Anita A. Mehta

Oculohypotensive effect of angiotensin-converting enzyme inhibitors in acute and chronic models of glaucoma.

We have studied the effects of various angiotensin-converting enzyme (ACE) inhibitors on intraocular pressure (IOP) of rabbits with experimentally induced ocular hypertension and their mechanism of action. Acute ocular hypertension was induced by infusion of 5% glucose (15 ml/kg) through marginal ear vein, whereas chronic glaucoma was induced by injection of alpha-chymotrypsin into the posterior chamber of the eye. IOP was measured by tonometer. All ACE inhibitors were instilled topically in the eye in a sterile solution. The effect of ACE inhibitors also was studied on serum cholinesterase (true and pseudo) and the enzyme ACE in vitro. Enalaprilat, ramiprilat, and fosinopril produced a time-dependent decrease of IOP in both acute and chronic models of ocular hypertension in rabbits. The decrease in IOP was observed for >4 h, and the extent of decrease was comparable to that with both pilocarpine and betaxolol. Prodrugs enalapril and ramipril failed to produced any change in IOP. Losartan also produced a significant decrease in IOP in the chronic model of ocular hypertension in rabbits. All the three ACE inhibitors were found to inhibit ACE activity in aqueous humor. The enzyme cholinesterase was found to be inhibited by enalaprilat, ramiprilat, and fosinopril. However, atropine did not alter the IOP-lowering effect of enalaprilat in rabbits. Indomethacin pretreatment produced slight but significant inhibition of the IOP-lowering effect of enalaprilat in rabbits. Our data suggest that ACE inhibitors enalaprilat, ramiprilat, and fosinopril produce a significant ocular hypotensive effect in acute and chronic models of ocular hypertension in rabbits. Inhibition of ACE in aqueous humor, and in ocular tissues, resulting in reduced angiotensin II formation, could be one of the major mechanisms responsible for the IOP reduction by ACE inhibitors in rabbits.

Antiasthmatic activity of Moringa oleifera Lam: A clinical study

The present study was carried out to investigate the efficacy and safety of seed kernels of Moringa oleifera in the treatment of bronchial asthma. Twenty patients of either sex with mild-to-moderate asthma were given finely powdered dried seed kernels in dose of 3 g for 3 weeks. The clinical efficacy with respect to symptoms and respiratory functions were assessed using a spirometer prior to and at the end of the treatment. Hematological parameters were not changed markedly by treatment with M. oleifera. However, the majority of patients showed a significant increase in hemoglobin (Hb) values and Erythrocyte sedimentation rate (ESR) was significantly reduced. Significant improvement was also observed in symptom score and severity of asthmatic attacks. Treatment with the drug for 3 weeks produced significant improvement in forced vital capacity, forced expiratory volume in one second, and peak expiratory flow rate values by 32.97 ± 6.03%, 30.05 ± 8.12%, and 32.09 ± 11.75%, respectively, in asthmatic subjects. Improvement was also observed in % predicted values. None of the patients showed any adverse effects with M. oleifera. The results of the present study suggest the usefulness of M. oleifera seed kernel in patients of bronchial asthma.

Protective Effect of Ethanolic Extract of Seeds of Moringa oleifera Lam. Against Inflammation Associated with Development of Arthritis in Rats

The present investigation was carried out to study the anti-arthritic activity of ethanolic extract of seeds of Moringa oleifera Lam. (MOEE) in adjuvant-induced arthritis in adult female Wistar rats. During the experimental period, body weight, paw edema volume (primary lesion) and arthritic index (secondary lesion) was observed. On the 21st day, serum from each animal was used for estimation of Rheumatoid Factor (RF) value and levels of selected cytokines (TNFα, IL-1, and IL-6). Whole blood was used for measurement of erythrocyte sedimentation rate (ESR). Liver homogenate was utilized for assessment of oxidative stress and histopathology was performed to measure degree of inflammation in synovial joint. Our results suggest that, percentage reduction in body weight was less, paw edema volume and arthritic index score was decreased significantly as compared to diseased control animals. Serum levels of RF, TNF-α, IL-1, and IL-6 also showed decreased levels as compared to those in the diseased control group. Treatment with MOEE also altered oxidative stress in relation to its anti-inflammatory activity. Histopathological observations showed mild or less infiltration of lymphocytes, angiogenesis and synovial lining thickening. From all above results and observations, it can be concluded that Moringa oleifera possesses promising antiarthritic property.

