This report examines the presence of proteolytic activity detected in media collected from in vitro cultures of Giardia intestinalis, and the partial characterization by gelatin-substrate polyacrylamide gel electrophoresis and inhibition studies. Gelatin-substrate polyacrylamide gel electrophoresis revealed 6 bands with proteolytic activity, with estimated molecular weights of 36, 59, 63, 72, 103, and 175 kDa. These bands were not present in the control medium. On the other hand, G. intestinalis trophozoite lysates showed proteolytic bands at 16, 20, 66, 82, 108, and 120 kDa, thus indicating that intracellular proteases could be different from the excretory/secretory (E/S) products. Based on inhibition studies, 2 bands of 59 and 63 kDa were inhibited by iodoacetic acid, indicating the presence of cysteine proteases. Partial inhibition of a band of 36 kDa was found with EDTA, a metal-chelating agent, suggesting the possible presence of metalloproteases. The presence of aspartic and serine proteases were not detected under the assay conditions used. As G. intestinalis E/S may be involved in differentiation mechanisms of the parasite and also be responsible for the mucosal alterations that occur in giardiasis, the characterization of these proteases may facilitate their evaluation as targets in the therapy of the disease.

Background:  There are many kinds of tropical fruit available in Venezuela. Two of these fruits are the focus of our study: blackberry (“mora”) and soursop (“guanábana”). These fruits have extraordinary bioactive components. For example, blackberry has antioxidant compounds such as anthocyanins, which are characteristic of the Rosaceae family. Acetogenins present in the Annonaceae family have been shown to possess cytotoxic properties that act against different types of tumor cells. In previous research, we have discovered how lyophilized soursop pulp has an elevated cytotoxic effect with a IC50 of 7.1940±1.06 in human cervix carcinoma cells (HeLa) and 0.8460±1.29 in human prostate carcinoma cells (PC3).Objective: This study focused on the health benefits and properties of the soursop and the blackberry. Our main focus was to determine the antioxidant and cytotoxic properties in a formulated beverage based on blackberry, soursop, and yogurt containing probiotics and prebiotics.Methods: The research includes the study of soursop pulp (SP), blackberry pulp (BP), and two formulations of the functional beverage selected through a sensorial analysis, F2 (BP + SP + Yogurt + Truvía® + Sacarose) and F3 (BP + SP + Yogurt + Truvía® + Sacarose + Sodium tripolyphosphate). Cell viability of prostate carcinoma cells (PC3), breast carcinoma without over-expression of the HER2/c-erb-2 gene (MCF-7), breast carcinoma in which the HER2/c-erb-2 gene is over-expressed (SKBr3) and healthy cells of human connective tissue used as control (Fibroblasts).  The previous indicated samples were assessed using MTT (3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide). The antioxidant activity of the functional beverage was also done using a freshly preparation of 1,1-diphenyl-2-picrylhydrazyl (DPPH). Results: The BP demonstrated the highest cytotoxicity for both lines of breast cancer cell lines, MCF-7 and SKBR3. The values of the minimum concentration required to inhibit 50 % of the cell population (IC50) was 0.12 ± 1.10 and 1.81 ± 1.68% v / v respectively, followed by SP in MCF-7 and PC3 with values of 1.40 ± 1.03 and 1.34 ± 1.06 respectively. At the same time, the effectiveness of the formulations used found that 3.60 ± 1.04% v / v of F2 beverage was necessary to achieve 50 % inhibition of cell viability of MCF-7 line. For the formulation F3, it was necessary to use a concentration of 5.21 ± 1.04% v / v for that tumor cell line. However, the F2 and F3 formulations demonstrated IC50 values of 3.69 ± 1.08% v / v and 2.50 ± 1.08% v / v respectively for the PC3 cell line. On the other hand, the antioxidant capacity of BP and SP reached elevated values at 30 minutes of exposure to DPPH, obtaining a rate of 85.28 ± 0.11 and 80.94 ± 0.07 % respectively by using a concentration of 12.5 %, F2 and F3 formulations also reached values of 83.97 ± 0.46 and 85.62 ± 0.11 % at 100 % concentration of both drinks respectively.Conclusion: We discovered that the cytotoxic activity of both formulations prepared as well as the pulps were fairly good, revealing highly effective consequences for the inactivation of breast tumor cells MCF-7 and prostate tumor cells PC3. Moreover, BP and SP demonstrated a high antioxidant activity, with a synergistic effect accomplished by the mixture on F2 and F3.Keywords: Functional beverage, cytotoxic, antioxidant, soursop, blackberry, yogurt.

