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

Enhanced rosmarinic acid production in cultured plants of two species of <i style="mso-bidi-font-style:normal">Mentha</i>

817-825  In the present investigation an attempt has been made to enhance rosmarinic acid level in plants, grown<i style="mso-bidi-font-style: normal"> in vitro, of 2 species of Mentha in presence of 2 precursors in the nutrient media during culture. For <i style="mso-bidi-font-style: normal">in vitro culture establishment and shoot bud multiplication, MS basal media were used supplemented with different concentrations and combinations of different growth regulator like NAA (α-napthaleneacetic acid), BAP (6-benzylaminopurine). The medium containing NAA (0.25 mg/L) and BAP (2.5 mg/L) gave the highest potentiality of shoot formation (average 58.0 numbers of shoots) per explant for Mentha piperita L. and the medium containing BAP (2.0 mg/L) gave the highest potentiality of shoot (average 19.2 numbers of shoots) formation per explant for Mentha arvensis L. The complete plants were regenerated in above mentioned media after 8 weeks of subculture. For in vitro enhancement of rosmarinic acid production, the 2 precursors tyrosine (Tyr) and phenylalanine (Phe) were added in the nutrient media at different levels (0.5 mg/L to 15.0 mg/L). Tyrosine was found to be very effective for augmenting rosmarinic acid content in Mentha piperita L. It nearly increased the production up to 1.77 times. In case of Mentha arvensis L., phenylalanine significantly affected the production of rosmarinic acid and the production was nearly 2.03 times more than the control. No significant increase in biomass was observed after addition of these precursors indicating that the added amino acids acting as precursors for rosmarinic acid synthesis were readily utilized in producing rosmarinic acid without promoting growth. Total protein profile also revealed the presence of a specific band in polyacrylamide gel electrophoresis

Fatty acid Represses Insulin Receptor Gene Expression by Impairing HMGA1 through Protein Kinase Ce

It is known that free fatty acid (FFA) contributes to the development of insulin resistance and type2 diabetes. However, the underlying mechanism in FFA-induced insulin resistance is still unclear. In the present investigation we have demonstrated that palmitate significantly (p < 0.001) inhibited insulin-stimulated phosphorylation of PDK1, the key insulin signaling molecule. Consequently, PDK1 phosphorylation of plasma membrane bound PKCe was also inhibited. Surprisingly, phosphorylation of cytosolic PKCe was greatly stimulated by palmitate; this was then translocated to the nuclear region and associated with the inhibition of insulin receptor (IR) gene transcription. A PKCe translocation inhibitor peptide, eV1, suppressed this inhibitory effect of palmitate, suggesting requirement of phospho-PKCe migration to implement palmitate effect. Experimental evidences indicate that phospho-PKCe adversely affected HMGA1. Since HMGA1 regulates IR promoter activity, expression of IR gene was impaired causing reduction of IR on cell surface and that compromises with insulin sensitivity

Involvement of novel PKC isoforms in FFA induced defects in insulin signaling

Involvement of novel PKCs (nPKCs) in the negative regulation of insulin-signaling pathway is a current interest of many workers investigating the cause for insulin resistance and type 2 diabetes. Free fatty acids (FFAs) are recently shown to be the major players in inducing insulin resistance in insulin target cells. They are also found to be involved in activating nPKCs associated with the impairment of insulin sensitivity. In this overview, we describe PKC δ, θ and ε linked to the FFA induced damage of insulin-signaling molecules

Multiple roles for basement membrane proteins in cancer progression and EMT

Metastasis or the progression of malignancy poses a major challenge in cancer therapy and is the principal reason for increased mortality. The epithelial-mesenchymal transition (EMT) of the basement membrane (BM) allows cells of epithelial phenotype to transform into a mesenchymal-like (quasi-mesenchymal) phenotype and metastasize via the lymphovascular system through a metastatic cascade by intravasation and extravasation. This helps in the progression of carcinoma from the primary site to distant organs. Collagen, laminin, and integrin are the prime components of BM and help in tumor cell metastasis, which makes them ideal cancer drug targets. Further, recent studies have shown that collagen, laminin, and integrin can be used as a biomarker for metastatic cells. In this review, we have summarized the current knowledge of such therapeutics, which are either currently in preclinical or clinical stages and could be promising cancer therapeutics.Data availability: Not applicableScientific Research at Majmaah University [R-2022-117]Dr. Niraj Kumar Jha is thankful to Sharda University for the infra-structure and facility. The author would like to thank Deanship of Sci-entific Research at Majmaah University for supporting this work under project number No. R-2022-117. The authors would like to acknowledge the support from their respective institutes throughout the review writing process

