Source: Nath et al, 1999. Note t = <0.05%.
required by gall tissue did not differ fundamentally from those required by healthy tissue. Optimum callusing of explants occurred on a medium containing 2,4-D (10 mg/l), kinetin (0.1 mg/l) and beta-mercaptoethanol (1—2 mM). Callus grew better in a medium fortified with 2, 4-d (4 mg/l) and kinetin (0.4 mg/l). Gall tissue grew faster than healthy tissue. Healthy tissue failed to grow in an auxin-free medium. One-year old cultures of both healthy and gall tissues grew on a medium devoid of cytokinin for a long time. The addition of caffeic acid and catechol (pyrocatechol) enhanced the growth of both normal and gall tissues, but these phenolies had no effect in the absence of auxin. Joshi and Tandon (1991) also reported that both normal and gall tissues showed indolepyruvic acid pathway of auxin biosynthesis. A direct correlation between tryptophan and auxin contents was recorded suggesting a substrate dependent regulation of IAA. Joshi and Tandon (1989) also observed a gradient of auxin protection activity in leaf galls (from young to the brown stage). Three auxin protectors with molecular weights of about 200, 8 and 2 Kda respectively, were isolated from gall tissue using Sephadex gel filtration. These protectors appeared to be oligomers or polymers of lower molecular weight phenolic substances.
The essential oil of the leaves of C. tamala exhibited fungal toxicity against A. flavus and A. parasiticus at 3000 ppm and 1000 ppm, respectively. The fungi-toxic property was not affected by temperature, autoclaving or storage. The active constituent in the oil was identified as eugenol. Alcohol extract of C. tamala was also shown to have above 50% schizomatocidal activity against Malarial parasites (Praomys natalensis and Plasmodium berghei) both in vivo and in vitro when tested at a dose of 1 g/kg X four days and 100mg/ml respectively (Misra etal, 1991).
The oil of C. tamala exhibited absolute antidermatophytic activity against two ringworm fungi, Microsporum audouini and Trichophyton metagrophytes at 500 ppm. The ointment containing essential oil, prepared in polyethylene glycol (0.5 ml of oil in 50 ml base), showed promising efficacy as a herbal antifungal agent in treating dermatomycosis of guinea pigs, with zero positive culture recovery after 21 days following twice daily application of 2 ml of the ointment. C. tamala oil was assessed for its oral toxicity in mice and its LD 50 was recorded as 5.36 ml/kg (Dubey etal., 1998; Yadav etal, 1999).
Chughtai et al. (1998) reported that the aqueous extract of C. tamala significantly increased the rate of gene conversion and reverse mutation in diploid yeast (Saccharomyces cerevisiae, strain D7) and also caused cell death and the inhibition of cell division.
C. tamala has also been found to have hypoglycaemic and hypolipidemic effects. Oral administration of a 50% ethanolic extract of leaves (single dose of 250 mg/kg) significantly lowered the plasma glucose levels in normoglycemic and streptozotocin-induced hyperglycemic rats. The extract also exhibited antihypercholesterolaemic and antihypertriglyceridaemic effects in streptozotocin-induced hyperglycemic rats (Sharma etal, 1996).
Was this article helpful?