Suppression of ovalbumin-induced Th2-driven airway inflammation by β-sitosterol in a guinea pig model of asthma.

In the present study, the efficacy of β-sitosterol isolated from an n-butanol extract of the seeds of the plant Moringa oleifera (Moringaceae) was examined against ovalbumin-induced airway inflammation in guinea pigs. All animals (except group I) were sensitized subcutaneously and challenged with aerosolized 0.5% ovalbumin. The test drugs, β-sitosterol (2.5mg/kg) or dexamethasone (2.5mg/kg), were administered to the animals (p.o.) prior to challenge with ovalbumin. During the experimental period (on days 18, 21, 24 and 29), a bronchoconstriction test (0.25% acetylcholine for 30s) was performed and lung function parameters (tidal volume and respiration rate) were measured for each animal. On day 30, blood and bronchoalveolar lavaged fluid were collected to assess cellular content, and serum was collected for cytokine assays. Lung tissue was utilized for a histamine assay and for histopathology. β-sitosterol significantly increased the tidal volume (V(t)) and decreased the respiration rate (f) of sensitized and challenged guinea pigs to the level of non-sensitized control guinea pigs and lowered both the total and differential cell counts, particularly eosinophils and neutrophils, in blood and bronchoalveolar lavaged fluid. Furthermore, β-sitosterol treatment suppressed the increase in cytokine levels (TNFα, IL-4 and IL-5), with the exception of IL-6, in serum and in bronchoalveolar lavaged fluid detected in model control animals. Moreover, treatment with β-sitosterol protected against airway inflammation in lung tissue histopathology. β-sitosterol possesses anti-asthmatic actions that might be mediated by inhibiting the cellular responses and subsequent release/synthesis of Th2 cytokines. This compound may have therapeutic potential in allergic asthma.

Beneficial role of telmisartan on cardiovascular complications associated with STZ-induced type 2 diabetes in rats

We studied the effect of an eight-week treatment with telmisartan (5 mg kg(-1)day(-1)) on cardiovascular complications that are associated with type 2 diabetes in a neonatal rat model. Type 2 diabetes was induced by the administration of 90 mg/kg streptozotocin (STZ), ip, in two-day-old rats. The development of diabetes was checked 12 weeks after STZ administration, and the animals were divided into different groups. Telmisartan treatment was given for eight weeks. At the end of the eight-week treatment, various biochemical and cardiac parameters were measured. Diabetic rats exhibited hyperglycemia, hyperinsulinemia, hyperlipidemia, increased blood pressure and heart rate, increased creatinine, cardiac enzyme and C-reactive protein (CRP) levels, a reduction in the rate of pressure development and decay, cardiac hypertrophy and oxidative stress. Chronic treatment with telmisartan significantly prevented STZ-induced hypertension and tachycardia and elevated fasting glucose and insulin levels. It significantly prevented the dyslipidemia and significantly reduced the elevated creatinine and CRP levels and the levels of other cardiac enzyme markers, like lactate dehydrogenase and creatinine kinase, in diabetic rats. There was an increase in rate of blood pressure development and decay with telmisartan treatment. Telmisartan also produced beneficial effects by preventing cardiac hypertrophy, which was evident from left ventricular collagen levels, the cardiac hypertrophy index and the left ventricular hypertrophy index in diabetic rats. Telmisartan successfully prevented oxidative stress, which was evidenced by a decrease in malondialdehyde and an increase in glutathione, catalase, superoxide dismutase levels. In conclusion, our data suggest that telmisartan prevented STZ-induced metabolic abnormalities and cardiovascular complications in type 2 diabetes.

