Abstract:
Both herbalism and conventional synthetic medicines provide options for immunomodulation.
However most of the synthetic drugs accompany undesirable side effects. Apparently, plantbased
medicines leave no side effects and provide more safe therapies. The present study was
undertaken to elucidate toxic effects, anti-oxidant capacity and immunomodulatory potential of
ethanolic extracts of Alpinia calcarata (dried rhizome) and Solanum surattense (dried root bark)
which are used by traditional and Ayurvedic practitioners of Sri Lanka to treat various ailments.
No significant behavioral or morphological changes were observed in rats after treating with
high doses (1000mg/kg, 500mg/kg) of both plants. In these rats, liver enzymes namely Alanine
Transaminase (ALT) and Gamma Glutamyl Transpeptidase (GGT) levels were measured using
ELISA. Crude extracts of both plants were tested using DPPH method, TAC assay and Cayman
assay to survey antioxidant potential. A.calcarata was further investigated to study its effects
on cytokine expression in rats and IFN gamma expression on cultured human leukocytes. In
those studies rats were orally fed with A.calcarata extract for a period of 45 days at dose of
200mg/kg in 2 days intervals while control group was given normal saline. Cultured human
leukocytes were treated with different concentrations of A.calcarata for 2 days. No significant
increase of ALT and GGT were observed in A.calcarata treated rats (p> 0.05). However, high
doses (1000mg/kg, 500mg/kg) of S.surattense treatment elevated ALT and GGT levels
significantly (p< 0.05). Both extracts possess significantly high anti-oxidant capacity when
compared with commonly known anti-oxidants (p< 0.05). IL2, IL5, IL17, IFN-ɣ cytokine
secretions were significantly increased after 30 and 45 days of administration (p < 0.05).
A.calcarata extracts stimulated the increase in TH1 cytokine (IFN-γ) level in cell culture
supernatant in a dose dependent manner. According to the results of this study A.calcarata
rhizome extract is a positive immunomodulator in all aspects.
