Effect of Centella asiatica L (Umbelliferae) on normal and dexamethasone-suppressed wound healing in Wistar Albino rats.

Centella asiatica is a reputed medicinal plant used in the treatment of various skin diseases in the Indian system of medicine. The objective of the study presented in this article was to evaluate the wound-healing potential of the ethanolic extract of the plant in both normal and dexamethasone-suppressed wound healing. The study was done on Wistar albino rats using incision, excision, and dead space wounds models. The extract of C asiatica significantly increased the wound breaking strength in incision wound model compared to controls (P < .001). The extract-treated wounds were found to epithelize faster, and the rate of wound contraction was significantly increased as compared to control wounds (P < .001). Wet and dry granulation tissue weights, granulation tissue breaking strength, and hydroxyproline content in a dead space wound model also increased at statistically significant levels as shown. The extract of the leaves had the effect of attenuating the known effects of dexamethasone healing in all wound models (P < .001, P < .05). The results indicated that the leaf extract promotes wound healing significantly and is able to overcome the wound-healing suppressing action of dexamethasone in a rat model. These observations were supported by histology findings.

Effect of Ocimum sanctum Linn. on normal and dexamethasone suppressed wound healing.

Ethanolic extract of leaves of O. sanctum was investigated for normal wound healing and dexamethasone depressed healing using incision, excision and dead space wound models in albino rats. The extract of O. sanctum significantly increased the wound breaking strength in incision wound model. The extract treated wounds were found to epithelialize faster and the rate of wound contraction was significantly increased as compared to control wounds. Significant increase in wet and dry granulation tissue weight, granulation tissue breaking strength and hydroxyproline content in dead space wound model was observed. The extract significantly decreased the antihealing activities of dexamethasone in all the wound models. The results indicated that the leaf extract promotes wound healing significantly and able to overcome the wound healing suppressing action of dexamethasone. Histological examination of granulation tissue to determine the pattern of lay-down for collagen confirmed the results.

Wound healing studies of Aristolochia bracteolata Lam. with supportive action of antioxidant enzymes.

Aristolochia bracteolata is a perennial herb, the leaves of which are used by the native tribals and villagers of the Chittoor District of Andhra Pradesh in India for the rapid healing of cuts and wounds. The ethanol extract of the shade-dried leaves of Aristolochia bracteolata Lam. was studied for its effect on wound healing in rats, using incision, excision and dead-space wound models, at two different dose levels of 400 and 800 mg/kg/body wt./day. The plant showed a definite, positive effect on wound healing, with a significant increase of the level of two powerful antioxidant enzymes, super oxide dismutase and catalase, in the granuloma tissue.

Wound healing property of ethanolic extract of leaves of Hyptis suaveolens with supportive role of antioxidant enzymes.

Ethanolic extract of leaves of Hyptis suaveolens was evaluated for its wound healing activity in ether-anaesthetized Wistar rats at two different doses (400 and 800 mg/kg) using incision, excision, and dead space wound model. Significant increase in skin breaking strength, granuloma breaking strength, wound contraction, hydroxyproline content and dry granuloma weight and decrease in epithelization period was observed. A supportive study made on granuloma tissue to estimate the levels of catalase and superoxide dismutase recorded a significant increase in the level of these antioxidant enzymes. Granuloma tissue was subjected to histopathological examination to determine the pattern of lay-down for collagen using Van Gieson and Masson Trichrome stains. Enhanced wound healing activity may be due to free radical scavenging action of the plant and enhanced level of antioxidant enzymes in granuloma tissue. Better collagenation may be because of improved antioxidant studies.

Indigenous drugs and atherosclerosis.

Coronary artery disease (CAD) is a major health problem worldwide and its increasing prevalence in younger age groups is of serious concern. Precipitating factors include changes in lifestyles, food fads and stress, as well as the impact of longevity resulting from the control and prevention of communicable diseases. Dietary practices can often lead to increased levels of lipids in blood or trigger an underlying disposition to atherosclerosis. Hence, dietary modification has been an important method for the management of CAD, with the aim of lowering lipid levels. However, long-term trials have shown that this approach reduces cholesterol and triglycerides only moderately. Drug therapy with clofibrate, cholestyramine, etc., has been successful but some disadvantages limit their long-term use. An alternative approach to the treatment of atherosclerosis has been the use of indigenous drugs. This article reviews some of the drugs of the traditional Indian system of medicine, Ayurveda, which have been shown to possess antiatherogenic properties. (c) 2001 Prous Science. All rights reserved.

