Antistressor activity of Ocimum sanctum (Tulsi) against experimentally induced oxidative stress in rabbits.

Jyoti S, Satendra S, Sushma S, Anjana T, Shashi S.
Department of Physiology, Pt. B. D. Sharma Post Graduate Institute of Medical Sciences, Rohtak, Haryana, India.

Fresh leaves of Ocimum sanctum (O. sanctum) were evaluated for antistress activity against experimentally induced oxidative stress in albino rabbits. Animals of the test group received supplementation of 2 g fresh leaves of O. sanctum per rabbit for 30 days. Anemic hypoxia was induced chemically by injecting the rabbits with 15 mg sodium nitrite per 100 g body weight intraperitoneally. Results indicated that O. sanctum administration blunted the changes in cardiorespiratory (BP, HR, RR) parameters in response to stress.

A significant (p < 0.01) decrease in blood sugar level was observed after 30 days of dietary supplementation of O. sanctum leaves. Significant increase (p < 0.05) in the levels of enzymatic (superoxide dismutase) and nonenzymatic (reduced glutathione) antioxidants was observed in the test group after the treatment with O. sanctum. Oxidative stress led to a lesser depletion of reduced glutathione (28.80%) and plasma superoxide dismutase (23.04%) in O. sanctum-treated rabbits. The results of this study suggest that the potential antistressor activity of O. sanctum is partly attributable to its antioxidant properties.

Constituents of Ocimum sanctum with antistress activity.

Gupta P, Yadav DK, Siripurapu KB, Palit G, Maurya R.
Division of Medicinal and Process Chemistry, Central Drug Research Institute, Lucknow, India.

Three new compounds, ocimumosides A (1) and B (2) and ocimarin (3), were isolated from an extract of the leaves of holy basil (Ocimum sanctum), together with eight known substances, apigenin, apigenin-7-O-beta-D-glucopyranoside, apigenin-7-O-beta-D-glucuronic acid ( 4), apigenin-7- O-beta- d-glucuronic acid 6''-methyl ester, luteolin-7-O-beta-D-glucuronic acid 6''-methyl ester, luteolin-7-O-beta-D-glucopyranoside, luteolin-5-O-beta-D-glucopyranoside, and 4-allyl-1-O-beta-D-glucopyronosyl-2-hydroxybenzene (5), and two known cerebrosides.

The structures of the new compounds were determined on the basis of extensive 1D and 2D NMR spectroscopic analysis. The new compounds (1- 3) and the known compounds 4 and 5 were screened at a dose of 40 mg/kg body weight for acute stress-induced biochemical changes in male Sprague-Dawley rats. Compound 1 displayed promising antistress effects by normalizing hyperglycemia, plasma corticosterone, plasma creatine kinase, and adrenal hypertrophy. Compounds 2 and 5 were also effective in normalizing most of these stress parameters. In contrast, compounds 3 and 4 were ineffective in normalizing any of these effects.

Oxidative stress in brain and antioxidant activity of Ocimum sanctum in noise exposure.

Samson J, Sheeladevi R, Ravindran R.
Department of Physiology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, India. drjsamson@hotmail.com.

Noise is a pervasive aspect of many modern communities, work environments and its damaging effects, particularly the production of free radicals are not limited to the auditory organ. The oxidative stress in three discrete brain regions, in wistar strain male albino rats subjected to three different durations of noise exposures (acute, sub-acute and chronic noise stress) and the in vivo as well as the in vitro antioxidant activity of Ocimum sanctum has been analyzed. Broadband white noise (100dB) exposure significantly increased the levels of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), glutathione peroxidase (EC 1.11.1.9), lipid peroxidation, oxidized glutathione (GSSG) and decreased the levels of reduced glutathione (GSH), GSH/GSSG ratio. However, administration of ethanolic extract of O. sanctum attenuates the alterations induced by noise exposure.

The antioxidant activity of O. sanctum is also evident from its effectiveness in scavenging the free radicals in a dose dependent manner in the herbal antioxidant assays. The results indicate that adaptation to noise does not occur in the brain regions even after 30 days of noise exposure. The abundance of phytochemicals such as phenolics and flavanoids in O. sanctum may be held responsible for its attenuating activity. Therefore, this study indicates that O. sanctum has the potential for further evaluation as an ideal antioxidant for the noise induced oxidative stress.