Effect of Moringa oleifera Lam. Seed Extract on Toluene Diisocyanate-Induced Immune-Mediated Inflammatory Responses in Rats

Moringa oleifera Lam. is a small tree cultivated throughout India. We have investigated the effect of ethanolic extract of seeds of Moringa oleifera (MOEE, an herbal remedy) on the potential prevention of immune-mediated inflammatory responses in toluene diisocyanate (TDI as antigen)-induced asthma in Wistar rats. Rats were divided into five different groups (n = 8/group): Group-I = unsensitized control; Group-II = TDI control/vehicle; Group-III = dexamethasone (DXM) 2.5 mg/kg; and, Groups IV and V = 100 mg/kg and 200 mg/kg body weight [BW] of MOEE, respectively. All rats (except unsensitized controls) were sensitized by intranasal application of 10% TDI to induce airway hypersensitivity. Animals in Groups II–V were given their respective drug treatment per os from 1 wk prior to initiation of sensitization until the day of final provocation with 5% TDI. After this last challenge, all rats were examined for hyperreactivity symptoms and then sacrificed to determine their total and differential leucocytes in blood and bronchoalveolar (BAL) fluid and levels of TNF ∝, IL-4, and IL-6 in their BAL and serum. Homogenates of one lung lobe from each animal were utilized to assess oxidative stress; a separate lobe underwent histologic examination to assess airway inflammatory status. The results suggest that asthmatic symptoms were found in TDI control rats only, while both MOEE- and DXM-treated rats did not manifest any airway abnormality. In MOEE- and DXM-treated rats, neutrophil and eosinophil levels in the blood were decreased significantly; levels of total cells and each different cell in their BAL fluid were markedly decreased as compared to those in TDI controls. TNF α, IL-4, and IL-6 were predominant in serum as well as in BAL fluids in TDI controls, but these levels were reduced significantly by MOEE treatment. The antioxidant activity in relation to antiinflammatory activity of the extract and histopathological observations also reflected a protective effect. Based on the above findings and observations, it can be concluded that Moringa oleifera may possess some beneficial properties that act against chemically stimulated immune-mediated inflammatory responses that are characteristic of asthma in the rat.

Inhibitory Effect of n-butanol Fraction of Moringa oleifera Lam. Seeds on Ovalbumin-Induced Airway Inflammation in a Guinea Pig Model of Asthma

Moringaceae, which belongs to the Moringa oleifera Lam. family, is a well-known herb used in Asian medicine as an antiallergic drug. In the present study, the efficacy of the n-butanol extract of the seeds of the plant (MONB) is examined against ovalbumin-induced airway inflammation in guinea pigs. The test drugs (MONB or dexamethasone) are administered orally prior to challenge with aerosolized 0.5% ovalbumin. During the experimental period, bronchoconstriction tests are performed, and lung function parameters are measured. The blood and bronchoalveolar lavage fluid are collected to assess cellular content, and serum is used for cytokine (tumor necrosis factor-α, interleukin-4, and interleukin-6) assays. Histamine assays of lung tissue are performed using lung tissue homogenate. The results suggest that in ovalbumin-sensitized model control animals, tidal volume is decreased, respiration rate is increased, and both the total and differential cell counts in blood and bronchoalveolar lavage fluid are increased significantly compared with nonsensitized controls. MONB treatment shows improvement in all parameters except bronchoalveolar lavage tumor necrosis factor-α and interleukin-4. Moreover, MONB treatment demonstrates protection against acetylcholine-induced bronchoconstriction and airway inflammation. These results indicate that MONB has an inhibitory effect on airway inflammation. Thus, MONB possesses an antiasthmatic property through modulation of the relationship between Th1/Th2 cytokine imbalances.

Investigation into the cardiac effects of spironolactone in the experimental model of type 1 diabetes.

