Staphylococcus aureus is a microorganism of great health risk because of its high resistance to antibiotics. Methicillin-resistant strains (MRSA) are most at risk, especially in hospital patients and children. In recent years, it has been shown that a combination therapy of two or more drugs is more efective than monotherapy traditional. Furthermore, it has also been seen that many natural substances and plant extracts can inhibit the MRSA growth and other microorganisms. However, litle has been studied about the combinations of diferent extracts or extracts combination with other commonly used drugs. The purpose of this work was to evaluate of extracts of propolis with garlic, oregano and ciproloxacin to inhibit growth of MRSA strains, using isobolographic method. The results showed that combinations of garlic with propolis inhibit the growth of MRSA, but only in small concentrations. High concentrations of these two extracts appear to have an antagonistic efect. Combinations of propolis and oregano show a synergistic efect at any concentration. Finally, the combination of propolis with ciproloxacin has an antagonistic efect. The action of ciproloxacin is decreased when was combined with propolis.Health professionals should know this to warn patients when they use a natural resource, especially if a drug is being administered.

The McFarland method is designed to estimate bacterial concentrations by means of a turbidity scale (absorbance) which consists of a series of tubes previously calibrated, and with an optical density produced by the precipitation of barium sulphate. This absorbance is compared to bacterial populations. The most used absorbance is the one corresponding to 0.5 on that scale, which assumes a population of 1.5×10 8 cfu/mL (colony forming units per milliliter). In order to verify the accuracy of this scale, 25 different bacterial species were tested, adjusting to 0.5 of the McFarland scale and then an aliquot in plate with agar was cultured in triplicate to account for the population. The results showed very diverse populations, with variations ranging from 30 to 300% of what was expected (0.5×10 8 to 3×10 8 cfu/mL). The most important implications of this are in studies of microbial ecology, in clinical microbiology, in studies on sensitivity to antibiotics and in areas of quality control. It is suggested to take special care when it is required to establish, with more accuracy, the population of a crop.

Stress, excessive consumption of processed foods, pollutants and many other factors of today's life have caused oxidative stress in our body and damage to genetic material in our cells, leading to diseases such as diabetes, hypertension, cancer, metabolic syndrome, among others. Medicine has returned to take up traditional remedies mainly in plants. Chaya (Cnidoscolus aconitifolius) has been studied in this regard, mainly for its antidiabetic effects; however, there is little information about its antioxidant and protective properties against genotoxic damage. The present study focuses on the evaluation of the antioxidant and protective properties to genotoxic damage of aqueous and methanolic extracts of chaya leaves (C. chayamansa) in a model in mice which were induced to oxidative stress and genotoxic damage by exposure to arsenic and low doses of streptozotocin. Genotoxic damage was assessed by micronucleus count and antioxidant properties were assessed in the extracts and plasmas of the mice by the ABTS radical and using Trolox as standard. Additionally, the extracts were analyzed by HPLC-MS/MS. Mice treated with aqueous extract showed better recovery than those treated with methanolic extract; however, no significant statistical differences were found between both groups. HPLC analysis suggests the presence of some compounds of interest such as ferulic acid, protocatechonic acid, riboflavin, kaempferol and beta carotene. These could be associated with the effects of protection against genotoxic damage and as antioxidants found in the study. The aqueous extract seems have the best performance against genotoxic damage and have better oxidative properties, so the consumption of chaya can be recommended.

No abstract

Currently, diabetes mellitus type two is a public health challenge worldwide. Even though there are many oral hypoglycemic agents, a large part of the population continues to use herbal remedies with proven benefits. However, there are few works aimed at evaluating combinations of drugs and herbal remedies. These combinations of drugs and herbal substances can lead to a decrease in the therapeutic effect of each of them. The present work was designed to evaluate the combination of Metformin with aqueous extracts of chaya (Cnidoscolus aconitifolius) in a group of Long Evans streptozotocin-induced diabetes rats. Several combinations of aqueous extracts of C. aconitifolius and Metformin were tested and glycemia was measured in streptozotocin-induced diabetes rats. Additionally, the chemical profile of the extracts was determined by high performance liquid chromatography coupled mass tandem detector (HPLC-MS / MS). Results revealed that the combinations tested suggested an antagonistic effect between both compounds since the glycemia remained high in three of the four treated groups. Some of the compounds detected in chaya extracts by HPLC-MS/MS could give a clue of the explanation of this behavior. Conclusively, the therapeutic effect of Metformin may decrease when chaya is regularly consumed as a complementary herbal remedy, as used in a part of the Mexican population. It is recommended to deepen in the future in the pharmacodynamic part to explain this behavior.