Effect of plumbagin on the radiation induced cytogenetic and cell cycle changes in mouse Ehrlich ascites carcinoma in vivo.

The effect of plumbagin, a naphthoquinone from the roots of the Indian medicinal plant Plumbago rosea, and Cobalt-60 gamma radiation was studied on Ehrlich ascites carcinoma in vivo, taking cytogenetic damage and cell cycle changes as experimental endpoints. Plumbagin (5 mg/kg body wt, P1) administered intraperitoneally produced a significant increase in the percentage of S-phase as well as G2-M cells with a corresponding decrease in the G1 phase at different post-treatment times. Radiation (7.5 Gy, RT) alone produced the classical G2 block at 1 hr, which persisted with a continuous increase throughout the post-treatment observation period. The combination treatment produced a similar effect as that of RT on G2-M cells, but its effect on the G1 phase was more pronounced than the latter. While P1 treatment produced a small increase in the percentage of labeled S-phase cells, combination treatment significantly reduced the labeled S-phase cells with a corresponding increase in the unlabeled fraction. Drug or radiation alone significantly increased micronuclei induction at various post-treatment times and the combination of the two further enhanced this effect additively. The mechanism of interaction of P1 with radiation in bringing about this effect is not clear.

Antitumor and radiosensitizing effects of withaferin A on mouse Ehrlich ascites carcinoma in vivo.

The antitumor and radiosensitizing effects of withaferin A (WA), a steroidal lactone from Withania somnifera, was studied on Ehrlich ascites carcinoma in vivo. The acute LD50(14) for WA in Swiss mice was approximately 80 mg/kg. Twenty-four hours after i.p. inoculation of 10(6) tumor cells, WA was injected i.p. at different dose fractions (5 or 7.5 mg/kg x 8, 10 mg/kg x 5, 20 or 30 mg/kg x 2) with or without abdominal gamma irradiation (RT, 75. Gy) after the first drug dose. Increase in life span and tumor-free survival were studied up to 120 days. The drug inhibited tumor growth and increased survival, which was dependent on the WA dose per fraction rather than the total dose. Combination of RT with all the drug schedules increased tumor cure and tumor-free survival, the best effect seen after 2 fractions of 30 mg/kg each. In another experiment WA was given as 2 (40 mg/kg x 2), 3 (30 mg/kg x 3) or 4 (20 mg/kg x 4) fractions at 5, 7 or 10 days after tumor inoculation with or without RT after the first drug dose. At 7 and 10 days after inoculation the drug was effective only at 40 mg/kg x 2, but with RT 30 mg/kg x 3 produced an equal effect (20% survival) on 7 day old tumors.

In vivo growth inhibitory and radiosensitizing effects of withaferin A on mouse Ehrlich ascites carcinoma.

Adult Swiss albino mice were inoculated intraperitoneally (i.p.) with 10 (6) Ehrlich ascites carcinoma cells. Twenty-four hours later they were given an i.p. injection of 10-60 mg/kg of withaferin A (WA), isolated from the roots of Withania somnifera. The tumor growth and tumor free animal survival were studied for up to 120 days. In another experiment 30 mg/kg WA was injected i.p. to mice at 1, 3 or 5 days after tumor cell injection with or without acute abdominal exposure to 7.5 Gy gamma radiation and the tumor growth and 120-day survival were studied. WA inhibited tumor growth and increased tumor free survival in a dose-dependent manner. The drug ED50 for 120-day survival was approximately 30 mg/kg body wt. Drug treatment before irradiation synergistically increased 120-day even in advanced tumors. A dose of 30 mg/kg seems to be optimum for combination with radiation.

In vivo tumor inhibitory and radiosensitizing effects of an Indian medicinal plant, Plumbago rosea on experimental mouse tumors.

Tumor growth inhibitory and radiosensitizing effects of the alcoholic root extract of P. rosea was studied on experimental mouse tumors, S-180 solid tumor and Ehrlich ascites carcinoma in vivo. Intraperitoneal injection of 50 mg/kg of Plumbago extract (PE) for 10 days starting from 24 hr after intradermal inoculation of S-180 cells in BALB/c mice produced about 16% complete response (CR). The CR% increased with increase in drug dose, to 50% at 100 mg/kg for 10 days. As 100 mg/kg produced toxic side effects, lower doses were used with other treatment modalities, radiation (RT) and hyperthermia (HT). Treatment of 50 mm3 tumor with PE (75 mg/kg) for 10 days with local RT (10 Gy) and/or HT (43 degrees C, 30 min) subadditively increased the CR% and tumor free survival. The combination also significantly reduced the growth rates of uncured tumors. The PE significantly reduced the tumor glutathione content and this effect was markedly enhanced by the combination of the three modalities. PE alone was not very effective in preventing the growth of Ehrlich ascites carcinoma in Swiss mice, though it increased mean survival time and ILS% of the mice. But with radiation it produced a synergistic effect in increasing the tumor inhibition and 120 day animal survival from 10% to 50%. The results demonstrate that though PE may have only a weak antitumor effect, it may be a good candidate for use with radiation to enhance the tumor killing effect.

