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Stouth DW, vanLieshout TL, Mikhail AI, Ng SY, Raziee R, Edgett BA, Vasam G, Webb EK, Gilotra KS, Markou M, Pineda HC, Bettencourt-Mora BG, Noor H, Moll Z, Bittner ME, Gurd BJ, Menzies KJ, Ljubicic V. CARM1 drives mitophagy and autophagy flux during fasting-induced skeletal muscle atrophy. Autophagy 2023. [PMID: 38018843 DOI: 10.1080/15548627.2023.2288528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 11/20/2023] [Indexed: 11/30/2023] Open
Abstract
CARM1 (coactivator associated arginine methyltransferase 1) has recently emerged as a powerful regulator of skeletal muscle biology. However, the molecular mechanisms by which the methyltransferase remodels muscle remain to be fully understood. In this study, carm1 skeletal muscle-specific knockout (mKO) mice exhibited lower muscle mass with dysregulated macroautophagic/autophagic and atrophic signaling, including depressed AMP-activated protein kinase (AMPK) site-specific phosphorylation of ULK1 (unc-51 like autophagy activating kinase 1; Ser555) and FOXO3 (forkhead box O3; Ser588), as well as MTOR (mechanistic target of rapamycin kinase)-induced inhibition of ULK1 (Ser757), along with AKT/protein kinase B site-specific suppression of FOXO1 (Ser256) and FOXO3 (Ser253). In addition to lower mitophagy and autophagy flux in skeletal muscle, carm1 mKO led to increased mitochondrial PRKN/parkin accumulation, which suggests that CARM1 is required for basal mitochondrial turnover and autophagic clearance. carm1 deletion also elicited PPARGC1A (PPARG coactivator 1 alpha) activity and a slower, more oxidative muscle phenotype. As such, these carm1 mKO-evoked adaptations disrupted mitophagy and autophagy induction during food deprivation and collectively served to mitigate fasting-induced muscle atrophy. Furthermore, at the threshold of muscle atrophy during food deprivation experiments in humans, skeletal muscle CARM1 activity decreased similarly to our observations in mice, and was accompanied by site-specific activation of ULK1 (Ser757), highlighting the translational impact of the methyltransferase in human skeletal muscle. Taken together, our results indicate that CARM1 governs mitophagic, autophagic, and atrophic processes fundamental to the maintenance and remodeling of muscle mass. Targeting the enzyme may provide new therapeutic approaches for mitigating skeletal muscle atrophy.
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Affiliation(s)
- Derek W Stouth
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | | | - Andrew I Mikhail
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Sean Y Ng
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Rozhin Raziee
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Brittany A Edgett
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Goutham Vasam
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, K1N 7K4, Canada
| | - Erin K Webb
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Kevin S Gilotra
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Matthew Markou
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Hannah C Pineda
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | | | - Haleema Noor
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Zachary Moll
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Megan E Bittner
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
| | - Brendon J Gurd
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Keir J Menzies
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, K1N 7K4, Canada
- Ottawa Institute of Systems Biology and the Centre for Neuromuscular Disease, Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, K1H 8M5, Canada
| | - Vladimir Ljubicic
- Department of Kinesiology, McMaster University, Hamilton, Ontario, L8S 4L8, Canada
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Aranas K, Al-Habyan L, Akhtar N, Ng I, Noor H, Poirier M, Dhir J, Wojkowski S. Entry-to-practice competency expectations for health justice in Canadian physiotherapy curricula: A scoping review protocol. MedEdPublish 2022. [DOI: 10.12688/mep.19126.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: In Canada, physiotherapists are expected to possess and demonstrate several essential competencies upon entry-to-practice. Over the past decade, knowledge and skills relating to health justice have become increasingly important for healthcare professionals. However, health justice is still an emerging topic among Canadian physiotherapy programs and current curricula may be lacking explicit content to develop knowledge, skills and behaviours related to health justice which can be used to prepare students for entry-to-practice. This paper outlines a protocol for a planned scoping review. The purpose of this scoping review will be to examine existing Canadian entry-level competencies for physiotherapy related to health justice. Methods: A comprehensive literature search will be completed on four databases: OVID MEDLINE, OVID Emcare, OVID Embase, and EBSCOhost CINAHL. This scoping review will include both quantitative and qualitative methodological study designs. A grey literature search will involve advanced Google searches. Two authors will independently screen titles and abstracts to select articles for full text review. Data extraction for each selected paper will be completed independently by two authors using the proposed data extraction form. The extracted data will be presented through tables and a narrative summary that aligns with the objectives and scope of this review. Conclusion: The data collected from this proposed review will identify existing competencies and gaps related to health justice in current entry-level physiotherapy curricula. This information will assist academic programs in understanding how to integrate and identify competencies and frameworks related to health justice into Canadian physiotherapy programs to ensure students are better prepared to provide culturally competent and inclusive care and promote health justice in practice.
