Novel activities of 1-adamantylthiopyridines as antibacterials, antimalarials and anticancers

To discover new bioactive lead compounds for medicinal purposes, herein, 2(1-adamantylthio)pyridine and derivatives (1-10) were prepared and tested for antibacterial (agar dilution method against 27 strains of microorganisms), antimalarial (against Plasmodium falciparum) and anticancer (MOLT-3, HepG2, HuCCA-1 and A549) activities. Results showed that all the tested derivatives selectively exerted antigrowth activity against Streptococci at 15-30 µg/mL. 3-Substituted (R) thiopyridines; 3 (R = NAc2), 5 (R = OH) and 6 (R = Br) exhibited antibacterials, antimalarials and anticancers. Significantly, 6-(1-adamantylthio) nicotinonitrile (10) is a promising antibacterial which selectively displays antigrowth activity against Vibrio cholerae, Vibrio parahaemolyticus, Edwardsiella tarda and beta-hemolytic Streptococcus group A with minimum inhibitory concentration of 30 µg/mL. The findings reveal that these 1-adamantylthiopyridines represent a novel class of antibacterial, antimalarial and anticancer agents with potential medicinal values

In vitro study of parasite elimination and endothelial protection by curcumin

Plasmodium falciparum infection can abruptly progress to severe malaria and cerebral malaria. Despite the current efficiency of antimalarial drugs in killing parasites, no specific effective treatment has been found for cerebral malaria. Thus, a new strategy targeting both parasite elimination and endothelial cell protection is urgently needed in this field. In this study, we determined whether curcumin, which has blood-brain permeability, antioxidative activity and/or immunomodulation property, provided a potential effect on both parasite elimination and endothelial protection. Murine brain microvascular endothelial cells (bEnd.3; ATCC) were cocultured with Plasmodium falciparum-infected red blood cells (Pf-IRBC), peripheral blood mononuclear cell (PBMC) and platelets. Apoptosis of endothelial cells was demonstrated by annexin V staining. Interestingly, curcumin exhibited high efficiency of antimalarial activity (IC50~10μM) and decreased bEnd.3 apoptosis down to 60.0% and 79.6% upon pre-treatment and co-treatment, respectively, with Pf-IRBC, platelets and PBMC. Our findings open up a high feasibility of applying curcumin as a potential adjunctive compound for cerebral malaria treatment in the future

Antimalarial and antimicrobial activities of 8-aminoquinoline-uracils metal complexes

8-Aminoquinoline (8AQ) derivatives have been reported to have antimalarial, anticancer, and antioxidant activities. This study investigated the potency of 8AQ-5-substituted (iodo and nitro) uracils metal (Mn, Cu, Ni) complexes (1-6) as antimalarial and antimicrobial agents. Interestingly, all of these metal complexes (1-6) showed fair antimalarial activities. Moreover, Cu complexes 2 (8AQ-Cu-5Iu) and 5 (8AQ-Cu-5Nu) exerted antimicrobial activities against Gram-negative bacteria including P. shigelloides and S. dysenteriae. The results reveal application of 8AQ and its metal complexes as potential compounds to be further developed as novel antimalarial and antibacterial agents

Bioactive 4-hydroxycinnamide and bioactivities of Polyalthia cerasoides

Constituents from Polyalthia cerasoides, stem bark methanol extract, were previously documented. This study reports the first isolation of bioactive N-(4-hydroxy-β-phenethyl)-4-hydroxycinnamide (1) from ethyl acetate extract of the plant species including stigmasterol and a mixture of triterpenes from hexane and dichloromethane extracts. Trace essential elements were found in the hexane extract in ppm level. The plant extracts were evaluated for their antimicrobial and antioxidative activities. The dichloromethane extract displayed the highest activity against Corynebacterium diphtheriae NCTC 10356 with MIC of 32 μg/mL, as well as, the highest SOD activity with an IC50 of 4.51 μg/mL

Lifestyle behaviors and serum vitamin C in the Thai population in Bangkok Metropolitan

This study aimed to investigate the influence of lifestyle behaviors on the vitamin C levels in the circulating blood of the Thai population in Bangkok Metropolitan. The participants (n=250) included community workers (i.e., construction and business office workers) from the Bangkok Metropolitan, and the participants were placed in various behavior and lifestyle groups (Group I: reference; Group II: alcohol drinkers; Group III: outdoor workers; Group IV: smokers; and Group V: combined). The results showed that the lowest and highest vitamin C intakes were 7 and 27 mg/day in Groups IV and III, respectively. Group I (indoor workers free of smoking and drinking), had the highest total serum vitamin C level (39.7 μmol/L), while Group V (outdoor workers with smoking and drinking), had the lowest value (12.5 μmol/L). Furthermore, Group V had the highest prevalence (44 %) of total serum vitamin C deficiency (<11 μmol/L), while Group I had the lowest deficient indication (8 %). The vitamin C dietary intake and total serum levels were positively correlated in the reference group (Spearman’s correlation=0.402, p < 0.05) but not in the other four groups. The significant adjusted odds ratio of inadequate total serum vitamin C (< 23 μmol/L) was 2.90 (CI: 1.15, 7.31) in Group IV and 3.73 (CI: 1.42, 9.81) in Group V. Moreover, the tendency to have an inadequate total serum vitamin C level was demonstrated in the following order: Group I < II < III < IV < V. Our results indicated that outdoor workers (Group III) and smokers (Group IV) had a greater likelihood of having a vitamin C deficiency than the reference group. A high percentage of deficiency was clearly observed among the outdoor workers with smoking and drinking behaviors (Group V)