Isoquinoline Alkaloid Berberine Research Articles

Spectral Analysis of Nanodiamond-Berberine Complex Interaction with Living Cells for Nanoparticle Mediated Drug Delivery

The natural isoquinoline alkaloid berberine has been demonstrated for its significant activity against a variety of deceases caused by bacterial and parasite infections. Nanodiamond (ND) has also been proven to have great potential for drug delivery. In this work, the complex of ND with berberine is constructed through surface functionalized ND, aiming for drug delivery applications. Spectroscopic analysis was performed on the complex interaction with human lung alveolar carcinoma epithelial cell (A549) and red blood cell (RBC) in comparison with berberine in solution. The studied cells were treated with carboxylated ND, ND-berberine complex and berberine, respectively. Their distributions in cells structures are visualized using ND and berberine’s fluorescence signals for detection. The distribution of ND and ND-berberine complex differs with the distribution of berberine introduced in solution form. The results show that the ND with attached drug molecules can act as a drug carrier allowing controllable localization of the drug into the cell. This result can have implication in drug delivery, release and delivery tracing applications.

Anticancer Chemodiversity of Ranunculaceae Medicinal Plants: Molecular Mechanisms and Functions.

The buttercup family, Ranunculaceae, comprising more than 2,200 species in at least 62 genera, mostly herbs, has long been used in folk medicine and worldwide ethnomedicine since the beginning of human civilization. Various medicinal phytometabolites have been found in Ranunculaceae plants, many of which, such as alkaloids, terpenoids, saponins, and polysaccharides, have shown anti-cancer activities in vitro and in vivo. Most concerns have been raised for two epiphany molecules, the monoterpene thymoquinone and the isoquinoline alkaloid berberine. At least 17 genera have been enriched with anti-cancer phytometabolites. Some Ranunculaceae phytometabolites induce the cell cycle arrest and apoptosis of cancer cells or enhance immune activities, while others inhibit the proliferation, invasion, angiogenesis, and metastasis, or reverse the multi-drug resistance of cancer cells thereby regulating all known hallmarks of cancer. These phytometabolites could exert their anti-cancer activities via multiple signaling pathways. In addition, absorption, distribution, metabolism, and excretion/toxicity properties and structure/activity relationships of some phytometabolites have been revealed assisting in the early drug discovery and development pipelines. However, a comprehensive review of the molecular mechanisms and functions of Ranunculaceae anti-cancer phytometabolites is lacking. Here, we summarize the recent progress of the anti-cancer chemo- and pharmacological diversity of Ranunculaceae medicinal plants, focusing on the emerging molecular machineries and functions of anti-cancer phytometabolites. Gene expression profiling and relevant omics platforms (e.g. genomics, transcriptomics, proteomics, and metabolomics) could reveal differential effects of phytometabolites on the phenotypically heterogeneous cancer cells.

Berberine augments ATP-induced inflammasome activation in macrophages by enhancing AMPK signaling.

The isoquinoline alkaloid berberine possesses many pharmacological activities including antibacterial infection. Although the direct bactericidal effect of berberine has been documented, its influence on the antibacterial functions of macrophages is largely unknown. As inflammasome activation in macrophages is important for the defense against bacterial infection, we aimed to investigate the influence of berberine on inflammasome activation in murine macrophages. Our results showed that berberine significantly increased ATP-induced inflammasome activation as reflected by enhanced pyroptosis as well as increased release of caspase-1p10 and mature interleukin-1β (IL-1β) in macrophages. Such effects of berberine could be suppressed by AMP-activated protein kinase (AMPK) inhibitor compound C or by knockdown of AMPKα expression, indicating the involvement of AMPK signaling in this process. In line with increased IL-1β release, the ability of macrophages to kill engulfed bacteria was also intensified by berberine. This was corroborated by the in vivo finding that the peritoneal live bacterial load was decreased by berberine treatment. Moreover, berberine administration significantly improved survival of bacterial infected mice, concomitant with increased IL-1β levels and elevated neutrophil recruitment in the peritoneal cavity. Collectively, these data suggested that berberine could enhance bacterial killing by augmenting inflammasome activation in macrophages through AMPK signaling.

