8 research outputs found
Augmentation of antioxidative potential of in vitro propagated Mentha piperita L.
131-137Mentha piperita L., as an aromatic culinary herb and a source of variety of phytochemicals including effective antioxidants, is overexploited by food industry. It demands rapid conservation by means of in vitro propagation of improved clones. Here, we have made an attempt to evaluate and augment the antioxidative potential of M. piperita L. by additing a precursor to the tissue culture derived clones and compared it with the in vivo plants so that tissue culture derived plants can serve as an alternative source of drug. M. piperita L. were analyzed for total phenol, flavonoids, total antioxidant activity, free radical scavenging activity and lipid peroxidase activity. Total phenol content in in vivo plants was lesser than in in vitro. In case of total flavonoid content, it also varies through the season where tissue culture derived plants showed similar and continuous production of total flavonoids content. The percentage inhibition of the in vitro plant extract of precursor fed clone was higher than that of in vivo plant extract. Antioxidant capacity of ascorbic acid was used as a reference standard from which plant extracts with potential antioxidant activity were compared. After addition of precursor, the in vitro mint plant proved more efficient in inhibiting lipid peroxidation after one hour than the in vivo plant, which has high absorbance value indicating lipid peroxide formation
Augmentation of antioxidative potential of in vitro propagated Mentha piperita L
Mentha piperita L., as an aromatic culinary herb and a source of variety of phytochemicals including effective antioxidants, is overexploited by food industry. It demands rapid conservation by means of in vitro propagation of improved clones. Here, we have made an attempt to evaluate and augment the antioxidative potential of M. piperita L. by additing a precursor to the tissue culture derived clones and compared it with the in vivo plants so that tissue culture derived plants can serve as an alternative source of drug. M. piperita L. were analyzed for total phenol, flavonoids, total antioxidant activity, free radical scavenging activity and lipid peroxidase activity. Total phenol content in in vivo plants was lesser than in in vitro. In case of total flavonoid content, it also varies through the season where tissue culture derived plants showed similar and continuous production of total flavonoids content. The percentage inhibition of the in vitro plant extract of precursor fed clone was higher than that of in vivo plant extract. Antioxidant capacity of ascorbic acid was used as a reference standard from which plant extracts with potential antioxidant activity were compared. After addition of precursor, the in vitro mint plant proved more efficient in inhibiting lipid peroxidation after one hour than the in vivo plant, which has high absorbance value indicating lipid peroxide formation
In vitro clonal propagation, organogenesis and somatic embryogenesis in Bacopa monnieri (L.) Wettst
Bacopa monnieri (L.) Wettst is a well-known medicinal herb in the Ayurveda. It is also used as laxative and curative for ulcers, inflammation, anaemia, scabies, leucoderma, asthma and epilepsy, enlargement of spleen, leprosy and others. In vitro propagation and regeneration through somatic embryogenesis of B. monnieri has played an important role in the production of healthy, disease-free plants with desirable traits. In B. monnieri, there are few reports which indicate rapid regeneration and somatic embryogenesis. For in vitro clonal propagation, the highest shoot formation was obtained when BAP 2 mg/ l used. The best response for rooting was obtained in IAA 1.0 mg/ l. The recorded survival rate of the plants was 70%. Plants were without any detectable phenotypic variations. Cytological study indicated that the chromosome number remain same (2n= 64) in in vitro and in vivo roots. A rapid, simple and efficient protocol for plantlet regeneration was achieved through embryogenic callus from leaf explants of B. monnieri. Callus induction and embryogenesis were significantly affected by presence/absence and type and concentration of growth regulators. Best organogenic callus induction was obtained in MS medium supplemented with BAP 5mg/ l. For induction of somatic embryogenesis, auxin (2, 4-D 1 mg/ l) was used in the culture medium subsequently in basal media for embryo maturation. Kn 0.2 mg/ l was the best for production of plantlet from embryo. Thus, this can be an easiest protocol for stable clonal propagation and plant regeneration through somatic embryogenesis in B. monnieri. The protocol used here for propagation and regeneration is much easier, low cost and reliable
Efflux Pumps In Antimicrobial Resistance: Mechanism, Regulation And Therapeutic Implications
Efflux pumps play a crucial role in antimicrobial resistance, enabling bacteria to extrude a wide range of antibiotics and other antimicrobial compounds, thereby reducing their intracellular concentration and rendering them ineffective. Understanding the mechanisms underlying efflux pump-mediated resistance is essential for the development of effective strategies to combat this growing threat. This review paper provides an overview of the various efflux pump systems, their regulation mechanisms, and their impact on antimicrobial resistance. Additionally, we discuss the potential therapeutic interventions that target efflux pumps to restore the efficacy of antimicrobial agents
Human placental lipid induces melanogenesis by increasing the expression of tyrosinase and its related proteins in vitro
Lipids, particularly sphingolipids, are emerging as
novel regulators of cellular activity. A placental total
lipid fraction (PTLF), the total lipid prepared from an
hydroalcoholic extract of fresh term human
placenta, was previously shown to have a pigmentinducing
activity in an animal model. The PTLF contains
sphingolipids which stimulate DNA synthesis
and melanin formation with marked morphological
changes in B16F10 melanoma cells. In order to identify
the mechanism underlying the increased melanin
synthesis, B16F10 cells were treated with PTLF
to assess the catalytic activities of tyrosinase (i.e.