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Aranas K, Al-Habyan L, Akhtar N, Ng I, Noor H, Poirier M, Dhir J, Wojkowski S. Entry-to-practice competency expectations for health justice in Canadian physiotherapy curricula: A scoping review protocol. MedEdPublish 2022. [DOI: 10.12688/mep.19126.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: In Canada, physiotherapists are expected to possess and demonstrate several essential competencies upon entry-to-practice. Over the past decade, knowledge and skills relating to health justice have become increasingly important for healthcare professionals. However, health justice is still an emerging topic among Canadian physiotherapy programs and current curricula may be lacking explicit content to develop knowledge, skills and behaviours related to health justice which can be used to prepare students for entry-to-practice. This paper outlines a protocol for a planned scoping review. The purpose of this scoping review will be to examine existing Canadian entry-level competencies for physiotherapy related to health justice. Methods: A comprehensive literature search will be completed on four databases: OVID MEDLINE, OVID Emcare, OVID Embase, and EBSCOhost CINAHL. This scoping review will include both quantitative and qualitative methodological study designs. A grey literature search will involve advanced Google searches for sources from Canada, the United States of America, Australia, and New Zealand. Two authors will independently screen titles and abstracts to select articles for full text review. Data extraction for each selected paper will be completed independently by two authors using the proposed data extraction form. The extracted data will be presented through tables and a narrative summary that aligns with the objectives and scope of this review. Conclusion: The data collected from this proposed review will identify existing competencies and gaps related to health justice in current entry-level physiotherapy curricula. This information will assist academic programs in understanding how to integrate and identify competencies and frameworks related to health justice into Canadian physiotherapy programs to ensure students are better prepared to provide culturally competent and inclusive care and promote health justice in practice.
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Noor H, Rapkins R, McDonald K. P04.16 TP53 mutations in codon 273 is predictive of overall survival in astrocytoma patients. Neuro Oncol 2019. [DOI: 10.1093/neuonc/noz126.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
BACKGROUND
Tumour Protein 53 (TP53) is a tumour suppressor gene that is mutated in at least 50% of human malignancies. The prevalence of TP53 mutation is much higher in astrocytomas with reports of up to 75% TP53 mutant cases. Rare cases of TP53 mutation also exist in oligodendroglial tumours (10–13%). P53 pathway is therefore an important factor in low-grade glioma tumorigenesis. Although the prognostic impact of TP53 mutations has been studied previously, no concrete concordance were reached between the studies. In this study, we investigated the prognostic effects of TP53 mutation in astrocytoma and oligodendroglioma.
MATERIAL AND METHODS
A cohort of 65 matched primary and recurrent fresh frozen tumours were sequenced to identify hotspot exons of TP53 mutation. Exons 1 to 10 were sequenced and pathogenic mutations were mostly predominant between Exons 4 and 8. The cohort was further expanded with 78 low grade glioma fresh frozen tissues and hotspot exons were sequenced. Selecting only the primary tumour from 65 matched tumours, a total of 50 Astrocytoma cases and 51 oligodendroglioma cases were analysed for prognostic effects of TP53. Only pathogenic TP53 mutations confirmed through COSMIC and NCBI databases were included in the over survival and progression-free survival analysis.
RESULTS
62% (31/50) of astrocytomas and 16% (8/51) of oligodendrogliomas harboured pathogenic TP53 mutations. Pathogenic hotspot mutations in codon 273 (c.817 C>T and c.818 G>A) was prevalent in astrocytoma with 58% (18/31) of tumours with these mutations. TP53 mutation status was maintained between primary and recurrent tumours in 93% of cases. In astrocytoma, overall survival of TP53 mutant patients was longer compared to TP53 wild-type patients (p<0.01) but was not significant after adjusting for age, gender, grade and IDH1 mutation status. In contrast, astrocytoma patients with specific TP53 mutation in codon 273 showed significantly better survival compared to other TP53 mutant and TP53 wild-type patients combined (p<0.01) in our multivariate analysis. Time to first recurrence (progression-free survival) of TP53 mutant patients was significantly longer than TP53 wild-type patients (p<0.01) after adjustments were made, while TP53 mutation in codon 273 was not prognostic for progression-free survival. In oligodendroglioma patients, TP53 mutations did not significantly affect overall survival and progression-free survival.
