Development of a Novel Herbal Formulation To Inhibit Biofilm Formation in Toxigenic Vibrio cholerae.

Vibrio cholerae, a causative agent of the waterborne disease cholera, still threatens a large proportion of world's population. The role of biofilm formation in V. cholerae pathogenesis is well established, as it provides the bacterium enhanced tolerance to antimicrobial agents and increased transmission. In the present study, four medicinal plants used in traditional medicines with antidiarrheal properties were evaluated for its antibiofilm activity. Methanol extracts of these plants (Centella asiatica, Elephantopus scaber, Camellia sinensis, and Holarrhena antidysenterica) showed promising antibiofilm activity against V. cholerae with crystal violet and air-liquid interface coverslip assays. Results revealed that C. asiatica, E. scaber, C. sinensis, and H. antidysenterica extracts significantly inhibited biofilm formation by approximately 75, 76, 78, and 55% at concentrations of 3, 2, 1, and 0.6 mg/mL, respectively. A promising antibiofilm activity of ∼89% inhibition at 1.5 mg/mL concentration was observed when a combination of E. scaber and C. sinensis was used. The herbal extracts were thermostable at a temperature range of 40 to 100°C. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay revealed that the viability of bacteria was not affected by treatment with these plant extracts. Gene expression studies revealed that extracts of H. antidysenterica leaf, H. antidysenterica bark, and the whole plant of E. scaber and C. asiatica down-regulate aphA or aphB, the major regulator genes modulating both virulence and biofilm formation. Hence, we propose that these herbal combinations could serve as a multifaceted approach to combat the pathogen and also, in turn, reduce antimicrobial resistance development.

Resveratrol--a potential inhibitor of biofilm formation in Vibrio cholerae.

Resveratrol, a phytochemical commonly found in the skin of grapes and berries, was tested for its biofilm inhibitory activity against Vibrio cholerae. Biofilm inhibition was assessed using crystal violet assay. MTT assay was performed to check the viability of the treated bacterial cells and the biofilm architecture was analysed using confocal laser scanning microscopy. The possible target of the compound was determined by docking analysis. Results showed that subinhibitory concentrations of the compound could significantly inhibit biofilm formation in V. cholerae in a concentration-dependent manner. AphB was found to be the putative target of resveratrol using docking analysis. The results generated in this study proved that resveratrol is a potent biofilm inhibitor of V. cholerae and can be used as a novel therapeutic agent against cholera. To our knowledge, this is the first report of resveratrol showing antibiofilm activity against V. cholerae.

Bioactivity of marine organisms: Part IX--screening of some marine flora from the Indian coasts.

Alcoholic extracts of 48 identified species of marine flora were screened for a wide range of biological activities. Of these, 3 extracts showed diuretic activity while 2 extracts showed hypotensive effect.

Screening of Indian plants for biological activity: Part XVI.

Alcoholic extracts of 288 of plant materials from 199 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screening. Biological activities, ranging from moderate to good degree, have been observed in 61 plants extracts. Follow up studies have been carried out in these extracts and some of them have shown moderate degree of activities at this Institute. However, none of the extracts was found to be good enough for further development. Results of the present studies, along with chemical investigations on different species of similar genera which were screened earlier, are also discussed.

Bioactivity of marine organisms: Part VIII--Screening of some marine flora of western coast of India.

Methanolic extracts of 31 botanically identified species of marine flora, collected from Gujarat Coast, have been screened for a wide range of biological activities. Of these, 3 extracts showed anti-implantation, 2 had antiviral, 2 showed hypotensive, 1 had anti-inflammatory while 12 extracts showed diuretic activities. The antiviral activity; against EMCV, was confirmed in one alga. The active principles and results of these studies are reported.

Screening of Indian plants for biological activity: Part XV.

Alcoholics extracts of 266 botanically identified plant materials from 222 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screenings. Biological activities have been observed in 89 extracts. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.

Bioactivity of marine organisms: Part VII--Effect of seaweed extract on central nervous system.

Alcohol extracts of marine algae (Rhodophyceae, Phaeophyceae and Chlorophyceae) were screened for their effect on central nervous system. Of 69 species investigated 8 appeared biologically active, 6 being CNS stimulant and two depressant, sites and dates of collection are given.

Liposarcoma of the mesocolon--case report of a rare lesion.

A middle-aged man with a 2-month history of lower abdominal pain was found to have a large left-sided abdominal lump. Radiological investigations (barium enema, ultrasound, and computed tomography scan) revealed a mass lesion in the area of the descending colon, the sigmoid colon, and the rectum. Flexible sigmoidoscopy showed only mucosal edema and luminal narrowing. At laparotomy, a diffuse thickening of both the descending and sigmoid mesocolon extending into the mesorectum was seen, which suggested an inflammatory pathology. A left hemicolectomy with Hartmann's procedure was performed. After obtaining a histopathological diagnosis of liposarcoma of the mesocolon, an abdominoperineal resection of the rectum was done. The patient was advised to undergo postoperative radiotherapy but he did not comply and was thereafter lost to follow-up.

Bioactivity of marine organisms: Part VI--Screening of some marine flora from Indian coasts.

Alcoholic extracts of 50 botanically identified species of marine flora have been screened for a wide range of biological activities. Of these, 2 extracts exhibited anti-amoebic and antiviral activity each, 3 of them had anti-implantation activity; 9 had hypoglycaemic activity while hypotensive activity was associated with 11 extracts; 14 extracts were found to be diuretic and 1 of them had anti-inflammatory activity. Further, 10 of these extracts exhibited 2 types of activities while a combination of 3 and 4 types of activities was observed in one extract each. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.

Screening of Indian plants for biological activity: Part XIV.

Alcoholic extracts of 300 botanically identified plant materials from 275 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screenings. Biological activities have been observed in 111 extracts. Follow-up studies have been carried out in some plants with confirmed activity. The active principles and results of these studies are reported.

Circadian desynchronization in pulse rate, systolic and diastolic blood pressure, rectal temperature and urine output in traumatic tetraplegics.

An investigation was undertaken to study the circadian rhythmicity in pulse rate, systolic and diastolic blood pressure, rectal temperature and urine output in eight traumatic tetraplegics in view of the fact that diurnal rhythmicity in prolactin response to thyrotropin-releasing hormone was absent in such patients. The data, analysed by single cosinor procedure, showed absence of rhythmicity in all five parameters. Analysis of variance also showed no significant difference in these parameters at various time points. Knowledge of the alterations in circadian biology subsequent to cervical spinal cord trauma would provide useful guidelines towards chronotherapy and vocational rehabilitation of tetraplegics besides possible restoration of euchronism by pharmacological means.