marmelos, Cyperus rotundus, Psidium guajava and Zingiber officinale were screened against a heat-stable toxin-producing enterotoxigenic E. coli strain. Decoctions of these plants were studied for their effect on intracellular killing of the bacterial strain using murine monocytic cell line, J774. [(3)H] thymidine release assay was used to evaluate the apoptotic/necrotic effect. All plants at concentrations <1% enhanced intracellular killing of the bacteria by J774 cells. However, at higher concentrations, the decoctions induced apoptosis in J774 cells. The study demonstrates that these plants could control diarrhoea caused by heat-stable toxin-producing enterotoxigenic E. coli through their immunomodulatory effect.

Studies on the activity of Cyperus rotundus Linn. tubers against infectious diarrhea.

To study the antidiarrheal activity of the decoction of Cyperus rotundus Linn. tubers using representative assays of diarrheal pathogenesis and understand its mechanism of action.Antibacterial, antigiardial and antirotaviral activities were studied. Effect on adherence of enteropathogenic Escherichia coli (EPEC) and invasion of enteroinvasive E. coli (EIEC) and Shigella flexneri to HEp-2 cells was evaluated as a measure of effect on colonization. Effect on enterotoxins such as enterotoxigenic E. coli (ETEC) heat labile toxin (LT), heat stable toxin (ST) and cholera toxin (CT) was also assessed. The decoction showed antigiardial activity, reduced bacterial adherence to and invasion of HEp-2 cells and affected production of CT and action of LT. The decoction of C. rotundus does not have marked antimicrobial activity and exerts its antidiarrheal action by mechanisms other than direct killing of the pathogen.

A community-based bacteriological study of quality of drinking-water and its feedback to a rural community in Western Maharashtra, India.

A longitudinal study of the bacteriological quality of rural water supplies was undertaken for a movement towards self-help against diseases, such as diarrhoea, and improved water management through increased community participation. Three hundred and thirteen water samples from different sources, such as well, tank, community standpost, handpumps, percolation lakes, and streams, and from households were collected from six villages in Maharashtra, India, over a one-year period. Overall, 49.8% of the 313 samples were polluted, whereas 45.9% of the samples from piped water supply were polluted. The quality of groundwater was generally good compared to open wells. Irregular and/or inadequate treatment of water, lack of drainage systems, and domestic washing near the wells led to deterioration in the quality of water. No major diarrhoeal epidemics were recorded during the study, although a few sporadic cases were noted during the rainy season. As a result of a continuous feedback of bacteriological findings to the community, perceptions of the people changed with time. An increased awareness was observed through active participation of the people cutting across age-groups and different socioeconomic strata of the society in village activities.