tyrosine hydroxylase and DOPA oxidase), the key
regulatory enzyme of melanin synthesis. Tyrosine
hydroxylase (estimated by the release of 3H2O) as
well as DOPA oxidase (measured spectrophotometrically
and also in non-denaturing gels), was stimulated
significantly by PTLF. Western blot analysis
demonstrated an increase in the expression of
tyrosinase, tyrosinase related proteins 1 and 2
(TRP1 and TRP2) at the protein level and RT-PCR
analysis revealed stimulated transcription of tyrosinase,
TRP1 and TRP2 mRNAs in PTLF-treated B16F10
cells. Actinomycin D and cycloheximide, inhibitors
of transcription and translation, respectively, inhibited
PTLF-induction of tyrosinase activity with a corresponding
decrease in melanogenesis. In all cases,
the response to PTLF was similar to that induced by
a-melanocyte stimulating hormone, a well-known
stimulator of melanogenesis. Thus, these results
provide the basis of action of PTLF stimulated
melanogenesis in B16F10 cells showing that this placental extract is a strong inducer of pigmentation
at the transcriptional and translational levels
Human placental lipid induces melanogenesis through p38 MAPK in B16F10 mouse melanoma
Melanogenesis is one of the characteristic functional
activities of melanocyte/melanoma and is
regulated via mitogen-activated protein kinase
(MAPK) and Akt/protein kinase B (PKB) pathways.
Placental total lipid fraction (PTLF), prepared from
a hydroalcoholic extract of fresh term human placenta
contains sphingolipids and was recently
shown to stimulate melanogenesis via up-regulation
of the key enzyme tyrosinase in B16F10
mouse melanoma cells. How such lipids mediate
their effects on pigmentation and tyrosinase
expression is a particularly important aspect of
melanogenesis. To study the signaling that leads
to tyrosinase expression, we have investigated the
roles of the MAPK and Akt/PKB pathways in
B16F10 melanoma cells in melanogenesis in
response to PTLF. Treatment of cells with PTLF led
to the time dependent phosphorylation of p38
MAPK. SB203580, a p38 MAPK inhibitor, completely
blocked the PTLF-induced melanogenesis by
inhibiting promoter activity and subsequent
expression of tyrosinase. Phosphatidylinositol 3-
kinase (PI3K) inhibitor, LY294002 a blocker of the
Akt signaling pathway, or an inhibitor of MEK
(MAPK/ERK Kinase), PD98059 when included along
with PTLF was found to potentiate PTLF-induced
phosphorylation of p38 MAPK together with tyrosinase
expression and melanogenesis. The results
suggest that the activation of p38 MAPK plays a
crucial role in PTLF-induced B16F10 melanogenesis
by up-regulating tyrosinase expression
Transcriptional activation of tyrosinase gene by human placental sphingolipid
The sphingolipids, a class of complex bioactive
lipids, are involved in diverse cellular functions such
as proliferation, differentiation, and apoptosis as well as
growth inhibition. Recently sphingosylphosphorylcholine
(SPC), sphingosine-1-phosphate (S1P), and C2-ceramide
(C2-Cer), sphingolipid containing acetic acid are emerging
as melanogenic regulators. A bioactive sphingolipid (PSL)
was isolated from hydroalcoholic extract of fresh term human
placenta and it induced melanogenesis in an in vitro
culture of mouse melanoma B16F10 cells. Tyrosinase, the
rate-limiting enzyme for melanogenesis, is required to be
upregulated for the increased melanin production. The expression
of tyrosinase, both at protein as well as mRNA
level, was higher in the PSL treated B16F10 cells as evidenced
by Western blot and RT-PCR analysis. Actinomycin
D and cycloheximide, inhibitors of transcription and translation,
respectively, inhibited PSL-induced tyrosinase activity
and its protein expression showing decrease in melanogenesis,
correspondingly. The activity of GFP coupled tyrosinase
promoter was upregulated in transfected B16F10 cells after
treating with PSL as determined by fluorescence microscopy,
fluorometric analysis, and Western blot. These results, thus,
suggested that PSL upregulated tyrosinase gene expression
at transcription level through promoter activation to show
increased melanogenesis. Therefore, PSL as an inducer of
melanogenesis might account for the recovery of pigment in depigmentation disorder