CONCLUSION
In agreement with others, TP53 mutation is more prevalent in Astrocytoma and mutations in codon 273 are significantly associated with longer survival.
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Affiliation(s)
- H Noor
- University of New South Wales, Sydney, Australia
| | - R Rapkins
- University of New South Wales, Sydney, Australia
| | - K McDonald
- University of New South Wales, Sydney, Australia
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Basnet M, Quinn A, Noor H, Rana D, Thiryayi S, Shelton D, Al-Habba S, Narine N, McGrath S, Chandran U, Doran H, Joseph L, Bishop P, Chaturvedi A, Ganjifrockwala A, Paiva-Correia A, Saravana R, Nasir N, Nonaka D, Wallace A, Crosbie P, Bayman N, Blackhall F. 53: A survey of regional practice affecting small sample diagnosis and tissue managment of lung carcinoma samples, with development of a local guideline. Lung Cancer 2017. [DOI: 10.1016/s0169-5002(17)30103-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bayman N, Noor H. 34 Developing an integrated lung cancer system in Greater Manchester: a 3-step framework. Lung Cancer 2016. [DOI: 10.1016/s0169-5002(16)30051-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Naqvi R, Naqvi A, Akhtar S, Ahmed E, Noor H, Saeed T, Akhtar F, Rizvi A. Use of isoniazid chemoprophylaxis in renal transplant recipients. Nephrol Dial Transplant 2009; 25:634-7. [DOI: 10.1093/ndt/gfp489] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Naqvi R, Akhtar S, Noor H, Saeed T, Bhatti S, Sheikh R, Ahmed E, Akhtar F, Naqvi A, Rizvi A. Efficacy of Isoniazid Prophylaxis in Renal Allograft Recipients. Transplant Proc 2006; 38:2057-8. [PMID: 16979998 DOI: 10.1016/j.transproceed.2006.06.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The efficacy of isoniazid (INH) prophylaxis in renal allograft recipients who are on long-term immunosuppression in a region highly prevalent for tuberculosis (TB) was studied. INH (300 mg/d in patients weighing more than 35 kg and 5 mg/kg/d in patients with <35 kg body weight) together with Pyridoxine 50 mg/d for 1 year was started in randomly assigned renal allograft recipients. Occurrence of clinical tuberculosis during the initial 2 years posttransplantation was observed in the risk group and patients at no risk. Risks were defined as acute rejection episodes and exposure to antirejection therapy, past history of TB completely or incompletely treated, radiological evidence of past tuberculosis, history of tuberculosis in close contacts. Among 480 patients registered in the study, INH prophylaxis was given to 219 randomly assigned renal allograft recipients. Results were compared among patients developing TB during the initial 2 years posttransplantation in both the groups. Risk factors were analyzed for comparison in both groups. No significant difference was observed in terms of past history of TB, TB in close contacts, episodes of acute rejection during the initial 3 months, and comorbidities such as cytomegalovirus infection, hepatitis C virus infection, and posttransplant diabetes. One patient from the INH group and 10 patients from the non-INH group developed TB during the initial 2 years posttransplantation (P < .0001). None of patients required discontinuation of INH. INH was observed to be safe and effective as a chemoprophylactic agent in renal allograft recipients.
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Affiliation(s)
- R Naqvi
- Sindh Institute of Urology and Transplantation (SIUT), Civil Hospital, Karachi 74200, Pakistan.