Plant Isoquinoline Alkaloid Berberine Exhibits Chromatin Remodeling by Modulation of Histone Deacetylase To Induce Growth Arrest and Apoptosis in the A549 Cell Line.

Histone deacetylases (HDACs) are a group of epigenetic enzymes that control gene expression through their repressive influence on histone deacetylation transcription. HDACs are probable therapeutic targets for cancer treatment, spurring the progress of different types of HDAC inhibitors. Further, natural-source-based derived bioactive compounds possess HDAC inhibitor property. In this way, we hypothesized that plant isoquinoline alkaloid berberine (BBR) could be a HDAC inhibitor in the human lung cancer A549 cell line. BBR represses total HDAC and also class I, II, and IV HDAC activity through hyperacetylation of histones. Furthermore, BBR triggers positive regulation of the sub-G0/G1 cell cycle progression phase in A549 cells. Moreover, BBR-induced A549 cell growth arrest and morphological changes were confirmed using different fluorescence-dye-based microscope techniques. Additionally, BBR downregulates oncogenes (TNF-α, COX-2, MMP-2, and MMP-9) and upregulates tumor suppressor genes (p21 and p53) mRNA and protein expressions. Besides, BBR actively regulates Bcl-2/Bax family proteins and also triggered the caspase cascade apoptotic pathway in A549 cells. Our finding suggests that BBR mediates epigenetic reprogramming by HDAC inhibition, which may be the key mechanism for its antineoplastic activity.

Decreased Levels of Spleen Tissue CD4+CD25+Foxp3+ Regulatory T Lymphocytes in Mice Exposed to Berberine

The effects of isoquinoline alkaloid berberine (BER) on spleen tissue CD4+CD25+Foxp3+ regulatory T (Treg) cells were evaluated in BALB/c mice. Here, BER was administered daily by intraperitoneal injection at doses of 5 mg/kg and 10 mg/kg for 14 days. Following the exposure, mice spleen cellularities, IL-10 production by splenocytes, and spleen Treg/CD4+ cell profiles were studied in all the test groups of animals. The results showed that a high dose of BER (10 mg/kg) could decrease both the absolute and relative percentages of spleen Treg cells as well as decrease the production of IL-10 by splenocytes in the treated mice (p<0.05). BER at 5 mg/kg did not appear to affect any of these parameters. Based on the finding here, it would seem that BER has effective immunostimulatory properties, which contradicts the results from other studies indicating immunosuppressive effects of BER. Depending on the doses of BER used, it might have a broad spectrum from immunosuppressive to stimulatory effects. Further studies, including more doses, are required to better evaluate the effects of this natural product. Mechanistic studies are required, particularly in case of redox state of the immune cells, to elucidate and determine how BER functions to impart the toxicity effects demonstrated here and in other studies.

Spectroscopic investigation of the interaction between G-quadruplex of KRAS promoter sequence and three isoquinoline alkaloids

KRAS promoter can form G-quadruplex structure and regulate gene transcription. The drugs which can bind with G-quadruplex of KRAS promoter may be potential remedy for treatment of cancers associated with KRAS mutation. The interaction mechanism between the G-quadruplex of KRAS promoter and three isoquinoline alkaloids (jatrorrhizine, berberine and sanguinarine) has been investigated by UV-visible, fluorescence and circular dichroism spectroscopic methods. The results showed that the three alkaloids can form complexes with G-quadruplex KRAS promoter with the molecular ratio of 1:1, and the binding constants were (0.90±0.16)×106Lmol−1, (0.93±0.21)×106Lmol−1 and (1.16±0.45)×106Lmol−1 for jatrorrhizine, berberine and sanguinarine. The absorption spectra, KI quenching and fluorescence anisotropy and polarization studies suggested jatrorrhizine and berberine interacted with G-quadruplex by not only end-stacking binding mode but also grooves or loops binding mode, while sanguinarine by end-stacking binding mode. Sanguinarine was more beneficial to maintain the stability and parallel conformation of KRAS promoter G-quadruplex. MTT assay was performed to evaluate antiproliferation effects of the three isoquinoline alkaloids on SW620 cells, and the antiproliferation effects of the three alkaloids were sanguinarine > berberine > jatrorrhizine. All the three alkaloids can bind with KRAS promoter G-quadruplex, and sanguinarine had the better binding property and antiproliferation effects on SW620 cells. The results obtained are meaningful to explore potential reagents targeting the parallel G-quadruplex structure of KRAS promoter for gene theraphy of colorectal carcinomas.

