Effect of Zataria multiflora Boiss. essential oil on colony morphology and ultrastructure of Aspergillus flavus

The mode of inhibitory action of Zataria multiflora Boiss. essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The EO at concentrations used in this study suppressed the size of the colony as well as sporulation. SEM of mycelia treated with given concentrations of EO showed morphological alterations ranging from loss of turgidity and uniformity of mycelia at low concentrations of EO to evident destruction of the hyphae at higher concentration of EO. Semi-thin sections of mycelia exposed to different concentrations of EO were analysed by light microscopy and revealed that the major change at level as low as 50 ppm of EO was limited to vacuolisation of cytoplasm resulting in cell swelling, while at higher concentrations, detachment of the cell membrane from the cell wall, deformation of mycelia and shedding the cytoplasm from the cell were the main alterations. These damages were well documented by TEM, which showed that the main sites of action of EO were the plasma membrane and cell wall. In conclusion, morphological and structural changes observed in this study may be one of the mechanisms involved in growth inhibition of the fungi and reducing aflatoxin production.     

Beneficial effect of the leaves of Murraya koenigii (Linn.) Spreng (Rutaceae) on diabetes-induced renal damage in vivo

Ethnopharmacological relevance

Murraya koenigii (Linn.) Spreng (curry leaf) is widely used as a nephroprotective agent in kidney's infirmities among diabetics by the traditional practitioners in Malaysia. However, the latter role of curry leaf has been grossly under reported and is yet to receive proper scientific evaluation.

Aim of the study

The present study was designed to investigate the beneficial effect of the leaves of Murraya koenigii (Linn.) on diabetes-induced renal damage in vivo with regard to prove its efficacy by local traditional practitioners in the treatment of kidney frailties in diabetics.

Materials and methods

Aqueous (AQ) extract of the leaves of Murraya koenigii (Linn.) was administered to both normal and streptozotocin (STZ) induced diabetic male rats (Sprague-Dawley strain). Animals were divided into six groups (n = 6) and treated with variable dose levels of AQ extract (200 and 400 mg/kg body weight/day) for 30 days. At the end of 30 days, animals were sacrificed, blood was collected, processed and stored at −70 °C for the zestimation of serum urea and creatinine, changes in plasma antioxidant capacity by FRAP assay, and glutathione peroxidase levels, in the normal and STZ-induced diabetic rats. Histological changes of the kidneys of these animals were also evaluated by light microscopy to determine the beneficial effect of the leaves.

Results

Daily oral administration of variable dose levels of the AQ extract for 30 days, produced significant dose dependant decrease in serum urea and creatinine levels (p < 0.001), and marked increase in the levels of plasma antioxidant capacity (p < 0.01) in diabetic treated rats, compared to the control (non-diabetic) subjects. However, the normal treated rats showed minimal variation in these parameters in comparison to normal controls. Histological studies of the kidneys of these animals showed comparable tissue regeneration by the AQ extract.

Conclusion

The results of our study scientifically support the traditional belief for using the leaves of Murraya koenigii (Linn.) as adjuvant, in the treatment of pain disorders related to renal impairments among diabetics.     

White light-mediated Cu (II)–5FU interaction augments the chemotherapeutic potential of 5-FU: an in vitro study

5-Fluorouracil (5-FU) is a potent photosensitizer used in colon and rectal cancers. 5-FU on galvanostatic electrolysis or radiation-induced oxidation of aqueous solution yields N₁–C₅-linked dimmer hydrate of 5-FU. Copper is presently associated with chromatin; in cancer cells the concentration of copper is very high. It has been shown to be capable of mediating the action of several anticancer drugs through the production of reactive oxygen species (ROS). The objective of the present study is to determine the Cu (II)-mediated anticancer mechanism of 5-FU under photo-illumination as well as 5-FU alone. We have shown that a pro-oxidant action was enhanced when Cu (II) was used with 5-FU as compared to 5-FU alone. This may be due to the inhibition of dimerization of 5-FU when present in combination with Cu (II) under photo-illumination. It was also shown that 5-FU alone as well as in combination with Cu (II) was able to generate oxidative stress in lymphocyte which is inhibited by scavengers of ROS. Moreover, the results of Fourier-transformed infrared spectra lead to the conclusion that the dimerization of 5-FU was inhibited when used in combination with Cu (II). It was due to the interaction of 5-FU with Cu (II). Hence, we propose that during chemoradiotherapy with 5-FU, the endogenous copper is mobilized by 5-FU, leading to the generation of ROS which cause oxidative stress and possibly cancer cell death by apoptosis.     

Bone inductive proteins to enhance postorthodontic stability: A pilot study

Objectives:To evaluate the use of bone morphogenetic proteins to enhance postorthodontic stability in sheep and to develop a biological method of postorthodontic retention.Materials and Methods:First incisors were extracted in four mature and healthy sheep, and the second incisors were tipped reciprocally toward the midline and then retained. Dried bone matrix was injected into the distal periodontal space of the left second incisor. The right second incisor was left as a control. Both incisors were retained in the tipped position for 4 weeks. Then, the orthodontic appliance was removed and the teeth were left without retention. Six weeks later, the animals were killed and serial sections were prepared for histologic observation.Results:Unlike the control, the experimental second incisor maintained its tipped position with minimal relapse. On the distal periodontal space of the experimental tooth, areas of focal fusion between newly formed bone and newly formed areas of hypercementosis were observed. In the distal periodontal space of the control tooth, osteoclastic activity was observed along most of the socket wall, and the periodontal space appeared narrow and compressed. This brought the tooth close to the boundary of the alveolar bone, confirming the relapse observed on that side.Conclusion:This study proposes a new method of retention in which a biologically safe osteoinductive material is used to retain the teeth via induction of points of approximation between the cementum and alveolar bone.