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Aim: To find an in vitro system for the measurement of the androgenic effects of different extracts of Hibiscus macranthus (Malvaceae) and Basella alba (Basellaceae). Methods: The production of testosterone from testes slices incubated in two media, either Krebs-Henseleit buffer containing 0.5 % Bovine serum albumin (BSA) or Dubecco’s Modified Eagle’s medium-F12 Ham nutrient mixture (DME/Ham F12), under a mixture of 5 % CO2 in 95 % air was determined either in the presence or absence of cofactors and Hibiscus macranthus plus Basella alba (HMBA) extracts. Results: The testosterone production was increased in testes slices incubated in DME/Ham F12 medium in response to the cofactors (49 %) and aqueous extracts (34 %–60 % according to dilutions). Under the same atmospheric conditions, there was no positive response of the testes slices to either cofactor or HMBA extract stimulation in Krebs-Henseleit buffer containing 0.5 % BSA. In further investigations related to the effect of HMBA, the DME/ Ham F12 medium was used. The results obtained from the in vitro test showed that the activity was present mainly in methylene chloride and methanol, since these extracts induced an increase in testosterone production by testes slices. Conclusion: The testes slice system is suitable to be used for further in vitro investigations of the isolation of androgenic bioactive components of plants. (Asian J Androl 2006 Jan; 8: 111–114)

International audience; Catala-Gregori, P., Mallet, S., Travel, A., Orengo, J. and Lessire, M. 2008. Efficiency of a prebiotic and a plant extract alone or in combination on broiler performance and intestinal physiology. Can. J. Anim. Sci. 88: 623-629. A 36-d trial was conducted to evaluate two potential alternatives to antibiotic growth promoters in broilers. The products tested were a prebiotic (PROFEED (R)) and a plant extract (XTRACT (TM)). Ross mate broiler performance and digestive tract function responses were studied. To evaluate the effect of these potential alternatives alone or in combination, seven diets were tested: positive control avilamycin 10 ppm (PC);negative control antibiotic-free (NC); NC+PROFEED (R) 600 ppm (P); NC+XTRACT (TM) 100 ppm (X); NC+PROFEED (R)/XTRACT (TM) 600/100 ppm (XPH); NC+PROFEED (R)/XTRACT (TM) 450/75 ppm (XPM); NC+PROFEED (R)/XTRACT (TM) 300/50 ppm (XPL). From 22 to 36 d of age, body weight gain (BWG) was improved by P, X, and XPM compared with NC (P < 0.05). Throughout the trial, broilers fed PC, P, X and XPL had a better feed conversion ratio (FCR) than those fed NC (P < 0.1). No relevant negative effect was observed for the parameters relative to the digestive tract function:ileal histomorphometry, anaerobic sulphite-reducing bacteria count (ASR), intestinal and caecal pH, caecal volatile fatty acids production (VFA) and litter score (LS). With the higher mixture dose (XPH), no improvement in broiler performance was observed, suggesting no synergistic effect of the two additives.

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Pig weaning period is frequently associated with infectious disease, mainly caused by enterotoxigenic Escherichia coli (ETEC) K88. Plant extracts exert different beneficial effects and may represent antibiotic alternatives to reduce piglet infection. In this study, plant extracts and other natural substances (PENS) have been evaluated on the pig intestinal IPEC-1 cells, for potential protection against ETEC K88 induced membrane damage. Several PENS have been considered: yeast extract, yeast nucleotides, unsaturated oligo-mannuronic acid, ulvan, bromelain and three fractions of bovine colostrums, as anti-inflammatory and immunomodulatory compounds; daidzein and Chlorella vulgaris extract, as anti-oxidant compounds; allicin, cinnamaldehyde and carvacrol, as anti-bacterial compounds. First, possible toxic effect of PENS on cell membrane permeability was verified by assessing the transepithelial electrical resistance (TEER) and paracellular flux of the extracellular marker phenol red. The highest non-toxic PENS concentration was added to ETEC infected cells to test the protection against membrane damage. The results showed that yeast extract, daidzein, bovine colostrum, bromelain and allicin protected the cells against the increased membrane permeability caused by ETEC, whereas the other PENS did not show this ability. Allicin protection was not due to its anti-bacterial activity, since ETEC growth was unaffected by the presence of allicin.