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Alcoholic and aqueous extracts were obtained from red sweet pepper (Capsicum annuum L.) by different methodologies to evaluate their cytotoxic, antioxidant and antimicrobial properties. Alcoholic extracts (MFP, MSd, SFP, SDP, SSd) from fresh red sweet pepper (FP) and dry pulp (DP) and seed (Sd) were obtained by maceration (M) and Soxhlet (S) equipment using methanol as extraction solvent; whereas aqueous extracts (LFP, LSd) were obtained by decoction followed by lyophilization (L). Human tumoral cell lines from breast (MCF-7 and SKBr3), prostate (PC3) and cervix (HeLa), and fibroblasts (as control) were used to determine the cytotoxic properties by the MTT assay. Antioxidant and antimicrobial properties were determined by DPPH and disc diffusion method, respectively. The extracts SDP and SFP showed the higher cytotoxic activity. The SDP extract had a significant (P < 0.05) in-vitro effect on HeLa (1.9 ± 1.4 µg/mL) and PC3 (< 1 µg/mL) cells with a moderated impact on fibroblasts (26.1 ± 1.2 µg/mL); whereas, SFP had a significant (p < 0.05) effect on MCF-7 cell line (2.1 ± 1.2 µg/mL) with a moderated impact on fibroblasts (25.9 ± 1.0 µg/mL). The higher antioxidant activity was found for MFP (80.3 ± 0.2%) and SFP extracts (75.5 ± 0.5%). Mild antimicrobial activity was only observed for alcoholic extracts. The results showed the potential of red sweet pepper (C. annuum L.) as a source of antioxidant and cytotoxic compounds, and suggest the need of further studies to isolate and characterize the bioactive compounds that impart those properties.

Alcoholic and aqueous extracts were obtained from red sweet pepper (Capsicum annuum L.) by different methodologies to evaluate their cytotoxic, antioxidant and antimicrobial properties. Alcoholic extracts (MFP, MSd, SFP, SDP, SSd) from fresh red sweet pepper (FP) and dry pulp (DP) and seed (Sd) were obtained by maceration (M) and Soxhlet (S) equipment using methanol as extraction solvent; whereas aqueous extracts (LFP, LSd) were obtained by decoction followed by lyophilization (L). Human tumoral cell lines from breast (MCF-7 and SKBr3), prostate (PC3) and cervix (HeLa), and fibroblasts (as control) were used to determine the cytotoxic properties by the MTT assay. Antioxidant and antimicrobial properties were determined by DPPH and disc diffusion method, respectively. The extracts SDP and SFP showed the higher cytotoxic activity. The SDP extract had a significant (P < 0.05) in-vitro effect on HeLa (1.9 ± 1.4 µg/mL) and PC3 (< 1 µg/mL) cells with a moderated impact on fibroblasts (26.1 ± 1.2 µg/mL); whereas, SFP had a significant (p < 0.05) effect on MCF-7 cell line (2.1 ± 1.2 µg/mL) with a moderated impact on fibroblasts (25.9 ± 1.0 µg/mL). The higher antioxidant activity was found for MFP (80.3 ± 0.2%) and SFP extracts (75.5 ± 0.5%). Mild antimicrobial activity was only observed for alcoholic extracts. The results showed the potential of red sweet pepper (C. annuum L.) as a source of antioxidant and cytotoxic compounds, and suggest the need of further studies to isolate and characterize the bioactive compounds that impart those properties.