Changes

:Chromosome number: ''x''= unknown;''T. cordifolia'': 2''n''= 24, 26

*''Tinospora crispa'' (L.) Hook.f. & Thomson, *''T. glabra'' (Burm.f.) Merr.

It is perhaps in the Indian subcontinent where the widest use is made of ''Tinospora'' . The main species is ''T. cordifolia'' (Willd.) Miers, which does not occur in Malesia. In present-day Ayurvedic medicine in India, all parts of the plant find wide use for their general tonic, anti-inflammatory, anti-arthritic, anti-allergic, antimalarial, antidiabetic, hepato-protective and aphrodisiac properties. Categorized as "rasayana" in Ayurveda, it is also used for its general adaptogenic and pro-host immuno-modulatory activity in fighting infections. ''T. cordifolia'' is thus claimed to be useful in e.g. skin diseases, jaundice, diabetes, anaemia, fever and rheumatism. In fact the plant is part of almost all decoctions mentioned in Ayurvedic textbooks for use in joint diseases. The starch from the stems and roots is used as a nutrient in chronic diarrhoea and dysentery. Juice of the fresh plant is a powerful diuretic (urinary diseases), and also used in gonorrhoea with advantage. Besides its antimalarial activity, the root is known for its antistress and antileprotic activities. Finally, ''T. cordifolia'' is also used as veterinary medicine.

A number of chemical constituents have already been isolated from different parts of ''T. crispa'' , e.g. diterpenes, alkaloids and flavonoids. Most extensively investigated are a series of furano-diterpene (glycoside) compounds: tinotufolin A-F (leaves), borapetoside A-H (glycosides, stems), borapetol A, B (stems, aglycones of borapetoside A, B) and the bitter tinocrisposide (glycoside, stems). In addition to these furano-diterpenes, a series of clerodane-diterpene glycosides has also been isolated from the stems and named rumphioside A, B, C, C-1, Ac-D, E and F.

Toxicity of ''Tinospora'' extracts proved to be low in tests with rats (LD₅₀values of over 5 g/kg orally, 3 g/kg dermally). ''Tinospora'' extracts in high concentrations can cause infection in the liver and follicular atresia in mice, but the kidneys are not much affected. Crude extracts showed protective effects in mice with experimental urinary tract infection caused by ''Pseudomonas aeruginosa'' .

A number of compounds have been isolated from the stems of ''T. cordifolia'' , including diterpenes and alkaloids. The diterpenes comprise the major group of components isolated: the norditerpene-furan-glycosides cordifoliside A-E, the clerodane-diterpenes tinosponone, tinosporaside (= tinosponone-glycoside) and tinocordioside (glycoside) and the clerodane-furano-diterpenes cordioside (glycoside), together with 4 other furano-diterpene compounds: colombin, one being an epimer of 6-hydroxy-arcangelisin, and two being a set of optical isomers (not yet named). The biosynthesis of the clerodane-furano-diterpene skeleton has also been investigated.

Considerable efforts have been made to investigate the biological effects of ''T. cordifolia'' . An aqueous, alcoholic and chloroform extract of the leaves after oral application exerted a significant hypoglycaemic effect in both normal and alloxan-diabetic rabbits. The reaction in alloxan-diabetic animals, in which almost all pancreatic β-cells have been destroyed, appears to be like a direct effect, probably by a mechanism similar to insulin. However, the stronger effect in normo-glycaemic rabbits suggests that the mechanism of action consists not only of this direct insulin-like effect, but that there is also an indirect action by stimulating the insulin release from pancreatic β-cells. Besides the hypoglycaemic activity, no effects were found on the blood lipid levels, and acute toxicity studies did not reveal visible signs and symptoms of toxicity. Further investigations in albino rats and different groups of rabbits confirm the hypoglycaemic effect and the proposed mechanism of action.