Effects of isoquinoline alkaloid berberine on lipid peroxidation, antioxidant defense system, and liver damage induced by lead acetate in rats

Objectives: Liver is considered a target organ affected by lead toxicity. Oxidative stress is among the mechanisms involved in liver damage. Here we investigated the effects of the natural alkaloid berberine on oxidative stress and hepatotoxicity induced by lead in rats.Methods: Animals received an aqueous solution of lead acetate (500 mg Pb/l in the drinking water) and/or daily oral gavage of berberine (50 mg/kg) for 8 weeks. Rats were then weighed and used for the biochemical, molecular, and histological evaluations.Results: Lead-induced oxidative stress, shown by increasing lipid peroxidation along with a concomitant decrease in hepatic levels of thiol groups, total antioxidant capacity, the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, and reduced versus oxidized glutathione ratio. Berberine corrected all the disturbances in oxidative stress markers induced by lead administration. Berberine also prevented the elevated levels of enzymes (alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) and the decrease in body weight and albumin. The protective effects of berberine were comparable with silymarin. Furthermore, berberine attenuated liver damage, shown by decreased necrosis and inflammatory cell infiltration.Discussion: Berberine represents a potential therapeutic option against lead-induced hepatotoxicity through inhibiting lipid peroxidation and enhancing antioxidant defenses.Conclusion: Berberine exerted protective effects on lead-induced oxidative stress and hepatotoxicity in rats.

Synthesis of Mannich base derivatives of berberine and evaluation of their anticancer and antioxidant effects

The 9-demethylated derivative of the isoquinoline alkaloid berberine was derivatised in its isoquinoline moiety using enamines derived from formaldehyde and morpholine, piperidine, carbazole and six variously substituted piperazines to form Mannich base products which were evaluated for their in vitro biological effects. Standard tests determined their radical scavenging potential and their ferric reducing antioxidant power (FRAP). Cancerous growth inhibitory efficacies were assessed using cervical cancer cell lines HeLa and CaSki and their cytotoxicities towards normal cell lines were evaluated using Madin–Darby canine kidney (MDCK) cell lines. Piperazine derivatives bearing a heterocyclic nitrogen substituent such as a pyridyl or a pyrimidyl ring were the most active antioxidant and anticancer agents. A carbazole moiety attached to the berberine core also demonstrated excellent inhibitory effects on cancerous cells.

The Isoquinoline Alkaloid Berberine Augments Radiation Effect by Enhancing the DNA Damage at Molecular Level in HeLa Cells Irradiated with Various Doses of γ-Radiation: Correlation Between DNA Damage and Clonogenicity