Hypolipidemic activity of three indigenous drugs in experimentally induced atherosclerosis.

The effect of orally administered indigenous drugs Terminalia arjuna, T. belerica and T. chebula were investigated on experimental atherosclerosis. Rabbits were fed a cholesterol-rich diet to induce atherosclerosis. The three drugs were fed along with cholesterol. At the end of the experimental period the animals were killed and their plasma and tissue lipid components estimated. Atherosclerotic lesions of the aorta were examined histologically. T. arjuna was found to be the most potent hypolipidemic agent and induced partial inhibition of rabbit atheroma. The results indicate that T. arjuna may play an anti-atherogenic role.

Inhibition of lysyl oxidase by isoniazid and its effect on wound healing.

Isoniazid, an antitubercular drug, is known to be a potent inhibitor of monoamine oxidases. Effects of this drug, on lysyl oxidase (also a monoamine oxidase) and other wound healing parameters were studied in albino rats, in presence and absence of pyridoxal phosphate, using a dead space wound model. Tensile strength, collagen and glycosaminoglycan contents as well as lysyl oxidase activity were estimated in the granuloma tissue harvested from 10 day old dead space wounds. Isoniazid inhibited lysyl oxidase activity and a decrease in tensile strength as well as collagen content were observed. The effects were reversed on administration of a stoichiometric amount of pyridoxal phosphate. Hexosamine level was increased and hexuronic acid level decreased in the drug treated animals. Therefore, isoniazid may decrease the mechanical strength of collagen by inhibiting lysyl oxidase, by competiting for its obligatory cofactor pyridoxal phosphate, as well as by interfering in electrostatic interactions between collagen and the ground substance.

Preventive actions of Terminalia belerica in experimentally induced atherosclerosis.

Hypercholesterolaemia and atherosclerosis were induced experimentally in rabbits by cholesterol feeding. The effect of an indigenous drug, T. belerica, was evaluated in these hypercholesterolemic rabbits. T. belerica reduced the levels of lipids in hypercholesterolemic animals. There was also a significant decrease in liver lipids and heart lipids (P < 0.05) in the drug-treated animals.

The possible site of anti-asthmatic action of Tylophora asthmatica on pituitary-adrenal axis in albino rats.

The effects of the alcoholic extract, the petroleum ether fraction, and the aqueous fraction of the alcoholic extract of Tylophora asthmatica on weight of the adrenal gland and its functional activities (as evidenced by its cholesterol and vitamin C content, plasma steroid, hydroxyproline content in skin) and pituitary-adrenal axis were studied using normal, unilaterally adrenalectomised, dexamethasone-treated (steroid suppression of ACTH), and stereotaxically hypophysectomised male albino rats. The extracts showed similar actions (i.e. stimulation of adrenals as indicated by increase in weight and decrease in cholesterol and vitamin C contents). The plasma steroid level was increased but skin hydroxyproline level findings were not conclusive. T. asthmatica was found to antagonise dexamethasone/hypophysectomy-induced suppression of pituitary on activity of the adrenals. It may be concluded that T. asthmatica may act by a direct stimulation of the adrenal cortex.

Influence of Tridax procumbens on lysyl oxidase activity and wound healing.

The effects of an indigenous drug, Tridax procumbens L. (Compositae), on developing granulation tissue in rats were studied. Subcutaneously harvested granuloma tissue formed on dead space wound was removed at 4 day intervals up to 32 days of wounding. Lysyl oxidase activity, protein content, specific activity, and breaking strength were all increased in drug-treated animals as compared to controls. A fall in the lysyl oxidase activity was observed in drug-treated animals after day 8. The drug may be having a dual role: one a stimulatory (direct) effect in the initial phase of wound healing and the other a depressant (indirect) effect in the later stage.