We have studied the effect of 8-week treatment with spironolactone (20 mg·kg−1·day−1) on cardiovascular complications associated with streptozotocin (STZ)-diabetic rats. Wistar rats were made diabetic with STZ (45 mg/kg, intravenously). Various biochemical and cardiac parameters were measured at the end of 8 weeks. STZ produced hyperglycemia; hypoinsulinemia; hyperlipidemia; increased blood pressure; increased creatinine, cardiac enzyme, and C-reactive protein levels; reduction in heart rate; and cardiac hypertrophy. Chronic treatment with spironolactone significantly prevented STZ-induced bradycardia, hypertension, and elevated fasting glucose level with simultaneous increase in serum insulin levels. It significantly reduced the elevated cholesterol, very-low-density lipoprotein, and triglyceride levels and increased the lower high-density lipoprotein-cholesterol levels in diabetic rats. Furthermore, spironolactone also produced a significant reduction in the elevated creatinine levels, C-reactive protein, and levels of lactate dehydrogenase and creatinine kinase. It also produced beneficial effect in diabetic rats by preventing cardiac hypertrophy as evident from decrease in left ventricular collagen levels, cardiac hypertrophy index, and left ventricular hypertrophy index. Our data suggest that spironolactone prevents not only the STZ-induced metabolic abnormalities but also cardiovascular complications.

Effect of Moringa oleifera Lam. Seed Extract on Ovalbumin-Induced Airway Inflammation in Guinea Pigs

To determine the therapeutic potential of herbal medicine Moringa oleifera Lam. family: Moringaceae in the control of allergic diseases, the efficacy of the ethanolic extract of the seeds of the plant (MOEE) against ovalbumin (OVA)-induced airway inflammation in guinea pigs was examined. During the experimental period, the test drugs (MOEE or dexamethasone) were administered by oral route prior to challenge with aerosolized 0.5% OVA. Bronchoconstriction tests were performed and respiratory parameters (i.e., tidal volume and respiratory rate) were measured. At the end of experiment, blood was collected from each animal to perform total and differential counts and serum was used for assay of IL-4, IL-6, and TNFα. Lung lavage fluid (BAL) was collected for estimation of cellular content and cytokine levels. Lung tissue histamine assays were performed using the homogenate of one lobe from each animal; a separate lobe and the trachea were subjected to histopathology to measure the degree of any airway inflammation. The results suggest that in OVA-sensitized control animals that did not receive either drug, tidal volume (Vt) was decreased, respiration rate (f) was increased, and both the total and differential cell counts in blood and BAL fluid were increased significantly. MOEE-treatment of sensitized hosts resulted in improvement in all parameters except BAL TNFα and IL-4. Moreover, MOEE-treatment also showed protection against acetylcholine-induced broncho-constriction and airway inflammation which was confirmed by histological observations. The results of these studies confirm the traditional claim for the usefulness of this herb in the treatment of allergic disorders like asthma.

Characteristics and Prevalence of Latent Autoimmune Diabetes in Adults (LADA).

Diabetes, one of the most commonly seen metabolic disorders, is affecting a major area of population in many developing as well as most of the developed countries and is becoming an alarming concern for the rising cost of the healthcare system. Latent Autoimmune Diabetes in Adults (LADA) is a form of diabetes which is less recognized and underdiagnosed type of diabetes which appears to have characteristics of both type 1 (autoimmune in nature) and type 2 diabetes (adult age at onset and initial response to oral hypoglycemic agents). An epidemiological study was carried out on 500 patients in the western region of India. Various parameters such as age at onset, duration of diabetes, gender, basal metabolic index (BMI), type of diabetes, family history, HbA1c levels, cholesterol levels, and current treatment regimen were evaluated and correlated with type 1 and type 2 diabetes. Moreover, diagnostic markers for LADA, namely, GAD autoantibodies and C-peptide levels, were determined for 80 patients selected from the epidemiological study. Some of the results obtained were found to be consistent with the literature whereas some results were found to be contradictory to the existing data.