The passage of ionizing radiations through aqueous medium of biological material leads into the generation of a burst of free radicals owing to radiolysis of water. These free radicals are extremely reactive and interact with important macromolecules of cells resulting in the cytotoxicity. It is well known that ionizing radiation induce damage to the DNA triggering a cascade of events that result in eventual cell kill. Earlier we found that berberine chloride an isoquinoline alkaloid present in certain plants inflicts damage to the molecular DNA. Therefore we wanted to know whether berberine chloride will increase the effects of radiation in HeLa cells exposed to various doses of γ- radiation. HeLa cells were treated or not with 0, 1, 2, 4, 6 or 8 μg/ml of berberine chloride prior to 0, 0.5, 1, 2, 3 or 4 Gy γ-irrradiation and the molecular DNA damage was assessed immediately after irradiation (within 15 minute of irradiation) by single cell gel electrophoresis. The migration of fragmented DNA into comet tails was considered as a measure of molecular damage to DNA and has been expressed as Olive tail moment. Irradiation of HeLa cells to 0, 0.5, 1, 2, 3 or 4 Gy γ-irradiation caused a radiation dose-dependent rise in the Olive tail moment indicating an elevation in the DNA damage in HeLa cells. Treatment of HeLa cells with different concentrations of berberine chloride for 2 or 4 h before irradiation further raised the DNA damage denoted by a rise in the amount of tail DNA of the comets and Olive tail moment immediately after irradiation. The clonogenic assay revealed that clonogenic potential of HeLa cells alleviated with an increase in irradiation dose and treatment of HeLa cells with 1, 2 or 4 μg/ml berberine chloride further reduced the clonognenicity of cells. Our study indicates that berberine is a potent DNA damaging agent and could enhance radiation damage during cancer treatment in clinical conditions and clonogenicity of cells is directly related to the ability of berberine to inflict damage to DNA.

Evaluation of the biological potencies of newly synthesized berberine derivatives bearing benzothiazole moieties with substituted functionalities

Benzothiazole moieties substituted with various functional groups were utilized to link with the isoquinoline alkaloid berberine through a pentyl side chain. Entitled analogs were screened for antioxidant potency using the DPPH and ABTS bioassays and for their in vitro anticancer activities against HeLa, CaSki (cervical cancer), and SK-OV-3 (ovarian cancer) cell lines using the SRB bioassay. The compounds were evaluated for their toxicity to the Madin–Darby canine kidney (MDCK) cell line. The final compounds demonstrated significant antioxidant potency with IC50 levels of 13.03–24.50μg/mL and 4.958–7.570μg/mL in the DPPH and ABTS radical scavenging bioassays, respectively. The 5e analog with a methoxy functional group and the 5m analog with a cyano functional group had the most significant DPPH and ABTS radical scavenging activities, respectively. Moreover, the 5m cyano-based analog had the highest potency against all cancer cell lines, with IC50 levels of 5.474, 5.311, and 32.61μg/mL against the HeLa, CaSki, and SK-OV-3 cell lines, respectively. All the synthesized compounds were characterized by IR, 1H NMR, 13C NMR spectroscopy and elemental analysis.

A new bisbenzylisoquinoline alkaloid isolated from Thalictrum foliolosum, as a potent inhibitor of DNA topoisomerase IB of Leishmania donovani

Chemical investigation of the stem of Thalictrum foliolosum resulted in the isolation of two new bisbenzylisoquinoline alkaloids (1 and 2) along with known protoberberine group of isoquinoline alkaloids thalifendine (3) and berberine (4). The structures of the new compounds were established by detailed 2D NMR spectral analysis with their configurations determined from their optical rotation values and confirmed using circular dichroism. Inhibitory activities of these four compounds against DNA topoisomerase IB of Leishmania donovani were evaluated. Compound 2 exhibited almost complete inhibition of the enzyme activity at 50μM concentration and it was found to be effective in killing both wild type as well as SAG resistant promastigotes of the parasite.

Synthesis of piperazine based N-Mannich bases of berberine and their antioxidant and anticancer evaluations

