BackgroundAmpicillin-resistant S. aureus (ARSA) now poses a serious problem for hospitalized patients, and their care providers. Plant-derived antibacterial that can reverse the resistance to well-tried agents which have lost their original effectiveness are the research objectives of far reaching importance. To this aim, the present study investigated antibacterial and synergistic activities of Stephania suberosa extracts (SSE) against ARSA when used singly and in combination with ampicillin.ResultsThe majority chemical compounds of SSE were alkaloid (526.27 ± 47.27 mg/1 g of dried extract). The Minimum inhibitory concentration (MICs) for ampicillin and SSE against all ARSA strains were >512 μg/ml and 4 mg/ml, respectively. Checkerboard assay revealed synergistic activity in the combination of ampicillin (0.15 μg/ml) and SSE (2 mg/ml) at fractional inhibitory concentration index (FICI) <0.5. The killing curve assay had confirmed that the viability of ARSA was dramatically reduced from 5x105 cfu/ml to 103 cfu/ml within 6 h after exposure to SSE (2 mg/ml) plus ampicillin (0.15 μg/ml) combination. Electron microscopic study clearly revealed that these ARSA cells treated with this combination caused marked morphological damage, peptidoglycan and cytoplasmic membrane damage, and average cell areas significant smaller than control. Obviously, Immunofluorescence staining and confocal microscopic images confirmed that the peptidoglycan of these cells were undoubtedly disrupted by this combination. Furthermore, the CM permeability of ARSA was also increased by this combination. Enzyme assay demonstrated that SSE had an inhibitory activity against β-lactamase in concentrations manner.ConclusionsSo, these findings provide evidence that SSE has the high potential to reverse bacterial resistance to originate traditional drug susceptibility of it and may relate to three modes of actions of SSE: (1) inhibits peptidoglycan synthesis, resulting in morphological damage, (2) inhibits β-lactamases activity, and (3) increases CM permeability. It is widely recognized that many types of drugs are derived from alkaloids. So, this SSE offers the prominent potential to develop a novel adjunct phytopharmaceutical to ampicillin for the treatment of ARSA. Further active ingredients study, toxicity of it, and the synergistic effect on blood and tissue should be performed and confirmed in an animal test or in humans.

BackgroundGlobally, staphylococci have developed resistance to many antibiotics. New approaches to chemotherapy are needed and one such approach could be to use plant derived actives with conventional antibiotics in a synergestic way. The purpose of this study was to isolate α-mangostin from the mangosteen (Garcinia mangostana L.; GML) and investigate antibacterial activity and mechanisms of action when used singly and when combined with oxacillin against oxacillin-resistant Staphylococcus saprophyticus (ORSS) strains. The isolated α-mangostin was confirmed by HPLC chromatogram and NMR spectroscopy. The minimum inhibitory concentration (MIC), checkerboard and killing curve were determined. The modes of action of these compounds were also investigated by enzyme assay, transmission electron microscopy (TEM), confocal microscopic images, and cytoplasmic membrane (CM) permeabilization studies.ResultsThe MICs of isolated α-mangostin and oxacillin against these strains were 8 and 128 μg/ml, respectively. Checkerboard assays showed the synergistic activity of isolated α-mangostin (2 μg/ml) plus oxacillin (16 μg/ml) at a fractional inhibitory concentration index (FICI) of 0.37. The kill curve assay confirmed that the viability of oxacillin-resistant Staphylococcus saprophyticus DMST 27055 (ORSS-27055) was dramatically reduced after exposure to isolated α-mangostin (2 μg/ml) plus oxacillin (16 μg/ml). Enzyme assays demonstrated that isolated α-mangostin had an inhibitory activity against β-lactamase in a dose-dependent manner. TEM results clearly showed that these ORSS-27055 cells treated with this combination caused peptidoglycan and cytoplasmic membrane damage, irregular cell shapes and average cell areas were significantly larger than the control. Clearly, confocal microscopic images confirmed that this combination caused considerable peptidoglycan damage and DNA leakage. In addition, the CM permeability of ORSS-27055 was also increased by this combination of actives.ConclusionsThese findings provide evidence that isolated α-mangostin alone has not only some activity but also shows the synergistic activity with oxacillin against ORSS-27055. The chromone and isoprenyl structures could play a significant role in its action. This synergistic activity may involve three mechanisms of action. Firstly, potential effects of cytoplasmic membrane disruption and increases permeability. Secondly, inhibit β-lactamase activity. Finally, also damage to the peptidoglycan structure. We proposes the potential to develop a novel adjunct phytopharmaceutical to oxacillin for the treatment of ORSS. Future studies require clinical trials to establish if the synergy reported can be translated to animals and humans.