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Naqvi R, Noor H, Ambareen S, Khan H, Haider A, Jafri N, Alam A, Aziz R, Manzoor K, Aziz T, Ahmed E, Akhtar F, Naqvi A, Rizvi A. Outcome of Pregnancy in Renal Allograft Recipients: SIUT Experience. Transplant Proc 2006; 38:2001-2. [PMID: 16979978 DOI: 10.1016/j.transproceed.2006.06.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The course of pregnancy and its outcome was studied in renal allograft recipients. Between November 1985 and November 2005, a total of 1481 renal transplants were carried out at the Sindh Institute of Urology and Transplantation (SIUT); among them were 348 females, with 73 potential females for pregnancy. All patients received cyclosporine and prednisolone, with 82% also receiving azathioprine and 4 patients mycophenolate mofetil as a third immunosuppressant drug. We evaluated incidence of hypertension, diabetes, pre-eclampsia, urinary tract infection (UTI), rejection during pregnancy and during 3 months' postdelivery as well as outcomes of pregnancy. Among 73 potential candidates, 31 had 47 pregnancies, after an average of 31 months (8-86 months). Of 31 subjects, 21 subjects were hypertensive on one or two drugs prior to conception. A rise in blood pressure during pregnancy was noticed in 7 patients. Albuminuria from trace to 3+ appeared in 13 patients and glycosuria in one other. Blood sugar levels remained within normal range in all subjects. UTIs occurred during pregnancy in 7 patients. Among 47 pregnancies, 9 had abortions (7 spontaneous, 2 therapeutic) and 6 had preterm deliveries. The others were full-term deliveries: 12 via a lower segment caesarean section and 20 were normal vaginal deliveries. Average birth weight was 4.8 lbs. At an average follow-up of 38 months the serum creatinine values ranged from 0.94 to 2.3 mg %. One patient developed acute irreversible graft dysfunction soon after delivery. Our study demonstrated that pregnancy did not reduce renal graft survival, but newborns are at greater risk of premature birth and low birth weight.
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Affiliation(s)
- R Naqvi
- Sindh Institute of Urology and Transplantation (SIUT), Civil Hospital, Karachi 74200, Pakistan.
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Awang MB, Jaafar AB, Abdullah AM, Ismail MB, Hassan MN, Abdullah R, Johan S, Noor H. Air quality in Malaysia: impacts, management issues and future challenges. Respirology 2000; 5:183-96. [PMID: 10894109 DOI: 10.1046/j.1440-1843.2000.00248.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Observations have been made on the long-term trends of major air pollutants in Malaysia including nitrogen dioxide, carbon monoxide, the ozone and total suspended particulate matter (particularly PM10), and sulfur dioxide, emitted from industrial and urban areas from early 1970s until late 1998. METHODOLOGY The data show that the status of atmospheric environment in Malaysia, in particular in highly industrialized areas such as Klang Valley, was determined both by local and transboundary emissions and could be described as haze and non-haze periods. RESULTS During the non-haze periods, vehicular emissions accounted for more than 70% of the total emissions in the urban areas and have demonstrated two peaks in the diurnal variations of the aforementioned air pollutants, except ozone. The morning 'rush-hour' peak was mainly due to vehicle emissions, while the late evening peak was mainly attributed to meteorological conditions, particularly atmospheric stability and wind speed. Total suspended particulate matter was the main pollutant with its concentrations at few sites often exceeding the Recommended Malaysia Air Quality Guidelines. The levels of other pollutants were generally within the guidelines. Since 1980, six major haze episodes were officially reported in Malaysia: April 1983, August 1990, June 1991, October 1991, August to October 1994, and July to October 1997. The 1997 haze episode was the worst ever experienced by the country. Short-term observations using continuous monitoring systems during the haze episodes during these periods clearly showed that suspended particulate matter (PM10) was the main cause of haze and was transboundary in nature. Large forest fires in parts of Sumatra and Kalimantan during the haze period, clearly evident in satellite images, were identified as the probable key sources of the widespread heavy haze that extended across Southeast Asia from Indonesia to Singapore, Malaysia and Brunei. The results of several studies have also provided strong evidence that biomass burning is the dominating source of particulate matter. The severity and extent of 1997's haze pollution was unprecedented, affecting some 300 million people across the region. The amount of economic costs suffered by Southeast Asian countries during this environmental disaster was enormous and is yet to be fully determined. Among the important sectors severely affected were air and land transport, shipping, construction, tourism and agro-based industries. The economic cost of the haze-related damage to Malaysia presented in this study include short-term health costs, production losses, tourism-related losses and the cost of avertive action. Although the cost reported here is likely to be underestimated, they are nevertheless significant (roughly RM1 billion). CONCLUSIONS The general air quality of Malaysia since 1970 has deteriorated. Studies have shown that should no effective countermeasures be introduced, the emissions of sulfur dioxide, nitrogen oxides, particulate matter, hydrocarbons and carbon monoxide in the year 2005 would increase by 1.4, 2.12, 1.47 and 2.27 times, respectively, from the 1992 levels.
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Affiliation(s)
- M B Awang
- Centre for Environmental Technology and Natural Resource Management, Universiti Putra Malaysia, Serdang, Selangor.