Isoquinoline alkaloids possess versatile biological activities. Hence, in the current research an effort has been made to improve structurally important part of isoquinoline alkaloid berberine because it is recognized as the marking compound for the crude drugs. Synthesis of rationalized berberine has been performed via substituting various piperazine moieties bearing disubstituted electron withdrawing and electron donating groups to the berberine core via Mannich reaction. Intended scaffolds were inspected for their in vitro antioxidant potential using different bioassays, FRAP, DPPH and ABTS as well as anticancer efficacies against cervical cancer cell lines HeLa, CaSki adapting SRB assay. Also, an inspection of the cytotoxic nature of titled analogues has been carried out towards Madin-Darby canine kidney (MDCK) cell lines. Radical scavenging potential of the final derivatives 4a–i was found to be excellent with IC50s, <20 and <12 µg/mL in DPPH and ABTS assay, respectively, whereas some dichlorophenyl piperazine analogues revealed important Fe3+ decreasing power with absorption at around 2 nm in FRAP assay. Moreover, compounds 4a–i appeared with significant inhibitors of the cervical cancer cell lines HeLa and CaSki with IC50s ranging 4.346–6.321 and 3.408–6.081 µg/mL, with low level of cytotoxic values and higher therapeutic indices ranging 20.42–42.45 and 21.23–43.25, respectively. Therefore, from the bioassay results it can be mentioned that these analogues are effective double agents as the scavengers of reactive oxygen species and inhibitors of the cancerous cells. The correct structure of the final compounds was adequately confirmed on the basis of FT-IR, 1H NMR and mass spectroscopy data as well as elemental analyses.

Berberine chloride pretreatment exhibits neuroprotective effect against 6-hydroxydopamine-induced neuronal insult in rat.

Parkinson's disease (PD) is a rather common movement disorder as a result of the degeneration of dopaminergic neurons within the substantianigra. Current treatments for PD afford symptomatic relief with no prevention of disease progression. Due to the neuroprotective and anti-apoptotic potential of the isoquinoline alkaloid berberine (BBR), this study was conducted to assess whether BBR pretreatment could attenuate behavioral and neuronal derangement in 6-hydroxydopamine (6-OHDA)-induced model of PD in the rat. Unilateral intrastriatal 6-OHDA-lesioned rats received BBR at doses of 25 and/or 50 mg/kg (i.p.) three times at an interval of 24 h, started 2 days before the surgery. After 1 week, apomorphine caused significant contralateral rotations and a significant reduction in the number of Nissl-stained and tyrosine-hydroxylase (TH)-positive neurons on the left side of the substantianigra. BBR pretreatment at a dose of 50 mg/kg significantly reduced rotations and prevented loss of TH-positive neurons. These results indicate pre-lesion administration of BBR could protect against 6-OHDA toxicity and this may be of benefit besides other available therapies in PD.

Immunotoxicity induced in mice by subacute exposure to berberine

The immunotoxic effects of the isoquinoline alkaloid berberine (BBR) were investigated in Balb/c mice. Here, BBR was administered daily by intraperitoneal injection at doses of 5 and 10 mg/kg for 14 days. Following the exposure, host spleen weight, cellularity and histopathology, as well as delayed-type hypersensitivity (DTH) responses, hemagglutination titers (HA), spleen cell subtype profiles, splenocyte cytokine production and lymphocyte proliferation were studied in all of the test groups of animals. The results showed that the high dose of BBR (10 mg/kg) could suppress both cellular and humoral immune functions in the treated hosts. BBR at 5 mg/kg only appeared to impact on DTH responses and lymphoproliferation. Based on the finding here, it would seem that BBR has effective immunosuppressive properties. Mechanistic studies are required to determine exactly how this material is acting to impart many of the immunotoxic effects demonstrated here. At the same time, further research should also be performed on BBR to further develop its potential use as an effective immunosuppressant or co-adjuvant for the treatment of diseases caused by an exaggerated or unwanted immune response.

Dose-Dependent AMPK-Dependent and Independent Mechanisms of Berberine and Metformin Inhibition of mTORC1, ERK, DNA Synthesis and Proliferation in Pancreatic Cancer Cells.

