ABSTRACT
Multidrug-resistant (MDR) Gram-negative bacteria remain a global public health issue due to the barrier imposed by their outer membrane and their propensity to form biofilms. It is becoming imperative to develop new antibacterial strategies. In this context, this study aims to evaluate the antibacterial efficacy of Origanum vulgare essential oil (OEO), alone and in combination with antibiotics, as well as its antibiofilm action against multidrug-resistant Gram-negative strains. OEO components were identified by gas chromatography-mass spectrometry (GC-MS), and antibacterial activity was assessed using the agar diffusion test and the microdilution method. Interactions between OEO and antibiotics were examined using the checkerboard method, while antibiofilm activity was analyzed using the crystal violet assay. Chemical analysis revealed that carvacrol was the major compound in OEO (61.51%). This essential oil demonstrated activity against all the tested strains, with inhibition zone diameters (IZDs) reaching 32.3 ± 1.5 mm. The combination of OEO with different antibiotics produced synergistic and additive effects, leading to a reduction of up to 98.44% in minimum inhibitory concentrations (MICs). In addition, this essential oil demonstrated an ability to inhibit and even eradicate biofilm formation. These results suggest that OEO could be exploited in the development of new molecules, combining its metabolites with antibiotics.
ABSTRACT
Holarrhena pubescens seeds are used in the treatment of various diseases, especially diabetes and associated complications, in different parts of the world. The present study was undertaken to determine the hypolipidemic and antihyperlipidemic effects of methanolic extract of H. pubescens seeds in rats. The extract was subjected to LC-MS analysis to determine the chemical constituents. The hypolipidemic action was studied by determining the effect of 28-day oral administration of seed extract on serum cholesterol, serum triglycerides, and serum HDL-cholesterol levels. The antihyperlipidemic action was studied in rats fed with a high-fat diet containing cholesterol and saturated fat, and the same lipid parameters were estimated during 28-day treatment. To elucidate its probable mechanism of action, in vitro studies on the inhibition of lipid accumulation in preadipocytes, DPP-IV inhibitory effect, and lipase enzyme inhibition were studied. The seed extract reduced serum levels of cholesterol and triglycerides in both normal rats and animals fed with a high-fat diet without a significant effect on HDL-cholesterol levels. The seed extract was highly effective in inhibiting lipase enzyme activity but showed a modest effect on the inhibition of lipid accumulation and DPP-IV. The results demonstrated that H. pubescens seed extract has hypolipidemic and antihyperlipidemic effects mediated probably through inhibition of lipase enzyme activity.
ABSTRACT
Holarrhena pubescens is widely used in Indian and Chinese medicine in the treatment of diabetes. The current work determined the oral hypoglycemic and antidiabetic effects of seed extract in rats. The probable mechanism of action was evaluated in-vitro by α - glucosidase inhibition, glucose metabolism in insulinoma (INS-1) cells to reflect secretion of insulin, and protein glycation inhibition. Its potential for herb-drug interaction was evaluated in the cytochrome P450 3A4 (CYP3A4) inhibition assay. The seed extract increased serum insulin levels and reduced serum blood glucose levels in the oral glucose tolerance test. It also reduced the serum glucose levels in streptozocin-induced diabetes. The extract also inhibited α -glucosidase enzyme activity and demonstrated that it can increase the secretion of insulin from INS to 1-rat insulinoma cell line cells in-vitro in a concentration-dependent manner. However, it had a very weak inhibitory effect on protein glycation and it did not affect the activity of CYP3A4. The results of the study showed that H. pubescens seed extract increases insulin secretion and inhibits glucose absorption both in-vivo and in-vitro with a weak protein glycation inhibitory effect. The herb is devoid of CYP3A4 inhibitory effect indicating that it may not have pharmacokinetic interaction with the drug metabolized by this enzyme.
ABSTRACT
In several parts of the world, Boswellia sacra Fluck. is one of the most commonly used herbs for the treatment of arthritis. Its usage should be validated in light of recent findings of haematotoxicity. This study was aimed to determine the effect of chronic administration of standardized methanolic extract of frankincense on blood cell count in experimental animals. Using high-performance liquid chromatography, the active constituents of B. sacra extract; boswellic acids were analyzed. The effect of three different doses of the extract (250, 500, and 1000 mg/kg) on different blood cells and associated parameters was investigated. The behavior, food, and water consumption of the rats were recorded. Boswellic acids were present in varying amounts with α-boswellic acid and ß-boswellic acid present in more amounts compared to other boswellic acids in the extract. All three doses tested had no effect on the animals' behavior, food consumption, or weight gain. The administration of a low (500 mg/kg) and high (1000 mg/kg) dose of the extract resulted in a non-dose dependent reduction in MCH (p < 0.01 and p < 0.05, respectively), but no other blood parameters were significantly affected. The B. sacra extract produces hypochromic normocytic anemia in rats at higher doses of 500 and 1000 mg/kg and this effect was not dose-dependent.
Subject(s)
Boswellia , Frankincense , Animals , Boswellia/chemistry , Methanol , Plant Extracts/toxicity , Rats , Resins, PlantABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Frankincense (Boswellia sacra Fluck.,) is a widely used herbal drug and household medicine for treatment of several diseases. Earlier toxicological studies revealed its proulcerogenic effect and no significant hepatotoxic or nephrotoxic effects in rats. However, some other members of Boswellia species such as Boswellia papyrifera (Caill. ex Delile) Hochst and Boswellia carterii have been reported for testicular toxicity in rats. AIM OF THE STUDY: Testicular toxicity of standardized methanolic extract of B. sacra oleo gum resin was determined through repeated oral dose administration for 28 days. Biochemical, histological and genetic changes in rat testes were evaluated. MATERIALS AND METHODS: B. sacra extract was analyzed for its boswellic acid content by high performance liquid chromatography (HPLC) method. The extract was administered at three different doses to rats. Effect on behavior, weight, food and water consumption along with changes in serum testosterone levels and cytoarchitecture of testis, epididymis and adrenal gland were determined. Gene expression of GSTPi, IGFBP3 and HSP70 in testis was also studied. RESULTS: Boswellic acids (α and ß) were present in highest concentration whereas acetyl-11-keto beta boswellic acid was present in relatively smaller amounts. The extract did not produce any significant change in the behavior of the animals, food/water consumption or weight gain. Serum testosterone levels were significantly decreased only by highest tested dose of Boswellia extract (1000 mg/kg, p.o). Histological examination did not reveal any variation in the structure of testis, adrenal gland and epididymis after administration of the extract while the expression of all three studied genes was significantly decreased. CONCLUSION: The results indicate that B. sacra extract does not possess any toxic effect on testis. On the contrary, decrease in gene expression of GSTPi, IGFBP3 and HSP70 revealed its antioxidant potential that may protect testes against effect of toxicants. However, a significant reduction in serum testosterone levels point to mechanisms other than direct testicular toxicity.