Antitumor and radiosensitizing effects of Withania somnifera (Ashwagandha) on a transplantable mouse tumor, Sarcoma-180.

Antitumor and radiosensitizing effects of alcoholic root extract of W. somnifera and their modification by heat were studied in vivo on Sarcoma-180 grown on the dorsum of adult BALB/c mouse. Ashwagandha (AT) was injected (ip) at a dose of 500 mg/kg body wt for 10 consecutive days into mouse bearing tumor of 50 +/- 5 mm3, with or without a local treatment of 10 Gy gamma radiation (RT) or hyperthermia at 43 degrees C for 30 min (HT) or both on 5th day of AT. The response was assessed on the basis of tumor regression, growth delay, animal survival and changes in the tumor GSH content. Ashwagandha, RT and HT individually produced 18, 38 and 45% complete response (CR) respectively, but RT gave the best long term survival. Ashwagandha increased the effect of radiation on tumor regression as well as growth delay, but AT + HT gave a better tumor cure. However, both these combinations gave almost identical long term survival, which was not much higher than that produced by RT alone. The combination of Ashwagandha for 10 days with one local exposure to RT followed by HT significantly increased the tumor cure, growth delay of partially responding tumors and animal survival. This combination also significantly and synergistically depleted the tumor GSH level, with no recovery even at 3 hr after treatment. It is concluded that Ashwagandha, in addition to having a tumor inhibitory effect, also acts as a radiosensitizer and heat enhances these effects. The severe depletion in the tumor GSH content by the combination treatment must have enhanced the tumor response, as the inherent protection by the thiol will be highly reduced.

Toxic effects of crude root extract of Plumbago rosea (Rakta chitraka) on mice and rats.

The ethanolic root extract of Plumbago rosea (Plumbaginaceae) was studied for acute toxicity in mice and subacute toxicity in rats. The 24 h LD50 values of the extract in mice were 239.88 mg and 1148.15 mg/kg b.wt. for intraperitoneal and oral routes, respectively. Oral administration of doses above 1250 mg/kg produced severe diarrhea. In subacute toxicity studies no mortality was observed when 50 mg/kg of the extract was injected i.p. daily for 30 days; however, there was no weight gain in the treated rats. Significant reduction in the weights of liver, kidney, thymus and testes was observed in the male rats, while the spleen weight showed a significant increase from control. The females showed a significant loss in thymus weight and a gain in the weight of the uterus, but the liver and spleen did not show any weight change from the control. There was a significant increase in total WBC and neutrophil counts as well as in the levels of serum alkaline phosphatase and alanine transaminase (ALT) in both sexes. Similarly, the liver alkaline phosphatase level was significantly higher than control, but a significant reduction was observed in the DNA, RNA and total proteins. Thus, a higher drug dose (total dose of 15 g/kg b.wt.) was tolerated in fractionated administration, but it had a growth inhibitory effect in both sexes. The males appear to be more susceptible than females when individual organs are considered.

In vivo growth inhibitory effect of Withania somnifera (Ashwagandha) on a transplantable mouse tumor, Sarcoma 180.

Withania somnifera is a medicinal plant used in the treatment of a variety of ailments in the Ayurvedic system. Alcoholic extract of the root of the plant was injected(ip) at daily doses of 200 to 1000 mg/kg body wt for 15 days starting from 24 hr after intradermal inoculation of 5 x 10(5) cells of S-180 in BALB/c mice. Solid tumor growth was monitored for 100 days. Doses of 400 mg/kg and above produced complete regression of tumor after an initial growth, the percentage of complete response (CR) increasing with increasing drug dose. A 55% CR was obtained at 1000 mg/kg drug administration, but this dose also produced some mortality among the animals. A significant increase in the volume doubling time and growth delay was seen when the drug dose was increased from 500 to 750 mg/kg body wt, but further increase in drug dose to 1000 mg/kg did not produce any significant increase in these responses. Cumulative doses of 7.5 to 10 g at daily doses of 500 or 750 mg/kg seems to produce a good response in this tumor.