A Lupinoside prevented fatty acid induced inhibition of insulin sensitivity in 3T3 L1 adipocytes

The decrease in insulin sensitivity to target tissues or insulin resistance leads to type 2 diabetes mellitus, an insidious disease threatening global health. Numerous evidences made free fatty acids (FFAs) responsible for insulin resistance and type 2 diabetes. We demonstrate here that the damage of insulin acitivity by a free fatty acid, palmitate could be prevented by a lupinoside. An incubation of 3T3 L1 adipocytes with a FFA i.e. palmitate inhibited insulin stimulated uptake of 3H-2 deoxyglucose (2 DOG) significantly. Addition of a lupinoside purified from Pueraria tuberosa, lupinoside PA4 (LPA4) strongly prevented this inhibition. We then examined insulin signaling pathway where palmitate significantly inhibited insulin stimulated phosphorylation of Insulin receptor tyrosine kinase, IRS 1and PI3 kinase, PDK1 and Akt/PKB. LPA4 rescued this inhibition of signaling molecule by palmitate. Insulin mediated translocation of Glut4, the glucose transporter in insulin target cells, was effectively blocked by palmitate while, LPA4 waived this block. Administration of LPA4 to nutritionally induced diabetic rats significantly reduced the increase in plasma glucose. All these indicate LPA4 to be a potentially therapeutic agent for insulin resistance and type 2 diabetes

Inhibition of Insulin Receptor Gene Expression and Insulin Signaling by Fatty Acid: Interplay of PKC Isoforms Therein

Fatty acids are known to play a key role in promoting the loss of insulin sensitivity causing insulin resistance and type 2 diabetes. However, underlying mechanism involved here is still unclear. Incubation of rat skeletal muscle cells with palmitate followed by I125- insulin binding to the plasma membrane receptor preparation demonstrated a two-fold decrease in receptor occupation. In searching the cause for this reduction, we found that palmitate inhibition of insulin receptor (IR) gene expression effecting reduced amount of IR protein in skeletal muscle cells. This was followed by the inhibition of insulin-stimulated IRβ tyrosine phosphorylation that consequently resulted inhibition of insulin receptor substrate 1 (IRS 1) and IRS 1 associated phosphatidylinositol-3 kinase (PI3 Kinase), phosphoinositide dependent kinase-1 (PDK 1) phosphorylation. PDK 1 dependent phosphorylation of PKCζ and Akt/PKB were also inhibited by palmitate. Surprisingly, although PKCε phosphorylation is PDK1 dependent, palmitate effected its constitutive phosphorylation independent of PDK1. Time kinetics study showed translocation of palmitate induced phosphorylated PKCε from cell membrane to nuclear region and its possible association with the inhibition of IR gene transcription. Our study suggests one of the pathways through which fatty acid can induce insulin resistance in skeletal muscle cell

Molecular Mechanism of Insulin Resistance

Free fatty acids are known to play a key role in promoting loss of insulin sensitivity, thereby causing insulin resistanceNand type 2 diabetes. However, the underlying mechanism involved is still unclear. In searching for the cause of the mechanism, it has been found that palmitate inhibits insulin receptor (IR) gene expression, leading to a reduced amount of IR protein in insulin target cells. PDK1-independent phosphorylation of PKCε causes this reduction in insulin receptor gene expression. One of the pathways through which fatty acid can induce insulin resistance in insulin target cells is suggested by these studies. We provide an overview of this important area, emphasizing the current status