Evaluation of Antioxidant and Wound Healing Effects of Alcoholic and Aqueous Extract of Ocimum sanctum Linn in Rats.

Shetty S, Udupa S, Udupa L.
Department of Biochemistry, Melaka Manipal Medical College, Department of Biochemistry, KMC International Centre and Department of Pharmacology, Kasturba Medical College, Manipal 576104, India.

In recent years, oxidative stress and free radicals have been implicated in impaired wound healing. Ocimum sanctum (O. sanctum), a plant widely used in Ayurveda, possesses anti-inflammatory and antioxidant properties. The present study was undertaken to assess the potential of alcoholic and aqueous extracts in wound healing in Wistar albino rats.

The rats were divided into five groups of six animals each. Group 1 is normal wounded control and the other four groups were treated with two different doses each of alcoholic and aqueous extract of O. sanctum. The wound healing parameters were evaluated by using incision, excision and dead space wounds in extract-treated rats and controls. Both the doses of alcoholic and aqueous extract significantly increased wound breaking strength, hydroxyproline, hexuronic acid, hexosamines, superoxide dismutase, catalase, reduced glutathione and significantly decreased percentage of wound contraction and lipid peroxidation when compared with the control group. The results suggest that O. sanctum has antioxidant properties, which may be responsible and favorable for faster wound healing and this plant extract may be useful in the management of abnormal healing and hypertropic scars.

Adaptogenic activity of Siotone, a polyherbal formulation of Ayurvedic rasayanas.

Bhattacharya SK, Bhattacharya A, Chakrabarti A.
Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India.

Siotone (ST) is a herbal formulation comprising of Withania somnifera, Ocimum sanctum, Asparagus racemosus, Tribulus terristris and shilajit, all of which are classified in Ayurveda as rasayanas which are reputed to promote physical and mental health, improve defence mechanisms of the body and enhance longevity. These attributes are similar to the modern concept of adaptogenic agents, which are, known to afford protection of the human physiological system against diverse stressors. The present study was undertaken to investigate the adaptogenic activity of ST against chronic unpredictable, but mild, footshock stress induced perturbations in behaviour (depression), glucose metabolism, suppressed male sexual behaviour, immunosuppression and cognitive dysfunction in CF strain albino rats. Gastric ulceration, adrenal gland and spleen weights, ascorbic acid and corticosterone concentrations of adrenal cortex, and plasma corticosterone levels, were used as the stress indices. Panax ginseng (PG) was used as the standard adaptogenic agent for comparison.

Additionally, rat brain levels of tribulin, an endogenous endocoid postulated to be involved in stress, were also assessed in terms of endogenous monoamine oxidase (MAO) A and MAOB inhibitory activity. Chronic unpredictable footshock induced marked gastric ulceration, significant increase in adrenal gland weight and plasma corticosterone levels, with concomitant decreases in spleen weight, and concentrations of adrenal gland ascorbic acid and corticosterone. These effects were attenuated by ST (50 and 100 mg/kg, p.o.) and PG (100 mg/kg, p.o.), administered once daily over a period of 14 days, the period of stress induction. Chronic stress also induced glucose intolerance, suppressed male sexual behaviour, induced behavioural depression (Porsolt's swim despair test and learned helplessness test) and cognitive dysfunction (attenuated retention of learning in active and passive avoidance tests), and immunosuppression (leucocyte migration inhibition and sheep RBC challenged increase in paw oedema in sensitized rats).

All these chronic stress-induced perturbations were attenuated, dose-dependently by ST (50 and 100 mg/kg, p.o.) and PG (100 mg/kg, p.o.). Chronic stress-induced increase in rat brain tribulin activity was also reversed by these doses of ST and by PG. The results indicate that ST has significant adaptogenic activity, qualitatively comparable to PG, against a variety of behavioural, biochemical and physiological perturbations induced by unpredictable stress, which has been proposed to be a better indicator of clinical stress than acute stress parameters. The likely contribution of the individual constituents of ST in the observed adaptogenic action of the polyherbal formulation, have been discussed.