Several studies have focused on the immunotherapeutic effects. Pretreatment (oral) with an aqueous extract strongly reduced the mortality in a mouse model for ''E. coli'' peritonitis. This was associated with significantly improved bacterial clearance and improved phagocytic capacities of neutrophils in the group treated with ''T. cordifolia'' . ''T. cordifolia'' extract itself did not possess in vitro bactericidal activity. These results were confirmed in experiments with wistar rats in which abdominal sepsis was induced by caecal ligation. Both in rat and man, oral application of a ''T. cordifolia'' extract improved the surgical outcome in patients with obstructive jaundice, in which sepsis initiated by bacteria in the bile at the time of biliary tract surgery comprises a major risk. In the group receiving the extract, the phagocytic and killing capacities of neutrophils improved; thus ''T. cordifolia'' appears to act by strengthening host defences.

''Tinospora'' extracts are toxic to brown planthoppers ( ''Nilaparvata lugens'' ) and green leafhoppers ( ''Nephotettis virescens'' ), which are common pests in rice in the Philippines. Soaking the roots of rice seedlings in aqueous ''Tinospora'' extract in the field is effective in controlling the major rice pests, and broadcasting the ground stems on the seed-beds 10 days after sowing is also applied successfully. The extracts can control the diamondback moth ( ''Plutella xylostella'' ); the effectivity is comparable to malathion, and the extracts show antifeedant effects on the insect. In tests in Thailand, ''T. crispa'' extract showed mild repellency to the oviposition of the oriental fruit fly ( ''Darcus dorsalis'' ). It is also effective in controlling borers on maize, and bollworms ( ''Helicoverpa armigera'' ) in cotton. The extract showed high toxicity to fish in experiments in Malaysia. In vitro tests in the Philippines using mutant strains of ''Bacillus subtilis'' and ''Salmonella typhimurium'' showed that ''Tinospora'' extracts do not contain direct mutagens.

*Dioecious woody climbers up to 15 m long, sometimes scandent shrubs, usually entirely glabrous; stem woody, with bark often becoming detached on drying, striate when young, becoming tuberculate or warty with raised lenticels, usually glabrous but sometimes puberulous, sometimes producing very long filiform aerial roots. *Leaves arranged spirally, simple and entire (occasionally dentate or 3-lobed), often cordate, palmately veined, sometimes domatia present in axils of veins beneath, petiole swollen and geniculate at base; stipules absent. *Inflorescence axillary or cauliflorous, thyrsoid, pseudopaniculate, pseudoracemose or pseudospicate. *Flowers unisexual, 6-merous; sepals usually free, outer 3 usually smaller, elliptical, imbricate; petals free, often broadly cuneate-ovate with the lateral edges inrolled, usually fleshy and often glandular-papillose externally towards the base; male flowers with 6 free stamens; female flowers with 3 curved-ellipsoid carpels having short-lobed, reflexed stigmas, and 6 subulate staminodes. *Fruit a usually ellipsoidal drupe with terminal style scar, borne on a short or columnar carpophore; endocarp bony, dorsally convex and often verrucose or tuberculate, ventrally with central aperture or with shallow longitudinal groove. *Seed with usually ruminate endosperm.

''Tinospora'' belongs to the tribe ''Tinosporeae'' , characterized by the drupe with terminal style scar, and embryo with foliaceous cotyledons, together with ''Chlaenandra'' , ''Fibraurea'' , ''Parabaena'' and ''Tinomiscium'' .

''T. glabra'' has been much confused with ''T. crispa'' . Information on medicinal and chemical properties of ''T. crispa'' (or its synonym ''T. rumphii'' ) given in literature for the Philippines partly refers to ''T. glabra'' .

Larvae of the noctuid moth ''Othreis fullonia'' feed mainly on ''Tinospora'' leaves. The adult moth can cause considerable damage to commercial fruit tree plantations, especially of longan ( ''Dimocarpus longan'' Lour.) and citrus in Thailand, by piercing the skin of the fruits. The destruction of natural forest and the increasing area of secondary vegetation, preferred by ''Tinospora'' , promote the spread of the pest.

In Pakistan, ''T. cordifolia'' showed effective resistance to the root-knot nematodes ''Meloidogyne incognita'' and ''M. javanica'' .

*Umi Kalsom Yusuf, S.F.A.J. Horsten & R.H.M.J. Lemmens