Acute and subchronic dermal toxicity of Vitex negundo essential oil

Vitex negundo is a common herb in different herbal formulation. The potential acute and sub-chronic dermal toxicities were evaluated as per OECD (Organization for Economic Cooperation and Development) guidelines 402 and 411, respectively. Both sexes of Wistar rats were exposed to Vitex negundo oil of 2000?mg/kg body weight for acute dermal toxicity, whereas in the dermal sub-chronic toxicity study, rats were exposed to Vitex negundo oil 250, 500 and 1000?mg/kg body weight, respectively, for five times a week for 90?d. In acute and sub-chronic toxicity studies, all animals were normal without any behavioral, serum biochemistry, hematology, necroscopical and histopathological changes. The no observed effect level (NOEL) and no observed adverse effect level (NOAEL) of Vitex negundo oil were 250 and 1000?mg/kg/day, respectively. Vitex negundo oil is under the category 5 (Unclassified) according to the Globally Harmonized System, with an LD₅₀ value of over 2000?mg/kg.     

Late onset of dietary restriction reverses age-related decline of malate–aspartate shuttle enzymes in the liver and kidney of mice

Dietary restriction (DR) influences several physiological processes, retards the incidences and severity of various age-related diseases and extends lifespan of various animal species. The effect of DR on the activities of malate–aspartate shuttle enzymes, viz. cytosolic and mitochondrial aspartate aminotransferase (c- and m-AsAT) and malate dehydrogenase (c- and m-MDH) was investigated in the liver and kidney of adult (5-months) and old (21-months) male mice. The results show that the activity (U/mg protein) of both c- and m-MDH and AsAT is decreased significantly in the liver and kidney of old mice compared to adult ones. However, DR in old mice reverses significantly the enzyme activities to a level closer to adult animals. Polyacrylamide gel electrophoresis (PAGE) and specific staining of c-AsAT, one of the selected isoenzymes of the shuttle, showed a similar pattern of activity expression as observed by activity measurements in both the tissues studied. Slot blot analysis of c-AsAT confirmed the lower protein content of this isoenzyme in old mice compared to adult ones and a higher level in old-dietary restricted mice. Thus, our results suggest that the late onset of DR in older mice reverses decline in malate–aspartate shuttle enzymes and that it may allow a better metabolic regulation in older animals.     

Safety evaluation of an oat grain alkaloid gramine by genotoxicity assays

Gramine is a natural indole alkaloid that has been isolated from different raw plants occurring mainly in Avena sativa, etc. The study was aimed to investigate the possible in vitro antioxidant, in vitro mutagenic, in vitro antimutagenic, and in vivo genotoxic activity of gramine using ferric reducing ability of plasma (FRAP) assay, Metal chelating, Ames bacterial reverse mutation test, and the mouse bone marrow micronucleus assay as well as chromosomal aberration. Four concentrations of gramine viz. 250, 500, 1000, and 2000?μg/mL were evaluated for its antioxidant activity in FRAP Assay and Metal Chelating Test. Four concentrations of gramine (1250?μg/plate, 2500?μg/plate, 5000?μg/plate, and 10?000?μg/plate) were employed in Salmonella typhimurium strains to study the mutagenicity in the presence and absence of standard mutagens, 2-aminofluorene (2-AF), sodium azide (SA), and 2-nitrofluorene (2-NF). Three doses, i.e. 0.1, 0.2, and 0.3?×?the LD₅₀ of gramine (i.e. 50?mg/kg, 100?mg/kg, and 150?mg/kg) were administered orally to either sex of Swiss albino mice for 48?h to study the genotoxic activity in micronucleus assay as well as chromosomal aberration. Gramine showed potent antioxidant activity in both the assay. Gramine at the given dose lacks mutagenicity as well as found to possess antimutagenic efficacy. Interestingly, S9 enzymes increase the antimutagenic activity in a dose-dependent manner. There was no significant increase in the frequency of micronucleated polychromatic erythrocytes (MNPCEs), as well as no significant difference in the percentage of chromosomal aberrations was observed between the gramine groups and the negative groups but percentage of polychromatic erythrocytes (PCEs) is found to be higher in all the gramine groups. These results indicate significant antioxidant, non-mutagenic as well as non-genotoxic activity of gramine in vitro and in vivo in the given doses.     

Eleutherine indica L. accelerates in vivo cutaneous wound healing by stimulating Smad-mediated collagen production

Ethnopharmacological relevance

Eleutherine indica L. has been used for healing of wound, painful and irregular menstruation, dysentery and lesions, and topically used as antiseptic and antimicrobial agent in folk medicine. In the present study, methanolic extracts of Eleutherine indica was subjected to scientific investigation for in-vivo cutaneous wound healing in wistar rat.

Materials and methods

In-vivo wound healing activity of Eleutherine indica was evaluated by using circular excision experimental models, followed by histopathological and western blot analysis. The healing potential was comparatively assessed with a reference gentamicin sulfate hydrogel (0.01% w/w). Wound contraction measurement, hydroxyproline estimation and western blot for COL3A1, bFGF, Smad-2, -3, -4, and -7 were performed.

Results

The methanolic extract of Eleutherine indica showed accelerated wound healing activity as evidenced by fast wound contraction rate and higher hydroxyproline content of granulation tissue. Western blot revealed the Smad-mediated collagen production promoting property of Eleutherine indica methanolic extract. Histopathological examinations also supported the experimental findings.

Conclusion

The study revealed that Eleutherine indica promotes wound healing by augmenting Smad-mediated collagen production in wound granulation tissue.