Natural products represent a rich reservoir of potential small chemical molecules exhibiting anti-proliferative and chemopreventive properties. Here, we show that treatment of pancreatic ductal adenocarcinoma (PDAC) cells (PANC-1, MiaPaCa-2) with the isoquinoline alkaloid berberine (0.3–6 µM) inhibited DNA synthesis and proliferation of these cells and delay the progression of their cell cycle in G1. Berberine treatment also reduced (by 70%) the growth of MiaPaCa-2 cell growth when implanted into the flanks of nu/nu mice. Mechanistic studies revealed that berberine decreased mitochondrial membrane potential and intracellular ATP levels and induced potent AMPK activation, as shown by phosphorylation of AMPK α subunit at Thr-172 and acetyl-CoA carboxylase (ACC) at Ser79. Furthermore, berberine dose-dependently inhibited mTORC1 (phosphorylation of S6K at Thr389 and S6 at Ser240/244) and ERK activation in PDAC cells stimulated by insulin and neurotensin or fetal bovine serum. Knockdown of α1 and α2 catalytic subunit expression of AMPK reversed the inhibitory effect produced by treatment with low concentrations of berberine on mTORC1, ERK and DNA synthesis in PDAC cells. However, at higher concentrations, berberine inhibited mitogenic signaling (mTORC1 and ERK) and DNA synthesis through an AMPK-independent mechanism. Similar results were obtained with metformin used at doses that induced either modest or pronounced reductions in intracellular ATP levels, which were virtually identical to the decreases in ATP levels obtained in response to berberine. We propose that berberine and metformin inhibit mitogenic signaling in PDAC cells through dose-dependent AMPK-dependent and independent pathways.

The natural alkaloid sanguinarine promotes the expression of heat shock protein genes in Arabidopsis

Small-molecule heat shock response inducers are known to enhance heat tolerance in plants. In this paper, we report that a plant alkaloid enhances the heat tolerance of Arabidopsis. We investigated 12 commercially available alkaloids to determine whether they enhance the heat tolerance of Arabidopsis seedlings using an in vitro assay system with geldanamycin, which is a known heat shock response inducer, as a positive control. Accordingly we found that the isoquinoline alkaloid sanguinarine can enhance heat tolerance in Arabidopsis. No such effect was shown for the other 11 alkaloids. The sanguinarine treatment increased the expression of heat shock protein genes such as HSP17.6C-CI, HSP70, and HSP90.1, which were up-regulated by geldanamycin. Treatments with other isoquinoline alkaloids (berberine and papaverine), which showed few heat tolerance-enhancing effects, did not promote the expression of the heat shock protein genes. These results suggest that sanguinarine influenced the heat tolerance of Arabidopsis by enhancing the expression of heat shock protein genes.

Synthesis and Antitubercular Activity of Berberine Derivatives

The isoquinoline alkaloid berberine (1) was isolated from the roots of Berberis aristata and its new, 13-benzyl (3–6), 13-allyl (7, 8), 8-(2-oxopropyl) (2), and 9-hydroxy (9) derivatives have been synthesized under mild conditions with good yield. The structures of the new derivatives were confirmed by spectroscopic (UV, IR, NMR, and MS) analysis. The antitubercular activity of the derivatives against Mycobacterium tuberculosis H37Rv was studied (microdilution assay) and compared with rifampicin as standard drug. The results demonstrated that the 4-chlorobenzyl (4), 2,4-dichlorobenzyl (5), 4-fluorobenzyl (6), and 3′,3′-dimethylallyl (8) derivatives exhibited (MIC, 4–8 μg/mL) 2–4 fold more activity than berberine (MIC, 16 μg/mL), which is probably due to the 13-benzyl and allyl substitution in the molecule.