Obesity and hyperlipidemia are a major problem in the world. Pluchea indica (L.) Less. tea (PIT) is a beverage that has various indications. This study focused on the effect of the PIT on inhibiting adipogenesis of 3T3-L1 cells and pancreatic lipase enzyme activity. The viability of 3T3-L1 cells was not significantly decreased after exposure to 200 to 1000 μg mL−1 PIT compared to controls (p > 0.05). The PIT at 750 to 1000 μg mL−1 exhibited a significantly reduced lipid accumulation compared to the control (p < 0.05). The inhibitory effects of the PIT at 250 to 1000 μg mL−1 on lipase activity were significantly increased compared to control (p < 0.05). The FTIR results showed that the integrated areas of lipids, proteins, nucleic acids, glycogen, and carbohydrates of the PIT-treated 3T3-L1 adipocytes were significantly lower than the untreated 3T3-L1 adipocytes (p < 0.05). These findings may indicate that the PIT is not only capable of inhibiting lipids and carbohydrate accumulation in adipocytes but also has a potential to inhibit pancreatic lipase activity. So, the PIT may be further developed to the novel lipid-lowering herbal supplement for the management of overweight or obesity.

Pluchea indica (L.) Less. (P. indica) tea has been used for a health-promoting drink, especially in Southeast Asia. The effect of P. indica tea (PIT) on amelioration of hyperglycemia; dyslipidemia that was total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), and triglyceride (TG); and obesity in high fat diet-induced (HFD) mice was investigated. Oral glucose tolerance test (OGTT) displayed that PIT at 400 and 600 mg/kg orally ameliorated hyperglycemia with a dose-dependent manner compared to the untreated group. Moreover, PIT at these dosages exhibited significantly lower TC, LDL-C, TG, and perigonadal fat weight in HFD treated mice compared to HFD mice (P<0.05) with a dose-dependent manner. In contrast, HDL-C was higher than in the HFD group, but not a significant difference (P>0.05). The PIT chemical analysis results demonstrated that PIT contained total phenolic content (TPC), total flavonoid content (TFC), 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), 4,5-O-dicaffeoylquinic acid (4,5-CQ), beta-caryophyllene, and gamma-gurjunene that may play an important role in inhibiting hyperlipidemia and hyperglycemia. Also, histological analysis expressed that the mean area and amount of perigonadal fat adipocytes of PIT treated groups were significantly lower and higher than the HFD group (P<0.05), respectively. The toxicity test of PIT at 600 mg/kg/day in mice showed that serum creatinine, alanine transaminase (ALT), alkaline phosphatase (ALP), and complete blood count (CBC) levels of HFD and PIT treated groups were not significantly different compared to the normal control diet group (NCD) (P>0.05). These results suggest that PIT does not become toxic to the kidney, liver, and blood. In conclusion, PIT has the potential to develop into healthy food supplement or medicine for the prevention and treatment of hyperglycemic, hyperlipidemic, and obese patients.

Butea superba Roxb. (BS) has been used in Thai men as an aphrodisiac, and prevent erectile dysfunction. Nevertheless, the active ingredients, dosages, have not been cleared. Hence, this study was to investigate the effect of compounds from the BS on the reproductive parameters of male mice. The results revealed that BS was extracted to afford biochanin A and genistein, which were first reported on BS, and daidzein. The mice were treated by daidzein and genistein alone and in combination. The results showed that the sperm number and motility, cholesterol and testosterone level of all isoflavones-treated groups were significantly higher than controls (p < 0.01). Obviously, daidzein plus genistein exhibited a synergistic effect, which is also the first report, and resulted in significantly displayed higher levels of these parameters compared to others. So, the synergistic activity of these isoflavones may be useful in improving libido, erectile capacity and assist infertility of poor spermatozoa in men.