Ameliorative effects of hydroalcoholic extract of Lavandula officinalis L. on cyclophosphamide-induced nephrotoxicity in mice

Extracts obtained from the leaves of Lavandula angustifolia Mill. (Lamiaceae) are used in Iranian folk medicine as remedies for the treatment of various inflammatory diseases. For evaluation of its probable analgesic and anti-inflammatory effects, hydroalcoholic extract, polyphenolic fraction and essential oil of the leaves of the herb were prepared and their analgesic effects were studied in mice using formalin and acetic acid-induced writhing tests. Carrageenan test in rats was used for assessment of anti-inflammatory activity of above-mentioned fractions. Results showed that while the hydroalcoholic extract (400-1600 mg/kg, p.o.) inhibited only the second phase of formalin test, the polyphenolic fraction (800 and 1600 mg/kg, p.o.) and essential oil (100 and 200 mg/kg, p.o.) suppressed both phases. In acetic acid-induced writhing test, polyphenolic fraction (400 and 800 mg/kg, p.o.) and essential oil (100 and 200 mg/kg, p.o.) reduced the number of abdominal constrictions. Essential oil at a dose of 200mg/kg also inhibited carrageenan-induced paw edema. Results of the present study confirm the traditional use of Lavandula angustifolia for the treatment of painful and inflammatory conditions and calls for further investigations to determine the active chemical constituent(s).

Hematoxylin, a natural dye commonly used as a histological stain, generates superoxide upon oxidation to its quinonoid product, hematein. The parameters affecting this reaction were assessed in developing a new and versatile assay for superoxide dismutase. The autoxidation of hematoxylin to hematein was accompanied by an increase in absorbance between 400 and 670 nm. The autoxidation rate was proportional to hematoxylin concentration and increased with pH above 6.55. Trace metals accelerated the autoxidation and this effect was eliminated by EDTA. Superoxide dismutase inhibited the autoxidation 90-95% below pH 7.8, but above pH 8.1 the rate was augmented by superoxide dismutase. The rate inhibition at low pH was proportional to the superoxide dismutase concentration up to 70% inhibition. The rate acceleration at high pH was proportional to superoxide dismutase concentration up to approximately 200% acceleration. The autoxidation rate was not significantly affected by ethanol, cyanide, azide, hydrogen peroxide, or catalase. However, the reaction was inhibited by the reducing agents NADH, reduced glutathione, ascorbate, and dithiothreitol, and by undialyzed extracts of Escherichia coli B. When cell extracts were dialyzed prior to assay, the degree of inhibition observed was proportional to the concentration of superoxide dismutase in the extract. These observations form the basis for negative and positive assays of superoxide dismutase which are inexpensive and simple to perform. The negative assay has the added advantage of being applicable at physiological pH.

The study reported here presents a comparative screening of three medicinal plants including oregano (Origanum vulgare L.), lavender (Lavandula angustifolia) and lemon balm (Melissa officinalis) having the same geographical origin, the Southeast region of Romania, and growing in the same natural conditions. The contents of total phenolics and total flavonoids for the extracts of these were determined. Furthermore, the total antioxidant capacity was also evaluated. It was found that Origanum vulgare and Melissa officinalis extracts present the most effective antioxidant capacity in scavenging DPPH radicals, while Lavandula angustifolia is less active. High performance liquid chromatography-mass spectrometry analysis was used to identify the components of extracts. Major phenolic acids identified in the analysed species were ferulic, rosmarinic, p-coumaric and caffeic, while predominant flavonoids were quercetin, apigenin kaempherol, which were present as glucosides.