Isoquinoline Alkaloid Berberine Exerts its Antineoplastic Activity by Inducing Molecular DNA Damage in HeLa Cells: A Comet Assay Study

Molecular damage of DNA plays an important role in the cell killing and several anti-neoplastic agents exert their cytotoxic effects by inducing DNA damage in the cancer cells. DNA damaging effect of various concentrations of berberine chloride (BCL), an isoquinoline alkaloid was studied in HeLa cells by alkaline comet assay. The DNA damage has been expressed as olive tail moment (OTM). Incubation of HeLa cells with BCL for 4 h showed greater amount of DNA damage (OTM) than 2 h treatment. BCL treatment caused a concentration dependent rise in the DNA damage in HeLa cells and exposure of HeLa cells with 1 μg/ml BCL caused a10 fold rise in baseline DNA damage, whereasa maximum rise in DNA damage was observed in HeLa cells exposed to 8 μg/ml BCL. The study of DNA repair kinetics at different BCL post-treatment times revealed a constant rise in the DNA damage in BCL treated cells up to 24 h except for 1 -4 μg/ml BCL, where the highest DNA damage was observed at 12 h post-BCL treatment. The clonogenic assay showed that BCL treatment resulted in a concentration dependent rise in its cell killing effect. The cell survival and molecular DNA damage in HeLa cells treated with BCL has an inverse correlation indicating that with increased DNA damage cell survival declined. Our study demonstrates that anti-neoplastic effect of BCL is mainly due to its ability to cause damage to the cellular genome.

Berberine exerts nephroprotective effect against cisplatin-induced kidney damage through inhibition of oxidative/nitrosative stress, inflammation, autophagy and apoptosis

The aim of this study was to investigate the therapeutic activity of isoquinoline alkaloid berberine against cisplatin (CP)-induced nephrotoxicity in mice. Berberine was administered at daily doses of 1, 2 and 3mg/kg by gavage for two successive days, 48h after intraperitoneal CP injection (13mg/kg). Mice were sacrificed 24h after the last dose of berberine. Histopathological changes and the increase in serum creatinine and blood urea nitrogen (BUN) induced by CP were significantly ameliorated by berberine in a dose-dependent manner. Additionally, oxidative/nitrosative stress, evidenced by the increase in renal 4-hydroxynonenal (4-HNE), 3-nitrotyrosine (3-NT), cytochrome P450 E1 (CYP2E1) and heme oxygenase (HO-1) expression, was significantly reduced. The expression of nuclear factor-kappaB (NF-κB), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was markedly suppressed by berberine, indicating the inhibition of inflammatory response. Treatment of CP-intoxicated animals with berberine also significantly reduced the expression of p53, active caspase-3 as well as autophagy marker light chain 3B (LC3B) in the kidneys. The results of the current study showed the nephroprotective activity of berberine against CP-induced renal injury, which could be attributed to the inhibition of oxidative/nitrosative stress, inflammation, autophagy and apoptosis.

Genetic structure and diversity of Coscinium fenestratum: a critically endangered liana of Western Ghats, India

Coscinium fenestratum is a critically endangered medicinal plant, well-known for its bioactive isoquinoline alkaloid berberine. The species has been over harvested from its natural habitats to meet the huge requirement of raw drug market and industrial consumption. This has lead to a rapid decline in the population size and has also led to local population extinction at few locations in the Western Ghats, India. In this study, inter-simple sequence repeat markers were used to investigate the genetic variation and population structure of seven extant populations of C. fenestratum from the central Western Ghats, India. Eight primer combination produced a total of 57 unambiguous bands, of which (47.1 %) were polymorphic. The species exhibited a moderate to low level of intra population genetic diversity (Hs = 0.347 ± 0.008; Ht = 0.378 ± 0.006 (POPGENE) and Hs = 0.262 ± 0.0028; Ht = 0.204 ± 0.020 (HICKORY)). The populations were low to moderately differentiated from one another (GST = 0.221) and geographical distance was not significantly correlated with genetic distance, suggesting that these long-lived, geographically distant remnant populations were once connected through gene flow. There was a significant amount of genetic variation among populations (19.85 %). The Bayesian software STRUCTURE and HICKORY were used to further reveal the genetic structure of C. fenestratum. The results revealed weak population structure (K = 2) with one single widespread gene pool, and indicated that gene flow and inbreeding are likely to be the major driving force in shaping current population genetic structure of C. fenestratum. Thus, an understanding of the genetic diversity and population structure of C. fenestratum can provide insight into the conservation and management of this species.