Plumbagin exerts antiobesity effects through inhibition of pancreatic lipase and adipocyte differentiation.

Plumbagin is a naphthoquinone found in the roots of Plumbago zeylanica. Here, we report an investigation to evaluate its antiobesity activity. The preliminary binding affinity of plumbagin to human pancreatic lipase (PL) was determined using molecular docking simulation. The in vitro PL inhibitory potential and the kinetics of inhibition were studied to validate and confirm the results obtained from molecular docking. The IC50 for PL was found to be 82.08 ± 9.47 µM, and the kinetics of inhibition was found to be of the mixed type. Further, the in vivo evaluation revealed that rats treated with plumbagin 1 mg/kg showed significant decrease in serum triglycerides (TG) and area under the curve of serum TG when compared with vehicle-treated rats. It was also seen that plumbagin possessed significant antiadipogenic effect as demonstrated by reduced oil red O staining and decreased TG contents. Thus, we conclude that plumbagin is a promising molecule to combat obesity and further optimization of plumbagin to yield plumbagin analogues will result in its improved activity profile.

Attenuation of Acute and Chronic Restraint Stress-induced Perturbations in Experimental Animals by Nelumbo nucifera Gaertn.

Aqueous extract of leaves of Nelumbo nucifera was investigated on acute stress (immobilization stress)-induced biochemical alterations in Swiss mice. The animals were also subjected to acute physical stress (swimming endurance test) and acute chemical stress (writhing test) to gauge the antistress potential of the extract. Further to evaluate the antistress activity of Nelumbo nucifera in chronic stress condition, fresh Wistar rats were subjected to cold restraint stress (4 degrees for 1 h) for 7 days after 21 days of pretreatment with the extract. Stimulation of hypothalamus pituitary adrenal axis in stressful condition alters plasma glucose, triglyceride, cholesterol, total protein and corticosterone levels. Pretreatment with the extract significantly ameliorated the stress-induced variations in these biochemical levels in both acute and chronic stress models. The extract treated animals showed increase in swimming endurance time and reduced number of writhes in physical and chemical-induced stress models respectively. Treatment groups also reverted back perturbed neurotransmitter levels (norepinephrine, dopamine and 5-hydroxytryptamine) in brain as well as increase in adrenal gland weights and atrophy of spleen caused by cold chronic stress. In mice immunized with sheep red blood cells, treatment groups subjected to restraint stress prevented the humoral immune response to the antigen. Histopathological studies of adrenal gland of stress control group revealed vacuolar degeneration, loss of architecture and formation of lesions in the cortex, which was reversed by extract treatment. The results indicate that aqueous extract of Nelumbo nucifera has significant adaptogenic activity against a variety of biochemical, histological, physiological and immunological perturbations in acute and chronic stress models.

Enhanced production of the polysaccharide arabinogalactan using immobilized cultures of Tinospora cordifolia by elicitation and in situ adsorption.

Immobilized callus cultures of Tinospora cordifolia (Willd) Miers ex Hooks and Thoms were investigated to find out the combined effect of elicitation, cell permeabilization with chitosan and in situ product recovery by polymeric neutral resin-like Diaion HP 20. In this study, callus cultures of T. cordifolia were immobilized using sodium alginate and calcium chloride and the beads were cultured in Murashige and Skoog's basal medium along with benzyl adenine (BA), 2,4-dichlorophenoxy acetic acid (2,4-D) and 3% sucrose. The immobilized cultures, when subjected to elicitation and cell permeabilization with chitosan and in situ removal of the secondary metabolites by addition of resin, showed a 10-fold increase in production of arabinogalactan (0.490% dry weight) as compared to respective controls devoid of resin and chitosan. This indicates that in situ adsorption may have reduced the feedback inhibition caused by accumulation of secondary metabolites in the media, while the dual effect of elicitation and cell permeabilization by chitosan may have released the intracellular (secreted) berberine and the polysaccharide arabinogalactan, respectively.

Effects of alkaloidal extract of Phyllanthus niruri on HIV replication.

Phyllanthus niruri has been found to exhibit marked inhibitory effect on hepatitis B virus evident by its exhaustive utility in cases of chronic jaundice. However, till date, research has not been focused on identification and validation of active pharmacophores of Phyllanthus niruri responsible for the reported inhibitory effect of its aqueous extract on anti-human immunodeficiency virus. The present investigation examines the anti-HIV effects of the alkaloidal extract of Phyllanthus niruri in human cell lines. The inhibitory effect on HIV replication was monitored in terms of inhibition of virus induced cytopathogenecity in MT-4 cells. The alkaloidal extract of Phyllanthus niruri showed suppressing activity on strains of HIV-1 cells cultured on MT-4 cell lines. The CC50 for the extract was found to be 279.85 microgmL(-1) whereas the EC50 was found to be 20.98 microgmL(-1). Interestingly the Selectivity Index (SI) was found to be 13.34, which showed a clear selective toxicity of the extract for the viral cells. The alkaloidal extract of Phyllanthus niruri was thus found to exhibit sensitive inhibitory response on cytopathic effects induced by both the strains of human immunodeficiency virus on human MT-4 cells in the tested concentrations.