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Noor H, Yap CL, Zolkepli O, Faridah M. Effect of exposure to dust on lung function of cement factory workers. Med J Malaysia 2000; 55:51-7. [PMID: 11072491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Exposure to Portland cement dust has long been associated with the prevalence of respiratory symptoms and varying degrees of airway obstruction in man. Apart from respiratory diseases, it was also found to be the cause of lung and laryngeal cancer, gastrointestinal tumours and also dermatitis. This study was done to investigate the effect of dust exposure on ventilatory lung function of Portland cement factory workers in Rawang, Selangor. Spirometry tests of 62 male workers (exposed to total dust concentration of 10,180 micrograms/m3 and PM10 of 8049 micrograms/m3) and 70 subjects from UPM (exposed to mean total dust of 192 micrograms/m3 and PM10 of 177 micrograms/m3--controls) revealed significant differences in spirometry values between the groups. The workers showed i) significantly lower FEV1% and FEF25-75%, and higher FMFT, ii) reduced FEV1% with increasing level of dust exposure and iii) higher prevalence of respiratory symptoms. Therefore, we suggest that exposure to dust in the cement factory leads to higher incidence of respiratory symptoms and impaired lung function.
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Affiliation(s)
- H Noor
- Jabatan Biologi, Fakulti Sains dan Pengajian Alam Sekitar, Universiti Putra Malaysia, Selangor
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Abstract
The efficacy of Tinospora crispa (Menispermaceae) extract for the treatment of diabetes has previously been verified in animal models. In order to substantiate the antidiabetic effect, we characterised the antihyperglycaemic properties by studying its effect on intestinal glucose absorption and glucose uptake into adipocytes. We also performed experiments to characterise in more detail the mechanism of T. crispa-evoked insulin release by challenging it with insulin secretory antagonists viz. adrenaline, somatostatin, verapamil and nifedipine. In addition, we also performed experiments to determine the effect of the extract on cAMP content. The results clearly showed that the antihyperglycaemic effect is not due to interference with intestinal glucose uptake or uptake of the sugar into the peripheral cells. Rather, the antihyperglycaemic effect of T. crispa is probably due to stimulation of insulin release via modulation of beta-cell Ca2+ concentration. That the insulinotropic effect of T. crispa is physiological suggests that the extract contains compounds which could be purified for use in the treatment of type II diabetes.
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Affiliation(s)
- H Noor
- Nuffield Department of Clinical Biochemistry, John Radcliffe Hospital, Headington, Oxford, UK
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Noor H, Hammonds P, Sutton R, Ashcroft SJ. The hypoglycaemic and insulinotropic activity of Tinospora crispa: studies with human and rat islets and HIT-T15 B cells. Diabetologia 1989; 32:354-9. [PMID: 2668082 DOI: 10.1007/bf00277258] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In Malaysia, Tinospora crispa extract is taken orally by Type 2 (non-insulin-dependent) diabetic patients to treat hyperglycaemia. We have evaluated the claimed hypoglycaemic property by adding aqueous extract to the drinking water of normal and alloxan-diabetic rats. After one week, fasting blood glucose levels were significantly (p less than 0.01) lower and serum insulin levels were significantly (p less than 0.01) higher in treated diabetic animals (10.4 +/- 1.0 mmol/l and 12.8 +/- 1.1 muU/ml respectively) compared to untreated diabetic controls (17.4 +/- 1.7 mmol/l and 8.0 +/- 0.7 muU/ml respectively). The insulinotropic action of T. crispa was further investigated in vitro using isolated human or rat islets of Langerhans and HIT-T15 cells. In static incubations with rat islets and HIT-T15 B cells, the extract induced a dosage dependent stimulation and potentiation of basal and glucose-stimulated insulin secretion respectively. This insulinotropic effect was also evident in perifused human and rat islets and HIT-T5 B-cells. The observations that (i) in all three models insulin secretory rates rapidly returned to basal levels on removal of the extract and (ii) in rat islets, a second challenge with T. crispa induced an additional, stimulated response, are all consistent with physiological release of insulin by B cells. Moreover, the rate of HIT-T15 glucose utilisation was not affected by incubation with T. crispa, suggesting that the cells were viable throughout. These are the first studies to provide biochemical evidence which substantiates the traditional claims for an oral hypoglycaemic effect of Tinospora crispa, and which also show that the hypoglycaemic effect is associated with increased insulin secretion.
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Affiliation(s)
- H Noor
- Nuffield Department of Clinical Biochemistry, John Radcliffe Hospital, Headington, Oxford, UK
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